32接收通道并行采集全身MR血管成像技术的临床应用初探

目的初步探讨32接收通道并行采集全身MR血管成像技术在系统性动脉病变中的临床使用价值。方法30例接受三维增强全身MR血管成像(3D CE MRA)检查。仪器为1.5 T成像仪(M agnetom Avanto,S iem ens AG)配置32个接收通道和并行采集技术。病例包括临床诊断或怀疑的周围动脉闭塞性病变(PAOD)17例,多发性大动脉炎3例,结节性多动脉炎1例,Stanford B型夹层4例以及胸和(或)腹主动脉瘤5例。共使用68个表面线圈单元包绕患者全身。3D CE MRA共分4段采集,每段视野(FOV)为375 mm×500 mm,通过自动移床分段扫描,第1~3段使用并行采集技术。对比剂用量为0.3 mmol/kg,分两相注射,前0.15 mmol/kg注射流率为1.3 m l/s,后0.15 mmol/kg注射流率为0.6 m l/s。总的扫描长度约188 cm,覆盖颈动脉到小腿动脉分支(不包括颅内动脉和冠状动脉)。分析每段动脉的图像质量、各种动脉血管病变的显示效果,并同其他影像检查对照(包括DSA 9例,CT血管造影8例,单段MRA 1例)。结果所有病例均顺利完成全身3D CE MRA检查。动脉图像质量好,平均检查时间为17.4 m in。17例PAOD患者中发现70段下肢动脉病变,其中7例3D CE MRA显示了除下肢动脉病变以外的其他部位动脉狭窄。4例血管炎患者3D CE MRA显示全身多处动脉管腔不规则、狭窄或闭塞、动脉瘤以及侧支血管。3D CE MRA还清楚显示夹层和动脉瘤的严重程度和范围。与其他血管成像技术比较,除1例3D CE MRA高估血管狭窄程度外,其他均相符合。结论配置了32个接收通道和并行采集技术的新型MR成像仪能顺利完成全身3D CE MRA检查,该法操作简便,检查时间短,在全面显示各种系统性动脉病变的临床使用方面有重要价值。     

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。     

肾动脉高分辨力三维增强磁共振血管成像术:透视触发和并行采集技术使用初探

目的:评估透视触发和并行采集技术用于肾动脉高分辨力三维增强磁共振血管成像术的可行性和对肾动脉的显影诊断效果。方法:90例临床诊断或怀疑肾动脉或腹主动脉病变的患者行高分辨力肾动脉三维增强磁共振血管成像(3D CE MRA)。使用透视触发软件启动肾动脉3D CE MRA扫描,扫描采用K空间中心填充法和加速因子为2的并行采集技术。分析图象质量和病变显示情况,并与其它检查结果对照。结果:肾动脉3D CE MRA显示了90例患者共810支动脉段(100%显示率),平均显示等级为3.88。3D CE MRA显示8例11支副肾动脉,显示等级均为4.0。肾动脉段级分支的显示率为73%(66/90例)。所有病例在动脉显示区静脉均未显影或显影很淡,平均等级为0.20。3D CE MRA发现639支动脉段正常;66支动脉段管壁不规则;55支动脉段轻度狭窄;37支动脉段严重狭窄;2支动脉段闭塞;11支动脉段动脉瘤形成。其中96支肾动脉存在狭窄,11支副肾动脉均正常。共有43例病例,肾动脉3D CE MRA与其它血管成像技术作了比较,3D CE MRA的检查结果与之完全符合。结论:透视触发并行采集肾动脉高分辨力3D CE MRA简单可行,成像时间短,空间分辨力高,能清楚显示肾动脉且无静脉污染。     

多站式三维动态增强磁共振下肢血管造影成像技术进展

随着磁共振血管成像（MRA）技术不断发展成熟,多站式三维动态对比增强血管成像（3D CE MRA）应用于下肢动脉病变检查,可获得高信噪比及高分辩率的下肢血管图像,并具有无辐射、无创性、无肾毒性等优点,成为诊断下肢动脉疾病的重要检查方法,具有广阔临床前景。本文对下肢3D CE MRA的技术进展进行综述。     

