FAST SPIN-ECHO, MAGNETIC-RESONANCE IMAGING-MEASURED HIPPOCAMPAL VOLUME - CORRELATION WITH NEURONAL DENSITY IN ANTERIOR TEMPORAL LOBECTOMY PATIENTS

To assess the value of magnetic resonance imaging (MRI)-measured hippo campal volume in the detection of hippocampal sclerosis, we studied 28 patients undergoing anterior temporal lobectomy for medically intract able mesial temporal lobe epilepsy. Hippocampal volumetry and visual a nalysis of T2 signal change were performed using fast spin-echo T2-wei ghted MRI. Quantitative neuronal density measurements were performed i n the resected hippocampal specimens. There was a significant correlat ion between MRI-measured absolute hippocampal volume (AHV) and neurona l density in CA1, CA2, and CA3 subfields (p < 0.0001, p < 0.01, and p < 0.05, respectively). Differential hippocampal volume (side-to-side v olume difference) failed to detect bilateral atrophy in three patients , but the bilateral hippocampal atrophy was recognized by considering AHV in these patients. This study suggests that MRI-measured AHV can b e of value in evaluating patients with mesial temporal lobe epilepsy, especially when there is no side-to-side difference in hippocampal vol umetry.