Rapid study assessment in follow-up whole-body computed tomography in patients with multiple myeloma using a dedicated bone subtraction software.

Abstract

The diagnostic reading of follow-up low-dose whole-body computed tomography (WBCT) examinations in patients with multiple myeloma (MM) is a demanding process. This study aimed to evaluate the diagnostic accuracy and benefit of a novel software program providing rapid-subtraction maps for bone lesion change detection. Sixty patients (66years ± 10years) receiving 120 WBCT examinations for follow-up evaluation of MM bone disease were identified from our imaging archive. The median follow-up time was 292days (range 200-641days). Subtraction maps were calculated from 2-mm CT images using a nonlinear deformation algorithm. Reading time, correctly assessed lesions, and disease classification were compared to a standard reading software program. De novo clinical reading by a senior radiologist served as the reference standard. Statistics included Wilcoxon rank-sum test, Cohen's kappa coefficient, and calculation of sensitivity, specificity, positive/negative predictive value, and accuracy. Calculation time for subtraction maps was 84s ± 24s. Both readers reported exams faster using subtraction maps (reader A, 438s ± 133s; reader B, 1049s ± 438s) compared to PACS software (reader A, 534s ± 156s; reader B, 1486s ± 587s; p< 0.01). The course of disease was correctly classified by both methods in all patients. Sensitivity for lesion detection in subtraction maps/conventional reading was 92%/80% for reader A and 88%/76% for reader B. Specificity was 98%/100% for reader A and 95%/96% for reader B. A software program for the rapid-subtraction map calculation of follow-up WBCT scans has been successfully tested and seems suited for application in clinical routine. Subtraction maps significantly facilitated reading of WBCTs by reducing reading time and increasing sensitivity. • A novel algorithm has been successfully applied to generate motion-corrected bone subtraction maps of whole-body low-dose CT scans in less than 2min. • Motion-corrected bone subtraction maps significantly facilitate the reading of follow-up whole-body low-dose CT scans in multiple myeloma by reducing reading time and increasing sensitivity.