MR快速多时相造影增强与时间飞跃血管成像在颈部血管疾病中诊断价值的对比研究

目的　对比研究磁共振时间飞跃血管成像 (timeofflightmagneticresonanceangiograhy,TOF MRA)与快速多时相造影增强成像 (contrastenhancemagneticresonanceangiography ,CE MRA)在颈部血管疾病中的诊断价值。方法　临床怀疑颈部血管疾病患者 12 6例 ,同时进行颈部TOF MRA和CE MRA检查 ,所有病例均行DSA或者手术 ,并以此为金标准对TOF MRA和CE MRA的图像质量 [信噪比(SNR)、对比噪声比 (CNR)、伪影 ]、颈总动脉分叉区狭窄诊断 (准确性、特异性、敏感性 )及其在血管畸形中的诊断价值进行对比研究。结果　经DSA或手术证实阳性病例共 89例 (动脉瘤 3例、动静脉畸形 2例、颈总动脉分叉区动脉硬化狭窄 84例 ,共 12 2处狭窄 ) ,CE MRA在颈总动脉分叉区的SNR、CNR分别为 2 0 94± 2 5 7、11 10± 3 84 ,TOF MRA为 12 5 5± 1 71、2 70± 0 74 ,二者差异具有显著性意义 (t值分别为 13 36和 11 5 0 ,P值均 <0 0 0 1)。 12 6例的TOF MRA均出现伪影 ,而CE MRA未发现伪影。CE MRA对颈总动脉分叉区狭窄诊断特异性为 99 2 3% ,TOF MRA为 2 1 5 4 % ,二者差异具有显著性意义 (χ2 =12 0 85 ,P <0 0 0 1) ;CE MRA对颈总动脉分叉区狭窄诊断的敏感度为 90 88% ,TOF MRA为93 4 4 % ,二者差异无显     

多种MR血管造影对四肢血管性疾病和血管狭窄模型的应用研究

目的：通过多种MR血管影影技术在模拟狭窄血管的体外模型和四肢血管性疾病中的应用分析,评估其价值和限度。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磁共振血管造影（2D TOF MRA）、幅度对比磁共振血管造影（MCA）、增强（CE）MCA和三维增强磁共振血管造影（3D CE MRA）,测量并计算狭窄程度、长度及其对狭窄程度评估的准确性。（2）临床应用：对20例四肢血管性疾病的患者行3D CE MRA、2D TOF MRA和MC MCA,其中血管瘤12例,动脉粥样硬化4例,假性动脉瘤1例,脂肪瘤1例,骨转移瘤1例,动脉破裂修补术1例,均经手术病理证实。比较上述MRA的图像质量和血管显示情况。结果：（1）实验结果：2D TOF MRA、MCA、CE MCA和3D CE MRA对管腔狭窄程度为69％的分级准确性分别为36．4％、9．1％、18．2％和72．7％,3D CE MRA对狭窄＞69％的评估优于其他MRA方法（P＜0．001）,但比起真实值仍有高估（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％;对12例血管瘤的异常血管显示分别为0例、6例和11例。结论：3D CE MRA无论对图像质量、狭窄程度的评估还是对病灶的供血血管及病灶与血管关系的显示均具有明显优势,但对狭窄程度的高估仍不可避免。     

