Traditional imaging methods used in the detection and evaluation of metastatic bone disease lack either sensitivity (plain radiography) or specificity (bone scintigraphy). Magnetic resonance imaging now has been shown to be the most sensitive imaging technique available for the detection of bone metastases. On T1-weighted images bone metastases tend to stand out as focal or diffuse hypointense (dark) lesions against a background of higher-signal-intensity marrow. Use of fat suppression techniques may further increase the conspicuity of metastatic lesions. Magnetic resonance imaging is unlikely to replace bone scintigraphy as an initial screening technique for bone metastases because scintigraphy can image the whole skeleton quickly and at relatively low cost. Magnetic resonance is particularly useful for imaging the spine because vertebral bodies, paraspinal, and intraspinal soft tissues can be evaluated, providing a noninvasive method of detection of spinal cord compression. Magnetic resonance imaging also is useful in discriminating between benign and malignant vertebral collapse.