Computed tomography imaging of cardiac allograft vasculopathy

Cardiac allograft vasculopathy (CAV) is the main cause of morbidity and mortality beyond 1 year after heart transplantation. Ischemic symptoms are usually not present because of the denervated allograft and diffuse nature of the disease. Patients present with heart failure, ventricular arrhythmia, or sudden cardiac death as a result of advanced CAV. Therefore, clinical evaluation includes routine annual invasive coronary angiography (ICA) and transthoracic echocardiography to screen for CAV. Noninvasive imaging methods for the detection of CAV have not been widely adopted. Computed tomography (CT) permits detection of coronary stenoses and plaque in the nontransplant population. The strength of CT is its high negative predictive value. These attributes predispose CT to a role of a gatekeeper for further invasive testing in heart transplant recipients. We reviewed the available literature on CT evaluation of CAV. Technical challenges (eg, high heart rates, need for contrast and radiation, image quality) specific for patients who have received a heart transplant are emphasized, and solutions, including appropriate protocols and advances through the new CT technology, are summarized. We systematically analyze the results of studies that report the diagnostic performance of cardiac CT for the detection of coronary stenoses compared with ICA. Similar analysis is performed for the comparison between CT and intravascular ultrasound scanning for the detection of nonobstructive CAV. Finally, we suggest future directions in cardiac CT imaging research of CAV.     

^99mTc-MIBI心肌灌注断层显像假阴性与假阳性的临床分析

目的探讨^99mTc-MIBI（甲氧基异睛）心肌灌注断层显像与冠状动脉造影不一致的临床意义。方法136例临床诊断为冠心病患者,于冠状动脉造影术（CAG）前2周内行^99mTc-MIBI心肌灌注断层显像（运动或药物负荷及静息显像）。以CAG为金标准,分析^99mTc-MIBI心肌灌注断层显像假阳性与假阴性的临床意义。结果两者不相符合13例,^99mTc-MIBI心肌灌注断层显像阳性而冠状动脉正常者10例,^99mTc-MIBI心肌灌注断层显像阴性而冠状动脉造影阳性者3例。结论^99mTc-MIBI心肌灌注断层显像阴性而冠状动脉造影阳性提示冠脉临界病变,^99mTc-MIBI心肌灌注断层显像阳性而冠状动脉造影阴性提示冠脉微循环灌注不足。     

Giant coronary artery aneurysm secondary to Kawasaki disease: diagnosis in an adult by multi-detector row CT coronary angiography

We present the case of an adult female patient with a giant coronary artery aneurysm secondary to Kawasaki disease diagnosed for the first time, as far as the authors are aware, on multi-detector row computed tomography (MDCT). The long-term complications relate to the persistence of these aneurysms with giant coronary aneurysms having the lowest regression rate, the highest risk of stenosis and strongest association with myocardial infarction. MDCT coronary angiography represents an ideal, alternative non-invasive imaging modality for the diagnosis and follow-up of the coronary arterial complications of Kawasaki disease, thereby avoiding invasive coronary imaging, and its use in the management algorithm should be considered. We also aim to contribute to the expanding clinical role of MDCT coronary imaging.     

Magnetic resonance imaging demonstration of anomalous origin of the right coronary artery from the left coronary sinus associated with acute myocardial infarction

Coronary MR angiography can be useful for noninvasive diagnosis of potentially life-threatening coronary artery anomalies. However, there has been no report to date on MR demonstration of acute myocardial infarction associated with right coronary artery anomaly. A 55-year-old man was admitted with chest pain. Catheter coronary angiography revealed an anomalous origin with compression in the proximal segment of right coronary artery. Breath-hold MR angiography using spiral acquisition technique showed that the right coronary artery originated from the left coronary sinus with a separate os. The proximal segment of the artery was compressed by right ventricle outflow tract during the diastolic phase of cine MR imaging. Contrast-enhanced MR imaging 5 minutes after Gd-DTPA injection showed hyperenhancement suggestive of acute myocardial infarction in the posteroinferior wall of the left ventricle.     