3.0T MR多技术联合应用在头颈部动脉血管狭窄病变中的诊断价值

目的:分析3.0T MR 3D TOF MRA、高分辨CE MRA、双反转恢复颈动脉血管壁黑血成像在头颈部动脉血管狭窄病变检查中的技术特点,探讨其联合应用在头颈部动脉血管狭窄病变中的诊断价值。方法:研究所用技术经医院伦理委员会审查批准,向患者认真介绍后由患者签字同意。选择2009年5月~2009年6月在我院行头颈部TOF MRA检查患者95例,其中43例并行头颈部CE MRA检查,另52例并行颈动脉分叉部双反转恢复T2WI血管壁黑血成像。统计同时行TOF MRA和CE MRA患者组中两种技术完成的图像中脑血管、颈内动脉虹吸段、颈动脉分叉部、椎动脉起始部等多个部位动脉血管狭窄数量,对两种技术诊断结果行Kappa一致性检验。统计同时行TOF MRA和DIR颈动脉分叉部血管壁黑血成像患者组中狭窄血管数量,对两者行χ2检验判断有无统计学差异。结果:行头颈部TOF MRA和CE MRA患者组,各部位诊断结果Kappa值分别为:大脑前动脉A1段0.710,大脑中动脉M1段0.823,大脑后动脉P2段0.672,颈内动脉虹吸段0.729,颈动脉分叉部0.634,椎动脉起始部0.707。行头颈部TOF MRA和颈动脉分叉部DIR T2WI黑血血管壁成像患者组,两者诊断结果χ2=1.11,P0.05,无统计学差异。结论:3D TOF MRA和CE MRA技术均可明确诊断绝大部分头颈部动脉血管狭窄病变,但也有各自的不足,颈动脉血管壁黑血成像可明确诊断有无粥样硬化斑块形成,是对头颈部MRA成像的有效补充,三者的合理应用及结合可以从多方面来诊断头颈部血管狭窄性病变,弥补相互间的不足。     

三维动态增强MR血管成像的临床应用价值

目的 评价三维动态增强扫描MR血管成像(3D CEMRA)技术的临床应用价值. 资料与方法 评价3D CE MRA 对18例患者血管的显示情况. 结果 3D CE MRA 显示2例动脉狭窄或闭塞,2例静脉增粗、迂曲,5例显示血管瘤,3例血管畸形,1例右侧股骨下段骨肉瘤周边紊乱血管,5例正常. 结论 3D CE MRA可显示正常血管及异常.     

iPass技术在CE-MRA中的应用

目的　探讨iPass技术在增强MR血管成像 (CE MRA)的临床应用价值。资料与方法　 18例行CE MRA患者 ,男 12例 ,女 6例。其中腹部血管成像 15例 ,颈部血管成像 2例 ,股动脉成像 1例。CE MRA前 ,注射 2ml对比剂行iPass测试。扫描层面位于CE MRA冠状视野的远心端 1/ 3处 ,饱和板置于测试平面的近心端 ,iPass扫描1帧 /s,实时图像显示 ,同步绘制血管内信号强度 时间曲线 ,自动将曲线上升段超出基线 30 %的时间记为对比剂到达时间 ,自动将到达时间载入CE MRA序列 ,根据到达时间决定扫描延迟时间进行CE MRA扫描。原始图像减影后行最大信号强度投影 (MIP)重建 ,评价重建血管图像质量。结果　 17例一次顺利完成iPass测试和CE MRA ,1例首次未能测出峰值曲线 ,调整感兴趣区 (ROI)后 ,再行注射后测试成功 ,完成CE MRA。MIP血管图像质量评分 3.72±0 .5 7。结论　iPass测试可以提供较准确的对比剂到达时间 ,可以自动控制CE MRA的扫描延迟时间 ,有利于提高CE MRA的图像质量     

非增强MRA诊断下肢动脉病变的应用研究

目的：探讨QISS非增强MRA技术诊断下肢动脉闭塞性病变的临床应用价值。方法：51例下肢动脉病变患者行双下肢QISS-MRA和CE-MRA扫描,评价两种检查方法的图像质量,并以CE—MRA为参照标准,计算QISSMRA诊断下肢动脉显著性狭窄（≥50％）的敏感度、特异度、阳性预测值、阴性预测值和诊断准确性,并以配对χ2检验分析两种检查方法对诊断下肢动脉显著性狭窄（≥50％）的差异有无统计学意义,两种检查方法的相关性采用kappa检验。结果：51例中48例成功行QISS-MRA检查,其中图像质量优、良、差者分别为40（78．43％）、8（15．69％）和3例（5．88％）。按血管节段计算,QISS-MRA诊断下肢动脉显著性狭窄的敏感度和特异度分别为90．15％和98．87％,阳性预测值和阴性预测值分别为96．75％和96．42％,总体符合率为95．91％。对于下肢动脉显著性狭窄的诊断,QISS-MRA与CE-MRA的差异无统计学意义（χ2=3．76,P〉0．05）,且两种检查方法具有极好的相关性（r值为0．950,P〈0．001）。结论：QISS-MRA检查成功率较高、图像质量良好并且诊断效果接近CE—MRA,对诊断下肢动脉闭塞性病变有一定的临床应用潜力。     

