非对比剂增强的MRA技术对肾动脉的评估价值

目的 评价非对比剂增强的磁共振血管成像(NCE-MRA)技术对肾动脉解剖变异的临床诊断价值.资料与方法 30例患者先后使用同一设备进行NCE-MRA和对比剂增强磁共振血管成像(CE-MRA)扫描后获取肾动脉血管的影像解剖图像,分别由两位医师对每例图像质量进行技术评分,然后评价两种方法对于血管的显示价值.结果 NCE-MRA组和CE-MRA组中,图像质量为3分以上者分别占93.3%(28/30)和96.7%(29/30);两者显示共60个单肾的肾动脉血管的符合率为97%(57/60),均没有出现假阳性病例,NCE-MRA方法出现假阴性3个.两种方法差异无统计学意义(P＞0.05),并且两位诊断医师的一致性较高,Kappa值均＞0.75.结论 NCE-MRA是一种无需使用对比剂、非侵人性的MRA技术,可以有效地用于肾动脉评估.     

类风湿性关节炎手部非增强磁共振血管成像技术研究

目的:研究基于血流敏感散相的平衡稳态自由进动序列的非增强磁共振技术(FSD-bSSFP NC-MRA,FSD-bSSFP)在类风湿性关节炎手部血管成像的应用价值。方法:20例类风湿性关节炎患者采用FSD-bSSFP序列及增强MRA成像(CE-MRA)进行手部血管成像。由2名5年以上MRI诊断经验的放射科医师测量两种成像方式获得手部动脉血管影像的信噪比(SNR)、对比噪声比(CNR),并对图像质量、静脉污染及手部动脉及分支显示情况进行评分。结果:入组病例17例。FSD-bSSFP序列SNR高于CE-MRA(t=3.707,P<0.05),FSD-bSSFP序列与CE-MRA显示手部血管成像CNR无显著性差异(t=0.600,P>0.05);FSD-bSSFP序列动脉图像质量评分高于CE-MRA(Z=-2.271,P<0.05),静脉污染程度低于CE-MRA(Z=-2.722,P<0.05),动脉分支显示评分无统计学差异(Z=-1.027,P>0.05)。结论:FSD-bSSFP技术应用于类风湿性关节炎患者可获得较好的手部血管成像,避免对比剂对肾脏的潜在损害。     

非对比剂增强MR血管成像技术在肝动脉血管成像中的应用价值

【摘要】目的：以CTA为对照,探讨基于多反转空间标记脉冲技术的非对比剂增强MR血管成像技术（SLEEK-MRA）在肝动脉血管成像中的应用价值。方法：37例同时行CTA及SLEEK-MRA检查的临床怀疑肝脏占位患者纳入研究,CTA检查后7天内行SLEEK-MRA检查。由两位腹部影像诊断医师分别对CTA和SLEEK-MRA图像进行独立评估,评估内容包括四分法图像质量主观评价及最大显示分支级别评估。比较CTA与SLEEK-MRA在肝动脉成像图像质量及最大显示分支级别上的差异。结果：两位医师对CTA及SLEEK-MRA图像质量评分的一致性均为良好及以上（Kappa值:CTA为0.645~0.814;SLEEK-MRA为0.633~0.877）。除肝左动脉一级分支和肝右动脉一级分支外,SLEEK-MRA与CTA两种方法在肝总动脉、肝固有动脉、肝左动脉及肝右动脉血管成像图像质量评分上差异均无统计学意义（P值均>0.05）。CTA显示最大分支级别的能力优于SLEEK-MRA（P=0.020）。37例病例中,CTA显示有7例出现肝动脉变异,SLEEK-MRA显示了其中6例。结论：SLEEK-MRA作为一种无创、无辐射、无需使用对比剂的血管成像方法,在肝动脉血管成像上具有一定的应用价值。     

