冠状动脉狭窄和粥样硬化斑块血管造影、MRA和CTA的对比研究

目的以冠状动脉血管造影(CA)为参照,比较冠状动脉MRA和CTA诊断狭窄的准确性,探讨斑块的MRA表现.材料和方法30例冠心病患者在2周内接受冠状动脉MRA、CTA和CA检查.MRA使用呼吸导航触发的高分辨三维FIESTA序列,CTA检查使用64排螺旋CT.以CA为诊断金标准,评价MRA和CTA检测≥50%狭窄血管的患者,回顾性分析冠状动脉斑块的MRA表现.结果MRA和CTA判断狭窄的敏感性、特异性和准确性分别为83.0%、86.9%、86.1%和85.1%、87.2%、86.8%.斑块的MRA复杂信号是MRA高、低估冠脉狭窄的主要原因,钙化是导致CTA高估狭窄的主要原因,MRA可以校正CTA对钙化所致狭窄的错误判断.结论高分辨三维FIESTA序列MRA显示冠状动脉狭窄的效能与CTA接近,MRA对显示钙化斑块导致的管腔狭窄比CTA有优势;斑块的MRA表现比较复杂,给狭窄的判断带来困难,也为斑块性质的判断提供机会.     

多层螺旋CT和三维屏气MR冠状动脉成像的对比研究

目的比较16层螺旋CT（16 multi-detector CT,16-MDCT）冠状动脉血管造影（CTA）和三维屏气冠状动脉MR血管造影（MRA）的图像质量以及诊断冠状动脉显著性狭窄（＞50%）的准确性.方法40例疑有冠心病患者在3 d内均行冠状动脉CTA和MRA检查,其中31例患者在2周内行冠状动脉造影检查.将冠状动脉分成9个节段（右冠状动脉近、中、远段,左冠状动脉主干,前降支近、中、远段和旋支近、远段）,由2名影像科医生共同对各个节段的图像质量按0～4级评分,比较CTA和MRA上各个节段的图像质量.以冠状动脉造影为标准,计算并比较CTA和MRA诊断31例冠状动脉显著性狭窄（＞50%）各项准确性指标.结果CTA在右冠状动脉中段的图像质量低于MRA,右冠状动脉近段二者无区别,其他节段均优于MRA.冠状动脉造影显示31例患者共有43个节段狭窄＞50%,CTA和MRA分别正确诊断出36和27个,其敏感性、特异性、阳性预测值和阴性预测值分别为83%、84%、49%、97%和63%、90%、55%、93%.结论除右冠状动脉中段,CTA大部分节段的图像质量优于MRA.CTA诊断冠状动脉显著性狭窄的敏感性高于MRA,但特异性低于MRA.冠状动脉CTA和MRA均表现了较高的阴性预测值,对排除冠状动脉狭窄具有临床价值.     

肾动脉纤维肌层发育不良的高分辨力三维增强MR血管成像

目的:评价高分辨力三维增强磁共振血管成像术(3D CE MRA)诊断肾动脉纤维肌层发育不良(FMD)的价值.方法:5例经临床和DSA造影确诊的肾动脉FMD患者行肾动脉高分辨力3D CE MRA检查,扫描同时使用透视触发和并行采集技术.分析所有患者的肾动脉和FMD显示情况,并与DSA对照.结果:肾动脉3D CE MRA清楚显示5例患者10支肾动脉主干及其近端段级分支,且静脉均未显影或显影很淡.5例FMD均为单侧肾动脉受累,2例表现为肾动脉主干和近端段级分支串珠状改变,3例表现为肾动脉中段局限性狭窄.3D CE MRA显示结果与DSA一致.结论:高分辨力肾动脉3D CE MRA能较好检出肾动脉主干和近端分支的FMD.     

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。     

MSCT冠状动脉造影的临床应用

目的: 评价多层螺旋CT(MSCT)冠状动脉造影效果及其诊断冠状动脉狭窄的价值.材料和方法:65例临床疑诊冠心病患者作MSCT扫描,所有数据获得在一次屏气中完成.利用心电门控技术,将所得原始图像进行重建,分别对左主干(LMA)、左前降支(LAD)、回旋支(LCA)和右冠状动脉(RCA)及其分支的重建图像进行影像学评价;其中45例同时作常规冠状动脉造影(CAG),以造影结果为金指标,将两种方法所得结果进行对比,了解MSCT冠状动脉造影诊断冠脉狭窄的敏感性和特异性.结果:MSCT冠脉钙化积分诊断冠心病的敏感性79.6%,特异性84.9%;65例共260支血管经MSCT成像,228支(87.7%)可用于影像学评价;各节段冠状动脉重建图像,左主干和前降支近中段显示率最高;CAG发现狭窄49支, MSCT发现狭窄44支.MSCT对冠状动脉狭窄诊断的敏感性83.7%,特异性97.7%.结论: 在控制心率的情况下,MSCT冠状动脉造影可作为诊断冠状动脉狭窄的一种无创筛选检查方法.     

