Martín-Vaquero Paula, Da Costa Ronaldo C, Echandi Rita L, Tosti Christina L, Knopp Michael V, Sammet Steffen
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, USA.
Vet Radiol Ultrasound. 2011 Jan-Feb;52(1):25-32.
Magnetic resonance (MR) imaging of the canine brain is commonly acquired at field strengths ranging from 0.2 to 1.5 T. Our purpose was to compare the MR image quality of the canine brain acquired at 3 vs. 7 T 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 7 T. 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 7 T. High-resolution T2W was characterized by superior image quality at 3 vs. 7 T. Magnetic susceptibility and chemical shift artifacts were slightly more noticeable at 7 T. MR imaging at 3 and at 7 T provides high spatial resolution and contrast images of the canine brain. The use of 3 and 7 T MR imaging may assist in the elucidation of the pathogenesis of brain disorders, such as epilepsy.
犬脑的磁共振（MR）成像通常在0.2至1.5 T的场强下进行。我们的目的是比较犬在3 T和7 T场强下获得的犬脑MR图像质量。在3 T和7 T时，均在横断、背侧和矢状平面获取低分辨率快速自旋回波（TSE）T2加权图像（T2W），并在横断和背侧平面获取高分辨率TSE T2W和快速自旋回波质子密度加权图像。三位经验丰富的审阅者独立评估32个预先确定的脑结构，且不知道场强，以评估空间分辨率和对比度。还评估了整体图像质量和伪影情况。通过测量三个脉冲序列在横断平面图像感兴趣区域的信号强度，定量评估灰质和白质的对比度。总体而言，32个神经解剖结构中的19个在两种场强下具有相当的空间分辨率和对比度。低分辨率T2W图像的整体图像质量在3 T和7 T时相当。高分辨率T2W在3 T时的图像质量优于7 T。7 T时磁敏感性和化学位移伪影稍更明显。3 T和7 T的MR成像可提供犬脑的高空间分辨率和对比度图像。使用3 T和7 T的MR成像可能有助于阐明脑部疾病如癫痫的发病机制。