99Tcm-MIBI心肌灌注显像对代谢综合征患者并发冠心病的评价

目的 探讨核素心肌灌注显像对代谢综合征患者并发冠心病的诊断价值.方法 回顾性分析251例[男179例,女72例,年龄(59±10)岁]代谢综合征患者99Tcm-甲氧基异丁基异腈(MIBI)心肌灌注显像的结果,与冠状动脉造影进行比较,计算99Tc-MIBI心肌灌注显像诊断冠心病的灵敏度、特异性和准确性.结果 在251例代谢综合征患者中,163例(65%)患者冠状动脉造影示有狭窄病变,99Tcm-MIBI心肌灌注显像检出心肌缺血或心肌梗死116例;88例冠状动脉造影阴性患者中,82例心肌灌注显像结果正常;99Tcm-MIBI心肌灌注显像诊断冠心病的灵敏度为71%(116/163),特异性为93%(82/88),阳性预测值为95%(116/122),阴性预测值为64%(82/129),准确性为79%(198/251).诊断单支、双支和三支冠状动脉病变患者的灵敏度分别为58%(36/61),61%(22/36)和87%(57/66).结论 99Tcm-MIBI心肌灌注显像对检测代谢综合征患者有无并发冠心病有重要的应用价值.     

Magnetic resonance first pass perfusion imaging for detecting coronary artery disease

Magnetic resonance first pass perfusion imaging can be used to detect abnormalities in myocardial blood flow. This technique involves imaging the first pass of gadolinium based contrast through the myocardium. Images are initially read qualitatively for areas of reduced signal intensity. Additionally, at our institution a quantitative method is applied that can aid both detection and diagnosis of perfusion defects. This method involves fitting the myocardial signal intensity curves and then calculates absolute myocardial blood flow. Our approach to first pass perfusion imaging will be reviewed. Magnetic resonance first pass perfusion imaging has a complimentary role with coronary angiography either non-invasively using CT or with catheterization. Perfusion imaging defines the physiology and angiography in the anatomy of coronary artery disease.     

Giant fibroma in the left ventricle of an infant: imaging findings in magnetic resonance imaging,echocardiography and angiography

The diagnosis of a rare case of giant intraventricular fibroma in an infant by MRI in comparison with other imaging modalities, such as echocardiography and angiography, is discussed. For preoperative planning only MRI showed the myocardial infiltration. The myocardial blood supply of the tumor could be evaluated qualitatively by contrast-enhanced MRI, but the direct visualization of the distally located branches could only be assessed by coronary angiography. Magnetic resonance coronary angiography using the navigator technique failed to depict the distal part of the coronaries. The obstruction of the left ventricle outflow tract could be assessed and quantified by all imaging modalities.     

Clinical evaluation of the 99mTc-labeled myocardial imaging agent,hexakis (t-butylisonitrile)-technetium

^99mTc-TBI myocardial perfusion imaging has been studied in 7 normal subjects and 24 patients with coronary artery disease. Scintigraphic data revealed that ^99mTc-TBI myocardial perfusion imaging is more sensitive than ECG in detecting myocardial infarction. In comparing ^99mTc-TBI imaging with contrast angiography, its' sensitivity for the diagnosis of coronary artery disease was 91.7%.     

颈动脉超声、核素心肌显像与冠状动脉造影诊断冠心病的对比研究

 目的 探讨颈动脉超声、核素心肌灌注显像对冠心病的诊断价值.方法 对88例疑有冠心病者,以冠状动脉造影结果 作为诊断标准, 进行颈动脉超声检查和核素心肌灌注断层显像两种检查,并将结果 进行对比分析.结果 颈动脉超声诊断冠心病的敏感性为65.5%,特异性为73.3%.核素心肌灌注显像诊断冠心病的敏感性为86.2%,特异性为66.7%.结论 颈动脉超声结合核素心肌灌注显像诊断冠心病,敏感性与特异性较高,对冠心病的无创性诊断具有重要价值.     

Magnetic resonance imaging of ischemic heart disease: why cardiac magnetic resonance imaging will play a significant role in the management of patients with coronary artery disease

The role of magnetic resonance imaging in the diagnosis of ischemic heart disease has great potential impact on patient management, because a number of aspects of ischemic heart disease can be evaluated in one imaging session. High resolution coronary magnetic resonance angiography is currently available, although several technical improvements are awaited to make the technique routinely applicable. A major advance will probably include the availability of magnetic resonance blood pool contrast agents to improve vessel visualization. Contrast media, in combination with either first pass or delayed myocardial scanning, will also play an important role in myocardial perfusion imaging. Functional magnetic resonance assessment of regional and global ventricular function is currently a well-established technique and is considered a new gold standard, which may impact on routine cardiology practice. This review summarizes some of the recent magnetic resonance developments for evaluating various aspects of ischemic heart disease, including magnetic resonance coronary angiography, flow imaging, and imaging of myocardial perfusion and function.     

