Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
Radiology. 2010 Dec;257(3):879-87. doi: 10.1148/radiol.10100781. Epub 2010 Oct 19.
To evaluate a peripheral magnetic resonance (MR) angiographic protocol combining continuous table movement (CTM) MR angiography of the entire runoff vasculature with time-resolved (TWIST) 3-T MR angiography of the calves with a total gadolinium dose of 0.1 mmol per kilogram of body weight.
In this retrospective institutional review board-approved study, 31 consecutive patients (22 men, nine women; mean age, 65 years ± 14 [standard deviation]) with peripheral arterial occlusive disease who had undergone a low-dose MR angiographic protocol that consisted of CTM MR angiography (repetition time msec/echo time msec, 2.4/1.0; 21° flip angle; voxel size, 1.2 mm(3); gadolinium dose, 0.07 mmol per kilogram of body weight) and TWIST MR angiography (2.8/1.1; 20° flip angle; voxel size, 1.1 mm(3); temporal resolution, 4.8-5.5 sec, gadolinium dose, 0.03 mmol/kg), as well as digital subtraction angiography (DSA), were included. Two radiologists rated image quality and stenosis degree on four-point scales. The accuracy of stenosis gradation and, specifically, the detection of high-grade stenoses (stenosis of 70%-99%) with CTM MR angiography alone and with the combined protocol were compared with accuracy of stenosis gradation and detection of high-grade stenoses with DSA. Means and standard deviations were calculated for all data. Interobserver agreement was determined with κ statistics. Positive and negative predictive values, sensitivity, specificity, and overall diagnostic accuracy were calculated for CTM MR angiography alone and for the combined protocol.
For CTM MR angiography, image quality was good or excellent in 95.9% of vessel segments; for TWIST MR angiography, image quality was good or excellent in 94.3% and 97.8% of vessel segments for readers 1 and 2, respectively. The combined protocol resulted in high overall diagnostic accuracy of more than 80% for detection of stenosis and diagnostic accuracy of 93.5% for detection of high-grade vessel stenosis. Inclusion of TWIST MR angiography increased diagnostic value over that achieved with CTM MR angiography alone.
A combined MR angiographic approach in which a low total gadolinium dose (0.1 mmol/kg) is used yields excellent image quality and is accurate in the diagnosis of peripheral arterial stenosis.
评估一种外周磁共振（MR）血管造影方案，该方案结合了连续表移动（CTM）MR 血管造影术，对整个流出血管进行造影，同时对小腿进行时间分辨（TWIST）3-T MR 血管造影术，总钆剂量为每千克体重 0.1 毫摩尔。
在这项回顾性机构审查委员会批准的研究中，纳入了 31 例连续患者（22 名男性，9 名女性；平均年龄 65 岁±14[标准差]），这些患者接受了低剂量 MR 血管造影方案检查，该方案包括 CTM MR 血管造影术（重复时间毫秒/回波时间毫秒，2.4/1.0；21°翻转角；体素大小 1.2 毫米（3）；钆剂量 0.07 毫摩尔/千克体重）和 TWIST MR 血管造影术（2.8/1.1；20°翻转角；体素大小 1.1 毫米（3）；时间分辨率 4.8-5.5 秒，钆剂量 0.03 毫摩尔/千克），以及数字减影血管造影术（DSA）。两位放射科医生使用四点量表对图像质量和狭窄程度进行评分。单独使用 CTM MR 血管造影术和联合方案评估狭窄分级的准确性，特别是检测 70%-99%的重度狭窄的准确性，与 DSA 评估狭窄分级和检测重度狭窄的准确性进行比较。所有数据均计算平均值和标准差。使用κ 统计确定观察者间的一致性。单独使用 CTM MR 血管造影术和联合方案的阳性和阴性预测值、敏感性、特异性和整体诊断准确性均进行计算。
对于 CTM MR 血管造影术，95.9%的血管节段图像质量为良好或优秀；对于 TWIST MR 血管造影术，两位观察者 1 和 2 的血管节段图像质量分别为良好或优秀的比例为 94.3%和 97.8%。联合方案在检测狭窄方面具有超过 80%的高整体诊断准确性，在检测重度血管狭窄方面的诊断准确性为 93.5%。纳入 TWIST MR 血管造影术提高了单独使用 CTM MR 血管造影术的诊断价值。
使用低总钆剂量（0.1 毫摩尔/千克）的联合 MR 血管造影方法可获得优异的图像质量，并能准确诊断外周动脉狭窄。
