摘要
目的:探讨Gd-DTPA对中枢神经系统扩散加权成像(DWI)图像质量及表观扩散系数(ADC)值的影响。材料和方法:前瞻性选取41例头MR增强检查的患者,平均年龄(43.3±17.3)岁。采用GE Signa HDxt 3.0T超导型磁共振扫描仪,注药前肘静脉团注0.1 mmol/kg体质量的钆喷替酸葡甲胺(Gd-DTPA)后约3.4 min行横断面单次激发平面回波DWI扫描(b=0 s/mm2和1 000 s/mm2)。采用配对t检验评价增强前、后DWI图像信号噪声比(SNR)、对比噪声比(CNR)以及ADC值。P<0.05为有显著统计学差异。结果:增强前、后DWI图像上,正常脑组织的SNR、44处脑内病变的SNR及CNR均无显著统计学差异;11处脑外病变仅在b=0 s/mm2的DWI图像上,SNR及CNR增强后略有减低(P=0.026及0.017)。增强后正常脑组织及脑内病变ADC值无显著统计学差异,但脑外病变ADC值降低比例最明显且具有统计学差异(约5.9%,P=0.002)。结论:常规Gd-DTPA增强对脑外病变低b值DWI图像的信号及ADC值略有影响,富血供病变,如大部分脑外病变的DWI扫描应尽量在增强扫描前完成。
Objective： To evaluate the effect of intravenous Gd-DTPA on diffusion weighted imaging （DWI） and apparent diffusion coefficient （ADC） value. Materials and Methods： Forty-one patients were prospectively recruited with mean age （43.3±17.3） years. Transverse single shot echo planar imaging DWI was performed immediately before, and about 3.4 min after the injection of 0.1 mmol/kg Gd-DTPA on GE Signa HDxt 3.0T MR scanner. Signal-to-noise ratio（SNR） and contrast-to-noise ratio （CNR） of the lesion, and the SNR of normal brain tissue were calculated on b=0 s/mm^2 and b=1000 s/mm^2 DWI images respectively. ADC values were measured on ADC maps. A paired t-test was used to determine the significance of differences between the values before and after administration of contrast medium. P〈0.05 was considered statistically significant. Results： Images before and after contrast administration were not significantly different regarding SNR and CNR on DWI of either normal brain or 44 intraxial lesions. SNR and CNR were slightly decreased on b=0 s/mm^2 DWI of 11 extraaxial lesions （P=0.026 and 0.017）. ADC values decreased the most after contrast medium injection on DWI for extraaxial lesions （about 5.9%, P= 0.002）, and no significant statistical difference for ADC decrease shown in normal brain or intraaxial lesions. Conclusion： In routine clinical practice, Gd-DTPA has slight effects on low b-value DWI images and ADC values for extraaxial lesions. Therefore, it is better to perform DWI before contrast medium injection for those lesions with rich blood supply, especially extraaxial lesions.
出处
《中国临床医学影像杂志》
CAS
2013年第4期229-233,共5页
Journal of China Clinic Medical Imaging
基金
"十二五"国家科技支撑计划项目资助(2011BAI08B10)
关键词
中枢神经系统疾病
钆DTPA
磁共振成像
Central nervous system diseases
Gadolinium DTPA
Magnetic resonance imaging
