Potthast S, Schulte A-C, Bongartz G M, Hügli R, Aschwanden M, Bilecen D
Department of Diagnostic Radiology, University Hospital of Basel, Petersgraben 4, 4031, Basel, Switzerland.
Eur Radiol. 2005 Nov;15(11):2347-53. doi: 10.1007/s00330-005-2790-1. Epub 2005 Jun 21.
Multiple intra-arterial contrast agent injections are necessary during MR-guided endovascular interventions. In respect to the approved limits of maximum daily gadolinium dose, a low-dose injection protocol is mandatory. The objective of this study was to derive and apply a low-dose injection protocol for intra-arterial 3D contrast-enhanced MR aortography in patients. Injection rate (Qinj), concentration of injected gadolinium [Gd]inj and aortal blood flow rate (Qblood) were included for the theoretical evaluation of signal intensity (SI) of the arterial lumen. SI simulations were carried out at Qinj=2 versus 4 ml/s in the [Gd]inj range between 0-500 mM. Qinj and [Gd]inj with SI above the 75% threshold of the maximal SI were regarded as optimal injection parameters. [Gd]inj=50 mM and Qinj=4 ml/s were considered as optimal and were administered in five patients for 3D MR aortography. All images revealed clear delineation of the abdominal aorta and its major branches. Mean+/-SD of contrast-to-noise ratios of the abdominal aorta, common iliac and renal artery were 70.2+/-15.2, 58.6+/-12.3 and 67.4+/-12.3. Approximately seven intra-aortal injections would be permissible in patients during MR-guided interventions without exceeding the maximal dose of gadolinium.
在磁共振引导下的血管内介入治疗过程中，需要多次动脉内注射造影剂。鉴于钆每日最大剂量的批准限制，必须采用低剂量注射方案。本研究的目的是推导并应用一种针对患者的动脉内三维对比增强磁共振主动脉造影的低剂量注射方案。注射速率（Qinj）、注射钆的浓度[Gd]inj和主动脉血流速率（Qblood）被纳入用于对动脉腔信号强度（SI）进行理论评估。在[Gd]inj范围为0 - 500 mM时，分别以Qinj = 2与4 ml/s进行SI模拟。Qinj和[Gd]inj的SI高于最大SI的75%阈值时被视为最佳注射参数。[Gd]inj = 50 mM且Qinj = 4 ml/s被认为是最佳参数，并应用于5例患者进行三维磁共振主动脉造影。所有图像均清晰显示了腹主动脉及其主要分支。腹主动脉、髂总动脉和肾动脉的对比噪声比的平均值±标准差分别为70.2±15.2、58.6±12.3和67.4±12.3。在磁共振引导的介入治疗过程中，患者大约可以进行七次主动脉内注射而不超过钆的最大剂量。
