Translation of adapting quantitative CT data from research to local clinical practice: validation evaluation of fully automated procedures to provide lung volumes and percent emphysema

Abstract. Current clinical chest CT reporting includes limited qualitative assessment of emphysema with rare mention of lung volumes and limited reporting of emphysema, based upon retrospective review of CT reports. Quantitative CT analysis performed in COPDGene and other research cohorts utilize semiautomated segmentation procedures and well-established research method (Thirona). We compared this reference QCT data with fully automated QCT analysis that can be obtained at the time of CT scan and sent to PACS along with standard chest CT images. 164 COPDGene® cohort study subjects enrolled at Brigham and Women’s Hospital had baseline and 5-year follow-up CT scans. Subjects included 17 nonsmoking controls, 92 smokers with normal spirometry, 15 preserved ratio impaired spirometry (PRISm) patients, 12 GOLD 1, 20 GOLD 2, and 8 GOLD 3–4. 97% (n  =  319) of clinical reports did not mention lung volumes, and 14% (n  =  46) made no mention of emphysema. Total lung volumes determined by the fully automated algorithm were consistently 47 milliliters (ml) less than the Thirona reference value for all subjects (95% confidence interval −62 to −32  ml). Percent emphysema values were equivalent to the Thirona reference values. Well-established research reference data can be used to evaluate and validate automated QCT software. Validation can be repeated as software is updated.