Development of anatomically standardized map of the midbrain

在本研究中，为了建立中脑解剖标准化的大脑，进行了以下检查：(A)与常规1.5T磁共振成像仪相比，3T磁共振成像仪以更高的分辨率和更高的组织对比度显示了红核和黑质。因此，在MR图像上，中缝核和蓝斑的确切位置或相对位置有望得到更准确的识别。然而，高组织对比度和高分辨率的3D-IR(3D-IR)MR即使在MR-T1和T2弛豫时间下也很难获得两个核的组织对比度。推测这是由于各核团内神经体密度较低所致。灰质和白质的对比度即使在组织标本图像上也不能显示细胞核。(B)我们引入[F-18]FDOPA对接受多巴胺能投射的中脑核团进行定位，在中脑正中头端(中缝头端)和双侧第四脑室底部(蓝斑)检测到FDOPA内流速度轻度增加。将这些图像与3T中脑MR图像进行比较。MRI图像上在中脑内侧略有看到的区域被认为与中缝吻部相对应。在上述结果的基础上，得到了标准脑内核团的坐标，并将其应用于正电子发射计算机断层扫描(PET)和功能性磁共振成像中。

In this research, in order to create the anatomically standardized brain of the midbrains, the following examinations were performed.(A)The red nucleus and the substantia nigra are visualized with higher resolution and higher tissue contrast by 3T magnetic resonance (MR) imager than a conventional 1.5 T MR imager. Therefore, the exact position or relative position of the Raphe nucleus and the locus ceruleus were expected to be identified more correctly on MR image. However, we could hardly obtain the tissue contrast of both the nuclei even with MR-T1 and T2 relaxation time of 3D-IR (three dimensional inversion recovery) MR which has high tissue contrast and high resolution. It was speculated that this was caused by low density of neural body in each nucleus. The contrast of gray and white matter could not display the nuclei even on the image of tissue specimen. Then, a tissue enhancer was nesscessary as described in Following B.(B)We introduced [F-18]FDOPA to locate nuclei which receive dopaminergic projection in the midbrain Mild increase of FDOPA influx rate was detected in the rostral median midbrain (rostral raphe) and bilateral base of the fourth ventricle (locus ceruleus). These images were compared with the 3T MR image of the midbrain. An area slightly seen at the medial midbrain on MRI image was thought to correspond to the rostral raphe. The locus ceruleus was also located on MR image.(C)Based on the above results, the coordinates of the nuclei were obtained on the standard brain Applications to functional brain mapping for the midbrain by PET and functional MR imaging are expected.