MAGNETIC-RESONANCE EXAMINATION OF THE INNER-EAR AND CEREBELLOPONTINE ANGLE IN PATIENTS WITH VERTIGO AND OR ABNORMAL FINDINGS AT VESTIBULAR TESTING/

The inner ears of 167 patients with vertigo and/or abnormal findings a t vestibular testing were studied using magnetic resonance (MR). Patho logy potentially explaining vertigo was found in 54 patients, and was detected in the posterior fossa (28%), the internal auditory canal (28 %) and the membranous labyrinth (44%). The overall percentage of patho logy and the percentage of pathology found in the membranous labyrinth was high and was probably influenced by the referral pattern in our h ospital where high resolution MR of the inner ear (three dimensional F ourier transformation-constructive interference in steady state sequen ce; 3DFT-CISS sequence) is available. Unenhanced, and especially gadol inium (Gd)-enhanced T1-weighted spin-echo images, are needed to detect most of the pathology inside the internal auditory canal, and some of the lesions inside the membranous labyrinth. 3DFT-CISS images are the only images that can show fibrous obliteration of the intralabyrinthi ne fluid spaces, and are therefore necessary to recognise most of the intralabyrinthine pathology. Finally, T2-weighted spin-echo images are best suited to demonstrate cerebellar or brain stem infarction. An ad ditional MR-angiography sequence (three dimensional Fourier transforma tion-fast imaging with steady precession; 3DFT-FISP) is used when vasc ular compression of the cochleovestibular nerve is suspected. MR is th e method of choice to look for pathology in patients with vertigo, and allows detection of pathology that remains invisible with other imagi ng techniques. However, well adapted sequences are needed to detect th ese lesions.