平衡稳态自由进动序列非增强MR血管成像在糖尿病患者足部动脉成像中的应用研究

目的 评价基于血流敏感散相为准备脉冲的平衡稳态自由进动序列非增强MR血管成像(FSD-bSSFP NC-MRA,简称FSD-bSSFP),在糖尿病周围血管病变患者足部动脉成像中的临床应用价值.方法 对43例有足部症状的糖尿病患者采用FSD-bSSFP序列和三维对比增强序列(CEMRA)进行足部动脉成像.然后由2名有经验的放射科医师共同对2种成像技术的足部动脉图像质量、静脉污染和足部动脉分支的显示情况进行评分.采用Wilcoxon秩和检验对FSD-bSSFP和CEMRA图像质量、静脉污染情况、足背动脉及分支显示情况进行统计学分析;对2组图像足背动脉的信号强度(SI)、信噪比(SNR)和对比噪声比(CNR)采用配对t检验进行比较.结果 FSD-bSSFP的图像质量评分为(2.7±1.1)分,CE-MRA为(2.6±0.8)分,两种扫描序列的图像质量差异无统计学意义(Z=0.134,P＞0.05).FSD-bSSFP对足背动脉分支显示情况良好,为(3.2±0.9)分,CE-MRA为(2.5±0.9)分,两者间差异有统计学意义(Z=5.246,P＜0.05).FSD-bSSFP静脉污染为(1.8±0.4)分,CE-MRA为(2.1±0.8)分,两者间差异有统计学意义(Z=2.541,P＜0.05).FSD-bSSFP图像的SNR为148.6±26.7,CNR为88.3±19.0.3D CE-MRA图像的SNR为148.5±45.6,CNR为121.0±41.0.两者间SNR差异无统计学意义(t=0.013,P＞0.01),CE-MRA CNR高于FSD-bSSFP,差异有统计学意义(t=5.113,P＜0.05).结论 FSD-bSSFP非增强MRA可获得较好的足部动脉图像,可显示足背动脉及三级分支,为肾功能不全或其他原因不能使用对比剂的患者提供一个安全有效的补充方法.     

3.0T高时间分辨率对比增强MRA颅内血管成像

目的:评价3.0T高时间分辨率对比增强磁共振血管成像(TR 3DCE-MRA)在颅内血管成像的技术可行性和临床应用价值。方法:经医院伦理委员会批准,回顾性搜集21例患者,采用3.0T磁共振,首先行常规序列T1WI、T2WI和TOF MRA扫描,然后在确定病变处用TR 3DCE-MRA即快速小角度激发梯度回波序列(3DFLASH)。所有病例在检查后1～3d行高分辨率增强MRA(HR CE-MRA),测量动脉的信噪比和对比噪声比,由2位影像专家对TR CE-MRA和HR CE-MRA图像质量进行评价,分别对图像伪影、静脉污染、脑动脉显示效果进行评分。评分结果采用SPSS 13.0进行统计学分析,差异具有统计学意义(P<0.05)。结果:21例患者中动脉瘤3例,动静脉畸形7例,烟雾病2例,动脉狭窄9例。图像SNR和CNR测量均值分别为237±89和213±94,Wilcoxon test检验结果Z=-3.160,P=0.002<0.05,静脉污染组Z=-4.298,P=0.001<0.01,血管显示组Z=-4.491,P=0.001<0.01,差异有明显统计学意义。结论:TRCE-MRA比HR CE-MRA具有严重伪影少,没有静脉污染,良好的血管对比,能够同时评价动脉血管和静脉血管,将是颅内血管疾病的首选。     

