Correlative radionuclide and magnetic resonance imaging in evaluation of the spine.

The authors retrospectively compared magnetic resonance images and bone scintigraphy obtained from 144 patients. Fifty-six patients having a known primary malignancy were evaluated for metastases (Group 1), and 88 patients were evaluated for back pain (Group 2). Interpretation was normal in 36/144 patients (11 in Group 1 and 25 in Group 2), and similar abnormal foci were visualized in the osseous spine in 54/144 patients (32 in Group 1 and 22 in Group 2). Magnetic resonance imaging showed abnormalities in the osseous spine that were not visualized on bone scintigraphy in 43/144 patients (10 in Group 1 and 33 in Group 2); these included bone metastasis, benign neoplasm (hemangioma), Schmorl's node, intervertebral disk disease, and bone disease (osteophyte, spondylolisthesis, facet hypertrophy). In addition, magnetic resonance imaging showed epidural or paravertebral extension of the tumor or infection in 37/144 patients (30 in Group 1 and 7 in Group 2). Bone scintigraphy demonstrated abnormalities not visualized on magnetic resonance imaging in 11/144 patients (3 in Group 1 and 8 in Group 2). Bone scintigraphy showed abnormalities in locations not evaluated by magnetic resonance imaging but relevant to the symptomatology or disease in 42/144 patients (37 in Group 1 and 5 in Group 2). These data indicate that magnetic resonance imaging and bone scintigraphy are complementary. Bone scintigraphy remains the best screening procedure to show the location of abnormal areas in the spine and elsewhere in the skeleton. Magnetic resonance imaging is useful in differentiating neoplasm, infection, intervertebral disk disease, and, in some instances, degenerative bone disease.