Detection of vertebral metastases: a comparison between the modified Dixon turbo spin echo T2 weighted MRI and conventional T1 weighted MRI: a preliminary study in a tertiary centre

Objective: To compare the diagnostic performance of modified Dixon (mDixon) turbo spin echo (TSE) T-2 weighted MRI and conventional T-1 weighted MRI in vertebral metastasis detection. Methods: Between September 2014 and October 2016, 33 patients with 68 metastases who had undergone whole-spine MRI were enrolled. The following sagittal image sets were evaluated: T1WI, and mDixon TSE T-2 weighted water and fat images. Two radiologists independently evaluated each image-set for metastasis. The MR findings were compared with positron emission tomography-CT (PET-CT) scans. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for each sequence. The diagnostic performance of each sequence was evaluated using receiver operating characteristic (ROC) curves. Results: Sensitivity, specificity, PPV and NPV for reviewer 1 were 83.8, 99.1, 89.1 and 98.6%, respectively, with T1WI; 79.4, 98.8, 85.7 and 98.2%, respectively, with mDixon TSE T-2 weighted water imaging; and 86.8, 99.1, 89.4 and 98.8%, respectively, with mDixon TSE T-2 weighted fat imaging. For reviewer 2, the respective scores were 91.2, 99.2, 91.2 and 99.2%; 85.3, 99.5, 93.4 and 98.7%; and 89.7, 99.3, 92.4 and 99.1%. With PET-CT as the gold standard, the ROC curves of the three sequences showed no significant difference (all p > 0.05) Conclusion: The diagnostic performance of mDixon TSE T-2 weighted water and fat imaging was comparable to that of conventional T1WI in the detection of vertebral metastases. Advances in knowledge: mDixon TSE T2WI can be a good alternative to conventional T1WI for detecting vertebral metastases.