FAST SPIN-ECHO MRI IN OTOLOGY

Magnetic resonance imaging (MRI) using a fast spin echo protocol (FSE) gives greatly improved spatial resolution for the inner ear and its central connections. Excellent contrast resolution between bone, neural tissue and intracranial fluids is obtained on the heavily T2 weighted images. The contents of the internal auditory meatus (IAM) are shown more clearly than on T1 weighted images, even with gadolinium enhancement. Use of the technique for congenital, vascular, granulomatous and obliterative lesions of the inner ear is described. The cochlear and vestibular nerves can be seen side by side in the majority of cases thereby excluding the presence of even an intrameatal acoustic neuroma. This means that FSE can be used as a first line investigation to exclude small vestibular schwannomas without the need for gadolinium. Gadolinium-enhanced T1 weighted sequences are still necessary for confirmation of some tumours or for inflammatory lesions.