Clinical usefulness of magnetic resonance cisternography in patients having hemifacial spasm.

To evaluate the usefulness of MR cisternography fourteen patients that had hemifacial spasm and 20 control patients underwent MR cisternography. All the patients with hemifacial spasm had a confirmed vascular compression after surgery. MR cisternography was performed using a 1.5-tesla superconducting MR magnet in which a 3D (dimensional) heavily T2-weighted turbo spin-echo sequence was used. In 34 randomly selected individuals, we retrospectively determined whether MR cisternography images could be used to evaluate symptoms, and what the benefits of obtaining this image was. The results were correlated with the surgical findings. The sensitivity was 100% and the specificity was 94% in all patients having a hemifacial spasm. The offending vessels were the anterior inferior cerebellar artery (AICA) in six patients cases, the posterior inferior cerebellar artery (PICA) in six, both the vertebral artery and PICA in one, and the vertebral artery in one. All the images showed good resolution and contrast, and also showed the exact correlation between the facial nerve and intracranial vessels in the multiplaner image. The findings of neurovascular compression were well correlated with the surgical findings. We believe that high-resolution 3D MR cisternography is a very useful method for evaluating the neurovascular compression in patients that have hemifacial spasm.