Design of the MRI probe applicable to discrimination of the fine histological changes in brauns of laboratory animals

适用于辨别实验动物内脏细微组织学变化的MRI探头设计

基本信息

批准号：
05556051
负责人：
KUWABARA Mikinori
金额：
$ 7.81万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

Magnetic resonance imaging (MRI) is a unique method to noninvasively observe the structure inside body. Since this is not a method to observe the fine structures inside each tissue by magnifying its image, it is hard to apply this method to small laboratory animals as mice and rats. There is a method to magnify the image on CRT by computer technique, but this method requires the original image to be sharply taken with a high S/N ratio. The NMR theory teaches us that the higher the magnetic field the stronger are the NMR signals obtained. The superconducting magnet used for usual 200 or 300 MHz NMR spectrometry produces the strong and homogeneous magnetic field. We planned to image the inside of the laboratory animal by employing usual 200 MHz NMR spectrometer (Brucker MSL200) . For this purpose, we designed the MRI imaging probe suitable for this machine. As a preliminary experiment, we made a Dadok type Helmholtz coil (50 mm i.d.) resonating at a radiofrequency of 300 MHz as the imaging probe and apply it to the superconducting magnet (Oxford) with the relatively large size of magnet bore (183 mm) producing a magnetic field of 7T.An SIS 300/183 imaging system was operated on a Toshiba workstation. When the sagittal and coronal sections of brains of young (5 weeks old) and aged (24 months old)Wistar rats were imaged using this system, histological alterations of cerebral cortices and enlargement of the third ventricle and hypertrophy of cranical parietal bones relating to degeneration of brains with aging were clearly displayd by this system. The resolution of MR images was 0.8 mm. On the basis of these results, wa subsequently designed an imaging probe suitable for the Brucker MSL200 with a diameter of 25 mm. This probe is now utilized to accumulate imaging data and tested as an NMR microscopy.

磁共振成像（MRI）是一种非侵入性观察体内结构的独特方法。由于这不是通过放大图像来观察每个组织内部细胞结构的方法，因此很难将这种方法应用于小鼠和大鼠。有一种方法可以通过计算机技术放大CRT上的图像，但是此方法要求使用高S/N比迅速拍摄原始图像。 NMR理论告诉我们，强磁场越高，获得的NMR信号越高。用于通常200或300 MHz NMR光谱的超导磁铁会产生强且均匀的磁场。我们计划通过使用通常的200 MHz NMR光谱仪（Brucker MSL200）来对实验室动物的内部进行成像。为此，我们设计了适合该机器的MRI成像探针。作为一个初步实验，我们制作了Dadok型Helmholtz Coil（50 mm I.D.），以300 MHz的辐射共鸣，作为成像探针，并将其应用于超导磁铁（牛津），并与相对较大的磁铁孔（183 mm）产生了7t.ans 300/1的磁性磁场（183 mm）的磁场（183 mm）。工作站。当使用该系统的年轻人（5周大）和年龄（24个月大）的年轻人（5周）和年龄（24个月大）的介绍和冠状切片时，脑皮质的组织学改变以及第三个心室的肿大和颅骨骨的肥大的增大，与Aging与Aging的大脑有关的颅骨骨骼的肥大显然可以通过此系统显示。 MR图像的分辨率为0.8毫米。根据这些结果，WA随后设计了适用于直径为25 mm的Brucker MSL200的成像探针。现在，该探针用于积累成像数据并作为NMR显微镜进行测试。