高频超声结合经颅多普勒诊断锁骨下动脉窃血综合征2例

例1,患者,男,51岁。2010-05-20来我院正常体检。高频超声探测颈部血管结果:双侧颈总动脉分叉处后壁动脉粥样硬化斑块形成(混合斑),双侧颈内动脉起始部后壁动脉粥样硬化斑块形成(软斑),右锁骨下动脉起始部后壁动脉粥样硬化斑块形成(软斑)。右侧椎动脉走行、内径、彩色血流方向未见异常,多普勒频谱血流速度略增高。但在检测左侧     

3D CE-MRA联合2D TOF MRA诊断锁骨下动脉盗血综合征

目的:回顾性分析3DCE-MRA联合2DTOFMRA对锁骨下动脉盗血综合征(SSS)的诊断价值.方法:选择3例已证实的SSS患者,应用施加上饱和脉冲的2D TOF MRA行颈部定位像扫描,3D CE-MRA行颈部MRA检查.分析颈部动脉病变及椎动脉(VA)血流方向.结果:3例SSS患者定位像上一侧VA均未见显示,3D CE-MBA均见显示,提示血流反向.3D CE-MRA示3例同侧锁骨下动脉近端起始部重度狭窄或闭塞;1例伴同侧ICA重度狭窄和对侧CCA中度狭窄.结论:3D CE-MRA联合施加上饱和脉冲的2D TOF MRA诊断SSS快速、准确、可靠;同时能提供更多颈部动脉病变信息.     

大脑前动脉粥样硬化性狭窄球囊成形术一例

患者男,57岁,因左侧肢体无力1个月于2008年3月24日入院就诊.CT检查示:右侧颞叶、顶叶梗死.造影示:右侧颈内动脉起始段闭塞,右侧椎动脉开口处及左侧大脑前动脉A1段开口狭窄(图1),左侧椎动脉颅内段动脉瘤;双侧椎动脉、左侧颈内动脉、右侧颈外动脉参与右侧大脑半球供血.首先行左侧椎动脉颅内段动脉瘤栓塞及右侧椎动脉开口处支架植入,分期全身麻醉下行左侧大脑前动脉A1段狭窄球囊扩张,扩张术后左大脑前动脉A1段狭窄消失(图2).术后患者左侧肢体无力症状缓解.22个月后造影复查示左侧大脑前动脉A1段管径正常,无再狭窄(图3).     

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。     

永存舌下动脉1例

患者男,57岁.因头晕半年来就诊.门诊查颅颈三维对比增强磁共振血管成像(3D CEMRA),示右侧颈总动脉分出颈外动脉后,颈内动脉节段性血管粗大,后分出1支异常血管(图1),向上走行,经枕骨髁前上方向颅内走行(图3),后与基底动脉吻合(图2),基底动脉远端于正常水平分出两侧大脑后动脉.此异常血管全程约5 cm,与右侧颈内动脉起始端及颈总动脉起始端距离分别约3.3 cm、15 cm.原两侧椎动脉全程明显狭窄,向上走行吻合成细小血管.     

彩色多普勒超声定位下压迫治疗介入后股动静脉瘘一例

患者男,76岁。因"左侧肢体无力4个月余,加重12h"于2008年1月1日入院,入院诊断"①多发性脑梗死;②高血压病1级极高危",入院后行头颈部64排CTA提示"①左侧椎动脉起始部局限性狭窄,狭窄程度80%以上;②双侧颈总动脉软斑块,血管腔最大狭窄程度40%以上;③右侧锁骨下动脉起始部软斑块,血管腔最大狭窄程度50%以上。"患者于入院后2周行"经股动脉全脑血管造影术 左侧椎动脉支架置入血管成形术",手术顺利,术后右下肢加压包扎,     

症状性永存三叉动脉1例

正患者男,39岁。因头晕1个月来我院就诊。颈、颅血管频谱多普勒超声提示右侧颈内动脉虹吸段血流速度增快,VS=137cm/s,频窗充填,声音粗糙(图1),余颅内动脉血流速度及频谱形态大致正常。头颅MRI及MRA检查,可见右侧颈内动脉海绵窦段后外侧壁发出一较粗大血管,沿鞍背右侧缘向后走行与基底动脉汇合,汇合部以下基底动脉及双侧椎动脉较细(图2)。颅脑MRI显示脑实质形态、信号未见明显异常。MRI诊断:永存三叉动脉。     

