肝炎肝硬化螺旋CT门静脉造影扫描延迟时间的合理选择

Optimal scan delay time in spiral CT portography of posthepatitic cirrhosis

目的 应用时间—密度曲线选择正常人和肝炎肝硬化患者螺旋 CT门静脉造影的合理扫描延迟时间 .方法 2 0例正常人和 1 8例肝炎后肝硬化患者于第一肝门水平门静脉主干分叉以下 1 0 mm处行同层动态增强扫描 .造影剂量 1 .5m L· kg-1 ,注射速率 3 m L· s-1 ,经外周静脉注射造影剂后1 5 s开始扫描 ,以后每隔 5 s扫描 1次 ,持续至 1 2 0 s.分别测量同一层面门静脉、肝脏的 CT值 ,并计算各点门静脉与肝脏的密度差 (P- L) ,描绘时间 -密度曲线 .结果 正常组与肝硬化组门静脉平均强化峰值分别为 (1 81± 34) Hu,(1 59± 2 9)Hu(P<0 .0 5) ,峰值到达时间分别为 (54± 7) s,(65± 9) s(P<0 .0 5) .肝脏平均强化峰值分别为 (1 1 8± 1 9) Hu,(96±1 3) Hu(P<0 .0 5) ,峰值到达时间分别为 (64± 9) s,(75±1 0 ) s(P<0 .0 5) .门静脉和肝脏密度差最大值两组分别为(9 0± 2 8) Hu,(73± 1 6) Hu(P<0 .0 5) ,其达到最大密度差时间分别为 (50± 7) s,(65± 3) s(P<0 .0 1 ) .结论 行肝脏螺旋 CT门静脉造影成像显示肝内门静脉分支 ,造影剂量为 1 .5m L· kg-1 ,注射速率为 3m L· s-1 ,正常人最佳扫描延迟时间为 40 s,肝炎后肝硬化患者最佳扫描延迟时间为 50

AIM To optimize the scan delay time for spiral CT portography (SCTP) by using time density curves in normal individuals and posthepatitic cirrhosis patients. METHODS 20 normal individuals and 18 patients with posthepatitic cirrhosis were involved in this study. Single level dynamic CT scanning was performed at the level of the first hilus, the contrast dose was 1.5 mL·kg -1 , and injection speed was 3 mL·s -1 , starting scan from 15 s to120 s at 5 s intervals. CT values of the portal vein and liver were calculated at identical slice and the time density curves was drawn. RESULTS Average maximal value of the portal vein in the normal group and the cirrhotic group were (181±34) Hu, (159±29) Hu ( P <0.05). The time of peak enhancement were (54±7) s and (65±9) s, respectively ( P < 0.05). The same measurements of hepatic parenchyma in two groups were (118±19) Hu and (96±13) Hu ( P < 0.05), and the peak time were (64±9) s and (75±10) s, respectively ( P < 0.05). The maximal density differences between the portal vein and liver parenchyma (P L) in the two groups were 90±28 Hu and 73±16 Hu, respectively ( P < 0.05), and it was observed at (50±7) s and (65±3) s, respectively ( P <0.01). CONCLUSION In SCTP, the optimal contrast dose was 1.5 mL·kg -1 , and the injection speed was 3 mL·s -1 , In order to demonstrate portal vein tributaries clearly, optimal scan delay time in normal individuals and cirrhotic individuals should be 40 s and 50 s, respectively.