Assessment of coronary flow reserve with fast cine phase contrast magnetic resonance imaging: comparison with measurement by Doppler guide wire.

Fast cine phase contrast magnetic resonance imaging (fast cine phase contrast MRI) can measure phasic coronary flow velocity in humans. The purpose of this study was to compare the coronary flow velocity reserves measured by MR IMAGING with those obtained by Doppler guide wire. Nineteen patients with ischemic or valvular heart disease were studied. Fast cine phase contrast MR images of the left anterior descending (LAD) artery were acquired during breath-hold time in the basal state and after administration of dipyridamole. Flow velocity in the LAD artery was also measured with Doppler guide wire before and after venous injection of dipyridamole in all subjects. Flow velocity in the coronary artery measured with MR IMAGING in the basal state (12.5 +/- 4.9 cm/sec) was significantly lower than that obtained with Doppler guide wire (32.4 +/- 12.1 cm/sec, P < 0.01). However, MR assessments of coronary flow velocity reserve showed a good linear correlation with those measured by Doppler guide wire (r = 0.91). In conclusion, fast cine phase contrast MR imaging is a useful technique, which can provide a noninvasive assessment of flow reserve ratios in patients with coronary artery disease. J. Magn. Reson. Imaging 1999;10:563-568.     

Velocity-encoded,phase-difference cine MRI measurements of coronary artery flow: Dependence of flow accuracy on the number of cine frames

Phase-contrast magnetic resonance imaging (PC-MRI) can be used to produce multiframe cine flow images of the coronary arteries. Accurate coronary flow measurement requires the elimination of respiratory motion artifacts using k-space segmentation to acquire the data in a single breath-hold. However, the duration of the breath-hold is proportional to the number of cine frames. In the present study, the number of cine frames was varied and the accuracies of the coronary flow measurements were assessed using perivascular US. For the range of flows studied (2 ml/min to 147 ml/min), the correlation coefficients for PC-MRI and US increased (.70–.98) and the limits of agreement improved (±45 ml · min^?1 to ± 10 ml · min^?1) as the number of cine frames increased from one to six. The results suggest that the accuracy of breath-hold cine PC-MRI measurements of coronary artery flow improves as the number of cine frames increases.     

Left ventricular regional wall motion assessment by radionuclide ventriculography: a comparison of cine display with Fourier imaging

Radionuclide ventriculography and contrast ventriculography were performed in two comparable projections on 50 patients with suspected coronary artery disease. The efficacy of conventional cine display and Fourier image analysis of the radionuclide ventriculogram was compared using contrast ventriculography as the gold standard. Of seven different combinations of Fourier images, the combination of left anterior oblique amplitude and phase and left posterior oblique amplitude and phase provided the highest sensitivity (87%), specificity (83%), accuracy (86%), and kappa coefficient (0.64). To increase statistical power, segment data were collapsed to global data in which a heart was considered normal if all segments were normal and abnormal if one or more segments were abnormal. Fourier images had higher sensitivity (Fourier 87%, cine 47%); lower specificity (Fourier 83%, cine 92%), higher accuracy (Fourier 86%, cine 58%), and higher kappa coefficient (Fourier 0.64, cine 0.25), and these differences were statistically significant (p less than 0.01).     

Haemodynamic analysis of the effect of different types of plaques in the left coronary artery

PurposeCoronary plaque has been shown to directly affect the blood parameters, however, haemodynamic variations based on the plaque configuration has not been studied. In this study we investigate the haemodynamic effects of various types of plaques in the left coronary bifurcation.MethodsEight types of plaque configurations were simulated and located in various positions in the left main stem, the left anterior descending and left circumflex to produce a >50% narrowing of the coronary lumen. We analyse and characterise haemodynamic effects caused by each type of plaque. Computational fluid dynamics was performed to simulate realistic physiological conditions that reveal the in vivo cardiac haemodynamics. Velocity, wall shear stress (WSS) and pressure gradient (PSG) in the left coronary artery were calculated and compared in all plaque configurations during cardiac cycles.ResultsOur results showed that the highest velocity and PSG were found in the type of plaque configuration which involved all of the three left coronary branches. Plaques located in the left circumflex branch resulted in highly significant changes of the velocity, WSS and PSG (p < 0.001) when compared to the other types of plaque configurations.ConclusionOur analysis provides an insight into the distribution of plaque at the left bifurcation, and corresponding haemodynamic effects, thus, improving our understanding of atherosclerosis.     

