正常肝脏和肝硬化门静脉高压患者CT增强扫描参数研究

摘要

Objective:To study the effect of scanning protocol on image quality when the normal and cirrhotic livers were examined by contrast-enhanced MSCT. Methods:Sixty healthy volunteers were divided into group A and B,which had the conventional and high dose respectively. And ninty patients were divided into group C,D and E,which had the conventional dose,high dose and high dose and delay time respectively. The CT values of hepatic artery,portal vein,liver parenchyma,hepatic vein and the density difference values between portal vein and liver parenchyma were measured. The image quality was scored with double-blind method. Results:The CT values of hepatic artery,portal vein,hepatic vein and the density difference values between portal vein and liver parenchyma had obvious statistical differences between group A and B (P＜0.05),and liver parenchyma had no statistical difference. The image quality score had no statistical difference between group A and B. The CT values of hepatic artery,portal vein,liver parenchyma,hepatic vein and the density difference values between portal vein and liver parenchyma had obvious statistical differences between group C and D (P＜0.05). The CT values of hepatic artery and portal vein in group E were lower than those in group D,but had no statistical difference (P＞0.05),while the CT values of hepatic vein and liver parenchyma in group E increased and the density difference values between portal vein and liver parenchyma decreased ,and they had significant differences to those in group D (P＜0.05). The image quality scores had statistical differences in group C, D and E (P＜0.05). Conclusions:When the livers are examined by contrast-enhanced MSCT with the injection rate of 3 mL/s, the optimal protocol for normal livers: contrast agent dose is 1.5 mL/kg,start time of hepatic arterial phase is 28 s,start time of portal vein phase is 60 s. The optimal protocol for cirrhotic livers: contrast agent dose is 2.0 mL/kg ,start time of hepatic arterial phase is 33 s,start time of portal vein phase is 70 s.%目的:探讨正常肝脏和肝硬化门静脉高压患者增强扫描参数对图像质量的影响. 方法:收集正常志愿者(60例)和肝硬化门静脉高压患者(90例),依据对比剂剂量、扫描时间,将正常志愿者分为常规组(A组)和大剂量组(B组),将肝硬化门静脉高压患者分为常规剂量常规扫描组(C组)、大剂量常规扫描组(D组)、大剂量延时扫描组(E组),每组各30例.获得双期图像后,测量动脉期肝动脉CT值,门静脉期门静脉、肝实质、肝静脉CT值及门静脉肝实质CT值差值,并对双期图像质量进行双盲目测评分. 结果:A 组与B 组肝动脉、门静脉、肝静脉CT 值及门静脉与肝实质 CT 值差值比较差异均有统计学意义(P＜0.05),肝实质CT值2组间比较差异无统计学意义;A组、B组图像质量评分差异无统计学意义. C组与D组比较,肝动脉、门静脉、肝实质、肝静脉CT值、门静脉与肝实质CT值差值差异有统计学意义(P＜0.05). E组与D组比较,肝动脉、门静脉强化程度差异无统计学意义;肝静脉CT值、肝实质CT值上升,门静脉与肝实质CT值差值减小,差异有统计学意义(P＜0.05);C组、D组、E组图像质量评分差异有统计学意义(P＜0.05). 结论:当对比剂注射速率为3 mL/s时,正常人对比剂剂量为1.5 mL/kg体质量,动脉期扫描起始时间28 s,门静脉期扫描起始时间60 s,可获得较满意图像;肝硬化门静脉高压患者对比剂剂量为2.0 mL/kg体质量,动脉期扫描起始时间33 s,门静脉期扫描起始时间70 s,可获得较满意图像.