Tsuboyama Takahiro, Jost Gregor, Pietsch Hubertus, Tomiyama Noriyuki
From the *Department of Radiology, Osaka University Graduate School of Medicine, Osaka, Japan; and †MR and CT Contrast Media Research, Bayer Pharma AG, Berlin, Germany.
Invest Radiol. 2017 Sep;52(9):547-553. doi: 10.1097/RLI.0000000000000383.
The aim of this study was to compare power versus manual injection in bolus shape and image quality on contrast-enhanced magnetic resonance angiography (CE-MRA).
Three types of CE-MRA (head-neck 3-dimensional [3D] MRA with a test-bolus technique, thoracic-abdominal 3D MRA with a bolus-tracking technique, and thoracic-abdominal time-resolved 4-dimensional [4D] MRA) were performed after power and manual injection of gadobutrol (0.1 mmol/kg) at 2 mL/s in 12 pigs (6 sets of power and manual injections for each type of CE-MRA). For the quantitative analysis, the signal-to-noise ratio was measured on ascending aorta, descending aorta, brachiocephalic trunk, common carotid artery, and external carotid artery on the 6 sets of head-neck 3D MRA, and on ascending aorta, descending aorta, brachiocephalic trunk, abdominal aorta, celiac trunk, and renal artery on the 6 sets of thoracic-abdominal 3D MRA. Bolus shapes were evaluated on the 6 sets each of test-bolus scans and 4D MRA. For the qualitative analysis, arterial enhancement, superimposition of nontargeted enhancement, and overall image quality were evaluated on 3D MRA. Visibility of bolus transition was assessed on 4D MRA. Intraindividual comparison between power and manual injection was made by paired t test, Wilcoxon rank sum test, and analysis of variance by ranks.
Signal-to-noise ratio on 3D MRA was statistically higher with power injection than with manual injection (P < 0.001). Bolus shapes (test-bolus, 4D MRA) were represented by a characteristic standard bolus curve (sharp first-pass peak followed by a gentle recirculation peak) in all the 12 scans with power injection, but only in 1 of the 12 scans with manual injection. Standard deviations of time-to-peak enhancement were smaller in power injection than in manual injection. Qualitatively, although both injection methods achieved diagnostic quality on 3D MRA, power injection exhibited significantly higher image quality than manual injection (P = 0.001) due to significantly higher arterial enhancement (P = 0.031) and less superimposition of nontargeted enhancement (P = 0.001). Visibility of bolus transition on 4D MRA was significantly better with power injection than with manual injection (P = 0.031).
Compared with manual injection, power injection provides more standardized bolus shapes and higher image quality due to higher arterial enhancement and less superimposition of nontargeted vessels.
本研究旨在比较团注造影剂时动力注射器注射与手动注射在对比增强磁共振血管造影（CE-MRA）中的团注形状及图像质量。
对12头猪在以2 mL/s的速度分别用动力注射器和手动注射器注射钆布醇（0.1 mmol/kg）后，进行三种类型的CE-MRA检查（采用团注测试技术的头颈部三维[3D]MRA、采用团注追踪技术的胸腹部3D MRA以及胸腹部时间分辨四维[4D]MRA）（每种类型的CE-MRA均进行6组动力注射器注射和手动注射器注射）。对于定量分析，在6组头颈部3D MRA的升主动脉、降主动脉、头臂干、颈总动脉和颈外动脉上，以及在6组胸腹部3D MRA的升主动脉、降主动脉、头臂干、腹主动脉、腹腔干和肾动脉上测量信噪比。在每组团注测试扫描和4D MRA的6组图像上评估团注形状。对于定性分析，在3D MRA上评估动脉强化、非目标强化的重叠情况及整体图像质量。在4D MRA上评估团注过渡的可视性。通过配对t检验、Wilcoxon秩和检验及秩和方差分析对动力注射器注射和手动注射器注射进行个体内比较。
3D MRA上动力注射器注射的信噪比在统计学上高于手动注射器注射（P < 0.001）。在所有12次动力注射器注射扫描中，团注形状（团注测试、4D MRA）均呈现为特征性的标准团注曲线（首过峰尖锐，随后是平缓的再循环峰），而在12次手动注射器注射扫描中仅1次呈现该曲线。动力注射器注射时增强峰值时间的标准差小于手动注射器注射。定性分析方面，虽然两种注射方法在3D MRA上均达到诊断质量，但由于动脉强化显著更高（P = 0.031）且非目标强化的重叠更少（P = 0.001），动力注射器注射显示出的图像质量显著高于手动注射器注射（P = 0.001）。4D MRA上动力注射器注射的团注过渡可视性显著优于手动注射器注射（P = 0.031）。
与手动注射器注射相比，动力注射器注射由于动脉强化更高且非目标血管的重叠更少，可提供更标准化的团注形状和更高的图像质量。