手动脉非增强磁共振血管成像的初步临床应用

目的 初步探讨基于血流敏感散相(FSD)和平衡稳态自由进动(SSFP)的非增强磁共振血管成像(NCE-MRA)技术在显示类风湿性关节炎患者手动脉的临床应用价值。资料与方法 22例类风湿性关节炎患者采用1.5T成像系统进行手动脉NCE-MRA和增强磁共振血管成像(CE-MRA)检查。对手动脉(划分为腕部、掌部和指部3个血管节段)的图像质量进行评分,并对图像信噪比(SNR)、对比度噪声比(CNR)和血管边缘锐利度进行测量。将NCE-MRA和CE-MRA的图像质量和测量值进行统计学比较。结果 22例患者24只手均成功完成NCE-MRA和动态CE-MRA检查。72个血管节段中,NCE-MRA有69个动脉节段的图像质量具有诊断意义,明显高于CE-MRA(96%比83%,P<0.05)。此外,NCE-MRA在手动脉各个部位的图像质量以及SNR、CNR和血管锐利度均优于CE-MRA(P<0.05)。结论 NCE-MRA能清楚地显示手动脉的各个分支,图像质量优于动态CE-MRA,对手动脉病变的诊断具有较好的临床应用潜力。     

磁共振B-TFE技术肾动脉成像与CE-MRA对照

目的：探讨磁共振三维平衡式快速场梯度回波（B-TFE）技术非对比剂血管成像在肾动脉成像中的临床应用价值。方法：选择17例临床怀疑有肾动脉狭窄的患者行B-TFE和CE-MRA检查;B-TFE组并行采集加速因子取值为1和2。B-TFE组在横轴面图像上测量双侧肾动脉在不同加速因子时的信号噪声比（SNR）、肾动脉与肾周脂肪的对比噪声比（CNR）,CE-MRA组在冠状面图像上分别测量肾动脉的SNR和CNR。所有原始数据经三维MIP重组后由两位放射科医师对肾动脉三维图像质量、肾动脉狭窄程度、肾动脉分支显示及肾静脉伪影等情况进行评分。测量数据和图像评分进行统计学处理。结果：B-TFE组加速因子为1时图像的SNR为118.0±25.1（左）和105.9±29.1（右）,CNR为103.7±33.5（左）和93.1±26.5（右）;B-TFE组加速因子为2时SNR为93.5±23.1（左）和81.5±31.7（右）,CNR为83.1±34.5（左）和69.8±28.8（右）。CE-MRA组肾动脉的SNR为103.8±31.5（左）和93.1±40.8（右）,CNR为88.7±30.1（左）和79.7±38.6（右）。组内和组间SNR及CNR差异均无统计学意义（P〉0.05）。B-TFE图像上肾动脉分支的显示情况好、肾静脉伪影较CE-MRA小,2组间肾动脉三维图像质量、狭窄程度的显示无明显差异。结论：3DB-TFE肾动脉成像技术具有较高的图像信噪比和对比噪声比,可以作为一种新的无创性磁共振血管成像技术应用于肾动脉成像。     

磁共振B-TFE肾动脉血管造影的临床应用

目的 探讨磁共振三维平衡式快速场梯度回波(B-TFE)非对比剂肾动脉血管造影的临床应用价值.方法 选择21例临床疑似肾动脉狭窄病人,行B-TFE、CE-MRA扫描,13例同时行DSA检查.由2位医师独立对图像进行评分,评价B-TFE及CE-MRA肾动脉图像质量、狭窄程度、肾动脉分支及肾静脉伪影显示;以DSA为金标准,用受试者操作特性(ROC)曲线分析B-TFE肾动脉狭窄的灵敏度、特异性、阳性预测值和阴性预测值.结果 肾动脉分支B-TFE组评分2.3～2.5,CE-MRA组评分2.3～2.8(P=0.043).肾静脉伪影B-TFE组评分3.7～3.9, CE-MRA组评分3.4～3.7 (P=0.033).B-TFE诊断肾动脉狭窄的灵敏度为94.7% 、特异性为87.5% 、阳性预测值为94.7% 、阴性预测值为87.5%, 其ROC 曲线下面积为0.904.结论 B-TFE可以准确诊断肾动脉狭窄.     

