CE MRA、MCA和2D TOF MRA对四肢血管性疾病和体外血管狭窄模型的应用研究

目的 通过多种磁共振血管造影（MRA）技术对模拟狭窄血管的体外模型和四肢血管性疾病应用研究分析，评估其临床应用价值和限度。材料与方法 （1）实验研究：对不同狭窄程度、长度的模型行二维时间飞跃法磁共振血管造影（2D TOF MRA）、幅度对比血管造影（MCA）、增强幅度对比血管造影（MCA）、增强幅度对比血管造影9CE MCA）和三维动态增强磁共振血管造影（3D CE MRA）检查，测量并计算狭窄程度、长度和分级准确度。（2）临床应用：对20例怀疑有四肢血管相关性疾病的患者行3D CE MRA、2D TOF MRA和幅度对比MRA（MC MRA）。比较其图像质量和血管显示情况。结果 （1）实验研究：2D TOF MRA、MCA、CE MCA和3D CE MRA对明显狭窄（69％）的分级准确度分别为36.4%、9.1%、18.2%和72.7%，3D CE MRA对明显狭窄（≥50％）的评估优于其他MRA方法（P＜0.001），但比起真实值仍有明显高估（P＜0.001）。（2）临床应用：2D TOF MRA、MCA和3D CE MRA的动脉显示率分别为92.6％、94.4％和98.1％，以及对12例血管瘤的异常血管显示分别为0例、6例和11例。3D CE MRA均能较好地显示血管狭窄程度、供血血管起源、病变部位及病灶对血管的关系。结论 3D CE MRA无论是图像质量、狭窄程度的评估还是病灶的供血血管及病灶与血管关系的显示具有明显优势，但对狭窄程度的高估仍不可避免。

Evaluation of CE MRA, MCA and 2D TOF MRA for Peripheral Vascular Disease: An in vitro Experiment and Clinical Application

Objective　To evaluate different magnetic resonance angiography (MRA) sequences in detecting peripheral vascular disease by means of a study in vitro with an arterial stenotic model.　Materials and Methods　(1) study in vitro : 2D TOF, magnitude contrast (MC, with or without Gd-DTPA) and 3D contrast-enhanced MRA were performed in nonpulsatile stenotic experimental model. The degree, length of the stenosis and the accuracy of stenotic grading were measured, The results of MRA in detecting the degree and length of stenosis were compared with the findings on conventional angiography (CA) and the actual values. (2) Clinical application: 3D CE MRA, 2D TOF MRA and MC MRA were performed in 20 patients with suspected vascular disease in extremities. A comparison of image quality and the displaying of vessels was made between different MRA sequences. 　Results　(1) Study in vitro: The grading accuracy of 2D TOF MRA, MCA, CE MCA and 3D CE MRA for significant stenosis (69%) was 36.4%, 9.1%, 18.2% and 72.7%, respectively. 3D CE MRA was superior to other MRA sequences in assessing the degree of significant stenosis (≥50%), P＜0.001, though the value was still overestimated compared to the actual value (P＜0.001). (2) Clinical application: The displaying rate of the artery with 2D TOF MRA, MCA and 3D CE MRA was 92.6%, 94.4% and 98.1%, respectively. Of 12 hemangiomas, 2D TOF MRA, MCA and 3D CE MRA demonstrated 0, 6 and 11, respectively. 3D CE MRA could well display the vascular stenosis, the source of the lesion-feeding artery and the relationship of the lesion with the blood supply. 　Conclusion　3D CE MRA is obviously superior to other MRA techniques in obtaining high imaging quality, actually assessing the severity of the stenosis and observing the anatomy of the diseased vessels, although overestimation of the stenotic degree is difficult to avoid.