Combined anatomical MRI differentiates pulmonary invasive adenocarcinoma from tuberculoma in noncalcified nodule: a retrospective comparison of CT with MRI

Background: Pulmonary adenocarcinoma is the most common pathological type of malignant pulmonary nodules, of which, invasive adenocarcinoma (IAC) is associated with a risk of recurrence. Pulmonary tuberculoma can sometimes present as noncalcified, solid pulmonary nodule with imaging characteristics such as lobulation, spiculation, and pleural indentation, which is difficult to distinguish from IAC. Magnetic resonance imaging (MRI) as a non-ionizing modality can be complementary tool for nodules assessment. This study aimed to evaluate the potential of the combined conventional and modified anatomical MRI sequences for differential diagnosis of IAC and tuberculoma. Methods: Sixty-seven patients with 82 noncalcified nodules underwent computed tomography (CT) and MRI (T1WI-starVIBE, T1WI-VIBE, T2WI-TSE-fBLADE). Two radiologists independently assessed nodule dimensions and morphologic features. The inter-method agreement of morphologic features assessment by CT and MRI sequences were compared using Kappa test. Multivariate logistic regression analyses were applied to identify independent predictors of IAC. Receiver operating characteristic (ROC) analysis was performed to investigate the differential diagnosis capability. Results: Thirty-eight IACs and 44 tuberculomas were identified. Readers 1 and 2 underestimated the nodules mean diameter with T1WI-starVIBE (T1WI-VIBE, T2WI-TSE-fBLADE) by 0.86±1.71 mm (1.19±2.06, 0.15±1.96 mm) and 0.99±1.75 mm (1.27±2.04, 0.19±1.91 mm). The inter-method agreements between MRI and CT were "fair" to "excellent" in the evaluation of morphological features except for spiculation. Compared with the tuberculoma group, the IAC group was significant with unclear margin (T1WI-starVIBE, T1WI-VIBE), irregular morphology (CT, MRI), lobulation (CT, MRI), spiculation (T1WI-starVIBE, T2WI-TSE-fBLADE) and air bronchogram (CT, T1WI-starVIBE and T1WI-VIBE) (P