Utility of chest CT in the diagnosis of additional suspicious lesions on MRI in women with breast cancer

BackgroundDedicated breast computed tomography (CT) is an emerging modality, but no study has compared breast lesions additionally detected on magnetic resonance imaging (MRI) with correlated CT lesions. Although there are differences between chest CT and dedicated breast CT, a preliminary evaluation would be valuable.PurposeTo evaluate the usefulness of contrast-enhanced chest CT in evaluating additional suspicious lesions preoperatively detected on MRI in patients with breast cancer.Material and MethodsBetween January 2020 and December 2021, 245 patients with breast cancer who underwent preoperative breast MRI and contrast-enhanced chest CT were included. Enhancing lesions detected on CT showing correlation with additional suspicious lesions detected on MRI were recorded as CT-correlated enhancements. The pathological findings were confirmed by subsequent percutaneous biopsy or lesion excision. The clinical and MRI features of additional suspicious lesions were compared according to the standard reference or the presence of CT-correlated enhancement.ResultsThere were 96 (39.2%) additional suspicious lesions detected on preoperative breast MRI and a malignancy rate of 39.6%. Of 96 lesions, chest CT revealed correlated enhancement in 64 (66.7%) lesions, including 33 malignant lesions. Among the 32 lesions that showed no correlation enhancement on chest CT, 5 (15.6%) were malignant. Malignancy, diffusion-weighted image restriction, and fast/washout kinetics were more frequently observed in lesions with CT-correlated enhancement than in those without correlated enhancement (<i>P</i> < 0.001, <i>P</i> = 0.001, and <i>P</i> = 0.020, respectively).ConclusionWhen evaluating MRI-detected additional suspicious lesions in patients with breast cancer, lesions with CT-correlated enhancement were significantly more likely to be malignant than those without CT-correlated enhancement.