Histologically Confirmed Hippocampal Structural Features Revealed by 3T MR Imaging: Potential to Increase Diagnostic Specificity of Mesial Temporal Sclerosis

Sample images from patient 4 depicting a coronal section showing left-sided hippocampal sclerosis (A) with enlarged images of the right (B) and left (C) sides. Note the yellow markers used to depict the superior, inferior, and lateral measurements (sample only, actual images with measurements from Advantage Workstation could not be exported). D, The enlarged image depicts the hippocampus in a sagittal section with the head of the hippocampus indicated by the dashed line, used to determine the appropriate coronal image from which measurements could be taken. E, Corresponding coronal T2 FLAIR image shows increased signal intensity on the left side, a radiographic marker for a sclerotic process suggestive of gliosis.

Cumulative hippocampal measurements of superior, inferior, and lateral margins comparing the MTS side with the contralateral internal control. Values are presented in millimeters (mean ± SD, P < .001; n = 20).

A, Postoperative ex vivo MR image of the hippocampal specimen in a coronal section. B, Scanned image of corresponding histologic slide (× 20 magnification) with CA1, CA2, and CA3 regions marked accordingly. Overlay of both images clarifies structural MR imaging information, such as the dark band that was ultimately identified as the stratum lacunosum (arrow).

A, Comparison of layer thickness within the CA1 between the control and 2 cases of MTS. Note the marked reduction in thickness, particularly in the stratum pyramidale and radiatum in cases 4 and 5. B, Thickness measurement of the distance between the stratum oriens and stratum lacunosum in all 3 CA regions. Again note the marked size reduction in cases 4 and 5 compared with all 3 controls (C1, C2, C3). C, Specific thickness measurements of the stratum pyramidale in regions CA1, -2, and -3 with marked size reduction apparent in the CA1 region of cases 4 and 5.