MR of the cerebellopontine angle: Fast imaging techniques and Gd-DTPA

The diagnostic efficiency of plain and Gd-DTPA-enhanced MR imaging with different spin-echo sequences and fast imaging techniques was studied in 110 patients with cerebellopontine-angle tumors. The examinations were carried out using a 1.5-T MR unit; during and after the application of Gd-DTPA subsequent FLASH images with a repetition time of 30 msec, an echo time of 12 msec, and a 200 flip angle were acquired over a period of 7 minutes. In all acoustic neuromas the signal intensity increased during the first 200 seconds following the injection of Gd-DTPA. The maximum signal intensity level was reached after 400 seconds; however, all glomus jugular tumors showed a fast increase in the first 200 seconds. Using fast imaging techniques and Gd-DTPA, glomus tumors and meningiomas could be differentiated from neuromas showing a typical contrast enhancement. MR sensitivity is far superior to CT for detecting cerebellopontine-angle tumors; fast imaging techniques enable differentiation between neuromas and other pathologic processes