RxPG News : Radiology

First breast PET/CT scanner to visualize suspected cancerous lesions in 3-D.

Fri, 04 Sep 2009 23:36:11 PST

( from http://www.rxpgnews.com ) An innovative collaboration among UC Davis engineers, physicists and radiologists has resulted in the first-ever fully 3-D breast imaging technique that uses both high-resolution PET and CT scanning.

After years of work to build the dedicated breast PET/CT scanner, the team of scientists has shown that use of the technology on an uncompressed breast can accurately visualize suspected cancerous lesions in three dimensions.

Researchers say their findings, published in the September issue of the Journal of Nuclear Medicine, boost efforts to personalize breast cancer treatment for patients.

“People have been talking about individualized chemotherapy for breast cancer, and this could be the technology that makes such a paradigm fly,” said Ramsey Badawi, a UC Davis physicist and co-author of the study.

Badawi said breast PET/CT would not replace mammography for regular breast cancer screening, but could be used, for example, to determine whether and which chemotherapy would be beneficial before surgical removal of the tumor. It also could be used to locate small tumors to improve staging and aid in surgery planning.

In developing the system, Badawi recognized the potential benefits of PET (positron emission tomography) combined with CT (computed tomography). PET scans measure physiological functions, help monitor how well drugs are working and distinguish benign from malignant tumors. CT scans provide information about the body’s structure. The combined technologies can result in much better images to help doctors make treatment decisions.

The problem was that the combined technologies are only available on full-body PET/CT scanners, which can’t easily pinpoint breast tumors smaller than one-half inch. A new approach would be needed to image small, early-stage tumors.

Badawi joined forces with UC Davis radiology physicist John Boone, who built the first dedicated breast CT scanner, and with Simon Cherry, director of the UC Davis Center for Molecular and Genomic Imaging, who built the first PET machine with enough resolution to accurately image tumors in mice. Badawi mounted a PET scanner onto Boone’s breast CT scanner to capture the dual data. The team was also assisted by UC Davis biomedical engineer Jinyi Qi, who developed advanced techniques for reconstructing the images.

A breast PET/CT scan takes about 10 minutes per breast. The patient lies on a padded table while the breast hangs down through a circular opening, an approach patients have said is far more comfortable than standard compression-based imaging. The CT images are generated using an X-ray source and detector that are rotated around the breast to produce a 3-D map of the breast structure. The PET scan is done next, using a pair of gamma ray detectors that rotate around the breast to produce a second, 3-D map of breast metabolism.

The combination of the two maps shows the precise location of cancer as “hot spots.” In their study of four patients, Badawi and his colleagues found that the scans produced high-resolution 3-D images that accurately showed the size, extent and location of biopsy-confirmed breast cancer.

Badawi said more clinical trials on the device are needed before it can be moved into commercial development. One trial will use the system to monitor women who will undergo chemotherapy prior to surgery to determine if PET/CT can accurately predict tumor response.

Drug eluting stents may save limbs

Tue, 10 Mar 2009 23:02:00 PST

( from http://www.rxpgnews.com ) Attempts to treat critical limb ischemia in peripheral arterial disease (PAD) patients with below-the-knee angioplasty are still thwarted by restenosis (the re-narrowing of the artery at the site of angioplasty or stenting), the need for repeat treatments and the continued progression of atherosclerotic disease, leading to tissue death (gangrene) and amputation. Interventional radiologists have been studying a potential solution—the use of drug-eluting stents—and have found that these types of stents lessened the rate of repeat procedures to open these small arteries, according to results presented at the Society of Interventional Radiology's 34th Annual Scientific Meeting.

"This is encouraging news for PAD patients with critical limb ischemia. The smaller blood vessels below the knee are more difficult to treat due to their size (3 millimeters) and are more prone to reclog than larger vessels. The use of drug-eluting stents in the tiny infrapopliteal arteries of the leg may significantly impact their care," said Dimitris Karnabatidis, M.D., assistant professor of interventional radiology at Patras University Hospital in Rion, Greece. "Drug-eluting (or drug-coated) stents have emerged as a potential solution to the limitations of endovascular treatment of PAD patients with critical limb ischemia," he added. An interventional radiologist performs a balloon angioplasty to open a clogged blood vessel and then places a drug-eluting stent in that artery. The stent acts as scaffolding to hold the narrowed artery open. Drug-eluting stents slowly release a drug for several weeks to block cell proliferation or regrowth, thus inhibiting restenosis.

Researchers from a single center studied 103 patients in a double-arm prospective registry who had critical limb ischemia and who underwent infrapopliteal revascularization with angioplasty and placement of either a drug-eluting stent (with sirolimus, an immunosuppressant drug) or a bare-metal stent (without a drug coating). The patients had regular follow-ups up to three years, and researchers studied how they did by stent type. In the first group, 41 patients (75.6 percent diabetics) were treated with bare-metal stents, and in the second group 62 patients (87.1 percent diabetics) were treated with drug-eluting stents.

At three years, those patients with drug-eluting stents had "significantly higher patency" (length of time the blood vessels stayed open and moved blood flow efficiently); reduced restenosis of the vessels; and consequently less clinical recurrence requiring repeat angioplasty, said Karnabatidis. "In the drug-eluting stent group, an estimated 60 percent of the treated arteries remained open at three years. This is significantly longer than the bare-metal stent group, where the arteries remained open only approximately 10 percent at 3 years," said Karnabatidis. "This corresponds to a more than 5 times increased risk of vessel reclogging when bare metal stents were used," he added. "Because of the reduced vessel restenosis, repeat angioplasties were necessary in only 15 percent of the patients in the drug-eluting stent group versus almost 35 percent in the bare-metal stent group up to 3 years—this being the equivalent to an almost 2.5-fold risk of repeat procedures in the case of bare metal stents," noted Karnabatidis. "These statistical results are based on three-year adjusted survival analysis after application of a Cox model for multivariable analysis," he explained.

If a person has critical limb ischemia, it means he or she is at great risk for tissue death due to lack of blood flow, which carries oxygen and nutrients to the cells. The severely restricted blood flow results in severe pain in the feet or toes, even while resting, and sores and wounds that will not heal. Tissue death (gangrene) and amputation are imminent at this advanced stage of PAD, which is caused by atherosclerosis, the hardening and narrowing of the arteries over time due to the buildup of fatty deposits called plaque.

"Multicenter randomized trials are necessary to support these promising results and build on the level of clinical evidence supporting the integral value of infrapopliteal drug-eluting stents in critical limb ischemia treatment," he added. In the United States, drug-eluting stents are FDA-approved for the coronary arteries but not for infrapopliteal arteries. In Europe, drug-eluting stents have CE Mark approval for below-the-knee use.

Combining patient photos with imaging improves diagnosis

Tue, 02 Dec 2008 23:00:00 PST

( from http://www.rxpgnews.com ) Combining a patient's photo with imaging results may yield a more exact interpretation of his or her condition, according to a study.

'Our study emphasises approaching the patient as a human being and not as an anonymous case study,' said study co-author Yehonatan N. Turner, radiology resident at Shaare Zedek Medical Centre - in Jerusalem.

A physician orders imaging exams like MRI or Computed Tomography -, and the radiologist interprets the results, never having met the patient.

Technological advances have further distanced the radiologist from the patient. For example teleradiology enables them to view images from remote locations.

Researchers set out to determine if the addition of a patient's photograph to the file would affect how radiologists interpreted the results, said a SZMC release.

For the study, 318 patients referred for CT agreed to be photographed prior to the exam. The images of the patients were added to their files in the hospital's Picture Archiving and Communication System -, a network for storage and retrieval of medical images. The photograph appeared automatically when a patient's file was opened.

After interpreting the results of the exams, 15 radiologists were given questionnaires to gather data about their experience. All 15 radiologists admitted feeling more empathy towards the patients after viewing their photos.

More importantly, the results showed that radiologists provided a more meticulous reading of medical image results when a photo of the patient accompanied the file.

All 15 radiologists agreed that the inclusion of a photograph in a patient's file should be adopted into routine practise. The photos can also be included in long-distance teleradiology practices.

These findings were presented on Tuesday at the annual meeting of the Radiological Society of North America -.

Ultrasound Imaging Improved by New Computer Model

Fri, 21 Nov 2008 14:32:48 PST

( from http://www.rxpgnews.com ) London, Nov 5 - Doctors rely on ultrasound to determine the health of organs and other internal structures of the body. Now a Dutch researcher has developed a computer model that will improve the ultrasound's imaging capacity.

Koos Huijssen of Delft University of Technology - has developed a computer model that can predict the sound transmission of improved designs for ultrasound equipment.

The computer model is capable of processing large quantities of data and can be run on both a PC and a parallel supercomputer. Erasmus University Medical Centre and Oldelft Ultrasound are now using this programme to design a new sonographic transducer.

Koos Huijssen went in search of a computer model that could predict the behaviour of ultrasonic waves. Over the past 10 years, the images produced by ultrasound or sonography have been vastly improved by making partial use of the nonlinear nature of acoustic waves. Thanks to these developments ultrasound can now be used for a larger group of patients.

Further improvements could be realised by refining the sonography equipment, the transducer that generates the ultrasound and the imaging method, according to Delft release.

However, this requires a computer model that can accurately predict the transmission of ultrasound. With funding from Technology Foundation STW, Huijssen could develop a model which makes calculations over a 3-D area that is larger than what existing computer models can handle.

The major challenges in producing such a model are the enormous complexity of the problem and dealing with the required storage capacity and processing power. The model was developed in cooperation with the company VORtech Computing and it has an excellent level of performance.

Computer model improves ultrasound image

Tue, 04 Nov 2008 05:00:00 PST

( from http://www.rxpgnews.com ) Doctors use diagnostic sonography or ultrasound to visualise organs and other internal structures of the human body. Dutch researcher Koos Huijssen has developed a computer model that can predict the sound transmission of improved designs for ultrasound instruments. The computer model is capable of processing large quantities of data and can be run on both a PC and a parallel supercomputer. Erasmus University Medical Centre and Oldelft Ultrasound are now using this program to design a new sonographic transducer.

Koos Huijssen went in search of a computer model that could predict the behaviour of ultrasonic waves. Over the past ten years, the images produced by ultrasound or sonography have been vastly improved by making partial use of the nonlinear nature of acoustic waves. Thanks to these developments ultrasound can now be used for a larger group of patients.

Further improvements could be realised by refining the sonography equipment, the transducer that generates the ultrasound and the imaging method. However, this requires a computer model that can accurately predict the transmission of ultrasound. With funding from Technology Foundation STW, Huijssen could develop a model which makes calculations over a three-dimensional area that is larger than existing computer models can handle.

The major challenges in producing such a model are the enormous complexity of the problem and dealing with the required storage capacity and processing power. The model was developed in cooperation with the company VORtech Computing and it has an excellent level of performance.

Indian American develops tool to image tumours

Fri, 11 Apr 2008 10:30:58 PST

( from http://www.rxpgnews.com ) New York, April 1 - A team of researchers led by Indian American Sanjiv Gambhir has developed a new type of imaging system capable of picturing tumours to a precision of a trillionth of a meter.

The new system, which uses Raman spectroscopy, will be of great use to doctors who are currently hampered by the limited extent to which they can see such tumours.

Using a microscope modified to detect Raman nanoparticles, Gambhir's team was able to see targets a thousand times smaller than what is currently obtainable.

Signals from Raman spectroscopy are stronger and longer-lived than other available methods, and the type of particles used in this method can simultaneously transmit information about several molecular targets.

'We can measure one or two things at a time, but with this, we can now likely see 10, 20, 30 things at once,' said Gambhir, director of the Molecular Imaging Programme at Stanford University Medical Centre and also head of nuclear medicine.

Gambhir compared Raman spectroscopy work to the development of positron emission tomography - over two decades ago. PET is now a routine imaging technique that uses radioactive molecules to generate a three-dimensional image.

'Nobody understood the impact of PET then,' Gambhir said, referring to its discovery. 'Ten or 15 years from now, people should appreciate the impact of this.'

Raman spectroscopy is named after physicist C.V. Raman, whose 1928 discovery of a radiation effect that bears his name - won him the 1930 Nobel Prize in physics.

Raman effect is created when light is shone on an object. Roughly one in 10 million photons bouncing off the object's molecules gains or loses energy, called Raman scattering. This scattering pattern, called a spectral fingerprint, is unique to each type of molecule and can be measured.

Injectable Microfoam for Varicose Veins safe in Phase II trial

Mon, 17 Mar 2008 04:46:42 PST

( from http://www.rxpgnews.com ) A small group of patients with a common heart defect who were treated for varicose veins with an injectable microfoam experienced no neurological, visual or cardiac changes as a result of the treatment, according to preliminary results from a phase II trial. The results are being presented today (March 17) in Washington, D.C., at the annual scientific meeting of the Society of Interventional Radiology (SIR).

Injectable foams are usually made by mixing a sclerosant, an irritant that causes damage to the vein wall and subsequent scarring, with room air. Sclerosant foams have been a standard treatment since 1997 for spider veins and small varicose veins. This is an alternative treatment to the traditional treatments such as Rejuva Health medical stockings. Varisolve®, a foam made with carbon dioxide, is relatively painless compared to other sclerosants, which can cause burning, said John D. Regan, M.D., clinical director of the Interventional Section in the Department of Radiology at Wake Forest University Baptist Medical Center.

Veins in the leg have valves that are designed to prevent blood from flowing backward as it returns to the heart. Varicose veins are caused by weakened valves (commonly in the great saphenous vein, the large vein running up the inner side of the leg) which allow blood to flow backward and pool in the veins in the leg. The resulting high pressure causes veins to expand like balloons and become tortuous or twisted. The latest treatments involve blocking the great saphenous vein (GSV) to prevent the backflow, called reflux. The Varisolve foam injection procedure is a less invasive alternative to surgical techniques and intravenous techniques that close the vein with radiofrequency ablation or laser energy.

Although any air-based foam carries a theoretical risk to the patient because of the insolubility of air in the blood, the risk is small, said Regan, the presenting author of the phase II trial’s preliminary results. “We believe that the carbon-dioxide-based foam used in Varisolve will be totally safe due to the small size of the bubbles, the consistency of the foam and the solubility of carbon dioxide.”