下肢动脉硬化性闭塞病的CTA,3D CE-MRA和DSA对照分析

本文通过CT血管成像(CT angiography,CTA)和三维增强磁共振血管成像(three-di mensional contrast enhanced magnetic resonance angiography,3D CE-MRA)及数字减影血管造影(DSA)的对照性研究,分析CTA、MRA显示下肢动脉狭窄的差异,评价CTA、MRA诊断下肢动脉硬化性闭塞病(arteriosclerotic occlusive disease,ASO)的临床价值。     

双源CT血管造影评价冠状动脉狭窄的临床价值

目的:评价双源CT定量诊断冠状动脉狭窄的准确性及临床价值。方法:对30例临床拟诊冠心病患者分别进行双源CT和传统冠状动脉造影检查,并将双源CT判定冠状动脉狭窄程度与冠脉造影结果进行对比分析。结果:30例共计450冠脉节段,双源CT均获得满意的评价图像(3例进行心电编辑)。双源CT判定轻度狭窄38个节段,中度狭窄23个节段,重度狭窄36个节段;与冠状动脉造影结果对比,双源CT诊断冠脉狭窄的敏感性、特异性和准确性分别为94.12%、95.34%和95.11%。结论:与冠状动脉造影对比,双源CT在定量诊断冠脉狭窄方面具有较高的敏感性和特异性,可为临床诊断冠心病提供一项准确可靠的无创手段。     

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。     

冠状动脉造影正常患者64排CT冠状动脉成像结果分析

目的 分析介入性冠状动脉造影正常患者64排CT冠状动脉成像的检查结果和影像特点.方法 对介入性冠状动脉造影结果为阴性的52例患者在1月内行64排CT冠状动脉成像检查,对阳性病例进行回顾性分析.结果 64排CT冠脉成像显示52例中,冠状动脉局限性管壁增厚29例(55.77%),管腔无狭窄23处,轻度狭窄6处,平均狭窄程度8%;弥漫性管壁增厚8例(15.38%),管腔无狭窄1例,轻度狭窄7例,平均狭窄程度为11%;单纯内膜钙化或管壁内钙化3例(5.77%),管腔未见明显狭窄.结论 64排CT冠状动脉成像更适宜作为冠心病诊断的首选影像检查方法.     

影像学在诊断颅外颈动脉狭窄及内膜切除术后随访中的应用

目的：对一例颈内动脉狭窄进行内膜切除术前后影像学系列观察,结合文献复习,初步探讨磁共振血管造影（MRA）,CT血管造影（CTA）,CT仿真内窥镜（CTVE）技术在诊断颈动脉狭窄中的应用价值。材料与方法：MRA采用TOF法,2D移动预饱和序列（Travelsat)及3D最佳倾斜非饱和激励（TONE）序列。CTA：Hispeed CT/i扫描机,经最大密度投影（maximum intensity projection,MIP)及遮盖表面显示法（threshold shaded surface display,SSD)行血管3D重建。CTVE：应用导航（Navigator smooth)功能实施颈动脉CTVE成像。将上述检查结果与数字减影血管造影（DSA）,手术对照。结果：96年MRA显示左颈内动脉狭窄30％,99年呈重度狭窄约90－95％。CTA：血管狭窄部位及程度同MRA,狭窄段可见钙化斑块。CTVE获得颈内动脉狭窄腔内仿真内窥镜图像,显示管增厚,钙化。DSA诊断左颈内动脉重度狭窄,病理证实。术后MRA,CT提示狭窄基本解除,钙化斑块消失。结论：MRA可用于发现,诊断外颈动脉狭窄及术后随访,CTA与CTVE有利于观察管腔内病理改变。     

"Soap-Bubble" visualization and quantitative analysis of 3D coronary magnetic resonance angiograms.