64层螺旋CT血管成像诊断椎动脉起源异常

目的 分析椎动脉起源异常的64层CT血管成像(CTA)表现,提高对该血管变异的认识.方法 回顾性分析135例经64层CTA诊断为椎动脉起源异常病人的影像学资料,分析椎动脉起源异常的发生率,起始血管及部位、起源异常椎动脉的行径及其合并症.结果 2757例行头颈64层CTA检查的病人中椎动脉起源异常的发生率为4.9%(135例病人136支椎动脉),其中左侧椎动脉起源异常133支(4.8%),右侧椎动脉起源异常3支;左侧椎动脉起源异常中,129支起源于主动脉弓,2例为重复畸形,1支起源于左侧颈内动脉,1支起于左锁骨下动脉根部.3支右侧椎动脉起源异常中,2支起自右侧颈总动脉,1支起源于头臂干.37例病人合并椎动脉行径异常(进入第4、5和7椎间孔);28支异常起源的椎动脉发育不良;5支起源异常椎动脉的远端游离(未与对侧椎动脉汇合);3例合并椎动脉-基底动脉成窗畸形,1例合并对侧椎动脉瘤.结论 64层CTA能清晰、快速、无创、准确地诊断椎动脉起源变异.     

对比剂增强的磁共振血管成像技术对比数字减影血管造影在颈部动脉诊断中的应用

目的：回顾性分析透视触发对化剂增强的磁共振血管成像（CE-MRA）技术对颈部血管的应用,与数字减影血管造影（DSA）对比,探讨其敏感性及应用价值。方法收集2011-2012年经MRA检查患者中临床表现有脑供血异常,疑颅内、颈内动脉或椎动脉狭窄、均进行透视触发CE-MRA和DSA检查的病例资料共28例进行分析。结果 CE-MRA检出狭窄部位30处,其中狭窄程度50％以上14处,完全闭塞6处,50％以下10处。 DSA检出狭窄部位28处,其中狭窄程度50％以上8处,完全闭塞4处,50％以下16处。2处MRA疑轻度狭窄,DSA未见异常;2处MRA示完全闭塞（颈内动脉）,而DSA示狭窄率90％以上。结论透视触发CE-MRA简便易行,敏感性与特异性均较高,可以作为可疑颈部及颅内动脉狭窄患者的首选检查方法。     

基于MR血管成像数据和快速原型技术建立类似于人颈内动脉虹吸段动脉瘤的犬模型

目的 建立载瘤动脉类似于人体颈内动脉虹吸段形态的犬动脉瘤模型.方法 用3.0 T MR行3维(3D)-时间飞跃(TOF)-MR血管成像(MRA)序列采集人头颅横断面医学数字图像通讯(DICOM)格式图像,导人Materialise Mimics和Pro-E软件重组,做出带孔管状3D数字模型.根据该文件利用快速原型技术制作出 TangoPlus材料的实体模型并硅胶涂层.分别将6只实验犬左侧颈总动脉远端和右侧颈总动脉近端结扎离断.将游离的左侧颈总动脉通过黑线牵引从下而上,游离的右侧颈总动脉从右剑左穿过模型,并从模型上的孔牵出.处理游离的双侧颈总动脉外膜后,行端侧吻合,得到形态类似于人颈内动脉虹吸段动脉瘤形态的动脉瘤模型.动物模型完成后即刻及1周MRA随访,1周行血管造影并置入测试支架测试.结果 6只犬均成功建立了形态类似于人颈内动脉虹吸段动脉瘤的动脉瘤模型.MRA显示6只犬的载瘤动脉通畅,显影良好.置人支架后1只犬死亡;5只术后1个月随访,模型内血管均通畅,其中3只弯曲处血管变扁,2 只无明显管腔形态改变.结论 制作的模型弯曲血管与人体颈内动脉虹吸段形态高度相似,可作为颅内神经介入材料及其输送系统的研究测试以及神经介入医师培训的工具.     

