SMALL ANIMAL MAGNETIC-RESONANCE-IMAGING - A MEANS OF STUDYING THE DEVELOPMENT OF STRUCTURAL PATHOLOGIES IN THE RAT-BRAIN

Small animal magnetic resonance imaging (SAMRI) was developed to detec t structural tissue changes associated with disease states in animal m odels. The disease state of particular interest here is that associate d with long-term alcohol abuse. The small animal model used for this s tudy was the thiamine-deficient Sprague-Dawley rat, a model that provi des a relatively rapid means of mimicking the ventriculomegaly frequen tly found in human chronic alcohol abusers. A custom-designed coil tun ed to the magnetic field of a 1.5 Tesla clinical magnetic resonance im ager provided the technology necessary to delineate discreet regions o f the rat brain with clarity. Adult, male rats ware imaged, placed on a thiamine-deficient pellet diet for similar to 6 weeks, and then reim aged. Treatment associated enlargement of the lateral ventricles ident ified in the images was verified by posttreatment histological analysi s of the brains of these rats. The results demonstrated that SAMRI is capable of providing dramatic and reliable visual evidence of patholog ical structural changes in smalt tissue volumes with high resolution a nd reproducibility. Furthermore, the noninvasiveness of SAMRI allowed for imaging of the same animals over time, thereby reducing the number s of animals needed for convincing documentation of the changes in ven tricular sire.