对比剂碘浓度在双源双能量CT检查中对血管和肝脏强化的影响

Effect of different iodine concentrations of contrast material on the vascular and hepatic enhancement during dual-source dual-energy CT

目的:根据体表面积(body surface area,BSA)调整碘剂量(17.1 g I/m2BSA)、固定注射时间(25 s),比较双能量CT(dual energy CT,DECT)增强扫描中两种不同碘浓度对比剂之间血管和肝实质的强化。方法:300例患者被前瞻性随机分为4组,A组及C组注射300 mg/m L对比剂,B组及D组注射370 mg/m L对比剂,碘剂量根据BSA调整,对比剂注射时间固定为25 s。分别于肝动脉晚期(A、B组)或门静脉期(C、D组)采用双能量扫描,在80 k Vp、140 k Vp及彩色编码碘覆盖图中,比较高、低碘浓度对比剂间腹主动脉、门静脉及肝实质强化程度。组间强化程度差异采用Mann-Whitney U检验。结果:在80 k Vp、140 k Vp或彩色编码碘覆盖图中,注射高碘浓度对比剂时,动脉期主动脉平均强化程度较高,但两组差异没有统计学意义;两种碘浓度对比剂间门静脉期门静脉及各扫描期内肝实质强化程度差异没有统计学意义(P>0.05)。结论:在肝脏增强DECT成像中,根据BSA调整碘剂量,固定注射时间,注射300 mg I/m L或370 mg I/m L对比剂,可获得相等的血管及肝实质的强化。

Objective：To compare vascular and parenchymal contrast enhancement in dual-energy CT of the liver using two contrast media with different iodine concentration （iopamidol 300 mgI/mL and 370 mgI/mL） ,use of a protocol with iodine dose adjusted for the patient＇s body surface area com-（ BSA;17.1 gI/m2 BSA） and fixed injection duration （25 s）. Methods：300 patients were prospectively randomized into four groups. Patients in groups A and C received iopamidol with an iodine concentration of 300mg l/mL, B and D received iopamidol with an iodine concentration of 370mg I/mL respectively. Iodine dose was adjusted according to BSA,with a fixed injection duration of 25 s. Dual-energy acquisition mode was performed during late hepatic-arterial phase（A,B） and portal ve- nous phase （ C, D）. Enhancement of the abdominal aorta,liver and portal vein were compared between high-concentration contrast medi- um and low-concentration contrast medium at 80kVp, 140kVp and color-coded iodine overlay images. The Mann-Whitney U test was used to enhance the difference between group. Results：At 80kVp, 140kVp or color-coded iodine overlay images,the mean contrast enhancement of the aorta was a trend towards higher contrast enhancement during the hepatic arterial phase, which was not statistically significant,when the higher concentration contrast medium was injected. And there was no significant difference between two iodine concentration contrast medium for the mean contrast enhancement of the portal vein during the hepatic portal venous phase and for the mean contrast enhancement of the hepatic parenchyma during each acquisition phase （ P 〉 0.05 ）. Conclusion ： With fixed injection duration （25 s） and iodine load being tailored according to BSA, comparable contrast enhancement can be achieved with 300rag I/mL and 370mg I/mL being injected in liver enhanced DECT imaging.