Dynamic MRI of brain tumor

We examined 44 patients with a brain tumor by dynamic MRI using a fast SE sequence at 1.5 T MRI, and evaluated the time intensity (TI) curves of the tumors. The serial images obtained by dynamic MRI for 10 to 20 seconds clearly demonstrated the tumors and the adjacent structures with no susceptibility artifacts. The TI curves obtained were classified into four groups on the basis of the peak values and the time to the peak on the TI curves. The data were related to the histological types of the tumors. In the first group, the TI curve showed a sharp increase towards the peak (less than 1 min) and a peak value greater than 3.5 (hemangioblastoma, 1 meningioma). In the second group, the TI curve exhibited a gradual increase to the peak (from 3 to 5 min), the peak value was moderately lower at less than 3.5 (7 pituitary adenomas, 7 meningiomas and 2 glioblastomas). In the third group. the TI curve increased slowly towards the peak (longer than 5 min), with a lower peak value of less than 3.5 (7 meningiomas, 4 glioblastomas, 6 acoustic neurinomas, 3 metastatic brain tumors, 1 malignant lymphoma and 1 ependymoma). In the fourth group, the TI curve showed no peak of enhancement or a low peak value of less than O.5 (1 Rathke's cleft cyst and 2 ependymomas). Even though the genesis of the enhancement remains obscure, dynamic MRI using a fast SE sequence with Gd-DTPA provides useful information for the differential diagnosis of brain tumors. (author)