三维对比剂增强MR血管成像对颈部动脉病变的诊断价值

目的　分析三维对比剂增强MR血管成像 (3DCE MRA)显示的颈部动脉常见病变 ;与DSA比较 ,明确 3DCE MRA诊断颈部动脉病变的价值。方法　对 741例超声多普勒怀疑颈部动脉疾病的患者进行 3DCE MRA成像 ,并根据其病变表现总结分类。 2 0 6例病人同时行DSA检查 ,将颈部动脉分为颈总、颈内、颈外、锁骨下及椎动脉 5个部位 ,由 2位放射学专家独立评估DSA及 3DCE MRA血管资料。结果　 3 6 7%病例 (2 72 / 741)显示无异常。 63 2 9% (469/ 741)显示颈部动脉有病变 ,共计 82 7段 ,其中动脉粥样斑块占 3 4 2 2 % (2 83段 ) ,动脉狭窄占 3 4 46% (2 85段 ) ,动脉闭塞占 3 3 8% (2 8段 ) ,动脉发育纤细占 14 87% (12 3段 ) ;动脉开口变异占 3 87% (3 2段 ) ,动脉扭曲占 3 63 % (3 0段 ) ,动脉瘤占 0 72 % (6段 ) ,动脉夹层占 1 2 1% (10段 ) ,肿瘤包绕或推压动脉占 1 45% (12段 ) ,术后复查占2 18% (18段 )。对 2 0 6例的 412段血管与DSA比较 ,3DCE MRA在颈总动脉、颈内动脉及椎动脉的阳性检出率差异有显著性意义 (P <0 0 1) ,主要是对动脉粥样斑块 (2 56段与 2 83段 )和动脉狭窄 (2 58段与 2 85段 )存在一定的高估。但对 412段血管整个样本 ,两种方法在同一部位诊断各种血管病变差异无显著性意义 (P >0 0     

磁共振新技术在颈动脉狭窄诊断中的应用

目的研究增强磁共振血管成像（CE—MRA）技术的成像影响因素,评价MR扫描序列对颈动脉狭窄硬化斑块的应用价值,探讨颈动脉狭窄血流动力学变化与临床症状的联系。方法颈动脉狭窄34例,男22例,女12例。年龄36～78岁,平均56岁。病人首先经多普勒超声（DUS）检查,然后行MRA及CE-MRA。22例同时采用亮血（Bright—blood）、黑血（Black—blood）技术、3例行血流测量分析（Flow measurements）。10例于磁共振检查后1周内接受颈动脉狭窄内膜剥除术。扫描技术：（1）MRA及CE-MRA：MRA：二维时间飞跃法MRA（2D TOF MRA）;CE-MRA：快速梯度回波扫描技术,冠状位采集。最佳扫描延迟时间主要采用造影剂团注试验（test-bolus）法。3例采用时间分辨回波分享血管成像技术（TRATE）。（2）斑块检查序列：亮血与黑血技术及增强前后T1序列。（3）血流测量分析：横断位心电门控2D相位对比序列,Argus系统分析血流方向、流速。结果血管覆盖范围：34例CE-MRA,23例良好显示颈部血管起始段至入颅段。2D TOF法11例。动脉狭窄评估程度：10例手术患者中,CE-MRA正确诊断血管狭窄者9例,低估狭窄程度1例。2D TOF正确诊断血管狭窄程度6例,高估3例,低估1例。22例亮血、黑血技术结合CE—MRA清晰显示血管壁及动脉硬化斑块。颈动脉单独成像24例中,Test—bolus法团注造影剂最佳扫描延迟时间为峰值时间-1s,且监视层面定于主动脉弓者18例。4例眩晕患者,颈动脉狭窄侧后交通动脉（PCOA）显示2例;PCOA粗大1例。狭窄侧未显示PCOA,同侧大脑后动脉主干增粗1例。2例锁骨下动脉窃血综合征血流方向异常,1例无名静脉狭窄,同侧颈静脉血流方向异常。结论（1）CE—MRA能完整、全程显示颈部血管,准确诊断颈动脉、椎动脉狭窄。（2）Test-bolus法确定扫描延迟时间为峰值时间-1s,并将监视层面定于主动脉弓时,可保证造影剂在动脉内达到高峰浓度时采集K空间数据,获得颈动脉单独成像的最佳图像。（3）亮血、黑血技术结合CE-MRA有助于显示颈动脉狭窄硬化斑块。（4）分析、测量颈动脉狭窄的血流动力学变化能全面评价狭窄后血流改变与临床症状的联系。     

