Metastatic disease of the spine: MR evaluation with Gd-DTPA

Gd-DTPA was used in the MR evaluation of 22 patients with metastatic disease of the spine. Ten patients had epidural lesions; ten patients had intradural extramedullary spread of tumor; two patients had intramedullary metastases. A 1.5-T superconductive magnet with surface coils was used to obtain 3- or 5-mm sagittal and axial sections of the spine. All patients also received myelography and postmyelographic CT. Gd-DTPA was very sensitive to intradural extramedullary disease. Both nodular metastases and nerve root thickening enhanced. Lesions often poorly defined or not visible at all without contrast were easily seen after administration of gadolinium. Gadolinium was also of benefit in patients with intramedullary metastases. Although abnormalities of cord contour and signal were present in noncontrast studies, the region of enhancement was more localized and focal, suggesting that much of the cord enlargement was due to edema. In patients with extradural disease, gadolinium proved to be useful in selected cases. Generally, epidural tumor extension was visible without contrast. In specific cases, administration of gadolinium was beneficial, for example in localizing regions of tumor for biopsy or in distinguishing possible herniated nucleus pulposus from epidural disease. In conclusion, gadolinium is of significant benefit in intradural extramedullary disease. Metastatic lesions of the cord itself may also be more fully evaluated with contrast scans. However, epidural disease will probably prove to be adequately studied without contrast, although gadolinium may be of use in selected applications