3TMR重复动静脉标记技术的非增强肾血管成像与增强MR血管成像的对比研究:用于肾功能正常者

<正>摘要目的研究采用重复动静脉标记(RAVEL)技术行非对比增强MR血管成像(NC-MRA)评估肾动脉的可行性,并与对比增强MR血管成像(CE-MRA)进行比较。方法 在     

肾动脉狭窄的非对比增强MRA:猪模型的DSA验证

正摘要目的使用数字剪影血管造影(DSA)作为参考标准比较三维反转恢复平衡稳态自由进动(IR-b SSFP)非对比增强MR血管成像(MRA)和三维对比增强磁共振血管成像(CE-MRA)在肾动脉狭窄(RAS)评定中的价值。材料与方法对12只猪进行双侧肾动脉狭窄手术,在1.5 T MRI上进行IR-b SSFP和CE-MRA并与旋转DSA对比。3位有经验的心血管放射科医师独立评估IR-b SSFP和CE-MRA研究结果。用线性回归模型校准和评估IR-b SSFP和CE-MRA的准确     

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。     

Evaluation of carotid artery stenosis with multisection CT and MR imaging: influence of imaging modality and postprocessing

BACKGROUND AND PURPOSE: We prospectively evaluated the influence of different imaging techniques (time-of-flight MR angiography [TOF-MRA], contrast-enhanced MR angiography [CE-MRA], multisection CT angiography [CTA]) and postprocessing methods (maximum intensity projection [MIP], multiplanar reformation [MPR]) on carotid artery stenosis grading. MATERIALS AND METHODS: Fifty patients (34 men, 16 women) with symptomatic stenosis of the internal carotid artery were examined with a 16-section spiral CT and a 1.5T MR unit. Two MRA techniques were applied: 3D-TOF and CE-MRA. MPR was used for postprocessing with all modalities; MIP was used only with MRA. Four readers measured and calculated the percentage diameter stenosis independently according to NASCET criteria. The Wilcoxon test was used to measure interobserver variability, and the Friedman test was used to test the null-hypothesis of equality of the modalities. RESULTS: The hypothesis for global equality was rejected (P < .001). TOF-MRA and CTA assessed with MPR showed the highest concordance (difference, 0.6%; confidence interval [CI], -3.0, 4.3%), and CE-MRA with MIP and CTA showed the lowest concordance in stenosis grading (difference, 7.0%; CI, 3.4, 10.6%). MPR resulted in lower degrees of stenosis than MIP for both MRA sequences, although not statistically significant (CE, -3.0%; CI, -6.6, 0.6%; TOF, -2.2%; CI, -5.8, 1.4%). When only studies with good or excellent image quality were considered, the differences decreased, but the trends remained. CONCLUSION: Stenosis grading is dependent on the examination method and postprocessing technique. CTA and TOF-MRA evaluated with MPR revealed highest concordance.     

Steady-state free precession MRA of the renal arteries: breath-hold and navigator-gated techniques vs. CE-MRA

PURPOSE: To explore the use of breath-hold and navigator-gated noncontrast Steady State Free Precession (SSFP) MR angiography (MRA) protocols for the evaluation of renal artery stenosis (RAS). MATERIALS AND METHODS: Twenty patients referred to rule out RAS were imaged using two breath-hold and one navigator-gated SSFP MRA sequences. All patients underwent contrast-enhanced MRA (CE-MRA). Two radiologists evaluated all sequences both qualitatively (blur, artifacts, reader confidence) and quantitatively (maximum stenosis). Using CE-MRA as truth, a receiver operating characteristics (ROC) curve was generated and a statistical analysis of navigator-gated SSFP (Nav SSFP) was performed. RESULTS: Seven patients had >50% renal artery stenosis by CE-MRA. Nav SSFP performed significantly better than either breath-hold SSFP technique in terms of blur, artifacts, and reader confidence. Using a 50% threshold for stenosis, sensitivity for detecting RAS was 100%, with a specificity of 85% and a negative predictive value of 100%. The average mean stenosis difference between Nav SSFP and CE-MRA was 9 +/- 9%. CONCLUSION: Nav SSFP outperformed breath-hold SSFP in measures of image quality and reader confidence. Sensitivity and negative predictive value for detecting RAS with Nav SSFP was perfect, with an acceptable specificity of 85%. This suggests further study is warranted to evaluate Nav SSFP as a noncontrast screening technique for renal artery stenosis.     

