摘要目的:探讨不同浓度对比剂对CT门静脉成像质量的影响。方法:回顾性分析2019年2月至6月东南大学附属中大医院在相同条件下行腹部增强CT扫描的患者103例。根据所用对比剂的不同分为高浓度组（51例）和低浓度组（52例），高浓度组对比剂为碘美普尔（含碘400 mg/ml），低浓度组对比剂为碘克沙醇（含碘320 mg/ml）。选取门静脉期数据行门静脉血管重组，对图像质量进行评价，评估两组门静脉主干、肠系膜上静脉、脾静脉CT值以及门静脉的强化CT值，计算信噪比、对比噪声比，并对图像质量进行主观评分。采用独立样本 t检验比较两组间客观评价指标的差异，采用Mann-Whitney U检验比较主观评分的差异。 结果:高、低浓度组图像评分分别为4.00(3.97, 4.22）和4.00 (3.40, 4.02）分，差异有统计学意义（ Z=-2.329， P=0.020）。高浓度组的肝门静脉主干、肠系膜上静脉及门静脉强化CT值均高于低浓度组，差异有统计学意义（ P<0.05）；两组间的脾静脉CT值、肝门静脉主干的SNR与CNR差异无统计学意义（ P>0.05）。 结论:在同样扫描方案及对比剂注射方案的前提下，使用高浓度对比剂行门静脉CT成像可有效提高检查的成功率及图像质量。

abstractsObjective:To explore the effect of different contrast agent concentrations in CT portal venography and improve the success rate of examination.Methods:A total of 103 patients who underwent abdominal contrast-enhanced CT scan in Zhongda Hospital Southeast University from February to June 2019 were retrospectively analyzed. These patients were divided into two groups based on different contrast agent concentrations. Among them, 51 received high-concentration contrast agent (400 mg/ml) and 52 received low-concentration contrast agent (320 mg/ml). The data of portal vein phase were employed for portal venograpy reformation, and the CT values of the main portal vein, superior mesenteric vein, splenic vein, and portal vein enhanced were measured. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated to evaluate image quality objectively. Subjective assessment of image quality of CT images was performed by two experienced radiologists. Combining objective and subjective evaluations gave the overall evaluation of the image quality, implying whether different contrast agent concentrations would produce inconsistent image quality in portal venoraphy. Mann-Whitney U test and t test were used. Results:The image scores of the high and low concentration groups were 4.00 (3.97, 4.22) and 4.00 (3.40, 4.02), respectively. The difference was statistically significant ( Z=-2.329, P=0.020). The CT values of the portal vein, superior mesenteric vein, and portal vein enhanced in the high concentration group were higher than those in the low concentration group ( P< 0.05). However, no significant difference in CT value of spine vein, SNR nor CNR of the portal vein was detected between the two groups ( P>0.05). Conclusion:Using the same scanning technique and contrast injection protocol, portal venography examination with high contrast agent concentration can effectively improve the success rate and image quality.