透视触发并行采集高分辨率三维增强颈动脉磁共振血管成像术

目的评估透视触发和并行采集技术用于高分辨率三维增强颈动脉磁共振血管成像术(3DCEMRA)的可行性。方法80个临床诊断或怀疑颈动脉狭窄的病人接受3DCEMRA检查。使用透视触发软件触发启动颈动脉3DCEMRA扫描,同时采用K空间椭圆形中心填充法和加速因子为2的并行采集技术。对显示的各段动脉和有无静脉早期显影做分析。动脉狭窄分成动脉管壁不规则、轻度狭窄、严重狭窄和闭塞。颈动脉3DCEMRA的显示结果与其他检查结果做了对照。结果所有病例均顺利触发和完成颈动脉3DCEMRA检查。3DCEMRA显示了80例病人总共800支动脉段(100%显示率),所有病例在动脉显示区域内静脉均未显影或显影很淡,对诊断不构成影响。结果显示有680段动脉正常、41段动脉管壁不规则、24段动脉轻度狭窄、51段严重狭窄和4段闭塞。另外10段颈动脉狭窄处溃疡形成,12例患者除见颈动脉狭窄以外,还发现合并椎动脉和/或锁骨下动脉狭窄。36例病例,与其他血管成像技术作了比较,3DCEMRA的检查结果与之完全符合,未出现高估或低估血管狭窄程度。结论透视触发并行采集高分辨率3DCEMRA简单可行,成像时间短,空间分辨率高,能清楚显示颈动脉,它将在颈动脉狭窄的诊断中起重要作用。     

手动移床磁共振下肢动脉3D CE MRA技术及临床应用

目的：探讨手动移床磁共振下肢血管成像技术及其临床应用价值。方法：应用3D小角度激发快速梯度回波序列（3D FLASH）,对23例疑有下肢血管病变的患者,行磁共振下肢血管成像。使用Siemens Symphony 1.5T超导型磁共振扫描仪,使用头线圈及体表面线圈进行扫描,手动移床三段采集双下肢动脉血管图像,重组方法为MIP及MPR。结果：23例患者均获成功,其中16例经DSA证实,3D CE MRA图像直观、完整地显示腹、盆腔和下肢动脉结构和血管病变部位及范围。结论：手动移床磁共振下肢血管成像能较好的显示下肢动脉病变的范围和程度,快速、安全、有效,有利于血管疾病的检出,可以为临床提供更丰富的信息。     

Contrast-enhanced MR angiography of the carotid and vertebrobasilar circulations

BACKGROUND AND PURPOSE: Contrast-enhanced MR angiography (CE MRA) is a proven diagnostic tool in evaluation of the carotid arteries; however, few studies have addressed its accuracy in the vertebrobasilar system. The purpose of this study was to assess the sensitivity and specificity of CE MRA compared with digital subtraction angiography (DSA) for detection of vertebrobasilar disease. METHODS: Forty patients with suspected atherosclerotic disease of the carotid and vertebrobasilar circulations underwent CE MRA on a 1.5 T MR imaging scanner by use of a coronal 3D gradient-echo pulse sequence after intravenous injection of gadolinium diethylene triamine penta-acetic acid. All patients had correlative DSA within a 1-month period. CE MRA images were randomized and then independently assessed by 2 observers who were blinded to the DSA results. DSA examinations were analyzed in a similar manner. Each observer was asked to report the presence or absence of clinically significant stenosis (>50%), occlusion, fistula, aneurysm, and dissection. The MRA findings were then correlated with DSA. RESULTS: The sensitivity and specificity of MRA for detection of disease in the entire carotid and vertebrobasilar systems were 90% and 97%, respectively; for the carotid system alone, the sensitivity and specificity were 94% and 97%, respectively; and for the vertebrobasilar system they were 88% and 98% respectively. The overall interobserver reliability was 98% (kappa = 0.92). CONCLUSION: CE MRA is accurate at detecting disease not only in the carotid vessels, but also in the vertebrobasilar circulation, and has the potential to provide a comprehensive and noninvasive evaluation of the head and neck arteries in a single study.     

