Diagnosis of spinal metastasis: Usefulness of additional diffusion-weighted imaging

Purpose To determine the usefulness of diffusion weighted-MRI (DW-MRI) in the evaluation of spinal metastasis. Materials and Methods From July to August 2017, 48 whole-spine DW-MRI to detect metastasis in patients with extra-spinal tumors were retrospectively evaluated by three radiologists. The usefulness of DW-MRI was evaluated in four groups based on the change in confidence rating between two sessions: 1 (T1- and T2-weighted and contrast-enhanced images) and 2 (additional DW-MRI). The associations of the usefulness with age, sex, primary cancer, bone type with metastasis, number of probable metastatic segments in session 1, and anatomic locations were assessed in vertebral body and posterior element cases. Results According to the readers 1, 2, and 3, there were 18, 19, and 16 vertebral body cases, respectively, and 12, 13, and 9 posterior element cases, respectively. In the group with no excepted metastasis, DW-MRI was useful in 52–59% of vertebral body cases and 39–67% of posterior element cases. There were no significant differences in the usefulness with respect to the number of probable metastatic segments in session 1, age, sex, primary cancer, bone type with metastasis, or anatomic location. Conclusion DW-MRI could be used to evaluate spinal metastasis. However, there were no differences in the usefulness with respect to the anatomic location.