In order to compare coronary magnetic resonance angiography (MRA) data obtained with different scanning methodologies, adequate visualization and presentation of the coronary MRA data need to be ensured. Furthermore, an objective quantitative comparison between images acquired with different scanning methods is desirable. To address this need, a software tool ("Soap-Bubble") that facilitates visualization and quantitative comparison of 3D volume targeted coronary MRA data was developed. In the present implementation, the user interactively specifies a curved subvolume (enclosed in the 3D coronary MRA data set) that closely encompasses the coronary arterial segments. With a 3D Delaunay triangulation and a parallel projection, this enables the simultaneous display of multiple coronary segments in one 2D representation. For objective quantitative analysis, frequently explored quantitative parameters such as signal-to-noise ratio (SNR); contrast-to-noise ratio (CNR); and vessel length, sharpness, and diameter can be assessed. The present tool supports visualization and objective, quantitative comparisons of coronary MRA data obtained with different scanning methods. The first results obtained in healthy adults and in patients with coronary artery disease are presented.     

二维屏气结合三维导航技术对冠状动脉磁共振血管造影的研究

目的：研究二维屏气结合三维导航技术对冠状动脉磁共振血管造影的成像,以评价此技术在缺血性心脏病方面的诊断价值,方法：运用１．５Ｔ超导型ＭＲ扫描仪和体部相控制线圈,采用二维屏气下,脂肪抑制,心电门控,Ｋ空间分段采集快速自旋回波（２Ｄ－ｂｒｅａｔｈ－ｈｏｌｄｆａｔ－ｓｕｐｐｒｅｓｓｅｄＥＣＧ－ｇａｔｅｄＦＬＡＳＨｗｉｔｈＫ－ｓｐａｃｅｓｅｇｍｅｎｔａｔｉｏｎ）,多角度双倾斜层面扫描,结合三维导航技术（３     

Coronary artery magnetic resonance angiography

Coronary magnetic resonance angiography (coronary MRA) continues to advance rapidly from both a technical and clinical perspective. Coronary MRA has benefited directly from improvements in spatial resolution, contrast definition, and advances in motion correction, which have furthered its routine use in evaluating coronary artery bypass grafts and anomalous coronary arteries. Work in refining the techniques for more accurate identification of coronary artery disease (CAD) continues, with advances in navigator-gated and breath-hold motion correction techniques, novel k-space strategies (e.g., spiral and radial k-space filling), development and application of intravascular contrast agents, and imaging at higher field strengths. Ultimately, these developments may lead to the routine application of coronary MRA as a screening tool for CAD. This article reviews the development of coronary MRA, discusses the requirements and tools necessary for optimal visualization of the coronary arteries, and describes the application of coronary MRA to acquired and congenital CAD.     

Coronary MRA: use in assessing anomalies of coronary artery origin

PURPOSE: The purpose of this work was to describe the use of coronary MR angiography (MRA) in the clinical evaluation of a series of patients with anomalous origin of the coronary arteries suspected on coronary angiography. METHOD: Eight patients underwent coronary MRA to further define variant coronary anatomy that was found on coronary angiography. A 2D segmented k-space gradient echo sequence was used with breath-holding. MRA images were assessed for traversal of an anomalous artery between the aorta and pulmonary artery trunks, which carries the greatest clinical significance. RESULTS: Of six patients with anomalous origin of the right coronary artery on angiography, two were shown by MRA to have an interarterial course of the anomalous vessel. Neither of two left coronary arteries with ectopic origin coursed between the great arteries, although one passed through the septum. CONCLUSION: Coronary MRA is a useful adjunctive technique to angiography in the evaluation of the relationship of anomalous coronary arteries to the great arteries.     

Breath-hold 3D steady-state free precession coronary MRA compared with conventional X-ray coronary angiography

PURPOSE: To evaluate the use of breath-hold three-dimensional (3D) steady-state free precession (SSFP) coronary magnetic resonance angiography (MRA) in patients with coronary artery disease (CAD) in comparison with conventional coronary x-ray angiography (XRA). MATERIALS AND METHODS: Twenty-eight patients with suspected CAD were examined with the use of a breath-hold 3D-SSFP-MRA sequence and conventional XRA. To assess the accuracy of MRA, two clinicians who were blinded to patient information independently reviewed the MRA and XRA data, which were presented in a randomized order. To identify discrepancies between MRA and XRA, and assess features of coronary lesions on MRA, two additional clinicians examined MRA and XRA data that were presented side by side, divided into proximal, mid, and distal segments, and compared them segment by segment. RESULTS: The sensitivity and specificity for diagnosing significant coronary stenoses (> 50% diameter narrowing) were 64% and 94%, respectively. At sites of coronary lesions identified on XRA, bright signals and enlarged vessel profiles, in addition to the characteristic narrow lumen, were frequently observed on MRA. CONCLUSION: Breath-hold SSFP coronary MRA has good specificity but inconclusive sensitivity in diagnosing significant coronary stenoses, and provides important image features for depicting coronary lesions.     

