对比剂不同流率对门静脉CT血管成像质量的影响

目的 探讨对比剂不同注射流率对多层螺旋CT肝门静脉成像质量的影响.方法 30例患者随机分为3组,每组10例,年龄与体重无明显差异,行腹部CT增强扫描.按1.5 ml/kg剂量前臂静脉注射浓度为300 mg Ⅰ/ml的非离子型对比剂,注射流率分别为2.0 ml/s、3.0 ml/s和4.0 ml/s.腹主动脉兴趣区智能跟踪技术触发动脉期扫描,动脉期后延迟7 s与20 s行门静脉期扫描.在工作站测量3组CT源图像上门静脉(PV)与肝实质的CT值,并重组PV斜轴位与冠状位最大密度投影(MIP)图像,观察PV显示的分支级别.采用SPSS 11.5软件行统计学分析.结果 2.0 ml/s组、3.0 ml/s组、4.0 ml/s组门静脉CT值分别为(150.80±21.16)HU、(170.90±17.26)HU与(181.90±22.88)HU,2.0 ml/s组与4.0 ml/s组间有明显差别(P=0.017).2.0 ml/s组、3.0 ml/s组、4.0 ml/s组PV与肝实质CT值差别分别是(50.20±17.40)HU、(67.10±23.08)HU与(76.20±22.75)HU,2.0 ml/s组与4.0 ml/s组间有明显差别(P=0.039).2.0 ml/s组、3.0 ml/s组、4.0ml/s组对PV分支显示级别分别为4.20±1.14、4.90±0.99及5.50±0.53,2.0 ml/s组与4.0 ml/s组间有明显差别(P=0.013).结论 注射流率对PV CT血管成像的质量有影响,流率为4.0 ml/s时SCTP质量最佳.

Influence of Velocity of Flow of Contrast Media on Spiral CT Portography

Objective To investigate the effect of different injection rate of contrast medium on the quality of multislice spiral CT portography(SCTP). Methods Thirty patients with no prominent difference in the age and weight randomly divided into 3 groups (10 cases each group) underwent contrast-enhanced CT scan of abdomen. Non-ionic contrast medium (300 mgⅠ/ml, 1.5 ml/kg) was injected through antebrachium veins with power injector at the rates of 2.0 ml/s,3.0 ml/s and 4.0ml/s. Arterial phase acquisi-tion was made using the software of automated bolus triggering with a ROI placed on abdominal aorta when 100 HU was reached, and 7 seconds and 20 seconds later, portal phases were done respectively. The attenuations of portal vein(PV) and hepatic parenchy-ma of 3 groups were measured on source images. Then the oblique axial and coronal maximum intensity projection(MIP) maps were reconstructed at workstation and PVs were observed. Statistics analysis was made with software of SPSS 11.5. Results The attenu-ations of PV in 2.0ml/s, 3.0 ml/s and 4.0 ml/s groups were (150.80±21.16)HU, (170.90±17.26)HU and 181.90±22.88) HU respectively. There was obvious difference between 2.0ml/s and 4.0ml/s groups for atteuation of PV(P=0.017). The differences of CT attenuation of PV-hepatic parenchyma in three groups were (50.20±17.40) HU, (67.10±23.08) HU and (76.20±22.75) HU respectively. Prominent difference was also found between 2.0 ml/s and 4.0 ml/s groups(P=0.039). The grades of segment of PV displayed on SCTP maps were 4.20±1.14,4.90±0.99 and 5.50±0.53 in 2.0 ml/s,3.0 ml/s and 4.0 ml/s groups respectively, which were of obvious differences between them (P=0.013). Conclusion Injection rate of contrast medium dose influence the quality of SCTP of PV,SCTP quality is best with velocity of flow at 4.0 ml/s.