However, patients with a right-to-left shunt in their hearts – a common, usually asymptomatic heart defect in about one-fourth of the population – are at increased risk of foam bubbles crossing the shunt and going to the brain or heart without being filtered in the lungs, according to Regan. These patients, the subjects of the study, are continuously monitored by transcranial Doppler ultrasound of the brain before, during and after the procedure. They also undergo magnetic resonance imaging (MRI) of the brain, visual testing, neurological examinations and examinations for changes in cardiac markers in the blood.

During the procedure, a small catheter is placed in the malfunctioning GSV, and the Varisolve foam is injected into the vein. The GSV is compressed in the groin to trap the foam in the leg and additional foam is injected. The patient’s leg is then put in a compression dressing and stocking, and the patient is able to get up and walk immediately.

In more than 90 percent of the 28 patients studied so far (13 at Wake Forest Baptist) at six research sites across the country, tiny bubbles have been detected in the blood during the procedure. However, no neurological, visual or cardiac changes were observed in the monitoring. The study will continue until a total of 50 patients have been treated and monitored.

Newer Nonionic Contrast Agents Safe for Children

Thu, 07 Jun 2007 21:35:07 PST

( from http://www.rxpgnews.com ) Allergic-like reactions to newer iodine-containing contrast agents (nonionic contrast media), are rare in children according to a recent study conducted by researchers from the University of Michigan Medical Center and C.S. Mott Childrenâs Hospital both in Ann Arbor.

âA major, if not the main, risk associated with iodine-containing contrast agents is allergic types of reactions. Such reactions can be mild; for example, hives or severe such as difficulty breathing or even cardiopulmonary arrest,â said Jonathan R. Dillman, MD, lead author of the study.

âOver the past 20 years, we have changed the type of iodine-containing intravenous contrast agents used primarily for computed tomography (CT) and intravenous pyelogram (IVP) examinations in both adult and pediatric patients. The nonionic contrast media that we now use have been studied extensively in adults, but not as much in children. We performed our study because we wanted to find out what the exact risk of allergic reactions to these newer contrast agents was in children,â said Dr. Dillman.

The study evaluated 11,306 pediatric IV administrations of iodine-containing contrast agents over a seven year period. According to the study, acute allergic-like reactions were documented in 20 of the patients. Of these patients, 16 of the allergic-like reactions were categorized as mild, one as moderate, and three as severe. Six of the reacting patients had a history of allergic-like reactions, including two patients who had a history of reactions to iodinated contrast material. Five of the patients had a history of asthma.

âWhile we have long assumed that newer nonionic contrast agents are safe, this study re-affirms their safety and better determines what the risks actually are in children,â said Richard H. Cohan, MD, co-author of the study. âOur study confirms that doctors and parents alike can feel comfortable administering these agents to children,â he said.

Electromagnetic breast imaging techniques offer high contrast and ability to distinguish between healthy breast tissue and abnormal tissue

Wed, 06 Jun 2007 16:02:00 PST

( from http://www.rxpgnews.com ) Dartmouth physicians and engineers have published a paper with results from a five-year project testing three new imaging techniques to examine breast abnormalities, including cancer. The study finds that the new methods of electromagnetic imaging offer a high contrast and the ability to distinguish between healthy breast tissue and abnormal tissue. Their study appears in the May 2007 issue of Radiology, the journal of the Radiological Society of North America.

The interdisciplinary team includes researchers from Dartmouth's Thayer School of Engineering and Dartmouth Medical School working with experts at the Norris Cotton Cancer Center and the Department of Radiology at Dartmouth-Hitchcock Medical Center (DHMC). The electromagnetic techniques are electrical impedance spectral imaging (EIS), microwave imaging spectroscopy (MIS), and near infrared (NIR) spectral imaging.

A total of 150 women participated in this study, 97 of whom had an abnormal conventional breast image that was suspicious or highly suggestive of malignancy and were scheduled for a biopsy. The women with abnormal breast images underwent electromagnetic exams prior to biopsy. The researchers compared the abnormal area with the background breast tissue and with a mirror image area in the opposite breast and correlated the data with the biopsy findings. Further analysis led the researchers to determine that the new imaging techniques provided an increase in contrast between 150 to 200 percent to discriminate between breast cancer and benign tissue.

?We put our new imaging techniques to the test to quantify their effectiveness,? said Steven Poplack, associate professor of radiology and OB/GYN at Dartmouth Medical School, and co-director for breast imaging/mammography at DHMC, and the lead author of the paper. ?Our results show the potential power of using a variety of imaging techniques to get the best possible view of what?s going on in the breast tissue.?

Specifically, the three techniques demonstrated significant differences in region-of-interest image summaries of normal versus abnormal breasts for EIS, across diagnostic groups for NIR, and for MIS when analysis was restricted to lesions larger than one centimeter. The electromagnetic imaging modalities appeared even more accurate when all are used in concert.

EIS: This painless test uses a very low voltage electrode system to examine how the breast tissue conducts and stores electricity. Living cell membranes carry an electric potential that affect the way a current flows, and different cancer cells have different electrical characteristics.

MIS: This exam involves the propagation of very low levels (1,000 times less than a cell phone) of microwave energy through breast tissue to measure electrical properties. This technique is particularly sensitive to water. Generally, tumors have been found to have more water and blood than regular tissue.

NIR: Infrared light is sensitive to blood, so by sending infrared light through breast tissue with a fiber optic array, the researchers are able to locate and quantify regions of oxygenated and deoxygenated hemoglobin. This might help detect early tumor growth and characterize the stage of a tumor by learning about its vascular makeup.

Percutaneous radiofrequency ablation of liver tumors prove safe and effective

Sat, 05 May 2007 02:14:26 PST

( from http://www.rxpgnews.com )

The study showed that the percutaneous approach is better tolerated by the patients, with significantly less post-procedural pain.

Percutaneous imaging guided radiofrequency ablation (RFA) of hepatocellular carcinoma is a safe and effective technique, with benefits such as reduced post-procedural pain and length of hospital stay, according to a study conducted by researchers from Changi General Hospital in Singapore.

Radiofrequency ablation of a liver tumor may be performed in a number of ways, said Hui Seong Teh, MD, lead author of the study. Two commonly used techniques are the percutaneous approach and open surgery. There have been few studies that compare the efficacy of the two methods, Dr. Teh says.

The study showed that the percutaneous approach is better tolerated by the patients, with significantly less post-procedural pain. Based on an objective scoring system, average pain score was 0.1 for patients who underwent the percutaneous technique, compared to 1.4 for those who had ablation performed with open laprotomy. Patients also have a much shorter stay in the hospital if they were treated using the percutaneous method, Dr. Teh says. The average length of stay in hospital was 2 days for patients who had the percutaneous method, compared to 10 days for those who had open RFA. The shorter length of hospital stay allows patients to resume their activity of daily living faster and enable their early return to active economy, says Dr. Teh.

"Our study further revealed an interesting finding in that the approaches used for ablation do not affect the effectiveness of the ablation treatment," Dr. Teh added. "The choice of RFA methods will affect the hospital resources spent on these patients, and will have a significant impact on healthcare cost," he said.

The full results of this study will be presented on Wednesday, May 9, 2007 during the American Roentgen Ray Societyâs annual meeting in Orlando, FL.

CT and MRI accurate for pre-transplant evaluation of patients with cirrhosis

Sat, 05 May 2007 00:29:02 PST

( from http://www.rxpgnews.com ) CT and MRI are highly accurate at determining which patients would be optimal candidates for liver transplantation, says a recent study.

The study evaluated 1,029 cirrhotic patients who underwent liver transplantation at the University of Pittsburgh Medical Center. The researchers reviewed the last imaging report before surgery (970 on CT and 59 on MRI) and the pathologic report of the explanted liver. The patients were then assessed according to the Milan and University of California San Francisco criteria which describes which patients are the best candidates for transplant.

"The purpose of our study was to focus on the medical decision making process for liver transplant candidate selection and the utilization of CT and MRI to this end," said Alessandro Furlan, MD, one of the authors of the study.

According to the study, agreement between the radiology and pathology staging was demonstrated in 96.5% and 97.5% of the patients according to the Milan and UCSF criteria. The study revealed that imaging underestimated tumor stage in 2.7% (Milan) and 1.85% (UCSF) of the patients and overestimated tumor stage in 0.8% (Milan) and 0.7% of the patients (UCSF).

"The results support the current use of CT and MRI as tools to assist with candidate selection according to criteria from the United Network of Organ Sharing/Milan and UCSF," said Dr. Furlan. "The results essentially support the validity of current clinical practice in the use of CT and MRI in the workup of liver transplant patients," he said.

The full results of the study will be presented on Thursday, May 10, 2007 during the American Roentgen Ray Society Annual Meeting in Orlando, FL.

Stem cells used to regenerate healthy human liver tissue

Tue, 27 Mar 2007 01:12:54 PST

( from http://www.rxpgnews.com ) For the first time, researchers have used adult bone marrow stem cells to regenerate healthy human liver tissue, according to a study published in the April issue of the journal Radiology.

When large, fast-growing cancers invade the liver, some patients are unable to undergo surgery, because removing the cancerous tissue would leave too little liver to support the body.

Researchers at Heinrich-Heine-University in DÃ¼sseldorf, Germany, used adult bone marrow stem cells to help quickly regenerate healthy liver tissue, enabling patients to eventually undergo a surgical resection.

âOur study suggests that liver stem cells harvested from the patientâs own bone marrow can further augment and accelerate the liverâs natural capacity to regenerate itself,â said GÃ¼nther FÃ¼rst, M.D., co-author and professor of radiology.

In the study, researchers compared the results of portal vein embolization (PVE), a technique currently used to help regenerate liver tissue, to a combination of PVE and an injection of bone marrow stem cells into the liver.

PVE blocks blood flow to the diseased portion of the liver and diverts blood to the organâs healthy tissue, promoting liver growth. Bone marrow stem cells extracted from the patientâs hip bone and injected into the liver also help the liver regenerate.

The study included 13 patients with large central liver malignancies who were unable to undergo surgery because resection would leave less than 25 percent of their total liver volume.

Six of the patients underwent both PVE and injection of bone marrow stem cells. Seven patients underwent only PVE. Computed tomography (CT) scans were performed before and up to five weeks after PVE to determine the degree of liver growth.

Patients who received the combination of PVE and stem cell injection had double the liver growth rate and gain in liver volume, compared with those who underwent PVE alone. As a result, the patients who received the combined treatment were able to undergo surgery an average of 18 days sooner than patients who received PVE only.

âOur research demonstrates that stem cells are a powerful adjunct to PVE for patients undergoing surgical resection,â said Jan Schulte am Esch, M.D., co-author and surgery staff member. âBased on our results, we also believe that adult stem cell administration may be a promising therapy for regenerating livers damaged by other chronic and acute diseases.â

The researchers are currently embarking on a randomized controlled trial of the therapy.

Lung cancer screening regimen provides opportunity for cure

Tue, 27 Mar 2007 01:10:05 PST

( from http://www.rxpgnews.com ) Annual computed tomography (CT) screening identifies a high proportion of patients with early-stage lung cancer, according to the latest findings of the New York Early Lung Cancer Action Project (NY-ELCAP) published in the April issue of the journal Radiology.

âThe regimen of screening determines how early the cancer is diagnosed. This is critical, as it provides the opportunity for earlier treatment which can be curative,â said NY-ELCAP principal investigator Claudia I. Henschke, Ph.D., M.D., professor of radiology at Weill Cornell Medical College and chief of the divisions of chest imaging and health care policy and technology assessment at New York-Presbyterian Hospital/Weill Cornell Medical Center in New York City. âFollowing the appropriate regimen also markedly decreases unnecessary work-up and biopsies,â she added.

Lung cancer remains the leading cause of cancer death in both men and women, killing more people than breast, prostate and colon cancers combined, according to the American Cancer Society (ACS). According to the study, the estimated cure rate for lung cancer in the absence of screening is approximately 5 percent, but increases significantly when the cancer is diagnosed and treated at its earliest stage.

NY-ELCAP investigators at 12 medical institutions in New York State provided baseline (first-time) CT screenings to 6,295 people with no symptoms of cancer. The participants were age 60 or older with a history of smoking but no prior cancer and no chest CT in the past three years. A total of 6,014 annual repeat screenings were provided.

CT results prompted recommendations for further work-up on 14 percent of the 6,295 baseline screening participants and 6 percent of the 6,014 repeat screening participants.

A total of 124 people were diagnosed with lung cancer, all but three directly based on screening results, rather than interim symptom-prompted diagnoses. A high proportion of the 124 patients (89 percent in the baseline and 85 percent in the repeat rounds of screening) had no evidence of metastases when recommended for biopsy, indicating that a regimen of annual repeat screenings allows for detection of lung cancer at its earliest, most treatable, stage. Long-term follow-up, as shown in an International ELCAP study recently published in the New England Journal of Medicine, demonstrated a 10-year survival rate of 92 percent among patients with Stage 1 lung cancer when diagnosed early and promptly treated.

âIt is critical that physicians and the people being screened understand the importance of following an optimal screening regimen,â Dr. Henschke said. âDelay in the recommended diagnostic work-up detracted from the full benefit of CT screening, as it resulted in progression of the cancer in size, and sometimes resulted in a higher stage of the disease.â

While a recent JAMA study has suggested that screening CT does not reduce mortality rates for lung cancer, Dr. Henschke disagrees. âThe JAMA article was the first application of a newly developed computer model which predicted expected deaths from lung cancer, and there are numerous concerns about its validity,â she said. âThe main problem with that study is that it focused on too short a time period to assess the decrease in lung cancer deaths, which starts to be evident after the first five years of screening.â

Dr. Henschke recommends that smokers and former smokers considering CT screening should talk to their physicians and, if they decide to be screened, go to an imaging facility with a multidisciplinary team of physicians knowledgeable and experienced in CT lung screening.

RF ablation effective for treating inoperable lung cancer

Tue, 27 Mar 2007 01:02:46 PST

( from http://www.rxpgnews.com ) A minimally invasive procedure known as radiofrequency (RF) ablation is effective for treating lung cancer in patients who are not candidates for surgery, according to a Rhode Island Hospital study published in the April issue of the journal Radiology.