Nitrate-induced coronary vasodilation by stress-magnetic resonance imaging: a novel noninvasive test of coronary vasomotion

PURPOSE: To evaluate the feasibility of assessing coronary vasodilation following exogenous nitrates, using magnetic resonance angiography (MRA). The assessment of coronary response to exogenous nitrovasodilators may have a diagnostic and prognostic impact in patients with coronary artery disease. To date, stress imaging of coronary artery vasomotion has been confined to the catheterization laboratory. MRA is emerging as a noninvasive tool for coronary artery imaging. MATERIALS AND METHODS: Coronary MRA was performed in 20 healthy volunteers (12 males, age = 33 +/- 8). We used spiral spoiled gradient echo (SSGE) sequences for imaging of coronary artery lumen. After the baseline short-axis view of the coronary artery was obtained, sublingual nitroglycerin (NTG) (0.3 mg) was administered. In all subjects, short-axis views of the coronary artery were acquired repetitively (8-10 times) from 1 up to 10 minutes after NTG administration. Measurements were obtained by two independent investigators. RESULTS: Interpretable short-axis view of left anterior descending artery (LAD) was obtained in 15 subjects (75%); in the remaining five subjects the right coronary artery (RCA) was examined. The interobserver variability was 15%, and the intraobserver variability 4%. The NTG-induced maximal vasodilation was 43 +/- 22%. The vasodilator response over time after NTG was maximal on average at 279 +/- 112 seconds, but with substantial heterogeneity. CONCLUSION: Entity and time course of nitrate-induced coronary vasodilation in the left anterior descending and/or RCA can be assessed using MRA with high feasibility and reproducibility. Coronary MRA has potential for dynamic imaging of coronary vasomotion.     

Magnetic resonance angiography: the nuts and bolts

Magnetic resonance angiography (MRA) has matured into an extremely reliable and valuable diagnostic vascular tool. We are now able to acquire clinically diagnostic angiograms in all the major vascular territories by using MRA, thereby replacing invasive angiography. This paradigm shift has enormous clinical and financial ramifications, as MRA is safer, cheaper, and far more convenient for our patients than invasive angiography. Future magnetic resonance imaging research developments that are on the verge of being incorporated into clinical practice include real-time magnetic resonance fluoroscopy and endovascular therapeutic ability. It should therefore be incumbent upon the vascular and interventional community to embrace this powerful technology by collaborating and integrating with those physicians who possess the skills to perform high-quality magnetic resonance imaging. This article provides basic key fundamental concepts and protocol guidelines for state-of-the art MRA performance and elucidates future directions of this technology as it pertains to the interventional and vascular radiologist.     

脑动脉瘤的MR血管造影与IA—DSA的对照研究

对经手术证实的２０例脑动脉瘤的ＭＲＡ和ＩＡ－ＤＳＡ的影像进行了对照分析研究，经ＭＲＡ检出１９例（９５％）动脉瘤，１０ｍｍ以下的动脉瘤９例，最小的为４ｍｍ，与ＤＳＡ检出率（１９／２０）相仿。ＭＲＡ的定位符合率为８４％，低于ＤＳＡ（９５％）。１３／１９例（６８％）在ＭＲＡ图象上能显示动脉瘤的瘤颈。作者认为ＭＲＡ是一种新的非侵入性的血管影像方法，可作为脑动脉瘤高危病例的筛选检查，随着ＭＲＡ技术的进一步完善，ＭＲＡ有望在神经外科领域替代部分侵入性血管造影检查。     

Coronary MR angiography-a clinical experience in Japan.

Magnetic resonance angiography (MRA) has been expected to provide a useful noninvasive means of assessing coronary artery disease as this disease continues to increase due to westernization of life style. Several Japanese investigators have assessed the diagnostic value of two-dimensional (2D) and 3D coronary MRA in clinical patients evaluated for ischemic heart disease. Almost all reports indicate a high correlation between findings on 2D MRA and findings on conventional coronary angiography (CAG) in patients with severe stenosis of proximal arteries. However, in our study involving 153 patients with ischemic heart disease, 2D MRA tended to underestimate lesions in patients with moderate stenotic lesions. Furthermore, this method could not be applied successfully in approximately 15% of our patients due to difficulty with breath-holding. These findings indicate some of the limitations associated with breath-holding in the 2D method. Recently, several reports have described high diagnostic accuracy using respiratory-gated 3D MRA with navigator echo. Effective use of a suitable contrast agent with better spatial and time resolution and better image reconstruction methods will enable 3D MRA to serve a useful role, even in screening for coronary artery disease. J. Magn. Reson. Imaging 1999;10:709-712.