December 2012

Technique May Improve COPD Detection

An experimental method can distinguish between different types of chronic obstructive pulmonary disease (COPD) and track disease progression. The method may eventually lead to more accurate diagnoses and more effective treatments for COPD.

COPD is a lung disease that makes it hard to breathe. Airway tubes to the lungs narrow, making it hard to get air in and out. COPD is a major cause of disability. It’s also the third leading cause of death nationwide.

COPD can involve damage to the small airways of the lungs, called functional small airways disease. It can also involve more extensive destruction of lung tissue, called emphysema. If doctors could diagnose the extent of lung damage, they could track COPD and personalize treatments. An imaging technique called CT scanning can assess the extent of emphysema. But measuring functional small airways disease has remained a challenge.

To address this problem, NIH-funded researchers adapted an image analysis method called parametric response mapping (PRM). In PRM, a computer matches CT scans taken when a patient breathes in fully with scans taken when a patient breathes out fully. By comparing the two, a program can create 3-D maps of damage throughout the entire lung.

The scientists analyzed whole-lung CT scans of people with COPD acquired at both full inhalation and full exhalation. They found that PRM could successfully identify the extent of both functional small airways disease and emphysema. The researchers then analyzed images from people who had undergone CT scanning over time. The analysis showed that PRM could be used to monitor COPD progression.

“We believe this offers a new path to more precise diagnosis and treatment planning and a useful tool for precisely assessing the impact of new medications and other treatments,” says lead author Dr. Brian D. Ross of the University of Michigan.