数字电影摄影在冠状动脉造影中的应用

目的:探讨数字电影摄影在冠状动脉造影中的应用价值。方法:185例临床考虑冠心病的患者,采用Judkin’s法,行选择性冠状动脉造影数字电影摄影,对影像质量进行综合分析,分为良好和差。结果:185例冠状动脉造影中,发现冠状动脉血管病变的有153例。数字电影摄影共1352组,良好的有1327组,占98.2%,差的有25组,占1.8%。结论:数字电影在选择性冠状动脉造影的成像质量稳定而良好,能清晰地显示血管病变,数字图像能进行多种后处理,作定量分析并便于数字化储存和远程传输。     

Detection,visualization and evaluation of anomalous coronary anatomy on 16-slice multidetector-row CT

Early identification and evaluation of relatively frequent anomalous coronary anatomy is quite relevant because of the occurrence of sudden cardiac death or related symptoms of myocardial ischemia. Selective coronary angiography (CAG) is invasive, expensive and cannot always provide the required information adequately. Recently, non-invasive imaging techniques such as magnetic resonance imaging and multidetector-row computed tomography (MDCT) have been shown to provide a good anatomical view of the coronary artery tree. This study aims to demonstrate the value of 16-MDCT for evaluation of anomalous coronary anatomy. In 13 patients scanned using 16-MDCT, six different coronary anomalies were diagnosed [two absent left main, one single vessel left coronary artery (LCA), three LCA originating from the right (two with interarterial course), six right coronary artery originating from the left, one double left anterior descending (LAD)]. Mean diagnostic quality, recorded by two observers using a 5-point scale (1= non-diagnostic to 5= excellent diagnostic quality), resulted in a mean score of 3.73 (SD 1.19) without any non-diagnostic result. MDCT offers an accurate diagnostic modality to visualize the origin and course of anomalous coronary arteries by a three-dimensional display of anatomy. Shortcomings in CAG can be overcome by the use of contrast-enhanced MDCT.     

MR measurement of coronary blood flow.

The functional significance of coronary arterial stenosis can be evaluated by measuring the pharmacological flow reserve. Magnetic resonance (MR) imaging has a unique potential for noninvasive measurement of coronary blood flow and flow reserve in the native coronary artery and bypass graft. Restenosis after coronary balloon angioplasty and stenting in the left anterior descending artery can be detected noninvasively with serial MR measurements of the coronary flow reserve. Further refinement of the MR pulse sequences to improve spatial and temporal resolutions may permit accurate quantification of blood flow volume and flow reserve in all major coronary arterial branches. MR assessments of blood flow volume and flow pattern allow noninvasive detection of significant stenosis in the coronary artery bypass graft as well. By integrating MR blood flow measurement in the coronary sinus and cine MR assessment of left ventricular myocardial mass, altered myocardial micro-circulation in patients with diffuse myocardial diseases, such as hypertrophic cardiomyopathy and cardiac transplant, has been documented. J. Magn. Reson. Imaging 1999;10:728-733.     

屏气磁共振电影成像对冠心病患者左心室局部功能的评价

 目的 研究屏气磁共振电影成像对评价冠心病患者左心室局部功能的诊断价值.方法 对34例冠心病患者行电影成像,将左心室分为RCA、LAD、LCX支配节段.测量左心室局部功能参数,以CCA判断的冠状动脉狭窄程度为金标准,对各项局部功能参数行统计学评价.结果 WT%和WM灵敏度、准确度略高,WTES较WTED具有略高的灵敏度、准确度,LAD支配节段的参数具有较高的灵敏度和特异度,LCX支配节段的参数准确度较高.结论 对左室局部功能参数的定量评价能够提示冠状动脉狭窄所致的心肌缺血,为有症状冠心病患者提供早期诊断信息.     

MR evaluation of coronary stents with navigator echo and breath-hold cine gradient-echo techniques

The aim of this study was to evaluate coronary artery stents with MR. Thirty-eight patients underwent MR imaging 48.1 +/- 6.6 days (range 38-60 days) after placement of 47 coronary stents of 11 different types, using navigator echo (NE) and cine gradient-echo (GE) techniques. For both sequences the low signal artifact was used to localize the stent, whereas the flow-related high signal before and distal to the stent was considered as a patency sign. Exercise electrocardiographic test (EET) had been performed 1-7 days before MR. No adverse event with possible relation to the MR examination was observed. All the stents were recognized as signal void with GE, and all but one with NE. Of the 2 patients with positive EET, the first one, with a stent on the left anterior descending coronary artery, presented low signal distal to the stent at both MR sequences, suggesting dysfunction [60% stenosis at conventional coronary angiography (CCA)]; the second one, with two sequential stents on the right coronary artery, presented lack of signal distal to the stents at both MR sequences, suggesting occlusion (97% stenosis at CCA). For the 44 remaining stents in 36 patients with negative EET, MR high signal before and distal to the stent suggested patency at both sequences. MR seems to be a safe and promising technique for non-invasive evaluation of coronary stents.     

