二乙烯三胺五乙酸钆对多b值模式弥散加权成像中表观扩散系数值的影响  

Effect of Gd-DTPA on apparent diffusion coefficient in multi-b-value diffusion weighted imaging

作　　者：李伟[1] 龙晚生[1] 罗学毛[1] 梁卓栋[1] 黄列彬 蒋基荣 

机构地区：[1]中山大学附属江门医院放射科广东省江门市中心医院放射科,529030

出　　处：《中华生物医学工程杂志》2015年第1期64-69,共6页Chinese Journal of Biomedical Engineering

基　　金：江门市科技计划项目（江科[2010]73号.1）

摘　　要：目的：探讨二乙烯三胺五乙酸钆（Gd-DTPA）对不同b值弥散加权成像（DWI）中表观扩散系数（ADC）值在增强前后的变化规律，与增强后行DWI的可行性。方法39例经临床或病理证实的脑肿瘤患者，在Siemens Espree 1.5 T大孔径超导MR扫描仪上，行常规T1WI、T2WI轴位，T2WI矢状位，T2WI FLAIR冠状位，DWI轴位扫描后，再由Medrad高压注射器通过肘静脉向患者注射0.2 mmol/kg剂量的Gd-DTPA，后用20 ml生理盐水冲管。在高压注射器开始注射时，启动静脉期DWI扫描，后行T1WI轴位，FS T1WI矢状位与冠状位扫描，最后行排泄期DWI扫描。平扫、静脉及排泄期DWI为单次激发SE-EPI序列，参数完全一致，b值依次取0、500、800、1000、1200、1500 s/mm2等6个，扫描时间162 s。在sygno工作站上，通过ADC分析函数分别生成平扫、静脉及排泄期在b值为500、800、1000、1200、1500 s/mm2的ADC图，在ADC图上，分别测量出不同b值及时相下瘤体强化区、水肿区、半卵圆中心、侧脑室后角、内囊前肢、内囊膝部、内囊后肢、豆状核及脑干的ADC值，最后对同一b值及颅脑位置在平扫、静脉及排泄期的ADC值进行统计学分析。结果同一b值及颅脑位置的ADC值随着Gd-DTPA的注入，迅速下降，再上升，到了10分钟后，ADC值与平扫基本一致，即平扫的ADC值最大，静脉期最低，排泄期接近平扫，但三期的ADC值无统计学差异（P〉0.05），b值为1000 s/mm2时，瘤体强化区在平扫、静脉及排泄期的ADC值分别为1.38、1.29、1.36×（10-3 mm2/s）。同一b值，不同颅脑位置在增强前后ADC值的变化曲线不一致，其中瘤体强化区的ADC值曲线最陡峭，即瘤体强化区在静脉期的ADC值下降程度最大。同一颅脑位置及时相的DWI，随着b值增加，ADC值不断下降，即b值为500 s/mm2时， ADC值最大，1500 s/mm2时，ADC值最小，瘤体强化区在平扫DWI中，b值从500增加到1500 s/mm2， ADObjective To investigate the change in apparent diffusion coefficient （ADC） value before or after Gd-DTPA enhancement in diffusion weighted imaging（DWI）with different b values,and the feasibility of undergoing DWI after the enhancement. Methods Thirty-nine patients with brain tumor confirmed by clinical or pathological examination were included in the study. By using Siemens Espree 1.5 T large aperture superconducting MR scanner,all patients underwent conventional T1WI and T2WI axial,T2WI sagittal,T2WI FLAIR coronal,and DWI axial scans. Then,Medrad high pressure syringe was used to inject 0.2 mmol/kg dose of Gd-DTPA for each patient via elbow vein,with additional injection of 20 ml normal saline for rinsing of the venous lines. At the beginning of injecting by high pressure syringe,patients＆amp;nbsp;underwent venous phase DWI scan,followed by T1WI axial,fat saturation（FS）T1WI sagittal and coronal scans,and finally,the excretory phase DWI scan. The DWI in plain scan,venous and excretory phases was single-shot SE-EPI sequence with the same parameter set,and the b value was 0,500,800,1 000,1 200, 1 500 s/mm2,respectively. The scanning time was 162 s. In Sygno workstation,the ADC figures of plain scan,venous and excretory phases,with the b values of 500,800,1 000,1 200 and 1 500 s/mm2 inin,were generated by ADC analysis function,respectively. In ADC figures,the ADC values of different b value DWI at different time points were measured in the enhanced and edema regions of the tumor,centrum semiovale, posterior horn of lateral ventricles,anterior limb of internal capsule,genu of internal capsule,posterior limb of internal capsule,lenticular nucleus,and brainstem,respectively. At the end,the ADC value of DWI with the same b value at the same brain locationhj during plain scan,venous and excretory phases were statistically analyzed,respectively. Results The ADC value of DWI with the same b value at the same brain location decreased rapidly along with the injection of Gd-DTPA,and then resumed. At 10 minutes

关 键 词：磁共振成像 钆DTPA 肿瘤 

分 类 号：R743.33[医药卫生—神经病学与精神病学]