Lung volume reduction surgery for emphysema: correlation of CT and V/Q imaging with physiologic mechanisms of improvement in lung function

Abstract

Purpose: To compare the relationship between computer-derived and visually assessed ventilation-perfusion (V/Q) scintigraphy and computed tomographic (CT) scores in evaluating disease severity and distribution in identifying optimal candidates for lung volume reduction surgery (LVRS) and to correlate these radiologic indices with physiologic measures of outcome.

Materials and methods: In 39 patients, preoperative V/Q and CT scans were visually scored by two radiologists for disease severity and distribution. Results were compared with computer-derived scores for the same cohort. These indices were correlated with clinical improvement measured with forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), and ratio of FEV(1) to FVC.

Results: The disease distribution scores measured with the different methods correlated closely: computer-based and visually assessed CT scores (r = 0.89, P <.001), computer-based and visually assessed V/Q scores (r = 0.83, P <.001), visually assessed CT and V/Q scores (r = -0.50, P <.001), and computer-derived CT and V/Q scores (r = -0.57, P =.015). Similarly, a statistically significant correlation was noted between each of the radiologic methods and clinical outcome measurements (P <.001).

Conclusion: CT and V/Q preoperative assessment, with either visual scoring or computer-based algorithms, are nearly equivalent in their utility in predicting improvement in FEV(1) measures.