Vertebral compression fractures in multiple myeloma. Part II. Assessment of fracture risk with MR imaging of spinal bone marrow.

PURPOSE

To determine the utility of bone marrow magnetic resonance (MR) imaging in the assessment of risk of vertebral compression fractures in patients with multiple myeloma.

MATERIALS AND METHODS

In 50 patients with stage III multiple myeloma, 280 MR examinations of the thoracolumbar spine obtained at diagnosis and during treatment (mean follow-up, 28 months) were analyzed to determine MR patterns of bone marrow involvement before treatment and the occurrence of vertebral compression fracture at follow-up. Four MR patterns of marrow involvement were determined: A, normal marrow appearance; B, fewer than 10 focal lesions; C, more than 10 focal lesions; and D, diffuse infiltration. Fracture-free survival was compared according to these patterns.

RESULTS

During follow-up, 131 vertebral compression fractures appeared in 37 patients. Patients with pattern A (n = 10) or B (n = 16) had significantly longer fracture-free survival before occurrence of the first, second, and third fractures than those with pattern C or D (P < 10(-5)). Relative risks of first, second, and third fracture occurrence for patients with pattern C or D compared with those with pattern A or B were 6.2, 9.1, and 11.0, respectively.

CONCLUSION

Determination of MR patterns of spinal bone marrow involvement is a potential relevant factor to predict the risk of vertebral fractures in patients with stage III multiple myeloma.