Regional MRI Volumetry and Longitudinal Regional Volume Curve for Detecting Hippocampal Sclerosis in Temporal Lobe Epilepsy

ABSTRACT

BACKGROUND: In order to improve MRI volumetry of hippocampus, we obtained the Longitudinal Regional Volume Curve (LRVC) of hippocampi and compared the sensitivity of LRVC with those of conventional hippocampal volume-tries (total and regional) in temporal lobe epilepsy (TLE). METHODS: Thirty-eight normal subjects and 24 TLE patients were included in this study. The pathology of all patients showed hippocampal sclerosis. The volume of the hippocampus was measured by a manual tracing in 3 mm-thickness coronal MRI slices perpendicular to the long axis of the hippocampus and a three-dimensional reconstruction. Total volume and regional volumes (anterior, middle, and posterior 1/3) of the right and left hippocampi were measured. Then, the focal hippocampal volume of each of the coronal slices (3 mm) was plotted in a X-Y graph to obtain LRVC. The presence and pattern of HA were determined in LRVC. RESULTS: The mean volume of right hippocampus (2512+/-629 mm3) was bigger than that of the left one (2262.6+/-563.2 mm3) in normal subjects. The normal range of right-left total volume difference was 3.6~495.2 mm3. The sensitivities of conventional volumetry, regional volumetry, and LRVC were 66.7%, 75%, and 83.3%, respectively. Eleven patients showed diffuse HA (11/20, 55.0%) and nine had focal HA (9/20, 45.0%). In focal HA, the middle and posterior HA were more frequent (6/9, 66.7%) than anterior HA. CONCLUSIONS: LRVC improved the sensitivity of MRI volumetry in detecting hippocampal sclerosis and could reveal the pattern (diffuse or focal) of HA. (J Korean Neurol Assoc 19(2)125~131, 2001)