Coronary venous anatomy and anomalies

Coronary venous anatomy can be divided into the greater cardiac venous system and the lesser cardiac venous system. With protocol optimization, including appropriate contrast bolus timing, coronary veins can be depicted with excellent detail on CT. Knowledge of variant coronary venous anatomy can sometimes play a role in pre-procedural planning. Analysis of the coronary venous anatomy on CT can detect coronary venous anomalies that cause right to left shunts with risk of stroke, left to right shunts, and arrhythmias.     

先天性冠状动脉瘘心血管造影诊断及治疗

目的 介绍先天性冠状动脉瘘的心血管造影特点及其治疗方法。方法 35例均采用肝锁位、长轴斜位、右前斜位、后前位及侧位分别进行左心室、升主动脉和选择性冠状动脉造影。结果 35例冠状动脉瘘显示清晰,其中20例手术治疗成功,9例行弹簧钢圈堵塞术,8例成功。结论 先天性冠状动脉瘘是一种少见的畸形,一旦明确诊断,应及早治疗。目前除手术外,导管介入治疗不失为有效的方法。     

介入法建立长期可随访冠状动脉微栓塞动物模型

目的 应用微导管介入技术建立可随访的冠状动脉微栓塞动物模型.方法 10只巴马系小型猪经导管选择性的于前降支(LAD)内注入15×10~4个微栓塞球(直径45 μm),致使冠状动脉微血管栓塞.分别测量冠脉血流储备分数(CFR)和左室射血分数(LVEF);心肌组织切片染色和超微结构变化观察;及术后1个月再行血管造影及CFR测量等检验.结果 冠脉内注射微栓塞球可导致微血管完整性的破坏(CFR<2.0)及左室功能障碍(LVEF<50%).组织切片NBT和HE染色均证实存在微血管栓塞;透射电镜微梗塞区心肌细胞水肿、纤维化明显;术后动物存活率高(n=10),且可再行经皮血管造影及CFR的测量.结论 应用微导管介入技术可建立创伤小、死亡率低并可长期随访观察的小型猪冠状动脉微栓塞模型.是临床研究冠脉微血管栓塞发病机制的理想动物模型.     

冠心病的电影摄影诊断（附23例分析）

本文分析２３例冠心病患者的电影摄影所见，着重分析室壁瘤形成与冠状动脉狭窄的程度、部位、数目、侧支血管形成和临床病情等因素的关系。此外，对冠心病中继发二尖瓣返流的成因和机制进行了探讨。讨论中提出以下几点：（１）室壁瘤的发生与冠状动脉主要分支的严重狭窄关系最密切；（２）侧支循环能防止心肌梗塞范围扩大及室壁瘤形成；（３）二尖瓣返流与主要冠状动脉病变的狭窄程度及室壁瘤的存在有关。并对影响侧支循环显示的因素进行了探讨。     

Fast magnetic resonance imaging of the heart.

Fast MR imaging techniques have multiple applications for evaluation of cardiac disease. Cine MRI and MR tagging have been shown to be highly accurate and reproducible in evaluating regional and global myocardial function. Segmented k-space cine MRI and echo-planar imaging (EPI) can considerably improve time efficiency and thereby the clinical utility of these techniques. Double IR fast spin-echo sequences enable breath-hold acquisition of T2 weighted MRI with good suppression of the blood signal. Myocardial perfusion can be assessed with fast dynamic MRI after administration of contrast media. Multi-shot EPI improves temporal resolution and also provides full coverage of the left ventricle. Substantial progress has been made in respiratory gated 3D coronary artery MR angiography with navigator echoes. The newer approaches for coronary arterial imaging including breath-hold three-dimensional segmented EPI and high resolution spiral MRI may further improve clinical usefulness of coronary MR angiography. Assessment of coronary blood flow and flow reserve with phase contrast MRI has the potential for the non-invasive evaluating of the presence and significance of stenosis in the native coronary artery and bypass grafts. Fast cardiac MRI may emerge as a cost effective modality for comprehensive assessments of both cardiac morphology, function, blood flow and perfusion.     

冠状动脉瘘的双源CT诊断

目的:探讨双源CT(DSCT)冠状动脉成像对冠状动脉瘘的诊断价值.方法:对1000例患者行DSCT冠状动脉增强扫描,分析其断层图像,结合最大密度投影(MIP)、曲面重组(CPR)、多平面重组(MPR)和容积再现(VR)等方法观察冠状动脉的走行及心内外机构.结果:11例患者有冠状动脉瘘,其中右冠状动脉主干-肺动脉瘘5例,...     