High temporal and spatial resolution imaging of peripheral vascular malformations

Purpose:

To assess the performance of a recently developed 3D time‐resolved CE‐MRA technique, Cartesian Acquisition with Projection‐Reconstruction‐like sampling (CAPR), for accurate characterization and treatment planning of vascular malformations of the periphery.

Materials and Methods:

Twelve patient studies were performed (eight female, four male; average age, 33 years). The protocol consisted of three‐dimensional (3D) time‐resolved CE‐MRA followed by a single late phase T1‐weighted acquisition. Vascular malformations were imaged in the forearm, hand, thigh, and foot. Imaging evaluation was performed for accurate characterization of lesion type, identification of feeding and draining vessels, involvement with surrounding tissue, overall quality for diagnosis and treatment planning, and correlation with conventional angiography.

Results:

Time‐resolved CE‐MRA allowed for characterization of malformation flow and type. Feeding and draining vessels were identified in all cases. Overall quality for diagnosis and treatment planning was 3.58/4.0, and correlation with conventional angiography was scored as 3.89/4.0.

Conclusion:

The CAPR time series has been shown to portray the temporal dynamics and structure of vascular malformations as well as the normal vasculature with high quality. CAPR time‐resolved imaging is able to accurately characterize high and low flow lesions, allowing for pretreatment lesion assessment and treatment planning. Delayed imaging is important to capture complete filling of very slow flow vascular malformations. J. Magn. Reson. Imaging 2012;36:933–942. © 2012 Wiley Periodicals, Inc.     

3D TRICKS MRA对颈动脉粥样硬化狭窄的诊断价值

目的：探讨3D TRICKS MRA对颈动脉粥样硬化狭窄的诊断价值。方法：对43例临床疑诊颈动脉粥样硬化狭窄的患者行2D TOF MRA和3D TRICKS MRA检查,其中31例同期行DSA检查,以颈总动脉法（CC法）计算狭窄率。结果：颈动脉闭塞2支,重度狭窄10支,中度狭窄31支,轻度狭窄25支,正常18支。2D TOF MRA、3D TRICKS MRA与DSA对照,显示狭窄部位均与DSA所示相符。2D TOF MRA高估狭窄程度6支,3D TRICKS MRA高估狭窄程度1支。以DSA为标准,2D TOF MRA诊断颈动脉狭窄的敏感度、特异度、诊断符合率分别为91.6%,85.7%,90.3%（K=0.737）;3D TRICKS MRA诊断颈动脉狭窄的敏感度、特异度、诊断符合率分别为97.9%,100%,98.4%（K=0.955）。两种方法对诊断颈动脉狭窄的敏感度、特异度和诊断符合率差异均具有统计学意义（P〈0.05）。结论：3D TRICKS MRA与DSA对评估颈动脉粥样硬化狭窄具有极好的一致性（K=0.955）,明显优于2D TOF MRA（K=0.737,P〈0.05）,是对颈动脉粥样硬化狭窄筛查、术前评估、术后随访的最佳检查方法,能基本替代DSA检查。     

Noncontrast MR angiography for comprehensive assessment of abdominopelvic arteries using quadruple inversion-recovery preconditioning and 3D balanced steady-state free precession imaging

Purpose:

To develop a noncontrast magnetic resonance angiography (MRA) method for comprehensive evaluation of abdominopelvic arteries in a single 3D acquisition.