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.     

Initial experience with balanced turbo field echo in depicting carotid artery stenosis: comparison with multiple overlapping thin slab acquisition and 3D contrast-enhanced magnetic resonance angiography

PURPOSE: To compare balanced turbo field echo (bTFE) with multiple overlapping thin slice acquisition (MOTSA) and contrast-enhanced MR angiography (CE-MRA) in depicting carotid artery stenosis. MATERIALS AND METHODS: In this study 86 patients with cerebrovascular disease, who had been referred for a carotid examination, were imaged. All of the patients underwent MOTSA and one of four bTFE sequences followed by CE-MRA. Formatted maximum intensity projections (MIPs) and source images were read in a blinded fashion by a radiologist. Inter- and intrasequence statistical analyses were performed. RESULTS: We first compared image quality (IQ) and fat, background, and venous suppression using four distinct bTFE protocols in 118 carotid arteries, and found that bTFE4 performed the best. We then compared IQ, grades of stenosis, and background and venous suppression among bTFE4, MOTSA, and CE-MRA. bTFE produced significantly better IQ and venous suppression (P < 0.001), and higher SNR and CNR (P < 0.05) when compared to MOTSA. CONCLUSION: The bTFE sequence is robust and provides high-quality images in patients with mild to moderate carotid artery stenosis. Even though there is a tendency to overestimate stenosis with bTFE compared to CE-MRA, the shorter scan time of bTFE coupled with enhanced SNR and CNR measurements validates it as a clinically useful adjunct to MOTSA, if not a replacement.     

MR angiography of the great anterior radiculomedullary artery (Adamkiewicz artery) validated by digital subtraction angiography

BACKGROUND AND PURPOSE: Imaging of the anterior superficial spinal cord arteries by MR angiography is hindered by their small calibers and the similarity in configuration with the anterior superficial spinal cord veins. To validate the location and spatial configuration of the great anterior radiculomedullary artery, (ie, the Adamkiewicz artery [AKA]), contrast-enhanced MR angiography (CE-MRA) was compared with digital subtraction angiography (DSA). METHODS: Fifteen patients with suspected spinal cord vascular pathology underwent both spinal CE-MRA and selective spinal DSA. Two phase CE-MRA was performed with the use of a centric k-space filling scheme synchronized to the contrast bolus arrival. The level and side of the AKA origin were scored on the DSA and CE-MRA images and compared regarding image quality in terms of vessel conspicuity, contrast, continuity, sharpness, and background homogeneity on a relative 5-point scale. RESULTS: Localization and spatial configuration of the AKA by CE-MRA was in agreement with DSA findings in 14 of 15 cases. One mismatch of 1 vertebral level (not side) appeared as a result of the tangled vascular pathology. Comparison of image quality revealed that DSA is superior to CE-MRA concerning vessel continuity, sharpness, and background homogeneity (P < .001). Overall vessel conspicuity and contrast were judged to be similar. CONCLUSION: CE-MRA can visualize and localize the level of the AKA correctly. Image quality of CE-MRA is sufficient for detection of the AKA but is inferior to DSA.     

