MRI of inner ear and facial nerve pathology using 3D MP-RAGE and 3D CISS sequences

The aim of this study was to evaluate 3D CISS, unenhanced 3D MP-RAGE and contrast enhanced 3D MP-RAGE for the diagnosis of neoplastic, vascular and inflammatory lesions of the cerebellopontine angle, the inner auditory canal, the labyrinth and the facial nerve. 42 MR examinations were performed on a total of 38 patients (25 males, 13 females; aged 1-77 years, mean age 43 +/- 20 years) using a 1.5 T MR unit. A T-2(*) weighted 3D CISS sequence (TR 14.65 ms, TE 21 ms, flip angle 65 degrees, voxel size 0.7 x 0.7 x 0.3 mm(3)) and a T-1 weighted 3D MP-RAGE sequence (TR 12.5 ms. TE 5 ms, TI 300 ms, flip angle 15 degrees, voxel size 1.0 x 0.9 x 0.9 mm(3)) with and without contrast medium (gadolinium-DTPA, 0.1 mmol kg(-1) body weight) were used. Results of contrast enhanced 3D MP-RAGE-pathological enhancement was found in the following lesions: schwannomas of the cerebellopontine angle (CPA) and the internal auditory canal (IAC), 4; schwannomas of the IAC, ? and labyrinthine tumours, 3; posterior fossa lymphoma, I; meatal meningioma, 1; acute labyrinthitis, 15 and neuritis of the seventh cranial nerve, 10. Results of 3D CISS-filling defects were found with the following lesions: schwannomas of the CPA, the IAC or labyrinth, 14; lymphoma, 1; meningioma, 1; labyrinthine fibrosis, 13 and scar in the IAC, 4. These results suggest that unenhanced and contrast enhanced 3D MP-RAGE: and 3D CESS are complementary MR imaging modalities. T-1 weighted 3D MP-RAGE is preferred to T-1 weighted 2D (turbo) spin echo sequences because of the multiplanar reconstruction possibilities of 3D sequences, which are very useful in the case of the inner ear and facial nerve.