常规Gd-DTPA增强后脑DWI检查的可行性研究  

Feasibility of diffusion-weighted imaging on brain after conventional Gd-DTPA enhancement

作　　者：廖伟华[1] 王小宜[1] 姜新雅[1] 王润文[1] 邓利猛 周高峰[1] 

机构地区：[1]中南大学湘雅医院放射科,湖南长沙410008 [2]湖南省长沙市第四人民医院放射科,湖南长沙410000

出　　处：《中国医学影像技术》2007年第2期205-209,共5页Chinese Journal of Medical Imaging Technology

基　　金：国家自然科学基金资助(30370433)。

摘　　要：目的探讨常规增强扫描之后行DWI检查的可行性。方法采用西门子1.5T超导型MR扫描系统对86例颅内病变患者进行检查,先行常规T1WI、T2WI及DWI(b=0、1000s/mm2)横断面扫描,然后行常规增强T1WI扫描,对比剂为钆喷替酸葡甲胺(Gd-DTPA),剂量为0.1mmol/kg,注药速度为1ml/s,注入对比剂4min后以相同的参数再行一次DWI扫描,将增强前后的DWI原始图像均输入工作站获得表观弥散系数图。分别计算出肿瘤强化实质区、坏死囊变区、脑梗死区、正常脑灰质区、正常脑白质区,正常神经核团区域增强前后的DWI信号噪声比(SNR)、对比噪声比(CNR)、ADC值。采用配对t检验比较不同区域增强前、后SNR、CNR及ADC值的差别。结果正常脑组织DWI的SNR和ADC值于增强前后均无明显差别,P>0.05;增强前后肿瘤强化实质区、囊变坏死区、脑梗死DWI的SNR、CNR以及ADC值的差别也无统计学意义(P>0.05)。结论常规Gd-DTPA增强4min后,正常脑组织和不同的病变组织的DWI(b=0、1000s/mm2)SNR、CNR及ADC值无明显改变,常规Gd-DTPA增强4min后行脑DWI(b=0、1000s/mm2)扫描是可行的。Objective To assess the feasibility of diffusion-weighted imaging （DWI） on brain after conventional Gd-DTPA enhancement scanning. Methods Eighty-six patients who were verified various brain lesion were examined. DWI was obtained using single-shot echo-planar imaging with b value of 0, 1000 s/mm^2 before enhancement scanning. Patients were injected with Gd-DTPA （0.1 mmol/kg body weight; 1 ml/s）. Repetition of DWI was obtained 4 minutes later when conventional enhancement scanning was finished. We examined the signal-to-noise ratio （SNR） of the normal brain tissues and various brain lesions and evaluated the contrast-to-noise ratio （CNR） of each lesion. In addition, the ADC values calculated from the DWI images were compared before and after administration of Gd-DTPA. The statistical significance of differences between precontrast and postcontrast administration was determined by use of a paired t test. Results The SNR and CNR of the DWI were not significantly different before and after administration of Gd-DTPA （P〉0.05）. There were no significant differences of ADC value before and after administration of Gd-DTPA in the normal brain tissues, and even in lesions with enhancing parenchymatou tissues or necrosis/cyst regions, infarct regions （P〉0.05）. Conclusion There was no significant difference before and after administration of Gd-DTPA in the SNR or CNR of DWI and ADC value. This indicates the feasibility of DWI （b=0, 1000 s/mm^2） on brain after conventional enhancement scanning in clinical practice.

关 键 词：磁共振成像 扩散加权成像 钆喷替酸葡甲胺 可行性 

分 类 号：R742[医药卫生—神经病学与精神病学] R445.2[医药卫生—临床医学]