脑部磁化传递对比成像

目的:观察磁化传递对比成像(MTC)对脑组织图像对比的改变及影响因素,并初步评价MTC在定量研究组织特异性方面的应用潜力。材料和方法:对检查者进行补充MT脉冲前后配对轴位SE-T1加权扫描,测算各组织磁化传递率(MTR)进行分析比较。结果:MTC使脑组织信号下降,脑白灰质对比减低,出血性脑梗塞和部分胶质瘤病灶的显示改善。不同的脑组织MTR值各异,脑白质的MTR与其部位相关(p<0.05),单侧患者健侧脑组织与正常志愿者脑组织间MTR不具明显差异(P>0.05)。各型颅内肿瘤MTR值介于7.05～11.36之间,6例级别和恶性度较高的患者(6/46)在常规SE图像中显示正常的瘤周白质其MTR值较正常值降低。

Cranial Tissues and Brain Tumors; Use of Magnetization transfer contrast

Purpose: To evaluate whether magnetization transfer ratio (MTR) could be used to predict histological characteristic of cranial tissues and brain tumors. Materials and Methods: T1-weighted MR images with and without MT in 30 healthy volunteers were evaluated by means of MTR and another 46 patients with a variety of brain tumors underwent contrast material enhanced T1-weighted MR imaging prospectively with and without MT: MTR was also evaluated. Results: Magnetization transfer contrast (MTC) produced a significant reduction in signal from all tissues except cerebrospinal fluid and fat. MTR was 19. 33 in normal white matter and 12.49 in normal gray matter, and varied from 7.05 to 11. 36 in the- tumors. No statistically significant difference was found between the mean MTR of cerebral tissues in normal side of patients and in volunteers. MTR wasn't same in different regions of interesting in white matter. 6 patients' peritumoral white matter did not show any abnormality on SE image, the MTR decreased. Conclusion: MTC produce new patterns of tissue contrast, improve the depiction of lesion. MTR enables demonstrate peritumor white matter abnormalities not seen on SE MR images. As a quantitative index, MTR has shown potential to predict the histology characteristic of tissue.