联合改良呼吸训练与对比剂稀释方案减少磁共振Gd-EOB-DTPA上腹部增强动脉期一过性伪影

Reduction in respiratory motion artefacts in arterial phase on gadoxetate disodium-upper abdomen enhanced MRI by using gradual and non-gradual breath training methods combined with dilution method versus reduced injection rate

摘要:

目的：对比渐进式与非渐进式呼吸训练方案MR钆塞酸二钠（gadoxetate disodium，Gd-EOB-DTPA）上腹部增强检查肝脏动脉期图像质量，联合对比剂1∶1稀释法，探索合理动脉期图像质控的呼吸训练方案与注射方案组合。方法：选择2019年5月至9月在陆军军医大学第一附属医院放射科行MR上腹部Gd-EOB-DTPA增强检查的患者，纳入人口统计学资料无差异且完成MR检查的3组患者，第1组，渐进式呼吸训练法，30名患者，先行吸气后5 s闭气，全腹无起伏达标，之后闭气时间延长至10 s、15 s到20 s；第2组，33名患者，吸气后直接闭气20 s，达标要求同第1组；2组患者对比剂均采用1 mL/s的注射速度行高压注射，之后以相同速度注射20 mL生理盐水冲刷，透视法采集；第3组，32名患者采用非渐进式呼吸训练法，对比剂用1∶1生理盐水稀释，注射速度2 mL/s，共计95例。动脉期图像质量评分标准，1分=无呼吸伪影，2分=轻度呼吸伪影可诊断，3分=中度呼吸伪影可诊断，4分=重度呼吸伪影可诊断，5分=无法诊断。评估每名患者动脉期图像呼吸伪影、肝动脉、门静脉、腹主动脉、肝脏实质的图像评分，计算总分，Kruskal-Wallis检验比较3组各项得分差异性，若有差异则用Mann-Whitney检验两两比较。结果：第3组肝动脉、门静脉、腹主动脉、肝脏实质评分及总分略优于第1组、第2组对应指标评分，但差异不具有统计学意义（P=0.065、0.229、0.819、0.340、0.080）。第3组呼吸伪影明显小于第1组和第2组（P=0.004、0.046），非渐进式对比剂稀释法呼吸伪影更小。结论：采用第3组方案直接闭气20 s呼吸训练，Gd-EOB-DTPA稀释50%注射法可明显降低一过性呼吸运动产生的呼吸伪影。

Abstract:

Objective：To compare the image quality of gradual and non-gradual breath training protocols in gadoxetate disodium （Gd-EOB-DTPA） upper abdomen-enhanced magnetic resonance at hepatic arterial phase，combing with dilution method of 1∶1，so as to explore the most reasonable combination of breath training and injection program. Methods：A total of 95 patients underwent Gd-EOB-DTPA upper abdomen-enhanced MR imaging in our department from May to September 2019 with no significant difference in the population statistics were selected and divided into three groups：the group 1（30 patients were trained by gradual protocol with the breath time from 5 s，10 s，15 s to 20 s，as no ups and downs of whole abdomen for the standard），the group 2（33 pa－tients were trained by non-gradual protocol with the breath time of 20 s，as no ups and downs of whole abdomen for the stan－dard），and the group 3（32 patients were trained with the same protocol as the group 2）. The Gd-EOB-DTPA injection rate in the group 1 and the group 2 was 1 mL/s，with 20 mL normal saline flushing. The 1∶1 diluted with saline Gd-EOB-DTPA injection rate in the group 3 was 2 mL/s，with 20 mL normal saline flushing. All arterial phases were detected by MR fluoroscopic triggering technique. The scoring standard for image quality included：1= no artefact，2=mild and diagnosable artefact，3= moderate and diagnosable arte－fact，4=severe and diagnosable artefact and 5=undiagnosable. Imaging score of hepatic artery，portal vein，abdominal aorta and liver parenchyma was evaluated and the total score were calculated，and differences of the 3 group were analyzed by the Kruskal-Wallis test and Mann-Whitney test. Results：The mean score of hepatic artery，portal vein，abdominal aorta and liver parenchyma and the total score in the group 3 were slightly higher than those in the group 1 and the group 2（P=0.065，0.229，0.819，0.340，0.080）. The breath－ing artefact in the group 3 was significant smaller than that in the group 1 and the group 2（P=0.004，0.046）. The non-gradual diluted method had a smaller respiratory artefact. Conclusion：Holding breath for 20s in the group 3 is adopted and Gd-EOB-DTPA diluted 50% injection method can significantly decrease the respiratory motion artefacts.