串联线圈大鼠MR成像的初步应用研究

目的 探讨串联线圈进行大鼠3.0 T MR扫描的效果.方法 应用研制的串联线圈与随机所配的3个线圈,分别对自制的水溶液模型运用相同的快速恢复快速自旋回波序列(FRFSE-XL)进行扫描,选择4组图像中同一位置的层面,采用单幅图像测量信噪比(SNR).12只SD大鼠平均分为3个模型组和1个正常组.运用FRFSE-XL序列、快速扰相梯度回波(FSPGR)和多体素波谱(Probe-SI)序列,分别对大鼠脑损伤、脑氢质子MR波谱(1H-MRS)、脊髓损伤(SCI)和大鼠腹部进行了初步应用研究.结果 串联线圈的SNR(39.7)比随机所配的3个线圈中SNR(6.41)最好的膝关节线圈高出6倍以上.大鼠颅脑损伤的T2WI和T1WI能清楚分辨灰质和白质,很好地显示脑室的结构和血肿的位置及大小.注射6-羟基多巴胺(6-OHDA)2周后,大鼠脑部1H-MRS能显示氮-乙酰天冬氨酸/肌酸(NAA/Cr)的比值减小(注射6-OHDA前为1.240,注射2周后为0.781).大鼠胸髓T2WI可清楚显示卵圆形的脊髓,显示"H"形脊髓白质;大鼠SCI模型T2WI清楚显示大鼠胸部脊髓损伤的部位和程度.大鼠腹部扫描,FSPGR序列T1WI时间为8 s,有利于克服呼吸等运动的影响,清楚显示大鼠腹部的结构.结论 应用3.0 T MR结合串联线圈为活体大鼠模型的MR检查提供了很好的方法.

Preliminary study of MR imaging in rat with series coil

Objective To investigate the effect of MR imaging in rats with series coil. Methods MR scanning was performed on the self-made aqueous solution phantom with the series coil and other three coils respectively, using the same FRFSE- XL pulse sequence. SNR of the same image was obtained in the same position slice for all four coils. Twelve SD rats were divided into three model groups and one normal group. FRFSE-XL FSPGR and Probe-SI pulse sequence were respectively used to show the brain injury,1H-MRS, spinal cord injury (SCI) and abdomen with series coils. Results The SNR of series coil (39. 7)was over six times higher than the SNR of knee joint coil (6. 41 ), which was the best in other three coils.Grey matter and white matte; the brain structure and hematomas were clearly depicted in the rats'brain on T1WI and T2WI. From the second week after injection of 6-OHDA into the rats brain, the ratio of NAA/Cr decreased (before injection 1.24 ,two weeks after injection 0. 781 ). The spinal cord and the configuration of the white matter were clearly showed on T2WI image, and the location and degree of SCI in the rat thoracic spinal cord were also well defined on T2 WI image. The pulse sequence of FSPGR T1 WI was used for rat abdomen scanning. The scan time was only eight seconds. It is helpful to overcome the breathing movement effect and show the structure of rat abdomen. Conclusion It provided a good means for the rat MR in vivo to make use of 3.0T MR combined with series coils.