Damian Dupuy, MD, director of ablation at Rhode Island Hospital and professor of diagnostic imaging at The Warren Alpert Medical School of Brown University, conducted a study of 153 patients who were treated for early-stage, inoperable lung cancer with RF ablation. The procedure involves using a specialized needle inserted through the skin to transmit high-frequency electrical currents into a tumor. The overall results of the study show RF ablation to be safe and linked it with promising long-term survival and local tumor progression outcomes when compared to the older treatment method of external beam radiation (EBT).

EBT, which has been used for decades, requires many treatments over a six-week period. This can often lead to a variety of side effects. RF ablation, however, is performed in a single day on an outpatient basis, is minimally invasive and has few side effects.

Dupuy says, "Our study has shown that this minimally invasive procedure can successfully treat patients with lung cancer who could not undergo surgery in one fairly simple treatment. The study also shows that radiofrequency ablation is equal to or more effective in terms of both survival and tumor control." With RF ablation, the Rhode Island Hospital researchers noted a two-year survival rate at 57 percent compared to 51 percent using EBT.

"With lung cancer screening for at-risk individuals on the horizon, we will be able to detect lung cancers at earlier stages. In my lifetime, I foresee image-guided radiofrequency ablation replacing many surgical procedures for the treatment of cancer as we continue to improve these minimally invasive treatment methods."

Other survival rates for stage I, non-small cell cancer treated with RF ablation were 78 percent for one year, 57 percent for two years, 36 percent for three years and 27 percent for both four and five years.

Ultrasound could help couples undergoing IVF

Thu, 15 Mar 2007 06:04:55 PST

( from http://www.rxpgnews.com ) Ultrasound-based tests allowing women undergoing in-vitro fertilization (IVF) to count their chickens before they've hatched may provide alternatives to the hormone-based tests used today. Less costly and invasive than the current ovarian reserve tests, clinicians may in future consider using ultrasound scans of a woman's ovaries to predict her ovaries' response to IVF.

Research published today in Reproductive Biology and Endocrinology details how Janet Kwee et. al. from Vrije Universiteit Medical Centre in Amsterdam, The Netherlands studied 110 women aged 18-39 who had difficulty conceiving. She counted the number of antral follicles, small egg-bearing ovarian follicles about 2-10 mm in diameter, with transvaginal sonography (ultrasound).

Kwee compared the follicle count with ovarian volume with the results from ovarian reserve endocrine tests. The antral follicle count was an effective predictor of the number of eggs the patient would ultimately produce when her ovaries had been stimulated during IVF treatment.

A test that can be administered before IVF that indicates ovarian response might be used to counsel patients as to their chances of success, and help clinicians decide the starting dose of hormones used to stimulate the patient's ovaries for the best results. After around age 40, the ovaries' size decreases - an early sign that the number of follicles, and potential eggs, is depleted. Women with few eggs in their ovarian reserve are less likely to have an adequate ovarian response for successful IVF.

"The follicle count is just as good a test for ovarian response as expensive and time consuming endocrine tests," says Kwee, who adds that the count appears to be "the only test able to reliably predict low and high responders."

Patients prefer CT to MRI to evaluate coronary arteries

Wed, 28 Feb 2007 12:50:33 PST

( from http://www.rxpgnews.com ) Computed tomography (CT) is preferred to magnetic resonance imaging (MRI) by patients with heart disease. That is the result of a study performed at Charité Universitäts medizin Berlin and published on February 28, 2007 in PLoS ONE, the international, peer-reviewed, open-access, online publication from the Public Library of Science (PLoS).

The study compared these two noninvasive tests with invasive angiography. These imaging modalities play a crucial role in the diagnostic assessment of coronary artery disease, which affects about one in four to one in three individuals in Germany.

111 patients who were examined with all three modalities were asked for their assessment. Unsurprisingly, conventional coronary angiography which involves insertion of a catheter and administration of a contrast agent was least popular. About three quarters of the patients would prefer CT to MRI despite the fact that contrast administration is necessary for CT.

While computed tomography involves X-rays, MRI uses magnetic fields and radiowaves. The main advantage of CT is the short duration of the examination, which takes about 15 to 20 minutes. In contrast, patients who undergo MRI of the heart must lie still for up to an hour.

It is not only the accuracy of a diagnostic test that counts, says Dr. Marc Dewey who led the study, we think it is just as important that a
method is accepted by our patients.

Single-slice MRI is a fast, non-invasive way to measure intra-abdominal fat

Wed, 28 Feb 2007 03:23:04 PST

( from http://www.rxpgnews.com ) According to a new study featured in the March issue of Radiology, single-slice magnetic resonance imaging (MRI) is a fast, non-invasive way to measure intra-abdominal fat, which when excessive, may put children and teenagers at risk for developing heart disease, diabetes and other illnesses.

Unlike the fat that lies just beneath the abdominal wall, forming skin folds or "love handles," internal fat located in and around the abdominal organs may actually be more damaging, predisposing children to adult diseases.

"Because metabolic abnormalities appear to be more closely associated with intra-abdominal fat tissue, it is critical to be able to reliably and accurately assess this fat tissue in order to identify children at risk," said the study's lead researcher Marilyn J. Siegel, M.D., professor of radiology and pediatrics at Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, Missouri.

Results from the 2003-2004 National Health and Nutrition Examination Survey found that an estimated 18.8 percent of children (age 6 to 11) and 17.4 percent of adolescents (age 12 to 19) in the United States are overweight.

Current methods used to estimate body fat include anthropometry, which involves physical measurements including waist circumference, abdominal height and body mass index, and dual energy absorptiometry (DEXA), a whole-body scan that distinguishes lean mass from fat tissue. However, anthropometry is imprecise and DEXA requires exposure to ionizing radiation.

In Dr. Siegel's study, 30 adolescents had fat tissue measurements taken using anthropometry, DEXA and single-slice and whole-abdominal, multi-slice MRI. The study's 20 boys and 10 girls were between the ages of 10 and 18 and included nine overweight but non-diabetic individuals, 10 Type-2 diabetic and overweight patients, and 11 normal weight, non-diabetic adolescents.

The single-slice and multi-slice MRI measurements were compared and tested for correlations with anthropometric and DEXA measurements.

"Single- and multi-slice MRI measurements for assessing body fat distribution strongly correlated with clinical and DEXA measures," Dr. Siegel said. "The single-slice MRI, which takes just a few seconds, characterized body fat as well as the multi-slice exam."

While all participants had similar fat distribution patterns with a predominance of fat in the tissue of the abdominal wall, the total amount of fat tissue varied. Overall fat volume was highest in the diabetic, overweight adolescents

According to Dr. Siegel, fat tissue estimation through single-slice MRI is simple, fast and could be useful in many clinical and research applications, including patient management, monitoring interventions, and implementing multi-center clinical trials or epidemiologic studies.

"Our ability to accurately measure abdominal fat may substantially advance strategies for achieving healthy weights in children," she said.

Multislice CT speeds the diagnosis of chest pain in the emergency room

Wed, 21 Feb 2007 08:24:17 PST

( from http://www.rxpgnews.com ) Imagine coming to the hospital with crushing chest pain, only to find that emergency room doctors are uncertain whether youre having a heart attack. The electrocardiogram (ECG) is inconclusive and the blood tests that detect heart damage are normal. The only thing to do is wait, hour after hour, as doctors repeat the tests several times and scrutinize the results for diagnostic clues.

Soon, the wait may be much shorter. According to research reported in the February 27, 2007, issue of the Journal of the American College of Cardiology (JACC), a computed tomography (CT) scan of the heart can quickly detect whether there are fatty blockages or pockets of rock-hard calcium in the arteries of the heartclues that coronary artery disease may be the cause of the chest pain.

"The new 64-slice CT scanners give us amazing pictures of the heart," said James A. Goldstein, M.D., F.A.C.C., Director of Research and Education in the Division of Cardiology at William Beaumont Hospital, Royal Oak, MI. "With this very simple outpatient scan, you can rapidly determine whether the arteries are normal or abnormaland if theyre abnormal, whether the disease is mild, moderate, or severe."

Those who get a clean bill of health can safely go home from the hospital without further testing. "As a physician, its tremendously satisfying to tell an anxious patient, within about 30 minutes, that their heart and arteries are normal," Dr. Goldstein said.

Each year, some 6 million people in the United States are rushed to the emergency room with chest pain. At least half have inconclusive early test results; of these, approximately 65 percent are eventually found not to have suffered a heart attackbut not before racking up diagnostic costs totaling $10 billion to $12 billion annually.

Even low-risk patients with no history of heart disease can spend 18 to 24 hours in the emergency room as doctors repeat the ECG and blood tests. Thats because doctors want never to mistakenly send home a patient who is actually having a heart attack. "The consequences of missing a heart attack can be disastrous," Dr. Goldstein said. "So even if you appear to be completely healthy, if you come to the emergency room with chest pain, youre going to go through a very laborious, expensive, and time-consuming evaluation."

Dr. Goldstein and his colleagues wanted to see whether a CT scan of the heart could make the evaluation of chest pain more efficient and less costly, allowing emergency physicians to quickly send home patients with normal coronary arteries, while accurately identifying patients with serious heart disease who needed to be admitted to the hospital.

For the study, they recruited 197 patients with heart attack-like chest pain but no history of heart disease. In all patients, the results of the ECG and the blood tests that detect heart damage were normal, both initially and after being repeated four hours later. The researchers then randomly assigned half of the patients to have a CT scan of the heart and the other half to a standard diagnostic plan, which included additional rounds of ECG and blood testing, plus a nuclear scan of the heart.

Multislice CT first uses x-rays to measure the amount of calcium in the arteries supplying blood to the heart. Then, after injection of high-contrast intravenous dye, it creates detailed pictures of the heart and coronary arteries, including any soft, cholesterol-filled blockages. The scan takes only minutes to complete.

Nuclear scanning is a two-part test that uses radioactive material to evaluate blood flow to the heart during rest and again during stress, when the heart is pumping faster as the result of exercise or medication. By definition, nuclear imaging takes longer than a CT scan. Most doctors prefer to observe the patient in the emergency room for at least eight hours before stressing the heart, just to be safe. In addition, several hours must pass between the rest and stress portions of the test to allow the radioactive material to pass through the body.

In the new study, patients with a clearly normal CT or nuclear scan were allowed to go home immediately, and those with a clearly abnormal scan were sent to the cardiac catheterization laboratory for further, invasive testing. In the CT group, patients with uncertain test resultseither because the images were not clear, or because there was only a moderate amount of disease in the coronary arteriesalso had a nuclear scan to help determine whether invasive testing would be needed.

The researchers found that CT alone was able to determine that heart disease was the cause of chest painor reliably rule out that possibilityin 75 percent of patients. The remaining 25 percent of patients had a nuclear scan in addition to CT. Even so, both the cost and the time it took to reach a diagnosis were significantly lower in the CT group. Costs averaged $1,586 for patients who had a CT scan, as compared to $1,872 for patients who had a standard diagnostic evaluation (p<0.001). Similarly, the time it took to make a diagnosis averaged 3.4 hours with CT, as compared to 15 hours with the standard diagnostic approach (p<0.001).

"We were able to show a dramatic reduction in the time it took to reach a definitive diagnosis, even though in this small study we did not have the scanner operating 24 hours a day, seven days a week," Dr. Goldstein said. "For both individual patients and society, the use of CT to evaluate chest pain in the emergency room could have tremendous implications for the costs and efficiency of care."

"CT angiography has produced very impressive images of the coronary arteries without the need for catheterization, but where, when and how to use this information is uncertain," said Anthony N. DeMaria, M.D., F.A.C.C., Editor-in-Chief of JACC. "These data demonstrate a potential application of CT angiography for the rapid assessment of chest pain in the emergency room. However, it must be acknowledged that the patient population was limited, confined to low risk individuals based upon initial evaluation, and that the primary benefit was in detecting abnormalities sooner and more inexpensively, but not more accurately. The effect of the earlier diagnosis upon outcome also remains to be determined."

A large randomized controlled trial will put CT to a demanding test. Dubbed CT-STAT, the Coronary Computed Tomography for Systematic Triage of Acute Chest Pain Patients to Treatment trial will involve 750 low-risk patients evaluated for heart attack-like chest pain at 15 hospitals across the United States. Patient recruitment will begin soon.

CT does have limitations, Dr. Goldstein said. For example, if a patient is already known to have coronary artery disease, CT is less helpful. Thats because it cant determine whether a moderate blockage is substantial enough to interfere with blood flow to the heart, thereby causing chest pain. In addition, it often fails to produce clear images in very obese patientsalthough this barrier may fall as manufacturers work on new imaging methods.

Another concern is radiation exposure, noted Pim J. de Feyter, M.D., Ph.D., F.A.C.C., University Hospital Rotterdam, the Netherlands, in an accompanying editorial in the Feb. 27, 2007, issue of JACC. This is particularly true for patients with moderate arterial narrowings or unclear CT images. They receive one dose of radiation during CT scanning, a second dose of radiation during follow-up nuclear scanning, and in some cases, a third dose during cardiac catheterization. "If multislice CT does not give a definitive diagnosis, alternative diagnostic strategies that avoid radiation exposureshould be investigated," Dr. de Feyter said.

Dr. Goldstein reports no potential conflicts of interest regarding this topic.

Also in this issue of JACC

A report from Queens University, Kingston, Ontario, Canada, describes the development of new standards for identifying metabolic syndrome in adolescents. Metabolic syndrome is defined by a cluster of unhealthy characteristics that hike the risk of cardiovascular disease, including a large waist measurement, high blood pressure, high blood sugar, high blood levels of fats known as triglycerides, and low blood levels of "good" cholesterol, or HDL cholesterol.

In adults, the cut-off points for identifying metabolic syndromejust how large a waist circumference, or how high the blood pressure readingare well established and considered valid. Until now, the cut-off points used in adolescents have been arbitrary and have varied from one research study to the next. The Canadian research group created a more reliable set of standards by starting with the already validated adult cut-off points for 20-year-old women and men, then performing a statistical analysis to work backward to age 12. They displayed the data for each of the characteristics of metabolic syndrome as an age-related growth curve, just like the ones pediatricians routinely use in evaluating a childs age-related height and weight.

"Our goals were to provide age-appropriate and health-based metabolic syndrome component cut-points for adolescentsthat could be used consistently in clinical and research settings," the researchers noted. "In light of the increasing prevalence of obesity and other metabolic syndrome indicators in the pediatric population, it seems urgent to address this problem in this age group."