Materials and Methods:

A noncontrast MRA (NC MRA) pulse sequence was developed using four inversion‐recovery (IR) pulses and 3D balanced steady‐state free precession (b‐SSFP) readout to provide arterial imaging from renal to external iliac arteries. Respiratory triggered, high spatial resolution (1.3 × 1.3 × 1.7 mm³) noncontrast angiograms were obtained in seven volunteers and ten patients referred for gadolinium‐enhanced MRA (CE MRA). Images were assessed for diagnostic quality by two radiologists. Quantitative measurements of arterial signal contrast were also performed.

Results:

NC MRA imaging was successfully completed in all subjects in 7.0 ± 2.3 minutes. In controls, image quality of NC MRA averaged 2.79 ± 0.39 on a scale of 0–3, where 3 is maximum. Image quality of NC MRA (2.65 ± 0.41) was comparable to that of CE MRA (2.9 ± 0.32) in all patients. Contrast ratio measurements in patients demonstrated that NC MRA provides arterial contrast comparable to source CE MRA images with adequate venous and excellent background tissue suppression.

Conclusion:

The proposed noncontrast MRA pulse sequence provides high‐quality visualization of abdominopelvic arteries within clinically feasible scan times. J. Magn. Reson. Imaging 2011;33:1430–1439. © 2011 Wiley‐Liss, Inc.     

磁共振脑静脉系血管成像技术及其临床应用

目的探讨磁共振脑静脉系血管成像的技术方法和最佳扫描方案，评价磁共振静脉系血管成像技术(MR venography，MRV)对静脉系疾病的诊断价值及临床意义。方法采用二维时间飞跃法MR血管造影(2D-TOF-MRA)、二维相位对比血管造影(2D-PCA)和三维对比增强MR血管造影(3D-CE-MRA)3种血管成像技术分别对20例健康志愿者和20例临床或MRI疑有静脉系疾病的患者行MRV成像，并采用最大强度投影(MIP)、多平面或曲面重建(MPR)及数字减影MRA(DSMRA)技术对图像进行后处理，观察脑静脉系在MRV中的显示情况及脑静脉系疾病在MRV中表现形式，制定脑静脉系成像的最佳方案。结果本组经3D-CE-MRA静脉系成像诊断为13例颅内静脉窦血栓形成(CVST)及7例颅内肿瘤累及静脉系的阳性显示率为100％，均经临床治疗复诊及手术证实。2D-PCA及2D-TOF-MRA对细小引流静脉显示欠佳，且2D-TOF-MRA对复杂区域内静脉血管亦显示欠佳。结论3D-CE-MRA结合2D-PCA及2D-TOF-MRA静脉成像技术形成全脑静脉系成像，为脑静脉系的最佳成像方案，对临床术前评估和指导治疗有极其重要的意义。     

Comparison of image quality, diagnostic confidence and interobserver variability in contrast enhanced MR angiography and 2D time of flight angiography in evaluation of carotid stenosis

The aim of this study was to compare image quality, level of diagnostic confidence and interobserver agreement in assessment of carotid stenosis with contrast enhanced MR angiography (CE MRA) in comparison with 2D time of flight MR angiography (2D TOF MRA). 60 carotid arteries in 30 patients were examined by three observers. Image quality and diagnostic confidence were assessed on the basis of a visual analogue scale. Interobserver variability was assessed with the help of intraclass correlation coefficient. Median values on the visual analogue scale for image quality and diagnostic confidence were higher for CE MRA compared with 2D TOF MRA for all three observers. Higher intraclass correlation values were recorded for interobserver variability for CE MRA compared with 2D TOF MRA both for visual estimation of carotid stenosis as well as for measurement of carotid stenosis on the basis of North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST) criteria. CE MRA provides better image quality, higher level of diagnostic confidence and more interobserver agreement compared with 2D TOF MRA.