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。     

三维增强磁共振血管成像在糖尿病足病外周动脉病变中的应用

目的:探讨3D CE MRA在糖尿病足病外周动脉病变检查中的成像方法及应用价值。方法:对17例临床怀疑外周动脉病变的糖尿病足病患者,运用MR 3D FLASH自减影序列行CE MRA检查,检查范围自腹主动脉下段至足背动脉,对靶血管作最大强度投影(MIP)重组。另对其中4例小腿及足部动脉单独行二次增强扫描(Gd-DTPA 15ml,2.5ml/s)。对外周动脉进行观察,分析其狭窄情况并分级。结果:所有患者显示目标动脉基本满意,血管解剖形态较清晰,病变显示较明确。正常或轻度狭窄169个节段,中度狭窄94个节段,重度狭窄45个节段,闭塞49个节段。结论:3D CEMRA在糖尿病足病外周动脉病变检查中具有重要意义,但尚有一定局限性。     

Comparison of 3D TOF-MRA and 3D CE-MRA at 3 T for imaging of intracranial aneurysms

Purpose

To compare 3 T elliptical-centric CE MRA with 3 T TOF MRA for the detection and characterization of unruptured intracranial aneurysms (UIAs), by using digital subtracted angiography (DSA) as reference.

Materials and methods

Twenty-nine patients (12 male, 17 female; mean age: 62 years) with 41 aneurysms (34 saccular, 7 fusiform; mean diameter: 8.85 mm [range 2.0–26.4 mm]) were evaluated with MRA at 3 T each underwent 3D TOF-MRA examination without contrast and then a 3D contrast-enhanced (CE-MRA) examination with 0.1 mmol/kg bodyweight gadobenate dimeglumine and k-space elliptic mapping (Contrast ENhanced Timing Robust Angiography [CENTRA]). Both TOF and CE-MRA images were used to evaluate morphologic features that impact the risk of rupture and the selection of a treatment. Almost half (20/41) of UIAs were located in the internal carotid artery, 7 in the anterior communicating artery, 9 in the middle cerebral artery and 4 in the vertebro-basilar arterial system.All patients also underwent DSA before or after the MR examination.

Results

The CE-MRA results were in all cases consistent with the DSA dataset. No differences were noted between 3D TOF-MRA and CE-MRA concerning the detection and location of the 41 aneurysms or visualization of the parental artery. Differences were apparent concerning the visualization of morphologic features, especially for large aneurysms (>13 mm). An irregular sac shape was demonstrated for 21 aneurysms on CE-MRA but only 13/21 aneurysms on 3D TOF-MRA. Likewise, CE-MRA permitted visualization of an aneurismal neck and calculation of the sac/neck ratio for all 34 aneurysms with a neck demonstrated at DSA. Conversely, a neck was visible for only 24/34 aneurysms at 3D TOF-MRA. 3D CE-MRA detected 15 aneurysms with branches originating from the sac and/or neck, whereas branches were recognized in only 12/15 aneurysms at 3D TOF-MRA.

Conclusion

For evaluation of intracranial aneurysms at 3 T, 3D CE-MRA is superior to 3D TOF-MRA for assessment of sac shape, detection of aneurysmal neck, and visualization of branches originating from the sac or neck itself, if the size of the aneurysm is greater than 13 mm. 3 T 3D CE-MRA is as accurate and effective as DSA for the evaluation of UIAs.     

High-resolution carotid artery MRA. Comparison with fast dynamic acquistion and duplex ultrasound scanning

Purpose:
To determine whether the diagnostic accuracy of contrast-enhanced MR angiography (CE-MRA) of the carotid arteries is improved by using a slow-injection, high-resolution technique. Material and Methods:
In 22 patients suspected to have internal carotid artery (ICA) stenosis at duplex ultrasound scanning (DUS), CE-MRA was performed both with a fast, dynamic (8 s/phase) and with a slower, high-resolution technique (scan time 2:20 min). Results:
There was conformity between the CE-MRA techniques regarding the degree of stenosis in 34/40 extracranial ICAs. In 3/6 discrepant cases, short occlusions were seen with the fast dynamic technique, whereas both the high-resolution CE-MRA technique and DUS showed patent vessels. There was an overall tendency toward higher stenosis grading with the dynamic technique. Overlying veins could be removed on a workstation in all high-resolution examinations. Conclusion:
The high-resolution carotid CE-MRA technique proposed herein seems to improve the diagnostic accuracy, at least for differentiation between high-grade stenoses and occlusions.     