Does digital acquisition reduce patients' skin dose in cardiac interventional procedures? An experimental study

OBJECTIVE: It is necessary to reduce the exposure doses from both fluoroscopy and angiocardiography. Pulsed fluoroscopy clearly reduces patients' exposure. By contrast, whether digital acquisition reduces patients' exposure is not clear. This study simulated the skin radiation doses of patients in cardiac catheterization laboratories with various radiography systems used in percutaneous transluminal coronary angioplasty to determine whether digital acquisition reduces patient exposure as compared with cine film recording. MATERIALS AND METHODS: The entrance surface doses with cineangiography and fluoroscopy of acrylic phantoms were compared for 11 radiography systems at seven facilities; each performs more than 100 cardiac intervention procedures per year. The entrance surface dose for an acrylic plate (20 cm thick) was measured using a skin-dose monitor. RESULTS: The maximum dose exceeded the minimum dose by 6.44 times for cineangiography and by 3.42 times for fluoroscopy. The entrance surface dose with acrylic plate was lower with digital-only acquisition (mean +/- SD, 3.07 +/- 0.84 mGy/sec) than with film recording (6.00 +/- 3.04 mGy/sec). By contrast, the entrance surface frame dose, after correction for the cine frame rate, tended to be higher with digital acquisition than with film recording (0.210 +/- 0.053 vs 0.179 +/- 0.058 mGy/frame, respectively). CONCLUSION. The entrance surface dose was approximately 50% less with digital-only acquisition than with film recording. However, after correcting the dose for cine frame rate, filmless acquisition did not in itself reduce the exposure. For the surface dose to be reduced for cardiac interventional radiography, even with digital filmless radiography systems, a low recording speed is necessary for angiocardiography.     

Fast 3D cardiac cine MR imaging.

We describe a technique for three-dimensional cine MR imaging. By using short repetition times (TR) and interleaved slice encoding, volumetric cine data can be acquired throughout the cardiac cycle with a temporal resolution of approximately 80 msec. A T1-shortening agent is used to produce contrast between blood and myocardium. A comparison between the acquisition times of this and several other two-dimensional techniques is presented.     

冠状动脉介入治疗冠心病合并左心功能不全（附30例）

目的：分析冠心病合并左心功能不全患者介入治疗术临床疗效。方法：53例冠心病合并左心功能不全（LVEF〈50%）患者,介入组30例行冠脉内支架治疗,保守组23例行药物保守治疗。所有患者均于术前及术后6个月接受超声心动图检查,通过超声心动图观察两组的心功能变化。结果：与保守治疗组比较,介入治疗组在LVEF,缩小扩大的左心腔有明显的变化,术后运动耐量明显增加,生活质量明显改善。6min步行距离显著增加（P〈0.05）。结论：冠状动脉介入治疗对于合并左心功能不全的冠心病患者是一种安全有效的治疗方法,使患者心功能改善。     

MRI of left ventricular function

Cardiac magnetic resonance imaging (CMR) is widely recognized as the most accurate noninvasive imaging modality for the assessment of left ventricular (LV) function. By use of state-of-the-art magnetic resonance imaging (MRI) scanners, electrocardiography (ECG)-gated cine images depicting LV function with high contrast and excellent spatial and temporal resolution are readily acquired in breath-holds of 5 to 10 heartbeats. For patients in whom breath-holding and ECG gating are difficult, real-time cine imaging without ECG gating and breath-holding can be performed. LV function can be qualitatively assessed from cine images, or alternatively, parameters such as LV volumes, ejection fraction, and mass may be quantified via computer-based analysis software. In addition, techniques such as myocardial tagging and newer variants can be used to qualitatively or quantitatively assess regional intramyocardial strain, twist, and torsion. Many of the CMR methods have undergone clinical evaluation in the settings of high-dose dobutamine stress testing and determination of myocardial viability. These methods are also very accurate for prognosis in coronary heart disease patients and may be quite useful for the detection of contractile dyssynchrony. When used together with other CMR techniques such as first-pass perfusion imaging or late gadolinium enhancement, CMR of LV function provides a wealth of information in a single imaging study.     

Three-dimensional display of positron emission tomography of the heart

A method for producing images of 82Rb myocardial perfusion and 11C carbon monoxide gated blood pool images is described. In the case of 82Rb images, cylindrical projection displaying myocardial activity as viewed from the side is presented to complement the polar projection. Cubic display of the conventional short- and long-axis slices is described that permits interactive selection of any desired slices. A three-dimensional cine display of the left ventricle rotating about its long axis is produced that gives a very realistic presentation of myocardial activity. Very similar processing techniques are applied to gated carbon-11 blood-pool studies to yield beating images of the surface of the blood pool in multiple projections.