MR Imaging Features Of Multiple Myeloma And Correlated Analysis With Clinical Staging And Type Of Abnormal Protein

Objective: To describes the spinal MR imaging features of multiple myeloma and correlates the findings with clinical staging, the type of abnormal protein. Materials and Methods: Thirty two patients with newly diagnosed multiple myeloma were studied with MR imaging of the thoracic and lumbar spine, then correlated the findings with clinical staging and the type of abnormal protein. Results: The signal intensity is reduced on T1-weighted images and enhanced on T2-weighted images. Type IgG myeloma and type IgA myeloma had no difference in signal intensity. Five infiltration patterns were found: normal(n=5), focal(n=7), diffuse(n=10), focal and diffuse(n=9), and salt-and-pepper pattern(n=1). The infiltration patterns of MM with different clinical stage is different. Most patients of stage I are normal pattern, while stage II and III patients may present as many types ,among of them all patients with diffuse pattern were clinically stage III. The infiltration patterns of type IgA myeloma were different from type IgG myeloma. Type IgG myeloma could present as any MRI patterns ,while type IgA myeloma most be diffuse type. One hundred and twenty vertebral compression fractures were found, of which 14 appeared benign and 106 malignant. Most of malignant vertebral compression fractures were found in patients of clinically stage III (P<0.01) ,while most of benign ones were seen in patients of clinically stage I and II (P<0.01) . There were more malignant vertebral compression fractures in type IgA myeloma than in type IgG myeloma (P<0.01) .There were often paraspinal mess formation. Conclusion: The MR imaging features of multiple myeloma may correlate to clinical staging and types of abnormal protein.