How safe is "boutique ultrasonography"?

Mon, 05 Feb 2007 13:05:37 PST

( from http://www.rxpgnews.com )

Improvements in ultrasound technology have transformed antenatal scans from two dimensional black and white images to 3D, 4D and even moving pictures of the unborn child.

Expectant parent' desire to see images of their unborn children has given rise to commercial companies offering keepsake ultrasound scans without medical supervision, often referred to as "boutique ultrasonography."

In a special report in this week's BMJ, journalist Geoff Watts considers whether this non-medical use of the technique can be justified.

Improvements in ultrasound technology have transformed antenatal scans from two dimensional black and white images to 3D, 4D and even moving pictures of the unborn child. Expectant parents seeking a CD-ROM or a DVD of their scan can expect to pay £150-£250 (230-380; $300-490).

The companies say that ultrasound has not been shown to cause any harm to mother or baby, but the US Food and Drugs Administration (FDA), the American Institute of Ultrasound in Medicine, and the French Academy of Medicine are among several official bodies that have reservations about such use of the technology. The British Medical Ultrasound Society does not have a specific policy on non-medical imaging, but is currently updating its guidance.

The FDA says: "Although there is no evidence that these physical effects can harm the fetus, public health experts, clinicians and industry agree that casual exposure to ultrasound, especially during pregnancy, should be avoided."

There are also concerns about how staff deal with the discovery of a fetal abnormality.

Some doctors offer keepsake images after they have performed ultrasound for medical reasons. The FDA takes a dim view of this, but the American Institute of Ultrasound Medicine deems it to be consistent with their ethical principles.

Beyond spreading a little happiness, the case for non-medical imaging relies principally on bonding: the sense of attachment between a mother and her unborn child, says Watts. The evidence that ultrasound images can foster this comes from 2D scans, but there is no evidence that 3D scans are more effective in enhancing maternal-fetal attachment.

The controversy over 3D and 4D imaging would be partially resolved if genuine medical benefit could be shown, he adds. Research is currently under way to find out if seeing the fetus in 3D might help spot abnormalities such as cleft lip. Early indications are that it may be useful but, for the moment, it is by no means self evidently beneficial.

SCAI recommends maintenance of high standards while performing PCI without on-site cardiac surgery support

Mon, 05 Feb 2007 05:09:54 PST

( from http://www.rxpgnews.com ) The Society for Cardiovascular Angiography and Interventions (SCAI), a leading organization for interventional cardiologists, today released a document recommending the adoption of stringent quality standards by those who perform percutaneous coronary intervention (PCI) in hospitals not equipped for cardiac surgery. The document has been endorsed by 12 medical societies representing more than a dozen countries, including the Asia-Pacific region, Australia, Belgium, Brazil, Bulgaria, Egypt, Great Britain, India, Italy, Latvia, New Zealand, Poland, and Venezuela.

The document, which represents the consensus of a panel of experts in interventional cardiology, acknowledges that an increasing number of patients suffering from heart attack or coronary artery disease are undergoing stenting and other catheter-based heart therapies in hospitals without on-site cardiac surgery, both in the United States and around the world. When PCI is performed without on-site surgical back-up, physicians and hospitals should adhere to the highest standards of quality to ensure patient safety and excellent clinical outcomes, the document recommends.

"This is not an open endorsement of PCI without on-site surgical back-up. Instead, we are acknowledging that it may be appropriate in some settings, and offering our expert consensus on how such programs should be organized, supervised, and performed," said Dr. Gregory J. Dehmer, SCAI President and chair of the expert panel. "The goal is to improve the quality of coronary interventional care worldwide."

The consensus document recommends that PCI programs operating without on-site cardiac surgery:

Maintain case volumes of at least 200 PCIs per year;

Employ highly skilled interventional cardiologists who have performed more than 500 PCIs throughout their career, have an annual case volume of more than 100 PCIs, and meet national benchmarks for procedural success and complication rates;

Train all support personnel in the management of PCI patients;

Select patients carefully to control the risk of complications;

Establish a close alliance with cardiovascular surgeons, including formalized and tested protocols for emergency transfer of patients;

Activate emergency transport at the first clear signs of a PCI complication, thereby ensuring that the time to the initiation of cardiopulmonary bypass does not exceed 120 minutes; and

Collect appropriate outcomes data and submit them for comparison with state or national performance standards.

The consensus document addresses an ongoing health policy debate. Current PCI guidelinesco-authored by SCAI in partnership with the American College of Cardiology and the American Heart Association and released in November 2005indicate that performing PCI for heart attack patients in a hospital with cardiac surgery is widely accepted as beneficial, useful, and effective and is supported by scientific studies. (In the terminology of guidelines documents, it is designated a Class I indication.)

Performing PCI for heart attack patients in hospitals without on-site cardiac surgery is, in guidelines terminology, a Class IIb indication, meaning its usefulness and effectiveness are less well established by scientific evidence and opinion. As for routine "elective" PCI in hospitals without on-site cardiac surgery, the 2005 guidelines recommend against the practice, rating it a Class III indication, as did an earlier set of guidelines issued in 2001.

Many studies have shown that PCI is a highly effective treatment for heart attack and offers key advantages over clot-busting drugs. Rapid treatment is critical, however. Patients benefit most when blood flow is restored within 90 minutesa goal that can be considerably more difficult to meet if patients must be transferred to a PCI center with cardiac surgery. As a result, PCI for heart attack is being performed in hospitals without on-site cardiac surgery in all but 10 states.

"The advantages of PCI for the treatment of heart attack patients started the movement toward PCI without on-site surgery, especially in smaller communities without cardiac surgery," Dr. Dehmer said. "The sooner the patient undergoes PCI, the better."

Some hospitals performing PCI for heart attack have also started elective PCI programs, using stenting and other catheter-based procedures to treat patients with narrowed coronary arteries. Survey data collected by SCAI show that elective PCI without on-site cardiac surgery is increasingly common. In fact, it is performed in 28 states in the United States and in many other developed countries.

One key reason for offering elective PCI without on-site cardiac surgery is the difficulty of maintaining a high level of skill among the nurses, technicians, and physicians in a program that treats only a small number of heart attack patients each month. In addition, if elective PCI is unavailable in some rural areas, elderly or economically disadvantaged patients may forgo PCI altogether, rather than face travel to an urban medical center.

Also fueling the growing trend is the safety of PCI. The need for emergency bypass surgery after PCI has fallen dramatically over time, to around 36 in 1000 procedures. In fact, emergency surgery is so infrequent, hospitals with on-site cardiac surgery no longer hold operating rooms open while PCI is performed. Several small studies have shown good results for PCI without on-site surgery, but more definitive evidence must come from large randomized trials. One such study has just started to enroll patients.

"The focus of PCI programs must always be on providing the best quality of care for the patient under all circumstances," Dr. Dehmer said. "This document addresses the realities of our healthcare system while setting performance standards very high."

Technology can't replace doctors' judgment in reading mammograms

Mon, 04 Dec 2006 15:05:28 PST

( from http://www.rxpgnews.com ) Radiologists should not become too dependent on the use of computer-assisted detection (CAD) technology when reading screening mammograms because the doctors can see lesions that CAD sometimes misses. This is according to a study conducted at Group Health Cooperative, a Seattle based health care system. The research appears in the December issue of the American Journal of Roentgenology.

"Our study shows that radiologists must continue to rely on their own judgment when determining whether lesions seen on mammograms require further testing," said Stephen Taplin, MD, MPH, who led the research at Group Health before joining the National Cancer Institute as a senior scientist.

CAD uses computer software to identify and mark areas of concern on mammograms. Radiologists typically review the CAD-marked images after they interpret the original film.

While early CAD evaluations showed it improved cancer detection, more recent studies have raised questions about CAD's performance. For example, while it is believed that CAD alerts radiologists to potential areas of concern, experts have wondered whether CAD too frequently marks normal areas rather than only identifying problem areas that the radiologist should have detected.

To answer these questions, the researchers at Group Health designed a study using a sample from more than 56,000 screening mammograms taken between 1996 and 1998. By identifying cases of breast cancer diagnosed within two years after the mammograms were taken, they created a total set of 441 mammograms from three different groups. Included were mammograms from women who:

1) remained cancer-free two years after their mammograms
2) developed breast cancer within one year, or
3) developed breast cancer within 13 months to two years.

The sample was then used to test the performance of 19 radiologists, each of whom read 341 mammograms with and without CAD. The researchers then compared the results of the two approaches for each mammogram.

This is the first study of CAD using a random sample of cases from a screened population rather than using selected cases of visible cancers. In this way, it more closely resembles the way that radiologists use CAD in real practice.

The study showed that CAD assistance increased radiologists' ability to determine that a woman without cancer was, in fact, cancer free—a quality known as mammographic "specificity." Overall specificity increased from 72 percent without CAD to 75 percent with CAD. This 3 percent difference means that CAD allows 30 women in every thousand women screened to avoid further evaluation.

CAD assistance did not affect the radiologists' overall ability to spot cancer where it was present—a quality known as mammographic "sensitivity." The doctors performed equally well with and without CAD.

However, CAD does not mark all visible abnormalities. And when the researchers analyzed the radiologists' performance on mammograms with lesions that CAD did not catch, they found that the doctors were less likely to recommend further evaluation when they were using CAD than when they were not using CAD.

"This means that the radiologists may have been deferring to CAD and believing its interpretation rather than their own interpretation," said Taplin. "This is something the originators of the technology say radiologists should not do. This study shows that it is hard to ignore the technology, and it raises the question of whether there is a potential for CAD to do harm."

Taplin and his co-authors recommend training for radiologists that focuses on characteristics that CAD may miss, namely "masses, asymmetries, and architectural distortions" visible on the mammograms. They also note that research into these visible, unmarked lesions may offer the best chance to improve CAD-assisted mammography.

The researchers also found that breast density—a measure of the amount of fat tissue in the breast—did not affect CAD's performance

Inside the Head of an Ancient Pharaoh

Tue, 28 Nov 2006 18:38:43 PST

( from http://www.rxpgnews.com ) Egyptian radiologists who performed the first-ever computed tomography (CT) evaluation of King Tutankhamun's mummy believe they have solved the mystery of how the ancient pharaoh died.

Ashraf Selim, M.D., radiologist at Kasr Eleini Teaching Hospital, Cairo University in Egypt, was part of an international team of scientists that studied the 3,300-year-old mummy of King Tut in Egypt. Using a mobile multi-detector CT scanner, the researchers performed a full-body scan on the king's remains, obtaining approximately 1,900 digital cross-sectional images.

"We found the mummy was in a critical stage of preservation," said Dr. Selim. "The body was cut into several parts with some missing pieces."

With the help of the CT images, researchers estimated King Tut's age at death to be between 18 and 20 years. His height was 180 centimeters or approximately 5 feet 11 inches. The researchers discovered a possible premortem fracture to the femoral (thigh) bone. While they cannot assess how the injury occurred, the findings suggest that the injury may have been an open wound that became infected and ultimately fatal.

Since King Tut was first examined by x-ray in 1968, revealing what appeared to be a bone fragment in his skull, it has been widely speculated that a blow to the head killed the boy king. However, Dr. Selim and colleagues found several pieces of evidence to the contrary. In the cranial cavity, they found loose bone fragments that were not covered with the intracranial solidified embalming material. These bone fragments matched exactly a defect within the first vertebra in the neck. They found no evidence of skull fractures.

A mishap during the mummification process, or even damage incurred during that first x-ray examination may explain the misplaced—and misleading—bone fragments. Dr. Selim suggests the damage may have been caused by the expedition led by Howard Carter that first discovered Tut's tomb in 1922.

"We believe that this broken piece from the first vertebra of the king's spine may have been fractured and dislodged when Carter, Derry, Hamdy and their team tried to remove and free the gold mask, which was tightly glued and quite adherent to the body, by using some metal instruments that broke the thin, fragile piece of bone that lies immediately underneath the bone defect in the skull base through which the spinal cord emerges," Dr. Selim said.

Dr. Selim's team did not escape the so-called curse that is said to plague anyone who disrupts the remains of the boy king.

"While performing the CT scan of King Tut, we had several strange occurrences," he said. "The electricity suddenly went out, the CT scanner could not be started and a team member became ill. If we weren't scientists, we might have become believers in the Curse of the Pharaohs."

The CT examination of King Tut is part of a five-year initiative called the Egyptian Mummy Project to image and preserve Egypt's mummies and to solve various mysteries about the diseases and lifestyles of ancient Egyptians.

King Tutankhamun, who ascended to the throne when he was just eight years old, was mummified and buried with other ancient royals. His tomb, filled with 5,000 artifacts, was discovered near Luxor, Egypt in 1922. Artifacts from the tombs of King Tut and other royals buried in the Valley of the Kings are part of "Tutankhamun and the Golden Age of the Pharaohs," an exhibition currently at Chicago's Field Museum.

New way of tracking muscle damage from radiation

Tue, 07 Nov 2006 14:29:00 PST

( from http://www.rxpgnews.com ) Magnetic resonance imaging (MRI) could become a valuable tool for predicting the risk of muscle injury during and following radiation therapy, according to investigators at St. Jude Children's Research Hospital.

The researchers report that MRI can spot the immediate injury done by radiation therapy to the muscles of children undergoing radiation treatment for certain types of soft-tissue cancer. This also indicates that MRI might one day be able to help doctors predict the amount of long-term damage that radiation may cause. A report on these findings appears in the Oct. 25 online issue of Magnetic Resonance Imaging.

The study's findings are significant because as radiation treatments become more advanced and complex, clinicians must have a way to predict the outcomes--including side effects--on specific patients, according to Matthew Krasin, M.D., associate member of the St. Jude Department of Radiological Sciences.

The St. Jude study showed that changes in images taken of muscles before and after radiation therapy for soft tissue sarcoma and Ewing sarcoma are related not only to the amount of radiation the child received, but also to the child's age and the presence of a nearby tumor.

"We hope that detecting these changes at such an early stage may help clinicians predict which patients need an intervention to prevent late damage," Krasin said. Soft tissue sarcomas are cancers that arise in muscles, fat, blood vessels and other soft tissues. Ewing sarcoma is a cancer that arises in the bone or soft tissue, usually in the arms, legs, pelvis or chest wall.

