螺旋CT门静脉造影:不同注射速率的对比研究  

Spiral CT portography: correlation with different injection rate

作　　者：吴东[1] 周康荣[1] 陈祖望[1] 陈刚[1] 陈锦 陈惠明 

机构地区：[1]上海医科大学附属中山医院放射科,200032

出　　处：《中华放射学杂志》2000年第9期637-640,共4页Chinese Journal of Radiology

基　　金：国家自然科学基金项目!(396 70230)

摘　　要：目的　通过比较使用不同注射速率所获得的螺旋CT门静脉造影 (CTP)三维图像 ,优化注射速率的选择。方法　 37例患者随机分为 2组 ,各为 11例和 2 6例 ,于第 1肝门水平进行同层动态扫描 ,注射速率分别为 1 5ml/s和 3 0ml/s ,对比剂剂量 2ml/kg(体重 ) ,分别测量门静脉 (PV)与肝实质 (L)的CT值 ,描绘时间 -密度曲线 ,确定各自延迟时间。以前面步骤所设定的延迟时间 ,分别使用注射速率 1 5ml/s和 3 0ml/s进行慢、快速法螺旋CT门静脉造影 ,其中快速法 98例 ,慢速法 12例 ,并对其CTP三维图像评分。结果　快速法和慢速法PV L密度差平均最大值分别为 83 9HU和 5 3 4HU(t=16 418,P <0 0 0 1) ,平均到达时间分别为 6 0s和 80s(t =13 394,P <0 0 0 1) ,两组之间差异均具有显著性意义。快速法CTP三维图像平均综合评分为 12 5 ,慢速法为 9 3,两者差异也具有显著性意义 (t=3 5 14,P <0 0 1)。快速法在PV L ,门静脉级别和血管边缘清晰度方面均优于慢速法。结论快速法 (3 0ml/s)螺旋CT门静脉造影的门静脉与肝脏实质密度差最大值高 ,且到达时间缩短 ,相应CTP三维图像质量优于慢速法 (1 5ml/s)。Objective To choose optimal injection rate in spiral CT portography(CTP) by comparing 3D CTP images using different injection rates. Methods Thirty seven patients were randomly divided into 2 groups (11 and 26 cases in each group). Single level dynamic scan was completed at the first liver hilus, starting at 15 s or 30 s after initial contrast injection(2 ml/kg) with injection rate 1.5 ml/s (slow group) or 3.0 ml/s (rapid group). The continuous scan were repeated every 5 s for 120 s or 135 s. ROI was used to measure the CT value of the portal vein and the liver parenchyma, respectively, and then the time density curves were drawn. Spiral CT portography were performed at injection rate of 1.5 ml/s or 3.0 ml/s as the delay time designed described above, including 98 cases in rapid group and 12 cases in slow group. Both MPVR (multi projection volume reconstruction) and MIP (maximum intensity projection) were employed for reconstruction. All images were ranked according to the grade of portal vein, the different CT value between the portal vein and the liver parenchyma, the edge′s definition of blood vessel, the grade of hepatic vein and the display of IVC by 2 radiologists. Results The maximum density difference in average between the portal vein and the liver parenchyma was 53.4 HU and 83.9 HU, respectively ( t =16.418, P <0.001) in slow group and rapid one, and the mean reaching time was 80 s and 60 s, respectively ( t =13.394, P <0.001). In slow injection group, the average score of MPVR image was 9.3, while it was 12.5 ( t =3.514, P <0.01) in rapid injection group. Rapid group was better than slow one at the PV L, the grade of the portal vein, and the edge′s definition of blood vessel. Conclusion Using rapid injection rate (3.0 ml/s), the maximum density difference between the portal vein and the liver parenchyma increases, and the mean reaching time shortens. The quality of 3D CTP image of rapid injection rate (3.0 ml/s) is superior to that of slow injection rate (1.5 ml/s).

关 键 词：注射速率 门静脉造影术 螺旋CT 门静脉造影 

分 类 号：R814.42[医药卫生—影像医学与核医学] R816.2[医药卫生—放射医学]