Stage I multiple myeloma: value of MR imaging of the bone marrow in the determination of prognosis.

PURPOSE: To determine the prognostic value of bone marrow findings at magnetic resonance (MR) imaging in patients with stage I multiple myeloma. MATERIALS AND METHODS: In 24 patients with stage I multiple myeloma, findings from MR imaging of the vertebral, pelvic, and femoral bone marrow were analyzed and correlated to spontaneous outcome. Progressive multiple myeloma was observed in 12 patients and stable stage I multiple myeloma was observed in 12 after a follow-up period of 4-67 months (median, 27 months). RESULTS: In 17 patients, MR imaging findings were normal, and in seven patients, bone marrow abnormalities were depicted on MR images. Of the 12 patients with progressive multiple myeloma, six had bone marrow abnormalities that were depicted at MR imaging. In the group of patients with progressive multiple myeloma, the six patients with abnormal MR imaging findings showed earlier disease progression (median, 10 months) than the six patients in whom MR imaging findings were normal (median, 32 months) (P < .0001). Multivariate analysis of clinical and MR imaging findings showed that MR imaging (P = .006) were two independent factors in the prediction of disease progression. CONCLUSION: MR imaging of the bone marrow in patients with stage I multiple myeloma is an independent factor in the prediction of disease progression.