St. Jude researchers studied the muscles of 13 patients before, during and 12 weeks after they received radiation therapy for soft tissue sarcoma. The team used a technique called quantitative T2 to determine the extent of swelling in tissues before, during and after radiation therapy; and a technique called dynamic enhanced magnetic resonance imaging (DEMRI) to study what happens to the blood supply at a microscopic level.

"These techniques are powerful, non-surgical ways to look into the body and study the microscopic and biochemical changes that are occurring in each patient after radiation therapy," Krasin said.

The team made 60 images of the same area, including a dynamic view of what was happening in the muscles during a six-minute period following infusion of gadolinium, a contrast agent.

"The rate at which the contrast agent flows in and out of a region, or whether it leaks out of the blood vessel, helps us understand whether the blood supply is in poor or good condition," Krasin said. "Changes in T2 measurements may indicate an increase in swelling following radiation therapy, which is evidence of inflammation that could be treated."

The researchers believe that the early changes they see in muscle, such as swelling and leakage, might help them predict how much damage will occur in the muscles during the course of many months. By better understanding what causes these changes, clinicians will then be able to design better radiation treatments to avoid potential problems or treat the injury at an earlier stage, Krasin said.

Audit shows excellent performance of radiologists in interpreting mammograms

Tue, 26 Sep 2006 16:26:00 PST

( from http://www.rxpgnews.com ) A recent study of medical audit data funded by the National Cancer Institute (NCI) revealed that community mammography screening results surpass performance recommendations across the United States. Approximately 188 mammography facilities nationwide contributed to the study of more than 1.1 million women, who underwent at least one screening mammography exam between 1996 and 2002. The findings are reported in the October issue of Radiology.

"With a cancer detection rate of 4.8 per 1,000 women, our results show that most radiologists who are reading mammograms are performing well," said Robert D. Rosenberg, M.D., lead researcher and professor of radiology at the University of New Mexico in Albuquerque. "Mammography, combined with better breast cancer treatments, appears to be helping to decrease the number of deaths from breast cancer."

Up until now, there has been no national measurement with which radiologists could compare their individual cancer detection rates.

"There have been no data available for mammographers in the United States to give context to anyone's individual performance results. All prior guidelines were best guesses from a panel of experienced radiologists," Dr. Rosenberg explained.

In the study, data were collected from six NCI-funded research sites, for a total of nearly 2.6 million screening exams assessed by 807 radiologists. Each radiologist's assessment, along with every woman's outcome within 12 months of the initial screening exam, were tallied. The radiologists included in the analysis came from urban, rural, large and small practices of different organizational structures, across broad geographic areas.

Approximately 10 percent of mammograms yielded abnormal findings, for a recall rate of 9.8 percent.

"We found that radiologists are much more likely to err on the side of caution, for a higher recall rate," said co-author Bonnie Yankaskas, Ph.D., professor of radiology at the University of North Carolina at Chapel Hill.

After additional imaging work-up, cancer was ultimately diagnosed in 4.8 of 1,000 women. When a radiologist identified significantly abnormal findings and advised that biopsy be performed immediately, 34 percent of biopsy results yielded cancer.

The majority of women examined were 40 to 70 years old. Of all reported cancers, 21.6 percent proved to be ductal carcinoma in situ, and 78.4 percent were invasive cancers. Of invasive cancers, 37.2 percent were small tumors measuring 10 millimeters or less in diameter, 41.6 percent were mid-sized tumors measuring 11 to 20 millimeters, and 21.2 percent were large invasive tumors measuring 2 centimeters and larger.

The authors hope that their findings will allow radiologists to evaluate and improve the accuracy of their individual cancer detection rates when reading mammograms.

"Recalls and additional biopsies do add to the cost and anxiety of mammography," said Dr. Rosenberg. "However, we are continually working to improve the test from both ends--finding cancers while minimizing unnecessary work-ups."

Comparing MDCT and digital radiography in orthopedic patients

Thu, 03 Aug 2006 17:20:00 PST

( from http://www.rxpgnews.com ) Multi-detector computed tomography (MDCT) using high-quality 2D formatting is highly recommended as the primary imaging technique for the evaluation of bone healing, according to a study done by radiologists at the Medical University of Vienna in Vienna, Austria.

Forty-three patients with histories of fractures, arthrodesis (joint fusion) or spinal fusions who'd undergone MDCT and conventional radiography for the evaluation of bone healing were included in this study. Mutiplanar reconstructions and radiographs were analyzed by two musculoskeletal radiologists in consensus interpretation to determine bone healing.

According to the results, no evidence of bone bridging was shown in 14 patients, 23 patients showed evidence of partial fusion, and six patients showed complete fusion. In 27 patients (63%), MDCT and digital radiography were concordant with regard to the extent of bone healing, while in 16 patients (37%) the results were not concordant. In eight patients digital radiographs underestimated the extent of bone healing, while in another eight patients they overestimated the degree of fusion. "Most cases were dealing with bonehealing after spondylodiscitis, fractures or arthrodesis," said Christian R. Krestan, MD, lead author of the study. "However no scientific data were available concerning the value of MDCT in bone healing compared to radiographs, which had been used for decades in this indication," said Krestan.

"The results of this study have a considerable impact on orthopedic patients and lead to a substantial improvement in patient care," said Krestan. "The exact diagnosis or exclusion of bone healing provides a basis for decisions like mobilization or immobilization and even repeated surgery in these patients," he said.

New MRI technique shows emphysema in asymptomatic smokers

Wed, 31 May 2006 17:08:00 PST

( from http://www.rxpgnews.com ) A new imaging method has revealed early signs of emphysema in smokers with no external symptoms of the disease, according to a study published in the June issue of Radiology. The study, supported by the National Institutes of Health, details a new magnetic resonance imaging (MRI) technique that appears to be much more sensitive to lung changes than even the current modality of choice, computed tomography (CT).

"With this technology, we have shown that it is possible to measure the severity of emphysema and its progression through time without the radiation exposure of lung CT tests," said Sean B. Fain, Ph.D., lead author and assistant professor of medical physics and radiology at the University of Wisconsin, Madison.

Emphysema is a chronic, progressive lung disease, which permanently damages the air sacs in the lungs. As the size of the air sacs (or "airspaces") increase, cavities form in the lung tissue, hindering oxygen delivery. According to the American Lung Association, over 3 million people in the United States have been diagnosed with emphysema, and millions more are in the early stages of the disease before signs and symptoms appear. Smoking cigarettes triples the risk of developing the disease.

The researchers had 19 volunteers inhale a special kind of "hyperpolarized" helium before they performed two MRI tests of the lungs. Eleven of the volunteers were smokers with no symptoms of emphysema, and the remaining eight were nonsmokers. The first image the researchers acquired showed obstructed areas of the lungs, where the air was unable to pass. The second image they obtained is called an apparent diffusion coefficient (ADC) map, which shows the size of the airspaces in the lungs. Because emphysema increases airspace size, the ADC map shows the location and severity of the disease.

"The ADC maps are very sensitive to changes in the lung structure," Dr. Fain said. "With this tool, it was shown that even smokers that appear healthy have enlarged lung airspaces that suggest emphysema is already developing."

With increasing smoking history, the ADC maps showed progressive breakdown of the lung structure in all regions of the lungs. All smokers with a history greater than 18 pack-years (equivalent to one pack of cigarettes per day for 18 years) showed significant abnormalities compared to nonsmokers.

CT was performed after MRI, to allow comparison between the two modalities. Even though CT is the more established modality in the investigation of lung disease, it failed to show the same defects detected with MRI. Moreover, with the combination of MRI and hyperpolarized helium, the researchers were able to measure lung structures with 2½ times more precision than with CT, and 10 times more precision than with conventional MRI methods.

Age is a significant factor in the development of emphysema-like changes. The researchers found that, in general, the airspaces in the lungs enlarge with age. However, smoking compounds the problem. Dr. Fain and colleagues showed in a related study that these changes occur at a much slower rate in nonsmokers than in active smokers.

"On average, active smoking accelerates emphysema-like changes at about twice the normal rate found with aging," Dr. Fain explained.

In addition to early disease detection, hyperpolarized MRI can also be used to plan surgical therapies and to monitor patient response to drug therapies without the risks of exposure to CT-related radiation.

Dr. Fain believes that this new method of using polarized gases to study lung diseases will provide a clearer picture of the underlying mechanisms of poorly understood conditions like asthma and chronic pulmonary obstructive disease, leading to better treatments.

Safety profile for CT colonography (CTC) favorable

Wed, 03 May 2006 01:15:00 PST

( from http://www.rxpgnews.com ) The safety profile for CT colonography (CTC) is extremely favorable, particularly for the purposes of screening patients with no symptoms and when distending the colon using an automated carbon dioxide technique, a finding that goes against the higher complication rates for CTC reported by other groups, according to a new study.

For this study, researchers analyzed 21,923 CTC procedures, including both diagnostic and screening procedures. Colonic distention was achieved by manual room air insufflation in 60% of cases and by automated carbon dioxide delivery in 40%. No perforations were recorded in patients undergoing screening CTC or with those who underwent the automated carbon dioxide delivery technique. Perforations were recorded in only two patients undergoing diagnostic CTC, and manual room air insufflation was employed in both cases. Only one of the two needed treatment for the perforation, and the one who was treated was already symptomatic prior to CTC due to annular sigmoid carcinoma. Overall, the researchers found that the complication rate for this procedure was 0.018%, or 4 out of 21,923 procedures.

According to the researchers, automated carbon dioxide delivery is much simpler and safer for the CT technologist to employ than manual room air insufflation, which was the method of distention used in the previous studies that reported a higher complication rate due to perforations. "The automated nature of carbon dioxide delivery removes the guesswork and patient coaching necessary with manual distention. In addition, this automated approach with low-pressure carbon dioxide provides improved distention and reduced post-procedure discomfort," said Perry J. Pickhardt, MD, of the University of Wisconsin Medical School and lead author of the study.

"Our results provide reassurance to patients that this minimally invasive examination is a very safe colorectal screening tool. 'Primum non nocere' (first do no harm) is particularly applicable to the screening of asymptomatic adults, which raises some important issues for screening with invasive colonoscopy," said Dr. Pickhardt.

Modulating tube current to account for body symmetry reduces radiation exposure in CT

Wed, 03 May 2006 01:09:00 PST

( from http://www.rxpgnews.com ) By lowering the tube current to account for both the weight and body symmetry of a child, an abdominal CT radiation dose can be reduced by 60% without compromising the image quality, says a new study by researchers from the Children's Hospital of Philadelphia in Pennsylvania.

For the study, the researchers reviewed the abdominal CTs of 74 children. The researchers found that on average, modulating the tube current to account for body symmetry reduced the radiation dose by 15% over the usual weight-adjusted dose. In addition, the overall dose reduction from combining the two techniques into one ranged from 14% to 82%, depending on the weight group, for an average of 60%.

"CT is a large source of radiation exposure in medical practice for children. Although CT scans represent about 5% of all X-ray imaging, the radiation from CT is 40% to 67% of all medical radiation. By using the above technique, we can decrease the level of radiation risk to children, while still maintaining acceptable image quality. This is especially important because children have a longer lifetime in which to manifest radiation-related cancer," said Soroosh Mahboubi, MD, one of the researchers on the study.

Training on virtual 'patient' improves carotid angiography skills

Fri, 28 Apr 2006 02:14:00 PST

( from http://www.rxpgnews.com ) Cardiologists can learn to perform risky catheter procedures such as carotid angiography on a virtual patient simulator, rather than on real patients, according to a new study in the May 2, 2006, issue of the Journal of the American College of Cardiology.

"Virtual reality simulation technology has advanced to the point where we can actually use a virtual environment and have the trainee learn in a very 'patient-safe' way in a virtual patient environment and make mistakes on a virtual patient versus doing it on a real patient," said Christopher U. Cates, M.D., F.A.C.C., F.S.C.A.I. from the Emory University School of Medicine in Atlanta, Georgia.

Twenty interventional cardiologists participating in the Emory NeuroAnatomy Carotid Training program underwent an instructional course on carotid angiography and then performed five serial simulated carotid angiograms on the Vascular Interventional System Training (VIST) VR simulator.

The cardiologists committed fewer catheter errors, while performing the virtual procedure in less time, and subjecting the virtual patient to less X-ray imaging and smaller injections of contrast agent during the final run compared to the first one.

Dr. Cates noted that the study looked at only one specific model of simulator, the Procedicus Vascular Interventional System Trainer (VIST) made by Mentice AB in Gothenburg, Sweden. The company was not involved in the design or funding of this study. Dr. Cates said the performance of other simulators is not necessarily the same and would have to be studied individually before being used to measure the performance of doctors.

Trainees using the simulator use catheter controls that are identical to those on the ends of the catheters they use in actual procedures, but the other end of the catheters interact with sensors that feed movement data into a powerful computer. The trainees feel the "catheter" move and they watch the progress of the "tip" on a monitor image just like the fluoroscope X-ray image they would watch during and actual procedure. Cardiologists who have used the simulator say that what they see and feel is very realistic.

Carotid angiography, and the related procedure of carotid stenting, is a technically challenging procedure. The procedure involves threading thin catheters through blood vessels into a carotid artery in the neck. It is performed by a relatively small number of cardiologists, in part because of its inherent risks.

"In carotid angiography, where we are introducing catheters into the blood vessels that feed the brain, if a little piece of material breaks off or you do it incorrectly and knock a piece of blood clot or atherosclerotic plaque off the artery while you are putting the catheter in, it goes downstream and goes to the brain and causes a stroke. And that's a devastating event," Dr. Cates said.

Previously, practitioners learning new catheter procedures practiced on animals, cadavers or mechanical models and then were supervised as they worked on their first live patients. The researchers are currently doing studies to see if the patients of practitioners trained on this simulator have better clinical outcomes. But the researchers say one advantage of simulator training is already apparent. The progress of trainees (their "learning curve") is tracked objectively, so evaluators don't have to rely on the subjective reports of an instructor.

This study is the first to actually measure the "learning curve" of doctors trying a new procedure, documenting increasing proficiency and declining error rates of individual trainees.

