Preliminary observations on magnetic resonance imaging in refractory epilepsy.

We are studying the use of magnetic resonance (MR) imaging in localization of epileptogenic foci in patients with medically refractory partial epilepsy. Imaging is performed using a prototype resistive unit operating at 0.15 T. All studies include 7 mm axial sections obtained with a partial saturation sequence (TR = 200 msec) in which signals are recovered with a spin echo (TE = 11 msec) and images reconstructed using a modified 2D Fourier transform technique. Since the temporal lobe and limbic system are the commonest site of seizure foci in this group of patients, examinations were performed with the plane of section parallel to the temporal horns of the lateral ventricles. Consensus interpretations by a radiologist, neurologist and neurosurgeon have recognized findings considered possibly abnormal in six of 11 epilepsy patients and none of six normal volunteers. These preliminary results indicate that further study is warranted in this group of patients. Critical evaluation of such findings must be carried out in a larger group including normals and patients with a variety of neurologic disorders.