XML Feed for RxPG News   Add RxPG News Headlines to My Yahoo!   Javascript Syndication for RxPG News

Research Health World General
 
  Home
 
 Latest Research
 Cancer
 Psychiatry
 Genetics
 Surgery
 Aging
 Ophthalmology
 Gynaecology
 Neurosciences
 Pharmacology
 Cardiology
 Obstetrics
 Infectious Diseases
 Respiratory Medicine
 Pathology
 Endocrinology
 Immunology
 Nephrology
 Gastroenterology
 Biotechnology
 Radiology
 Dermatology
 Microbiology
 Haematology
 Dental
 ENT
 Environment
 Embryology
 Orthopedics
 Metabolism
 Anaethesia
 Paediatrics
 Public Health
 Urology
 Musculoskeletal
 Clinical Trials
 Physiology
 Biochemistry
 Cytology
 Traumatology
 Rheumatology
 
 Medical News
 Health
 Opinion
 Healthcare
 Professionals
 Launch
 Awards & Prizes
 
 Careers
 Medical
 Nursing
 Dental
 
 Special Topics
 Euthanasia
 Ethics
 Evolution
 Odd Medical News
 Feature
 
 World News
 Tsunami
 Epidemics
 Climate
 Business
 
 India
Search

Last Updated: Nov 18, 2006 - 12:32:53 PM

Radiology Channel
subscribe to Radiology newsletter

Latest Research : Radiology

   DISCUSS   |   EMAIL   |   PRINT
New MRI technique shows emphysema in asymptomatic smokers
May 31, 2006 - 5:08:00 PM, Reviewed by: Dr. Ankush Vidyarthi

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

 
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 2� 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.
 

- "Early Emphysematous Changes in Asymptomatic Smokers: Detection with 3He MR Imaging." Collaborating with Dr. Fain on this paper were Shilpa R. Panth, M.S., Michael D. Evans, M.S., Andrew L. Wentland, B.S., James H. Holmes, M.S., Frank R. Korosec, Ph.D., Matthew J. O'Brien, B.A., R.R.T., R.P.F.T., Harvey Fountaine, B.A., and Thomas M. Grist, M.D.
 

www.rsna.org

 
Subscribe to Radiology Newsletter
E-mail Address:

 

Radiology is a monthly scientific journal devoted to clinical radiology and allied sciences. The journal is edited by Anthony V. Proto, M.D., School of Medicine, Virginia Commonwealth University, Richmond, Va. Radiology is owned and published by the Radiological Society of North America, Inc. (RSNA.org/radiologyjnl)

The Radiological Society of North America (RSNA) is an association of more than 38,000 radiologists, radiation oncologists, medical physicists and related scientists committed to promoting excellence in radiology through education and by fostering research, with the ultimate goal of improving patient care. The Society is based in Oak Brook, Ill. (RSNA.org)


Related Radiology News

New way of tracking muscle damage from radiation
Audit shows excellent performance of radiologists in interpreting mammograms
Comparing MDCT and digital radiography in orthopedic patients
New MRI technique shows emphysema in asymptomatic smokers
Safety profile for CT colonography (CTC) favorable
Modulating tube current to account for body symmetry reduces radiation exposure in CT
Training on virtual 'patient' improves carotid angiography skills
Radiologic signs more than double sensitivity of MRIs
CT Enteroclysis Has a Superior Diagnostic Value in Crohn's Disease
Characteristic Cardiac Scar Pattern Predicts Risk Of Fatal Arrhythmias


For any corrections of factual information, to contact the editors or to send any medical news or health news press releases, use feedback form

Top of Page

 

© Copyright 2004 onwards by RxPG Medical Solutions Private Limited
Contact Us