"And so we now have some objectivity in how doctors are doing in their training versus the subjectivity of a mentor looking over the shoulder of a trainee doing the procedure and saying, 'I think he's doing a pretty good job,'" Dr. Cates said. "We can actually measure the doctor's performance doing the fine tasks in a simulator on a virtual patient and measure his task achievement against a benchmark, say of somebody who is expert in that technique, and show that he can reach that level of proficiency before he actually works on a patient for the first time. And that is a historic breakthrough in medicine."

Dr. Cates predicted that simulator training will become as routine in medicine as it already is in the airline industry and other fields.

"What we are seeing is a paradigm shift in the way we train physicians in procedural-based medicine, from looking over the shoulder of a doctor working on a real patient to where we are going to be able to measure the trainee's learning curve in a virtual environment and a 'patient-safe' environment, and make sure the doctor has reached a level of competence before he then works on his first patient," Dr. Cates said.

William A. Gray, M.D. from Columbia University in New York, New York, who was not connected with this study, said that although simulation is increasingly used in medical training, there is still a need to do basic validation studies to demonstrate repeatability and reliability of results.

"This article is a nice building block in the larger construct of validating simulation. The investigators have successfully demonstrated that physicians can not only be trained on a simulator; but also that the effects of training can be measured on a simulator through various metrics, including contrast volume, fluoroscope time, procedure time and so on. That is an important first step in the process of validation of simulation," Dr. Gray said.

Dr. Gray added that studies are needed that would look at whether simulators can distinguish between expert and novice practitioners. Also, he says it would be useful to know whether simulators can identify the specific strengths and weaknesses of individual physicians, in order to tailor further training and education.

Radiologic signs more than double sensitivity of MRIs

Sun, 12 Feb 2006 18:04:00 PST

( from http://www.rxpgnews.com ) Radiologists can make a more accurate preoperative diagnosis of damage to knee cartilage by using four radiologic 'signs', a recent study found. Using the four signs to identify the extent and type of damage to knee cartilage makes interpreting MRIs with higher degrees of accuracy easier for any radiologist, regardless of their level of expertise.

During the course of this study, reviewers correctly identified 17 (89%) of 19 radial meniscal tears using the four radiologic signs: the truncated triangle, cleft, marching cleft, and the ghost meniscus. Each of these signs describes a unique type of tear and damage to the cartilage of the knee. These types of tears are categorized based upon the easily recognizable patterns which show up on MRIs.

A meniscal tear exposes the underlying cartilage of the knee and can lead to accelerated wear and arthritis from the decreased structural integrity of the knee joint. Fortunately some types of meniscal tears can be repaired. However, "radial tears are significant in that they frequently are irreparable, and even a relatively small tear can lead to advanced wear," said Keith Harper, MD, lead author of the study.

"It is advantageous to preoperatively identify potentially non-repairable meniscal tears, such as radial tears," said Dr. Harper. "When possible and practical, repairing the damaged cartilage is significantly preferred to its removal." Since treatment of meniscal tears is dependent on their configuration, size, and location, the characterization of the tear can help the surgeon and patient decide what type of surgery is necessary as well as what type of rehabilitation will be needed.

"Radiologists can look for and easily recognize the four radiologic 'signs' in order to prospectively identify radial tears. Using these four radiologic 'signs' increased the prospective characterization and sensitivity for the detection of radial tears from 37% to 89%," said Dr. Harper.

"We feel that by using the four signs, most radiologists who interpret knee MRIs should have a high degree of success of prospectively identifying radial meniscal tears," said Dr. Harper. "Since using the four signs is fairly easy, similar degrees of accuracy can be achieved by radiologists who may not be experts in the field of musculoskeletal radiology."

"Actually, we were surprised to find in the study that the knowledge of specific and more objective signs for radial tears was a great help for even musculoskeletal radiologists with extensive experience interpreting knee MRIs," said Dr. Harper.

CT Enteroclysis Has a Superior Diagnostic Value in Crohn's Disease

Tue, 31 Jan 2006 19:38:00 PST

( from http://www.rxpgnews.com ) The diagnostic value of CT enteroclysis is superior to conventional enteroclysis, previously considered the gold standard, as an imaging method for the evaluation of the small bowel in patients with Crohn's disease, a new study shows.

Crohn's disease is an inflammatory disease of the intestinal wall. Complications of Crohn's disease, such as abscesses, and stenoses, are found in approximately 40% of patients. Patients with inflammatory and some-times even obstructive small-bowel disease require prompt and accurate treatment to relieve their symptoms and to minimize the risk of potential complications.

"CT enteroclysis and conventional enteroclysis were successfully performed in all 50 patients (100%), however significantly more Crohn's disease-associated abnormalities were diagnosed with CT enteroclysis than with conventional enteroclysis," said the authors of the study.

"The big advantage of CT enteroclysis is its ability to detect complications which exist outside normal parameters of the diagnosis and identification of Crohn's disease," said Johannes Sailer, MD, lead author of the study. "Our recent study proved that CT enteroclysis can detect fistula, abscess and conglomeration tumor superior to conventional enteroclysis, with no disadvantages in the detection of minimal mucosal changes (a sign of early stage Crohn's disease)."

"CT enteroclysis can also be performed in follow up examinations of patients," said Dr. Sailer. "These results can help the clinicians in adapting their treatment and in deciding whether a surgical resection is needed."

"CT enteroclysis is an excellent technique for diagnosis of all small bowel diseases, which show morphologic changes to the bowel wall," said Dr. Sailer. "We use it for detection of bowel wall pathologies such as tumors and inflammatory changes, especially in patients with inflammatory bowel disease, as well as for the diagnosis of lymphoma and other intestinal tumors. In our department it is already a standard procedure."

"CT enteroclysis is the imaging method of choice and should replace conventional enteroclysis in patients with Crohn's disease," said the authors of the study.

Characteristic Cardiac Scar Pattern Predicts Risk Of Fatal Arrhythmias

Wed, 02 Nov 2005 03:51:00 PST

( from http://www.rxpgnews.com ) Using magnetic resonance imaging (MRI) scans of the heart wall, researchers at Johns Hopkins have found that people whose muscle wall thickness contained more than 25 percent scar tissue were approximately nine times more likely to test positive for a fast and dangerous heart rhythm known as ventricular arrhythmia.

Patients at risk of such arrhythmias often have a heart defibrillator implanted, a small device that delivers an electrical shock to restore their cardiac rhythm in case the heart beats too rapidly to pump enough blood to the rest of their body. Statistics from the United States Centers for Disease Control and Prevention estimate that each year more than 400,000 Americans suffer a sudden cardiac death, at least 30 percent of which are due to arrhythmia.

If further tests confirm that MRI measurements of scar tissue accurately predict the risk of arrhythmia-related sudden death, these could become the gold standard for screening who really needs or does not need a defibrillator, says the studys senior author, electrophysiologist Henry Halperin, M.D., a professor of medicine, radiology and biomedical engineering at The Johns Hopkins University School of Medicine and its Heart Institute. While tests are widely available to screen patients with coronary artery disease for risk of sudden cardiac death, tests are not so effective for identifying the many who will die suddenly from arrhythmias.

Indeed, while the U.S. National Center for Health Statistics estimates that more than 1 million Americans currently have a defibrillator, national studies published early this year have shown that only 5 percent of these devices ever fire to correct a heartbeat.

The latest Hopkins findings, which appear in todays edition of the journal Circulation, are believed to be the first to search in the hearts architecture rather than its pumping function and electrical signaling and so far the only study to analyze this architecture for clues about arrhythmias in patients with poor heart function but no arterial disease.

According to the researchers, defibrillators are prescribed when tests show abnormalities in the hearts ejection fraction (ability to squeeze blood to the rest of the body) and/or its resistance to electrical impulses that try to stimulate an arrhythmia.

Our MRI technique has significant advantages over existing methods because it avoids the risks of infection that come with surgery, it is noninvasive, there are no catheters, and it is relatively easy to perform, taking only 45 minutes, says study co-author and cardiologist João Lima, M.D., an associate professor of medicine and radiology at Hopkins.

Lima notes that a patient with an ejection fraction of 60 percent has normal pumping ability, but anything less than 30 percent for a period of nine months or longer is considered low and an immediate risk factor for arrhythmia. He adds that if a patient has an ejection fraction that is slightly above 30 percent, then an electrophysiology test is used to determine if a patient requires a defibrillator. In this test, a thin catheter is inserted into the heart to try to induce an arrhythmia, something that will fail if the heart is healthy and not at risk. However, if it happens once, it is known to be two to four times more likely to happen again, he says.

Twenty-six patients from the Baltimore area participated in the study, which took place from July 2003 to February 2005. Participants were men and women, with an average age of 53, referred by community physicians to Hopkins for cardiac assessment. None had previous signs of coronary artery disease, another leading cause of sudden cardiac death, yet were experiencing other symptoms of heart disease, such as shortness of breath, instant fatigue and the inability to walk up stairs.

As part of a baseline MRI, the researchers used a technique developed at Hopkins to map and gauge the precise amount and distribution of scar tissue in the hearts muscle wall. The amount of scar tissue was measured as a percentage of the thickness of the muscle wall, which is on average about 1 centimeter. Composed of dense, fibrous tissue, with little to no blood supply, scar tissue was clearly visible on the image, the researchers say. After MRI, each patient underwent a standard electrophysiological assessment with a catheter.

Statistical analysis showed that the five patients who tested positive had the characteristic scar pattern, ranging from 26 percent to 75 percent scar tissue, with MRI. While MRI did not explain why the scar tissue forms, such scar patterns have been previously noted on autopsy studies of patients with heart disease. The researchers believe that previous inflammation, injury or excess stress on the heart wall may lead to this fibrosis and scar formation.

Our study is yet another example of the potential applications of cardiac MRI in the prevention and treatment of cardiovascular disease, says the studys lead author, Saman Nazarian, M.D., a cardiac electrophysiology, clinical and research fellow at Hopkins. Cardiac MRI is already useful for assessing the structure and function of the heart and the extent of structural changes due to coronary artery disease. MRI can also help identify patients in need of aggressive medical therapy and can help in the planning of invasive heart surgery or identification of the best candidates for bypass surgery.

Nazarian points out that these results also offer promise that cardiac MRI might prove useful in screening people at moderate risk of sudden cardiac death from arrhythmias those without significant coronary artery disease and ejection fractions between 30 percent and 50 percent.

Another therapeutic implication, he says, is that identifying the telltale scar pattern could potentially improve existing procedures to ablate, or burn off, regions of the heart muscle that trigger arrhythmia.

Remote Detection Makes NMR Compatible with Microfluidics

Tue, 11 Oct 2005 00:48:00 PST

( from http://www.rxpgnews.com ) A breakthrough in the technology of nuclear magnetic resonance (NMR), one of the most powerful analytic tools known to science, is opening the door to new applications in microfluidic chips, devices for studying super-tiny amounts of fluids. A team of scientists with Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley, has demonstrated a means by which NMR can be made compatible with microfluidic lab-on-a-chip devices. Our novel methodology bypasses the long-standing problem of optimizing the two basic steps of NMR, signal encoding and detection, by physically separating them, and, at the same time, adds an important dimension to the study of fluid flow dynamics with the possibility of time-of-flight measurements, said Alexander Pines, one of the worlds leading authorities on NMR technology. Pines holds a joint appointment as a chemist with Berkeley Labs Materials Sciences Division and with UC Berkeley, where he is the Glenn T. Seaborg Professor of Chemistry.

The technique in which NMR signal encoding and detection are carried out independently (in a conventional NMR setup, the two actions take place within a single device) is called remote NMR detection. In a paper published in the online edition of the Proceedings of the National Academy of Sciences (PNAS), for the week of October 3, Pines and his collaborators describe the use of remote NMR to study the flow of gases through microfluidic devices.

Remote detection of the NMR signal overcomes the sensitivity limitation of NMR and enables spatially resolved imaging in addition to time-of-flight measurements, said chemist Christian Hilty, a member of Pines research group and the principal author of the PNAS paper. We can use it to measure microfluidic flow without the introduction of foreign tracer particles. This is important for the design and the operation of microfluidic devices.

The work is supported by the U.S. Department of Energys Basic Energy Sciences program in the Office of Science.

When a sample is exposed to a strong external magnetic field, these "bar magnets" attempt to align their axes along the lines of magnetic force. The alignment is not exact, resulting in a wobbly rotation about the magnetic field lines that is unique for each type of nuclei.

If, while exposed to the magnetic field, the nuclei in a sample are also subjected to a sequence of radiofrequency (rf) pulses, they will absorb and re-emit energy at characteristic frequencies. This is called the signal encoding phase of NMR. In the detection phase, the frequencies of these encoded signals are measured to obtain an NMR spectrum. While NMR has long been a powerful tool for studying the chemical composition of macroscopic samples, its application to microfluidic chip devices has been hampered by low sensitivity. Obtaining an NMR signal depends upon an excess of nuclei in a sample with spins pointing in one direction or the other, but the natural population difference in a typical fluid sample, even under a powerful magnetic field, is usually no more than one in 100,000 at room temperature.

To overcome this low spin polarization so they can measure gas flow, Pines and his research group have been injecting their samples with xenon whose atomic nuclei have been hyperpolarized by laser light. Hyperpolarized xenon boosts the NMR sensitivity of a sample by at least four orders of magnitude, and, xenon being inert, does not interfere with the other sample constituents as it is carried along in the flow.

When working with microfludic samples of gas, Pines and his collaborators apply their NMR encoding technique to the hyperpolarized xenon. With its long spin-relaxation time (several minutes), hyperpolarized xenon is well-suited for transporting the encoded NMR information to a separate site for detection. By staging the encoding and detection phases at separate sites, each site can be customized to obtain optimal results.

Xenons long spin-relaxation time (several minutes), make it an ideal carrier of an NMR signal for remote measurements of gas flow, said Hilty.

Microfluidic devices are essentially miniaturized chemistry laboratories, featuring a series of micrometer-sized channels etched into a chip in which nanoliter-sized samples of fluids can be analyzed. Using remote NMR instead offers several advantages.

With remote detection of NMR, we dont need the addition of markers that perturb the flow because we can use the spins of the hyperpolarized xenon nuclei, said Hilty. Also, when we apply the hyperpolarized xenon for the encoding step of remote detection, we can individually tag a fluid sample in any and all points within the device, whereas we can inject a fluorescent marker only at a devices inlet.

According to Hilty and Pines, their NMR remote detection technology is ready to be applied to any existing microfluidic device, so long as the fluid is transported to the detection site within the spin relaxation time of encoded NMR information.

