Saade Charbel, Bourne Roger, Wilkinson Mark, Evanoff Michael, Brennan Patrick C
From the *Department of Radiology, Royal Prince Alfred Hospital, Sydney; †Discipline of Medical Radiation Sciences, The University of Sydney; ‡American Board of Radiology, The University of Sydney, Lidcombe, NSW, Australia; and §American University of Beirut, Lebanon.
J Comput Assist Tomogr. 2013 Sep-Oct;37(5):725-31. doi: 10.1097/RCT.0b013e31829e02b9.
Caudocranial scan direction and contrast injection timing based on measured patient vessel dynamics can significantly improve artery opacification and reduce contrast dose in the assessment of acute aortic syndrome using gated and non-gated thoracic CTA. This study aimed to investigate enhancement of the thoracic aorta using caudocranial scan direction and a patient-specific contrast regimen.
Electrocardiogram-gated (n = 120) and non-gated (n = 200) thoracic computed tomography angiography was performed on patients with nontraumatic acute aortic syndrome. Patients were assigned to one of 2 acquisition/contrast regimens, namely, regimen A, craniocaudal scan direction with 120 mL contrast, and regimen B, caudocranial scan direction using a patient-specific contrast formula. Opacity of 9 arterial and venous segments was measured, arteriovenous contrast ratio calculated, and values compared using Mann-Whitney U statistics. Receiver operating characteristic analyses and visual grading characteristic assessed diagnostic efficacy and clinical image quality. Interobserver variations were investigated using κ methods.
Regimen B when compared to A, for both scanning/contrast techniques, demonstrated higher opacification in the aorta (P < 0.01) and lower opacification in the venous system (P < 0.0001). For protocol B, arteriovenous contrast ratio was significantly increased (P < 0.0001) and mean contrast volume reduced (P < 0.05) during gated [94 (10 mL)] and non-gated [78 (5 mL)] thoracic computed tomography angiography compared to A. Receiver operating characteristic analysis Az scores and interobserver agreement were significantly higher with regimen B than A (P < 0.05).
Caudocranial scan direction and injection timing based on patient-specific vessel dynamics can optimize artery opacification and diagnostic efficacy while reducing contrast volumes.
在使用门控和非门控胸部CTA评估急性主动脉综合征时，基于测量的患者血管动力学的头尾扫描方向和对比剂注射时机可显著改善动脉显影并降低对比剂剂量。本研究旨在探讨使用头尾扫描方向和患者特异性对比剂方案对胸主动脉的强化效果。
对非创伤性急性主动脉综合征患者进行心电图门控（n = 120）和非门控（n = 200）胸部计算机断层扫描血管造影。患者被分配到2种采集/对比剂方案之一，即方案A，头足扫描方向，使用120 mL对比剂；方案B，头尾扫描方向，使用患者特异性对比剂公式。测量9个动脉和静脉节段的密度，计算动静脉对比率，并使用Mann-Whitney U统计量比较数值。采用受试者操作特征分析和视觉分级特征评估诊断效能和临床图像质量。使用κ方法研究观察者间差异。
与方案A相比，方案B在两种扫描/对比剂技术中，主动脉显影更高（P < 0.01），静脉系统显影更低（P < 0.0001）。对于方案B，与方案A相比，在门控[94（10 mL）]和非门控[78（5 mL）]胸部计算机断层扫描血管造影期间，动静脉对比率显著增加（P < 0.0001），平均对比剂体积减少（P < 0.05）。方案B的受试者操作特征分析Az评分和观察者间一致性显著高于方案A（P < 0.05）。
基于患者特异性血管动力学的头尾扫描方向和注射时机可优化动脉显影和诊断效能，同时减少对比剂用量。
