MRI-BASED HIPPOCAMPAL VOLUME MEASUREMENTS IN EPILEPSY

In the study of brain morphometry, it is accepted that a relationship exists between brain structure and function, both normal and abnormal. One descriptor of morphometric structure is volume. Abnormalities in hippocampal morphology, including unilateral or bilateral volume loss, are known to occur in epilepsy, Alzheimer's disease, and in certain a mnestic syndromes. Precise quantitation should improve understanding o f the role of any biologic system in normal function and in disease. T he objectives of magnetic resonance (MR)-based hippocampal volume meas urements are precise quantitation, identification of a normal range, a nd identification of the association between biologic variables and ab errations in this volumetric parameter. Volumetric measures introduce a level of precision in the estimation of hippocampal size that is not available simply by visually inspecting a set of MR images, thus enab ling statistically based hypothesis testing. To produce accurate hippo campal volume measurements with magnetic resonance imaging (MRI), atte ntion must be directed to the two major components of the operation as a whole, MR image acquisition and image processing.