CT scans may help diagnose COPD

Researchers in the Netherlands have reported that low-dose computed tomography (CT) scans used for lung cancer screening may also help physicians detect chronic obstructive pulmonary disease, known as COPD, in smokers.

Their study was released Tuesday by the journal JAMA.

COPD is one of the major causes of death among heavy smokers, and usually presents as chronic bronchitis or emphysema. Quitting smoking can keep the disease from progressing, but often people don’t know they have COPD in the first place. If looking at CT scans helps physicians catch the disease early, it might prevent illness and death.

The researchers, led by Onno M. Mets of the University Medical Center in Utrecht, looked at data collected from 1,140 current and former heavy smokers involved in an ongoing lung cancer screening trial. The men were between 50 and 75 years old and had smoked at least 16 cigarettes a day for 25 years or at least 11 cigarettes a day for 30 years. They received CT scans during inhalation and during exhalation. Researchers also measured their pulmonary function, providing a reference for comparison. (This type of test is the preferred method of screening for COPD today.)

Based on the results of pulmonary function testing, 437 of the men had COPD. Using the CT results, the team diagnosed 274 men with COPD, including 73% of the patients with moderate obstruction and all of the patients with severe obstruction.

The method isn’t perfect: 85 of the 274 turned out to be false positives. But, the authors wrote, even if CT scans are not appropriate as a primary screening method for COPD, they could be an additional tool to improve accuracy of diagnosis.

“Quantitative measures in low-dose CT scans may be useful in a lung cancer screening setting to identify heavy smokers with COPD,” they wrote.

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