Magnetic Resonance Imaging Of The Canine Brain At 3 And 7T

Magnetic resonance (MR) imaging of the canine brain is commonly acquired at field strengths ranging from 0.2 to 1.5T. Our purpose was to compare the MR image quality of the canine brain acquired at 3 vs. 7T in dogs. Low-resolution turbo spin echo (TSE) T2-weighted images (T2W) were obtained in transverse, dorsal, and sagittal planes, and high-resolution TSE T2W and turbo spin echo proton density-weighted images were obtained in the transverse and dorsal planes, at both 3 and 7T. Three experienced reviewers evaluated 32 predetermined brain structures independently and without knowledge of field strength for spatial resolution and contrast. Overall image quality and evidence of artifacts were also evaluated. Contrast of gray and white matter was assessed quantitatively by measuring signal intensity in regions of interest for transverse plane images for the three pulse sequences obtained. Overall, 19 of the 32 neuroanatomic structures had comparable spatial resolution and contrast at both field strengths. The overall image quality for low-resolution T2W images was comparable at 3 and 7T. High-resolution T2W was characterized by superior image quality at 3 vs. 7T. Magnetic susceptibility and chemical shift artifacts were slightly more noticeable at 7T. MR imaging at 3 and at 7T provides high spatial resolution and contrast images of the canine brain. The use of 3 and 7T MR imaging may assist in the elucidation of the pathogenesis of brain disorders, such as epilepsy.