MR imaging of the mamillothalamic tract.

PURPOSE: To demonstrate the normal and abnormal appearance of the mamillothalamic tract (MTT) on cranial magnetic resonance (MR) images. MATERIALS AND METHODS: Two formalin-fixed normal human brain specimens sectioned in axial and coronal planes were used to demonstrate the normal anatomy of the MTT. MR images were obtained in 32 volunteers. Proton-density-weighted coronal and axial pulse sequences were used. The images were evaluated for visualization quality and size and signal intensity of the MTTs in correlation with the specimens. Abnormal MTTs were identified on cranial MR images in two patients, and the imaging findings were analyzed. The clinical history of the patients was also reviewed to determine the effect of these findings on patient care. RESULTS: Normal MTTs were easily identified on MR studies of cadaveric brains and of the brains of the human volunteers. On MR images, normal MTTs were commonly symmetric in appearance, with signal intensity equal to that of other normal fiber tracts. The ...