Asbach Patrick, Meade Michael D, Sattenberg Ronald J, Klessen Christian, Huppertz Alexander, Heidenreich Jens O
University of Louisville Department of Radiology, Louisville, KY, USA.
Acta Radiol. 2014 Apr;55(3):266-72. doi: 10.1177/0284185113498535. Epub 2013 Sep 27.
Optimal vessel contrast is a prerequisite for vascular imaging. Consecutive stationary imaging of multiple fields of view is contrary to the continuous contrast material passage through the vascular tree. A continuous acquisition of a magnetic resonance (MR) sequence might overcome this limitation.
To investigate the image quality of a continuously moving table (CMT) acquisition compared with the established multistep approach for contrast-enhanced magnetic resonance angiography (CE-MRA) of the aorto-iliofemoral run-off.
Institutional review board approved this retrospective interindividual study of 60 consecutive patients referred to CE-MRA for peripheral arterial disease. Thirty patients underwent CE-MRA using the routine multistep acquisition and 30 patients were scanned using the CMT technique at 1.5 Tesla. All patients received a fixed contrast dose of 25 mL gadoterate meglumine. A quantitative analysis was performed to assess the relative contrast of 10 vascular segments from the proximal abdominal aorta to the distal calf arteries. A qualitative evaluation of three separate vascular regions (abdomen and pelvis, thighs, and calves) was performed. Two radiologists graded independently arterial vessel conspicuity, venous contamination, presence of artifacts, and diagnostic confidence on a 4-point scale. Overall scan time, including all localizer scans, was recorded. Statistical differences were tested using the Wilcoxon signed-rank test with Bonferroni correction.
No significant differences were found between the continuously moving table acquisition and the multistep acquisition with regard to the relative vascular contrast and the qualitative image criteria. The agreement between both readers was significant (Kendall tau rank correlation coefficient, 0.373). The absolute reader agreement was 71.4%. The mean overall scan time was 12 min 44 s for the CMT protocol and 21 min 41 s for the multistep protocol.
Aorto-iliofemoral run-off CE-MRA acquired with CMT technique provides a high image quality equivalent to a multistep technique at an overall scan time reduction of 41.3%.
最佳血管对比度是血管成像的前提条件。对多个视野进行连续静态成像与造影剂在血管系统中持续通过的情况相悖。连续采集磁共振（MR）序列可能会克服这一局限性。
与用于腹主动脉-髂股动脉分支的对比增强磁共振血管造影（CE-MRA）的既定多步方法相比，研究连续移动检查床（CMT）采集的图像质量。
机构审查委员会批准了这项针对60例因外周动脉疾病接受CE-MRA检查的连续患者的回顾性个体间研究。30例患者采用常规多步采集法进行CE-MRA检查，30例患者在1.5特斯拉场强下使用CMT技术进行扫描。所有患者均接受25毫升钆喷酸葡胺的固定造影剂剂量。对从腹主动脉近端到小腿远端动脉的10个血管节段进行定量分析，以评估相对对比度。对三个独立的血管区域（腹部和骨盆、大腿和小腿）进行定性评估。两名放射科医生独立地按照4分制对动脉血管清晰度、静脉污染、伪影的存在情况以及诊断可信度进行评分。记录包括所有定位扫描在内的总扫描时间。使用带有Bonferroni校正的Wilcoxon符号秩检验来检验统计学差异。
在相对血管对比度和定性图像标准方面，连续移动检查床采集与多步采集之间未发现显著差异。两位阅片者之间的一致性显著（肯德尔tau秩相关系数，0.373）。阅片者之间的绝对一致性为71.4%。CMT方案的平均总扫描时间为12分44秒，多步方案为21分41秒。
采用CMT技术进行的腹主动脉-髂股动脉分支CE-MRA可提供与多步技术相当的高图像质量，且总扫描时间缩短了41.3%。