Noncontrast 3D steady-state free-precession magnetic resonance angiography of the whole chest using nonselective radiofrequency excitation over a large field of view: comparison with single-phase 3D contrast-enhanced magnetic resonance angiography

OBJECTIVES: To evaluate the feasibility of three-dimensional (3D) steady-state free-precession (SSFP) magnetic resonance angiography (MRA) using nonselective radiofrequency excitation in the assessment of cardiac morphology, thoracic aorta, main pulmonary, and proximal coronary arteries. MATERIAL AND METHODS: Thirty consecutive patients (19 males; 11 females; age range, 20-74) with various cardiac and thoracic vascular diseases underwent free-breathing respiratory navigator-gated electrocardiogram-triggered noncontrast SSFP MRA and conventional high-resolution 3D contrast-enhanced MRA (CE-MRA) of the thorax at 1.5 T. Two readers evaluated both datasets for findings, vascular delineation and sharpness (from 0, not visualized to 3, excellent definition), artifacts, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in 14 vascular segments including aorta, supra-aortic, pulmonary, and coronary arteries, and in cardiac chambers. Statistical analysis was performed using Wilcoxon test for vessel delineation, and [kappa] coefficient for interobserver variability. RESULTS: 3D SSFP and CE-MRA were successfully performed in all patients. Scan time for SSFP MRA ranged from 5 to 10 minutes (mean +/- standard deviation, 7 +/- 2 minutes). On SSFP MRA, readers 1 and 2 graded 233 (97.1%) and 234 (97.5%) coronary arterial segments and cardiac chambers, and 275 (91.7%) and 278 (92.7%) noncoronary arterial segments with diagnostic definition (grades 2 and 3) (k = 0.86). On conventional CE-MRA, readers 1 and 2 graded 10 (4.2%) and 12 (5%) coronary arterial segments and cardiac chambers, and 272 (90.7%) and 270 (90%) noncoronary arterial segments with diagnostic definition (grades 2 and 3) (k = 0.89). Segmental visibility was higher for aortic root, pulmonary trunk, proximal coronary arteries, and heart chambers (P < 0.001), and lower for supra-aortic arteries (P < 0.001) on SSFP MRA for each reader. SNR and CNR values were higher for aortic root and aorta on SSFP MRA (P < 0.001 for both). No significant difference existed between SNR and CNR values for the other vascular segments and cardiac chambers on SSFP and CE-MRA (P > 0.05 for all). The 2 readers demonstrated vascular stenosis and dilatation/aneurysm in 7 and 35 segments on both datasets, respectively. CONCLUSION: Noncontrast 3D SSFP MRA with nonselective radiofrequency excitation provides high image quality and sufficient SNR and CNR for confident assessment of cardiac and thoracic vascular diseases including congenital heart diseases. Our results suggest that noncontrast SSFP MRA outperforms CE-MRA in visualization of cardiac chambers, proximal coronary arteries, pulmonary trunk, and aortic root.     

3 T contrast-enhanced magnetic resonance angiography for evaluation of the intracranial arteries: comparison with time-of-flight magnetic resonance angiography and multislice computed tomography angiography