16层螺旋CT下肢动脉造影中四种成像方案的比较分析

目的 探讨16层螺旋CT下肢动脉成像时四种成像方案的应用价值.方法 对160例临床疑为周围动脉闭塞性疾病患者行16层螺旋CT血管造影.采用经验值、智能跟踪（触发监测点设在腘动脉及腹主动脉两类）、Test Bolus技术等四种方法行血管成像,薄层重建横断面图像传入adw4.5工作站,进行血管三维重建.比较四组CTA图像质量并做t检验,P值小于0.05可认为有显著性差异.结果 四组方法在双侧股腘动脉段均能获得满意的图像质量.而双侧小腿及足部动脉段有明显图像质量差异.其中,Test Bolus技术D组图像质量优于经验值A组及智能跟踪B组（t=3.254、P＜0.05）.智能跟踪C组图像质量优于经验值A组及智能跟踪B组（t=3.377、P＜0.05）;Test Bolus技术D组与智能跟踪C组之间无显著差异（t=0.783、P＞0.05）.经验值A组与智能跟踪B组之间无显著差异（t=0.801、P＞0.05）.结论 16层螺旋CT下肢动脉成像四组方案在双侧股腘动脉段均能取得较好的图像质量.而腘动脉水平智能跟踪触发和Test Bolus技术对于小腿及足部动脉段的显示则更有优势.     

低管电压和低浓度对比剂结合Idose4迭代算法在CT对肾动脉血管成像的应用

目的探讨低碘浓度对比剂(300 mgI/ml)结合低管电压(100 kV)联合idose4迭代重建算法在肾动脉CT血管成像应用中的可行性。方法选取并分析在我院行肾动脉CTA检查的94例患者资料,随机分为标准组(52例)及双低组(42例)进行扫描,常规组扫描方案:管电压120 kVp,对比剂浓度350 mgI/ml。双低组扫描方案:管电压100 kVp,对比剂浓度300 mgI/ml;比较两组临床资料,图像质量主、客观评价指标、CT辐射剂量及对比剂用量。结果常规组及双低组别年龄及体重指数差异无统计学意义(P=0.576,P=0.621)。图像质量主观评价及分支显示差异无统计学意义(P=0.374,0.526),双低组血管衰减、信噪比、CNR明显高于标准组组(均P<0.05)。两组肾动脉分支的图像质量和显示情况相似(P>0.05)。与标准组相比,双低组CTDIvol、DLP和ED分别降低26.43%、35.22%和为32.76%。结论在100 kVp、欧乃派克300 mgI/ml条件下应用于肾动脉血管成像,可以提供良好的图像质量,同时较常规方案降低了患者的辐射剂量以及不良反应发生率。     

Assessment of aortoiliac and renal arteries: MR angiography with parallel acquisition versus conventional MR angiography and digital subtraction angiography

PURPOSE: To prospectively compare the image quality, sensitivity, and specificity of three-dimensional gadolinium-enhanced magnetic resonance (MR) angiography accelerated by parallel acquisition (ie, fast MR angiography) with MR angiography not accelerated by parallel acquisition (ie, conventional MR angiography) for assessment of aortoiliac and renal arteries, with digital subtraction angiography (DSA) as the reference standard. MATERIALS AND METHODS: The study was approved by the institutional review board; informed consent was obtained from all patients. Forty consecutive patients (33 men, seven women; mean age, 63 years) suspected of having aortoiliac and renal arterial stenoses and thus examined with DSA underwent both fast (mean imaging time, 17 seconds) and conventional (mean imaging time, 29 seconds) MR angiography. The arterial tree was divided into segments for image analysis. Two readers independently evaluated all MR angiograms for image quality, presence of arterial stenosis, and renal arterial variants. Image quality, sensitivity, and specificity were analyzed on per-patient and per-segment bases for multiple comparisons (with Bonferroni correction) and for dependencies between segments (with patient as the primary sample unit). Interobserver agreement was evaluated by using kappa statistics. RESULTS: Overall, the image quality with fast MR angiography was significantly better (P=.001) than that with conventional MR angiography. At per-segment analysis, the image quality of fast MR angiograms of the distal renal artery tended to be better than that of conventional MR angiograms of these vessels. Differences in sensitivity for the detection of arterial stenosis between the two MR angiography techniques were not significant for either reader. Interobserver agreement in the detection of variant renal artery anatomy was excellent with both conventional and fast MR angiography (kappa=1.00). CONCLUSION: Fast MR angiography and conventional MR angiography do not differ significantly in terms of arterial stenosis grading or renal arterial variant detection.