Novak P, Novak V, Kangarlu A, Abduljalil A M, Chakeres D W, Robitaille P M
Department of Neurology, Ohio State University, Columbus, OH 43210, USA.
J Comput Assist Tomogr. 2001 Mar-Apr;25(2):242-6. doi: 10.1097/00004728-200103000-00016.
A recently developed ultra high field MRI system operating at 8 T (UHFMRI) was applied for brainstem imaging. UHFMRI was performed in five healthy volunteers (three men, two women; age range 34--46 years). Sagittal and axial slices were obtained with the following settings: GE, TR 750--1,000 ms, TE 7-9 ms, FOV 20 cm, matrix 1,024 x 1,024 or 512 x 512 points, slice thickness 2 mm, resolution 195 or 390 microm/pixel. The brainstem structures were assigned based on anatomy and course. Images with good signal strength and homogeneity were acquired from the midbrain and the pons. Main intraaxial structures could be directly visualized. The periaqueductal gray matter and nuclei had higher signal intensity than the predominantly white matter structures such as the corticobulbar/corticopontine/corticospinal tracts, the sensory lemnisci, and the medial longitudinal fasciculus. Structures with high iron content such as the substantia nigra and the red nucleus were seen as prominent signal hypointensities. Numerous vessels traversing the brainstem including small perforators were also distinguished. It is concluded that UHFMRI enables the acquisition of high quality images of the upper brainstem with details approaching that of histologic specimen.
一台最近研发的、运行于8T的超高场强磁共振成像系统（UHFMRI）被应用于脑干成像。对五名健康志愿者（三名男性，两名女性；年龄范围34 - 46岁）进行了UHFMRI检查。矢状位和轴位切片的扫描参数设置如下：采用GE序列，重复时间（TR）750 - 1000毫秒，回波时间（TE）7 - 9毫秒，视野（FOV）20厘米，矩阵为1024×1024或512×512点，层厚2毫米，分辨率为195或390微米/像素。根据解剖结构和走行对脑干结构进行定位。从脑桥和中脑获取了信号强度和均匀性良好的图像。主要的轴内结构能够直接显示。导水管周围灰质和核团的信号强度高于主要为白质的结构，如皮质延髓束/皮质脑桥束/皮质脊髓束、感觉束以及内侧纵束。含铁量高的结构，如黑质和红核，表现为明显的信号低强度。还能分辨出众多穿过脑干的血管，包括小的穿支血管。研究得出结论，UHFMRI能够获取高质量的上脑干图像，其细节程度接近组织学标本。