PURPOSE: We sought to prospectively evaluate the image quality and visualization of the intracranial arteries using high spatial resolution contrast-enhanced magnetic resonance angiography (CE-MRA) at 3 T and to perform intraindividual comparison with time-of-flight (TOF) MRA and multislice CT angiography (CTA). MATERIALS AND METHODS: Twelve patients (5 men, 7 women, 37-71 years of age) with suspected cerebrovascular disease prospectively underwent MRA and CTA. MRA was performed on a 3 T MR system, including both 3-dimensional (3D) TOF (Voxel dimension: 0.6 x 0.5 x 0.9 mm in 5 minutes and 40 seconds) and 3D CE-MRA (voxel dimension: 0.7 x 0.7 x 0.8 mm in 20 seconds, using parallel acquisition with an acceleration factor of 4). CTA images were acquired on a 16-slice CT scanner (voxel dimension: 0.35 x 0.35 x 0.8 mm in 17 seconds). The image quality and visualization of up to 26 intracranial arterial segments in each study was evaluated by 2 experienced radiologists. The arterial diameter for selective intracranial arteries was measured independently on each of the 3 studies, and statistical analysis and comparative correlation was performed. RESULTS: A total of 312 arterial segments were examined by CE-MRA, TOF-MRA, and CTA. The majority of intracranial arteries (87%) were visualized with diagnostic image quality on CE-MRA with a significant correlation to TOF (R values = 0.84; 95% confidence interval 0.79-0.86, P < 0.0001), and to CTA (R values = 0.74; 95% confidence interavl 0.68-0.78, P < 0.001). The image quality for small intracranial arteries, including the anterior-inferior cerebellar artery, the posterior communicating artery, and the M3 branch of the middle cerebral artery, was significantly lower on CE-MRA compared with TOF and CTA (P < 0.03). There was a significant correlation for the dimensional measurements of arterial diameters at CE-MRA with TOF (r = 0.88, 95% confidence interval 0.81-0.93), and CTA (r = 0.83, 95% confidence interval 0.73-0.90). CONCLUSION: The described 3 T CE-MRA protocol, spanning from the cervical to the intracranial vessels, visualized and characterized the majority of intracranial arteries with image quality comparable with that obtained using TOF-MRA and CTA. Further clinical studies are required to establish the accuracy of the technique in a broader clinical setting.     

3D contrast-enhanced MR angiography of the abdominal aorta and its distal branches: Interobserver agreement of radiologists in a routine examination

RATIONALE AND OBJECTIVES: To evaluate the quality of images of the aorta and visceral arteries made at a high level of spatial resolution with thin slices and an optimized acquisition time by three-dimensional contrast-enhanced magnetic resonance angiography (3D CE-MRA). MATERIALS AND METHODS: 3D CE-MRA with a 1.4-mm slice thickness and 512-pixel base matrix was done on 62 consecutive patients with a 1.5-T magnetic resonance imaging MRI unit. A bolus test with a power injector was used to calculate the optimal scan delay time. For quantitative evaluation, the signal-to-noise ratio (SNR) was measured in 3 regions of interest. Qualitative image analysis was evaluated independently by two radiologists and graded on a scale of 0-3. Separate analyses were done for the aorta and distal visceral arterial branches. RESULTS: The means SNR values were respectively 56.2 +/- 15.2 (mean +/- SD) for the aorta, 59.2 +/- 15.1 for the celiac trunk, and 57 +/- 15.2 for the superior mesenteric artery, with a homogeneous distribution (P = .99). Consistent enhancement was confirmed by the lack of statistically significant differences between the SNR values. The average score for vessel visualization on source images ranged from good to excellent for different segments. After post-processing of images, the average score for distal arterial segments was significantly improved. The overall agreement between the 2 reviewers in the visualization of definite artery segments was excellent (k = .91). CONCLUSION: 3D CE-MRA with a 512-pixel base matrix and thin slices can be applied in a reproducible way with excellent depiction and delineation of small vessels. Such a protocol could be used routinely.     

3.0T高分辨率CE-MRA对颈部血管狭窄的诊断价值

目的探讨三维对比增强磁共振血管成像(3D CE-MRA)在颈部动脉血管狭窄诊断中的临床应用价值。方法对23例临床拟诊颈部动脉血管狭窄行数字减影血管造影(DSA)的患者行颈部3D CE-MRA。将两种方法检查结果进行相关性比较。结果 23例患者共230个节段血管,3D CE-MRA显示了227个节段,共诊断出74处(32.6%)狭窄,其中28处轻度狭窄,22处中度狭窄,20处重度狭窄,4处闭塞;DSA共显示了230个节段的血管,共诊断出69处(30.4%)血管狭窄,其中24处轻度狭窄,23处中度狭窄,19处重度狭窄,3处闭塞。与DSA相比,3DCE-MRA对颈部动脉轻度、中度、重度狭窄及动脉闭塞的显示敏感性均为100%,特异性分别为85.71%、90.91%、90%和75%,两种检查方法对颈部动脉狭窄程度的判断有良好的一致性(κ=0.921,P=0.000)。结论 3.0T 3DCE-MRA能够可靠的评价颈部动脉狭窄性病变,基本可以替代DSA检查。