OBJECTIVETo study the clinical characteristics and MR imaging features of intracranial metastasis from malignant tumors.

METHODS1271 patients who had history of primary tumor and suspected of cranial metastasis had MRI on Philips Gyroscan T5-NT MR scanner. The sequences included pre-contrast T(1)WI, FLAIR, and postcontrast transversal, sagittal, and coronal T(1)WI. All of the clinical data and MRI features of the patients were recorded and analyzed.

RESULTSOf 547 patients with intracranial metastasis, 393 came from lung cancer (71.9%), 10% of 547 patients were found to have the presenting symptoms of cranial metastasis. 526 had parenchymal cerebral metastasis, and 21 only meningeal metastasis. Of these 526 patients found to have brain metastasis, 164 had single metastasis (31.2%), and 362 multiple (68.8%). Most of the cerebral metastatic lesions showed uniform or ring enhancement after intravenous injection of contrast medium, dura-arachnoid metastasis showed continuous and thick-curve enhancement at the cerebral convex, but not extending to the sulcus, while pia-dura metastasis displayed as thin and linear or nodular enhancement extending to the adjacent sulci.

CONCLUSIONThe most common primary lesion with metastasis to the brain were lung cancers, followed by breast and gastrointestinal cancers. By using gadolinium-DTPA enhanced MR imaging, many single and small cerebral metastasis could be found earlier.