MR imaging of normal rat brain at 0.35 T and correlated histology.

A custom-built small-animal transceiver was used for in vivo imaging of normal rat brain at 0.35 T, with the objective of identifying anatomic components by comparison of images with corresponding histologic sections. The cerebrum, cerebellum, brain stem, ventricles, hippocampus, and subarachnoid space were identified and cerebrospinal fluid (CSF) was differentiated from gray matter and white matter on coronal and transaxial magnetic resonance (MR) images. These images compare favorably with those obtained by others at higher field strengths in regard to delineating major neuroanatomic structures. It is concluded that this technique will be useful for investigating small-animal models of human neurologic disease involving morphologic and morphometric changes in gray matter, white matter, and CSF-filled spaces.