Detection of lung carcinoma with predominant ground-glass opacity on CT using temporal subtraction method

Purpose To evaluate the usefulness of the CT temporal subtraction (TS) method for the detection of the lung cancer with predominant ground-glass opacity (LC-pGGO). Materials and methods Twenty-five pairs of CT and their TS images in patients with LC-pGGO (31 lesions) and 25 pairs of those in patients without nodules were used for an observer performance study. Eight radiologists participated and the statistical significance of differences with and without the CT-TS was assessed by JAFROC analysis. Results The average figure-of-merit (FOM) values for all radiologists increased to a statistically significant degree, from 0.861 without CT-TS to 0.912 with CT-TS ( p < .001). The average sensitivity for detecting the actionable lesions improved from 73.4 % to 85.9 % using CT-TS. The reading time with CT-TS was not significantly different from that without. Conclusion The use of CT-TS improves the observer performance for the detection of LC-pGGO. Key Points • CT temporal subtraction can improve the detection accuracy of lung cancer . • Reading time with temporal subtraction is not different from that without . • CT temporal subtraction improves observer performance for ground-glass/subsolid nodule detection .