MR VOLUMETRIC-ANALYSIS OF THE HUMAN ENTORHINAL, PERIRHINAL, AND TEMPOROPOLAR CORTICES

PURPOSE: Our purpose was to investigate the normal volumes of the huma n entorhinal, perirhinal, and temporopolar cortices on MR imaging stud ies using a customized program. METHODS: We designed a protocol in whi ch the volumes of the entorhinal, perirhinal, and temporopolar cortice s were determined from coronal MR images using anatomic landmarks defi ned on the basis of cytoarchitectonic analyses of 49 autopsy cases. MR volumetry of these cortical areas was performed in 52 healthy volunte ers. RESULTS: The overall mean volumes were 1768 +/- 328 mm(3)/1558 +/ - 341 mm(3) (right/left) for the entorhinal cortex, 2512 +/- 672 mm(3) /2572 +/- 666 mm(3) for the perirhinal cortex, and 2960 +/- 623 mm(3)/ 3091 +/- 636 mm(3) for the temporopolar cortex. The right entorhinal c ortex was 12% larger than the left. The volume of the temporopolar cor tex was reduced bilaterally by 13% in the older age group compared wit h younger subjects, while the volumes of the entorhinal and perirhinal cortices were unaffected by age. There were no differences between me n and women in the volumes of any of the three cortices. CONCLUSION: O ur method provides a tool by which to measure volumes of the entorhina l, perirhinal, and temporopolar cortices on coronal MR images.