CT findings of brain metastases.

In 121 proven cases of intracranial metastases, lung cancer was as high as 48 per cent. Multiple lesions were noted (67.8%) in almost every type of organ source. Brain parenchyma (80.3%), predominantly supratentorium was the major site of metastases. The minority was observed in leptomeninge, cranial bone and subgaleal tissue. Subarachnoid seeding tumors along CSF pathways spread mainly from pineal neoplasms; a few cases from lung and choriocarcinoma. Extensive brain edema occurred in metastases from almost every type of primary organ source. Calcification exhibited 5.8 per cent and their origins were lung and breast. Bleeding tumors were noted in 10.7 per cent mainly from choriocarcinoma, a few from lung and GI. Hyperdense tumors occurred in 86.8 per cent on noncontrast scans. Almost all tumors (95.2%) showed contrast enhancement, predominantly ring-shaped lesions. Their organ sources were GI, lung and breast. A few patterns of enhancement were homogeneous and heterogeneous. Non-enhanced lesion were noted in 4.8 per cent mainly due to the high density of calcium and blood inside the tumors. Apart from seeding, calcified and bleeding tumors, the CT findings were not specific for various types of metastases.