New Approach to Lung Imaging Could Improve COPD Diagnosis, Treatment
CT scan technique can differentiate types of lung damage (Oct. 7)
According to an October 7 announcement from the University of Michigan, a new approach to lung scanning could improve the diagnosis and treatment of chronic obstructive pulmonary disease (COPD) — a lung disease that affects approximately 24 million Americans and is the country’s third-highest cause of death.
In a paper published online in Nature Medicine, researchers at the university reported on a technique called parametric response mapping (PRM). They used PRM to analyze computed tomography (CT) scans of the lungs of patients with COPD who took part in the national COPDGene study funded by the National Heart, Lung, and Blood Institute.
The researchers reported that the PRM technique for analyzing CT scans allowed them to better distinguish between early-stage damage to the small airways of the lungs and more severe damage known as emphysema. They also showed that the overall severity of a patient’s disease, as measured with PRM, matches closely with the patient’s performance on standard lung tests based on breathing ability.
COPD limits a patient’s breathing ability, causing shortness of breath, coughing, wheezing, and reduced ability to exercise, walk, and do other things. Over time, many COPD patients become disabled as their disease worsens. Most often associated with smoking, COPD can also result from long-term exposure to dust and to certain gases and chemicals.
Originally developed to show the response of brain tumors to treatment, the PRM technique allows researchers to identify COPD-specific changes in three-dimensional lung regions over time.
With the PRM technique, researchers use powerful computer techniques to overlay the CT scan taken during a full inhalation with an image taken during a full exhalation. The overlaid, or registered, CT images share the same geometric space, so that the tissues in the inflated and deflated lungs align. The density of healthy lung tissue will change more between the two images than the density of diseased lung, allowing researchers to create a three-dimensional map of the patient’s lungs.
For more information, visit the University of Michigan Web site.