In our PNAS paper, we describe an application in which we measure gas flow in microfluidic devices by remote detection of NMR, said Hilty. Pines and his research group are working on the development of alternative, less expensive means of detecting encoded NMR signals for example, a magnetometer. According to Hilty, preliminary results on this line of research have been promising.

Batch Reading Mammograms Lowers Recall Rates

Wed, 07 Sep 2005 07:45:00 PST

( from http://www.rxpgnews.com ) Batch reading, the process of interpreting screening mammograms during a set-aside block of time in a quiet environment that prevents interruption or distraction, can significantly reduce the number of patients who have to return for additional mammogramsalthough few hospitals use it, say researchers from the University of Wisconsin.

For the study, the researchers analyzed the recall and cancer detection rates for 9,522 screening mammograms, 1,538 of which were interpreted by batch reading. They found that recall rates were 20.1% without batch reading and 16.2% with batch reading and that the accuracy of cancer detection was not adversely affected.

According to the authors, methods of reading screening mammograms can be categorized as batch reading or non-batch reading. Non-batch reading refers to reading screening mammograms in the midst of other duties such as diagnostic mammograms, phone calls, consultations with referring physicians or proceduresin other words, with continual interruptions.

Experts in the field of breast imaging have long believed that batch reading not only improves performance but contributes to cost-effective breast cancer screening. In 1994, researchers surveyed 1,057 facilities and found that only 20% used batch reading, said Elizabeth S. Burnside, MD, lead author of the study.

It may make sense that interpreting mammograms in a quiet, distraction-free environment would improve performance, but, say the authors, there are many competing pressures in a busy practice. Referring physicians want immediate access to radiologists for consultation on patients who are present in clinic, anxious patients desire immediate interpretation of mammograms and consultation with the interpreting physicians and the shortage of breast imaging specialists require these services be provided by a shrinking pool of individuals. It is tempting for efficiency sake to fit screening mammograms into the small bits of time between other clinical activities, but our research demonstrates that batch reading contributes to maintaining high cancer detection while decreasing false positive results, said Dr. Burnside.

This should encourage both the medical community and patients to support this practice. Despite the trade-offs, uninterrupted, distraction-free batch reading appears to be an essential component to high quality, accurate interpretation of screening mammography, said Dr. Burnside.

Fluorescence spectroscopy can detect inflammatory cells in blood vessels

Sun, 14 Aug 2005 14:35:00 PST

( from http://www.rxpgnews.com ) Because atherosclerotic plaque typically builds up without symptoms and leads to more than 1 million deaths in America each year, the search is on to develop early detection devices that will enable physicians to offer treatment before the disease progresses to advanced stages.

Now, in a study involving laboratory rabbits, a device that stimulates, collects and measures light emissions from body tissues has been able to detect the presence of inflammatory cells that are associated with critical atherosclerotic plaques in humans plaques that are vulnerable to rupture. The study is described in the August 2005 issue of the journal Atherosclerosis.

Recent atherosclerosis research has found that the composition of plaque and its "vulnerability" to rupture may be more significant than the degree of arterial blockage as a precursor to heart attack and stroke. The lining (intima) of a normal artery consists of several thin layers of cells and connective tissue. Segments containing stable atherosclerotic plaque become thickened with collagen while sections of vulnerable plaque are infiltrated by macrophages. In humans, the inflammatory process weakens the plaque's thin, fibrous cap, often leading to rupture of the plaque and blockage of blood vessels.

An experimental time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) device developed by researchers at Cedars-Sinai Medical Center was used to detect the presence of inflammatory cells in the aortas of animals, with results compared to those from pathology studies.

"This study demonstrates that TR-LIFS can be used to identify macrophage infiltration in the fibrous cap, a key marker of plaque inflammation," said Laura Marcu, Ph.D., director of the Biophotonics Research and Technology Development Laboratory in Cedars-Sinai's Department of Surgery. "While previous studies have reported that fluorescence spectroscopy could identify atherosclerotic plaques, we believe this is the first to demonstrate that a fluorescence-based technique is also sensitive to differences in macrophage content versus collagen content. We found that intima rich in macrophages can be distinguished from intima rich in collagen with high sensitivity and specificity,"

Marcu led the study with colleagues from Cedars-Sinai, the University of California, Los Angeles, and Johns Hopkins University.

Laser-induced fluorescence spectroscopy is based on the fact that when molecules in cells are stimulated by light, they respond by becoming excited and re-emitting light of varying colors. Just as a prism splits white light into a full spectrum of color, laser light focused on tissues is re-emitted in colors that are determined by the properties of the molecules. When these emissions are collected and analyzed (fluorescence spectroscopy), they provide information about the molecular and biochemical status of the tissue.

Time resolution adds a greater degree of specificity, measuring not only the wavelength of the emission but the time that molecules remain in the excited state before returning to the ground state. This information is valuable because some emissions overlap on the light spectrum but have different "decay" characteristics.

"The goal of our current research is to define how well the TR-LIFS technique can detect the features associated with plaque vulnerability, but our long-term objective is to develop a minimally invasive, intravascular probe that will monitor plaque over time or guide therapeutic interventions to prevent plaque rupture," Marcu said.

The TR-LIFS system consists of a laser, a two-way fiber-optic probe through which the laser light is delivered to the tissue and the fluorescence is collected, a spectrometer, a digital oscilloscope, and a computer workstation that provides user interface, coordination of components and interpretation software.

MRI is Better Than SPECT in Assessing Heart Damage in Patients with Hypertrophic Cardiomyopathy

Sat, 06 Aug 2005 16:58:00 PST

( from http://www.rxpgnews.com ) Contrast-enhanced MRI is better than SPECT in detecting heart damage in patients with hypertrophic cardiomyopathy, a disease that can lead to sudden death in young patients.

SPECT nuclear medicine studies are currently the most common way to look for myocardial damage in these patients; however; a new study, published in the August issue of the American Journal of Roentgenology, found that MRI is a more comprehensive examination than SPECT. MRI was better able to detect small areas of heart damage and was able to provide us with important data on cardiac function, said Yasuo Amano, MD, associate professor of radiology at the Nippon Medical School in Tokyo, Japan. Dr. Amano is the lead author of the study. MRI was able to properly reflect the myocardial damages that could lead to cardiac dysfunction in patients with hypertrophic cardiomyopathy, he said.

The study included 23 patients; 368 segments of their hearts were investigated. The patients were diagnosed with hypertrophic cardiomyopathy following an echocardiography screening examination. All of the patients had a SPECT and an MRI examination. The results of our study indicate that contrast-enhanced MRI should be used on patients diagnosed with hypertrophic cardiomyopathy to determine the level of damage to the heart. SPECT can be done if no abnormalities appear on the MRI examination, Dr. Amano said.

Hypertrophic cardiomyopathy is characterized by abnormal thickening of the heart wall. The disease results from several genetic abnormalities and environmental factors, said Dr. Amano. Its prevalence is not precisely known, although some reports indicate that it occurs in about 0.2% of the population, affecting men and women equally, he said.

MDCT Arthrography Good for Assessing Hip Dysplasia

Sat, 06 Aug 2005 11:39:00 PST

( from http://www.rxpgnews.com ) MDCT arthrography is an accurate method for assessing cartilage loss in patients with hip dysplasia and may be more reliable than MRI in such instances, says a new study by researchers from Osaka University Medical School in Japan.

Hip dysplasia is a malformation or alteration of the ball (femur head) and socket (acetabulum) joint bones of the hip that can wear away the surrounding cartilage, which can lead to arthritis and other problems. The condition is often caused by a birth defect or incomplete growth of the skeleton during childhood; women and those with a family history are the most at risk. In addition, reports have shown that 10 to 20% of Japanese people develop hip dysplasia, which is two to five times more than Caucasian people, said Takashi Nishii, MD, lead author of the study.

For the study, 18 patients with hip dysplasia underwent both MDCT arthrography and 3D spoiled gradient-echo MRI. The researchers found that MDCT arthrography had higher sensitivity (70-79%), specificity (93-94%) and accuracy (87-90%) rates than MRI (47-53%, 87-92% and 78-80%, respectively) in diagnosing cartilage loss.

According to the researchers, the advantages of MDCT arthrography over other methods of diagnosis such as X-ray and MRI include better 3D evaluation, higher resolution, higher signal-to-noise ratio, and better tissue contrast.

Detection of cartilage problems of any severity is important, say the researchers. A high incidence of cartilage abnormalities in patients with hip dysplasia indicates the need for more sensitive imaging methods than those previously used. Our study suggests that MDCT arthrography may become a prominent method for imaging patients with hip dysplasia, including precise assessment of osteoarthritis progression, adequate planning of surgery, and accurate monitoring of the effects of drug treatment and surgery, said Dr. Nishii.

Contrast Agent Allows Quicker, More Thorough MRI Screening of Living Liver Donors Before Surgery

Sat, 06 Aug 2005 11:39:00 PST

( from http://www.rxpgnews.com ) A single dose of the contrast agent gadobenate dimeglumine can help liver donors avoid multiple MRI examinations during the screening process, cutting down on time and cost without compromising accuracy, say researchers from the Yonsei University College of Medicine in Seoul, Korea.

For the study, 11 potential liver donors underwent MRI examinations after a single dose of gadobenate dimeglumine in order to screen them for donor adequacy. The researchers were able to find anatomical abnormalities in six of the patients that potentially could have affected either the selection or the surgery process. The MRI results were all corroborated at surgery.

Preoperative imaging is crucial for both the selection of potential living liver donors and the planning of surgery because it reveals the exact anatomy of the donor liver. By performing MRI on a potential donor, doctors can assess any abnormality or variation in the liver itself, its vessels or its bile duct. To improve the accuracy of MRI, contrast media is used, said Myeong-Jin Kim, MD, one of the researchers on the study.

According to the researchers, there are different types of contrast agents. The more widely used (gadolinium-based agents) are good for imaging the liver and pathologic lesions and vessels, but not the bile duct. Other types (such as mangafodipir trisodium) can improve imaging of the liver and bile duct, but not the vessels. As a result, the potential donor may need to undergo two separate MRI examinations so that the different contrast agents can be used. Gadobenate dimeglumine can help image the liver, bile duct and vessels all at once, said Dr. Kim.

Our study shows that the use of this new agent may decrease the examination costs and time for preoperative MRI for potential living liver donors. By accurate evaluation of both vascular and biliary anatomy, adequate preoperative planning can be ensured and it may be helpful to decrease the potential postoperative complications, said Dr. Kim.

CT Significantly Reduces the Need for Appendectomy

Wed, 08 Jun 2005 19:49:00 PST

( from http://www.rxpgnews.com ) Five years ago, the negative appendectomy rate at Massachusetts General Hospital (MGH) in Boston was 20%, but since the advent of CT screening, it has dropped to 3%, say MGH researchers. The negative appendectomy rate measures how often patients with symptoms of appendicitis have their appendix removed and then are diagnosed as not having acute appendicitis.

For the study, the researchers analyzed 663 patients who were examined on CT for suspected appendicitis. An appendectomy was performed on 268 of the CT-screened patients. Of these 268 patients, only 8 (3%) had a negative appendectomy.

Prior to CT the negative appendectomy rate was 20% because there was no way to be sure whether appendicitis was present or not in most patients without surgery. Because CT is very accurate in imaging the appendix and because CT is very good at finding other conditions which mimic appendicitis, the negative appendectomy rate following CT has fallen dramatically. Fewer people are having to undergo appendectomy because CT can find the normal appendix and can frequently determine what is wrong prior to surgery, said James T. Rhea, MD, lead author of the study at MGH and who is now at San Francisco General Hospital in California.

According to the study, if a patient is suspected of having appendicitis, CT can help diagnose before surgery whether appendicitis is present or whether something else other than appendicitis is causing the patients pain. The patients doctor should decide if CT is needed to increase the certainty that appendicitis is present or if something else is causing the problem, but in most patients CT will be helpful in deciding whether to remove the appendix. I know that if I had symptoms that might be appendicitis, Id want to have a CT scan, said Dr. Rhea.

MDCT Highly Accurate for Diagnosing Coronary Artery Disease in Patients With Zero to Moderate Coronary Calcification

Wed, 04 May 2005 18:02:00 PST

( from http://www.rxpgnews.com ) In patients with no or moderate coronary calcification, 16-slice MDCT allows the reliable detection of coronary artery stenosis with high diagnostic accuracy, say researchers from Tuebingen University Hospital in Germany. Coronary artery stenosis is the narrowing of coronary arteries due to the build-up of calcified plaques.

The study included 37 patients, 28 of whom had a calcium score of less than 1,000 (no calcification to moderate calcification). The researchers found that 16-MDCT was very accurate in diagnosing these patients, having a sensitivity and specificity of 93% and 94%, respectively.

When the remaining nine who had a calcium score of 1,000 or greater (severe calcification) were added, the overall sensitivity and specificity dropped to 59% and 87%, respectively. Severe coronary calcification reduces reliable visualization of the coronary arteries and may mask vascular stenosis, but 16-MDCT has improved the visualization of coronary arteries so that those with no or moderate coronary calcification can be diagnosed accurately, said Martin Heuschmid, MD, lead author of the study.

According to the researchers, coronary artery lesions are usually diagnosed by coronary angiography. Coronary angiography, though, is an invasive examination with certain risks for the patients. MDCT could help to circumvent those drawbacks. However, in patients with severe coronary calcification, conventional coronary angiography may still be necessary to diagnose or exclude high-grade stenosis of the coronary tree, said Dr. Heuschmid.

Chest X Rays can help Detect Osteoporosis

Tue, 26 Apr 2005 18:44:00 PST

( from http://www.rxpgnews.com ) Undetected osteoporosis in the elderly might be discovered if chest radiographs (x-ray images taken by an x ray tech) that are done for other reasons were examined for fractures of the vertebrae, according to an article in the April 25 issue of the Archives of Internal Medicine, one of the JAMA/Archives journals.

Previous studies estimate that 12 to 25 percent of people aged 50 to 60 years have one or more osteoporosis-related vertebral fracture, the most common fracture associated with osteoporosis, according to background information in the article. While only 30 percent of these fractures come to medical attention the other 70 percent are associated with illness, death, decreased quality of life and increased risk of future fractures. The authors suggest that the many chest radiographs elderly patients undergo for other health reasons might be examined to determine the presence of vertebral fractures.

