Document Type

Conference Proceeding

Publication Date


Publication Title

Medical Physics


Purpose: COPD (chronic obstructive pulmonary disease) is a collection of lung diseases that complicates breathing and causes irreversible lung damage. Given that it is a progressive disease, early detection is crucial for managing its symptoms. We recently developed a method for calculating pulmonary blood mass change (PBMC) apparent on paired inhale/exhale non-contrast computed tomography (CT) scans as a quantitative surrogate for lung perfusion. Our long term objective is to develop a PBMC biomarker for predicting COPD progression. As a first step, we hypothesize that PBMC is significantly lower for non-COPD smokers versus non-COPD non-smokers. Methods: CT scans from 77 healthy Caucasian participants from a well known dataset containing a healthy population without respiratory symptoms were analyzed. Lung volumes within each scan were segmented using a 3D convolutional neural network (denseNET). For each patient, PBMC was calculated using the inhale/exhale scans and segmentations. Two-tailed Wilcoxon Rank-Sum tests were run to compare the median PBMC values in smokers with > 3 pack years versus participants with < 3 pack years. Results: The median PBMC in smokers with > 3 pack years was 1.657 g/ml3 with an interquartile range (IQR) of 1.113 g/ml3, while the median PBMC in participants with < 3 pack years was 2.144 g/ml3 with an IQR of 1.419 g/ml3. The two-tailed Wilcoxon Rank-Sum test indicated the difference between the median PBMC values was significant between the two cohorts (p-value = 0.017). Conclusion: In this study of non-COPD patients, median PBMC values in smokers with > 3 pack years was significantly lower than that of participants with < 3 pack years, which confirms our initial hypothesis. This result supports the premise that PBMC is capable of measuring decreased perfusion induced by smoking, and suggests that PBMC has potential as an imaging biomarker for COPD severity.





First Page



American Association of Physicists in Medicine 65th Annual Meeting & Exhibition, July 23-27, Houston, TX