NEW YORK (Reuters Health), Dec 22 - In most patients with severe asthma, high-resolution computed tomography (HRCT) reveals airway wall thickening and other changes not otherwise detectable, U.K. researchers report in the December issue of Chest.
"Our report is the largest qualitative study of HRCT findings in severe asthma," senior investigator Dr. Christopher E. Brightling told Reuters Health. "We found that abnormalities in the airway wall were common and could not be identified by the physician without the CT scans."
Dr. Brightling, of the University of Leicester, and his colleagues reviewed data on 463 patients with difficult asthma, 185 of whom had HRCT scans for clinical indications.
The scans showed bronchial wall thickening in 62%, bronchiectasis in 40% and emphysema in 8%. These conditions often co-existed, and HRCT scans were normal in only 20% of cases.
The most common indication for HRCT was a clinical suspicion of bronchiectasis. Clinical evaluation had only a 74% sensitivity and a 45% specificity for identifying bronchiectasis in patients who had HRCT scans that revealed it.
An FEV1/FVC ratio of 75% or more was an important predictor of bronchial wall thickening and bronchiectasis, but had low discriminatory power in those without airway structural changes (sensitivity, 67%; specificity, 65%).
"The identification of these abnormalities," concluded Dr. Brightling, "potentially affects the way we treat a person's asthma and therefore underscores the importance of CT scans in severe asthma."
By David Douglas
Chest 2009; 136:1521-1528.
Last Updated: 2009-12-21 19:15:31 -0400 (Reuters Health)
Related Reading
Chest CT depicts H1N1 better than radiography, October 21, 2009
Copyright © 2009 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