Sumit R. Majumdar, M.D., M.P.H., of the University of Alberta Hospital, Edmonton, Canada, and colleagues selected a random sample of about 10 percent of patients older than 60 who had been evaluated in the emergency department of a large teaching hospital and had a chest radiograph done for any reason. The medical charts and radiographs were then reviewed in detail to determine whether the patient had a moderate-to-severe vertebral fracture.

Seventy-two (16 percent) of the 459 patients had a moderate-to-severe vertebral fracture on the basis of their radiograph. Forty-three (60 percent) of the fractures were documented in the original radiographic reports. Of the 72 patients with fractures, only 18 (25 percent) had histories of osteoporosis. "Even among the patients admitted to the hospital (198) who also had a vertebral fracture (32), there was no documented addition of osteoporosis medications during hospitalization or at discharge," the authors report.

"The most noteworthy finding in our study is the magnitude of the underdiagnosis and undertreatment of osteoporosis in elderly patients with a vertebral fracture," the authors write. "One in six elderly patients who underwent chest radiography in our emergency department had clinically important vertebral fractures. Nevertheless, only 43 (60 percent) of these fractures were reported, and only 25 percent of patients with fractures received a diagnosis of or treatment for osteoporosis."

Newer Imaging Techniques May Lead to Over-Treatment

Tue, 05 Apr 2005 17:47:00 PST

( from http://www.rxpgnews.com ) Newer imaging technologies allow physicians to visualize more of the arteries in the lungs, including detecting small blood clots not previously seen, but seeing more may have little impact on the patients outcome, a new study suggests.

The study included 198 patients with suspected pulmonary embolism. About half of the patients (98) had a multidetector CT (MDCT) examination; 100 patients had a single-detector CT examination. The radiology examinations came back negative, and the patients did not undergo anticoagulant treatment.

MDCT is now more widely used to examine patients with suspected pulmonary embolism. It allows radiologists to see more of the arteries throughout the lungs, and to detect small clots in those arteries, said J. David Prologo, MD, chief radiology resident at University Hospitals of Cleveland and lead author of the study. However, our study found no significant difference in the outcomes of patients ruled out for pulmonary embolism with MDCT vs. single-detector CT, he said. It is possible that we missed small clots in the patients that had a single-detector CT examination, but at three and six months, the outcomes were similar, he said.

Seeing more can have drawbacks as well, Dr. Prologo said. If we see the small clots, were more likely to treat them; and there are risks to anticoagulant therapy, he said. In fact, a recent study found a 10 times higher risk of hemorrhagic stroke in patients receiving oral anticoagulant therapy when compared to the general population, Dr. Prologo said. It is imperative that clinicians consider the risk-benefit ratio of therapy in patients with previously undetectable small clots in the peripheral pulmonary vasculature, he added.

Dr. Prologo recommends a large-scale prospective randomized study to determine if patients with small clots need to undergo anticoagulation treatment. Today a great many more patients are being evaluated for pulmonary emboli with scanners that can detect very small clots. This is likely to result in the discovery of many more patients with small clots who probably would not have been treated in the past and may have done fine. Improved technology is forcing us to face new clinical questions such as whether or not every small clot diagnosed with CT warrants the risks of treatment, he said.

Optical Coherence Tomography (OCT) may guide therapy designed to prevent heart attacks

Sun, 27 Mar 2005 16:24:00 PST

( from http://www.rxpgnews.com ) A catheter-based imaging technology called optical coherence tomography (OCT) can successfully identify the characteristics of coronary plaques in patients with various cardiac symptoms.

"More than 1.2 million people die from coronary artery disease every year, a quarter of them before or soon after arriving at the hospital," says Ik-Kyung Jang, MD, PhD, director of cardiovascular clinical research in the MGH Cardiology Division and lead author of the current study. "The ability to identify dangerous plaques before they rupture and produce a heart attack or sudden cardiac death will be crucial to innovative preventive therapies."

Plaques are deposits of fats, cholesterol and other materials that collect in major arteries, restricting or sometimes blocking blood flow. While some plaques are relatively stable, others are vulnerable to rupture and release their contents into the bloodstream, causing a blood clot to form. Heart attacks and other acute coronary events usually result from the rupture of high-risk, vulnerable plaques in coronary arteries, and the characteristics of those plaques have been determined primarily by autopsy studies.

OCT uses infrared light delivered via fiberoptic catheter to produce high-resolution, cross-sectional images of blood vessels. Study co-authors Guillermo Tearney, MD, PhD, of the MGH Pathology Department and the Wellman Center for Photomedicine at MGH, and Brett Bouma, PhD, also of the Wellman Center, developed the use of OCT to visualize coronary arteries, including vulnerable plaques. The technology developed in their laboratory was used for this first study to examine the structure of plaques in patients with cardiac disease.

The study enrolled patients scheduled to undergo cardiac catheterization for whom angiograms or other imaging techniques had identified the arterial lesion responsible for their symptoms. Participants either had experienced a recent heart attack or had acute coronary syndrome (ACS), a set of symptoms associated with reduced blood supply to the heart muscle. A third group had stable angina, chest pain that occurs with physical or mental stress, which is not usually related to plaque rupture. Clear OCT images of the suspicious lesions were obtained for 20 heart attack patients, 20 with ACS and 17 with stable angina.

Vulnerable plaques are believed to have three major characteristics a deposit of lipids (fats), a thin cap of fibrous material covering the lipid pool, and infiltration of the immune cells called macrophages. The OCT images showed that the heart attack and ACS patients had more lipid in their plaques and significantly thinner fibrous caps than did the stable angina patients. Overall, vulnerable plaques were identified in 72 percent of the heart attack patients, 50 percent of those with ACS and only 20 percent of stable angina patients.

"This is the first technique that allows us to study the structural changes underlying vulnerable plaques in living patients, and it supports the conclusions of previously reported postmortem studies," says Jang. "We still need to gather more data to confirm these characteristics, and our group will carry out further studies of how plaques develop and rupture. Someday OCT may provide information that will guide treatments to prevent plaque rupture and its disastrous consequences." Jang is an associate professor of Medicine at Harvard Medical School.

A New Dyssynchrony Imaging Technique to Aid Cardiologists in the Quantification of Left Ventricular Mechanical Dyssynchrony

Fri, 04 Mar 2005 12:16:00 PST

( from http://www.rxpgnews.com ) Designed to further enhance the accuracy and efficiency of ultrasound imaging in the diagnosis and treatment of heart failure, Toshiba America Medical Systems, Inc. (TAMS) today introduced Dyssynchrony Imaging (DI) as the latest innovation to the AplioTM CV, the companys all-digital ultrasound system for advanced cardiac applications. The new imaging technique will be presented to cardiologists for the first time at the 2005 Annual Scientific Session of the American College of Cardiology (ACC) in Orlando, Fla.

"With the development of Dyssynchrony Imaging, Toshiba is providing cardiologists with a new innovation that expands the quantification capabilities of ultrasound to aid in diagnosing cardiovascular disease," said Gordon Parhar, director, Ultrasound Business Unit, Toshiba America Medical Systems, Inc. "The DI method makes it easier for clinicians to determine the severity of dyssynchrony by having an automated detection of maximum values and a visual display of time to peak for each region. DI also will be a valuable tool in assessing patients for cardiac resynchronization therapy, providing clinicians with a pathway treatment from pre-implant to post implantation of the pacemaker."

"The Aplios Dyssynchrony Imaging is a new method to quantify radial mechanical dyssynchrony in heart failure patients and can assess improvements after cardiac resynchronization associated with the acute hemodynamic response," said John Gorcsan III, M.D., director, Echocardiography Laboratories, Professor of Medicine, University of Pittsburgh. Dr. Gorcsan is the primary investigator in the U.S. for Toshibas Dyssynchrony Imaging.

The Aplio CVs new DI technique aids cardiologists in the quantification of left ventricular mechanical dyssynchrony by providing a color-coded display that demonstrates the timing of events within the myocardium of the heart. Early mechanical events are green and severely delayed events are displayed red, allowing clinicians to quickly identify the presence and severity of the patients dyssynchronous events.

In addition, with the use of Toshibas angle corrected technology, cardiologists also have the ability to evaluate the synchronicity not only longitudinally but can use the short axis view to obtain radial information. As a result, the detailed clinical information provided by the DI method improves both the accuracy for evaluating dyssynchrony in heart failure patients as well as determining the most appropriate treatment plan for cardiac resynchronization therapy, including pacemaker implantation.

The DI method allows physicians to select the optimal candidates for cardiac resynchronization therapy because quantitative values are now available.

The Aplio CV is designed with next-generation tissue Doppler and contrast imaging technology based on Toshibas Intelligent Component Architecture to allow faster processing of more complex data, producing dramatically improved image quality and sensitivity. The ICA permits the system to perform highly complex data operations, such as Tissue Harmonic Imaging and Pulse Subtraction techniques with frequency compounding.

For high performance cardiac examinations as well as research and quantification studies, the Aplio CV offers a comprehensive packages for Doppler measurements and advanced clinical data analysis, including:

Tissue Doppler Imaging Quantification (TDI-Q):

This software performs various analyses for TDI images, measuring myocardial viability. The Tissue Strain Imaging (TSI) technique evaluates and clearly displays the regional myocardial strain quantitatively during systole. Tissue tracking and angle correction for radial information, performed with these advanced applications, expands the range of quantitative evaluations available. TSI, along with displacement imaging also can be utilized for bi-ventricular pacing. In addition to TDI-Q, Aplio CV offers Tissue Doppler Imaging, adding TDI Harmonics, which provides higher resolution and more quantifiable information.

Advanced Automated Contour Tracking (A-ACT):
When evaluating contractility of the heart, ejection fraction is very important and is part of every echocardiography report. Likewise, diastolic function is another area to take into consideration. With A-ACT users can obtain ejection fraction and diastolic function quickly and easily with one automatic calculation.

The Aplio CV also features Toshibas IASSIST remote controller, which was honored by Frost & Sullivan with its 2004 Technology Innovation Award for outstanding achievement in diagnostic imaging. Featuring Bluetooth wireless network technology, the IASSIST allows sonographers to achieve improved body positioning and reduce strain for greater comfort during examinations. In addition, IASSIST improves productivity and throughput with the use of protocol-assisted examinations, customized programming, as well as the ability for clinicians to define and activate their own clinical protocols with the touch of a single button.

Full body MRI can be used as screening tool for cancer and heart diseases

Fri, 04 Feb 2005 19:25:00 PST

( from http://www.rxpgnews.com ) The use of full-body cardiovascular and tumor MRI to screen for disease in patients who do not have any suspicious symptoms is technically feasible, but for the present, full-body MRI screening should not be performed outside of a research setting due to the uncertainty of whether the benefits outweigh the risks, according to a new study by researchers from the University Hospital of Essen in Germany. For the study, the researchers conducted 298 full-body MRI screenings of healthy patients. The screenings revealed that 21% of the study group exhibited signs of atherosclerotic disease and 12% had peripheral vascular disease. Twelve colon polyps, nine pulmonary lesions, two cerebral infarctions and one myocardial infarction were also discovered. In addition, 29% of the examinations revealed relevant additional findings in nontargeted organs.

Full-body MRI focuses on the brain, heart, arteries and colon, as well as the surrounding tissue. The whole process takes about an hour, with breaks scattered throughout for patient comfort, equipment set-up and dialogue with the doctor.

"Theoretically, screening with such proven MRI techniques could be of value to certain patients. There are some studies proving the benefit of early therapy for certain conditions such as cardiovascular disease and colon cancer, but this is not known for all diseases. The scanning gives a dramatic bundle of information. Although one might think that this increases health in the future, there is controversy. Not in relation to the actual MRI techniques, but whether finding an abnormality really alters the outcome--for example, with early lung cancer," said Susanne C. Gï¿½ehde, MD, lead author of the study.

"We do believe screening does some good for patients, but it is not yet proven. In addition, with full-body MRI screening, you can evaluate a variety of organs and detect a variety of diseases, making it dramatically more difficult to calculate risks and benefits. Our recommendation is not to advertise this to the population, but to first undertake long-term studies to see if the benefits outweigh the potential risks," said Dr. Gï¿½ehde.

However, the researchers admit, news of this technique is spreading and many patients are requesting it. "I think we cannot hinder patients from getting these exams, but they really must be very well-informed about risks, benefits, complications of false-negatives and false-positives, the potential necessity of additional clarifying examinations or operations and about the diseases one cannot see with MRI," said Dr. Gï¿½ehde.

The accuracy of mammographic interpretation

Thu, 16 Dec 2004 19:25:00 PST

( from http://www.rxpgnews.com ) The accuracy of mammographic interpretation can vary widely, but the source of the variability has not been explained. To investigate the relationship between radiologists' characteristics and actual performance, William E. Barlow, Ph.D., of Cancer Research and Biostatistics in Seattle, and colleagues surveyed 124 radiologists and tracked cancer outcomes from the more than 460,000 screening mammograms they interpreted between 1996 and 2001.

Greater volume of mammograms interpreted and more years of experience were not associated with greater accuracy. However, greater volume was associated with higher sensitivity (more true positive results in women who had breast cancer) and lower specificity (more false positive results in women who did not have breast cancer) whereas more experience was associated with lower sensitivity and higher specificity. The authors conclude that increasing volume requirements for radiologists is unlikely to improve the interpretation of mammograms.

"Although radiologists differ in performance, accuracy does not appear to be simply attributable to years of experience or number of mammograms interpreted," the authors write. "Direct feedback of performance characteristics couple with training may be more helpful than experience without feedback. The most instructive exercise may be to have an open discussion of misjudged mammograms, but concern about malpractice claims may prevent this opportunity from occurring."

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CT Significantly Reduces the Need for Appendectomy

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Chest X Rays can help Detect Osteoporosis

Newer Imaging Techniques May Lead to Over-Treatment

Optical Coherence Tomography (OCT) may guide therapy designed to prevent heart attacks

A New Dyssynchrony Imaging Technique to Aid Cardiologists in the Quantification of Left Ventricular Mechanical Dyssynchrony

Full body MRI can be used as screening tool for cancer and heart diseases

The accuracy of mammographic interpretation

Batch Reading Mammograms Lowers Recall Rates