THE FACIAL-NERVE IN THE TEMPORAL BONE AS VISUALIZED VIA THIN-LAYER PARATRANSVERSAL AND SAGITTAL MR TOMOGRAPHIC-IMAGES BY MEANS OF T-1 SPIN-ECHO AND FLASH SEQUENCES

Purpose: It is difficult to effect visualization and delineation of th e facial nerve and its neighbouring structures in the temporal bone wi th conventional MRI examination protocols. We tested temporal bone MRI with 2 mm slices and compared T-1-weighted FLASH (T-R = 400 ms, T-E = 10 ms, 90 degrees flip angle) and spin-echo (T-R = 540 ms, T-E = 15 m s) sequences. Patient and methods: 5 volunteers and 14 patients were e xamined with the head coil of a 1.O T whole body MRI scanner (Impact, Siemens, Erlangen) with para-transversal images orientated parallel to the inferior outline of the clivus and sagittal images orientated alo ng the brainstem. Results: The facial nerve and its neighbouring struc tures could be reliably visualized and differentiated along its entire course. The FLASH sequence was superior to the spin-echo sequence. 8 of 11 patients with peripheral facial nerve palsy showed contrast enha ncement. In two patients, local swelling of the affected facial nerve was evident. Conclusion: The MRI technique tested here seems promising for temporal bone examinations.