腺苷与运动负荷心肌灌注显像诊断不典型胸痛心肌缺血的临床价值

目的评价腺苷和运动负荷心肌灌注显像诊断不典型胸痛患者心肌缺血的价值。方法不典型胸痛患者67例行腺苷负荷心肌灌注显像，81例行运动负荷心肌灌注显像，结果分别与冠状动脉（简称冠脉）造影比较，得到显像诊断冠心病心肌缺血的灵敏度、特异性和准确性。结果腺苷负荷心肌灌注显像组67例中，23例冠脉造影有狭窄病变，腺苷负荷心肌灌注显像检出可逆性灌注异常即诊断心肌缺血16例，44例冠脉造影阴性者中，腺苷心肌灌注显像正常41例。腺苷负荷心肌灌注显像诊断冠心病心肌缺血的灵敏度为70％，特异性93％，准确性85％。运动负荷心肌灌注显像组81例中，31例冠脉造影阳性，运动负荷心肌灌注显像检出心肌缺血22例，50例冠脉造影阴性者中，运动负荷心肌灌注显像正常48例。运动负荷心肌灌注显像诊断冠心病心肌缺血的灵敏度为71％，特异性96％，准确性86％。结论腺苷或运动负荷心肌灌注显像出现可逆性灌注异常对诊断不典型胸痛患者冠心病心肌缺血有重要意义。     

Roles of nuclear cardiology, cardiac computed tomography, and cardiac magnetic resonance: Noninvasive risk stratification and a conceptual framework for the selection of noninvasive imaging tests in patients with known or suspected coronary artery disease.

This review deals with noninvasive imaging for risk stratification and with a conceptual approach to the selection of noninvasive tests in patients with suspected or known chronic coronary artery disease (CAD). Already widely acknowledged with SPECT, there is an increasing body of literature data demonstrating that CT coronary calcium assessment is also of prognostic value. The amount of coronary atherosclerosis, as can be extrapolated from CT coronary calcium score, has been shown to be highly predictive of cardiac events. The principal difference between myocardial perfusion SPECT (MPS) and CT coronary calcium for prognostic application appears to be that the former is an excellent tool for assessing short-term risk, thus effectively guiding decisions regarding revascularization. In contrast, the atherosclerosis imaging methods are likely to provide greater long-term risk assessment and, thus, are more useful in determination of the need for aggressive medical prevention measures. Although the more recent development of CT coronary angiography is promising for diagnosis, there has been no information to date regarding the prognostic value of the CT angiographic data. Similarly, cardiac MRI has not yet been adequately studied for its prognostic content. The selection of the most appropriate test for a given patient depends on the specific question being asked. In patients with a very low likelihood of CAD, no imaging test may be required. In screening the remaining asymptomatic patients, atherosclerosis imaging may be beneficial. In symptomatic patients, MPS, CT coronary angiography, and cardiac MRI play important roles. We consider it likely that, with an increased emphasis on prevention and a concomitant aging of the population, many forms of noninvasive cardiac imaging will continue to grow, with nuclear cardiology continuing to grow.     

Dobutamine myocardial scintigraphy for the prediction of cardiac events after heart transplantation

BACKGROUND: The long-term outcome after heart transplantation (HTx) is essentially influenced by the occurrence and extent of cardiac allograft vasculopathy (CAV). Single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) has been shown to be a useful and cost-effective non-invasive method in patients with known or suspected coronary artery disease, but its role in detecting CAV remains unclear. AIM: To evaluate the accuracy and predictive value of dobutamine MPI in patients after HTx during a 12-month follow-up. METHODS: Seventy-seven patients (60 males, 17 females) underwent a total of 216 dobutamine MPI examinations over a period of 5 years. Examinations were obtained an average of 89+/-42 months after orthotopic HTx according to a 1-day protocol using 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) with and without attenuation correction. For the present study, findings from 77 MPI examinations (one MPI examination per patient) were analysed visually and semiquantitatively using a 20-segment model. Summed stress scores (SSS) and summed rest scores (SRS) were calculated and receiver operating characteristic (ROC) analysis was performed to detect optimum threshold values. Patients were followed up for 12 months and cardiac events were registered. RESULTS: Cardiac events were observed in 10 of the 77 patients. Good interobserver agreement was found for global visual and SRS-/SSS-based analysis (kappa=0.74 and 0.66, respectively). SSS was superior to SRS in the detection of cardiac events. ROC analysis showed an optimized SSS threshold value of three. For predicting a cardiac event during the 12-month follow-up, global visual and semiquantitative analysis reached sensitivities of 90% and 90%, specificities of 72% and 88%, accuracies of 74% and 87%, positive predictive values of 32% and 53% and negative predictive values of 98% and 98%, respectively. The sensitivity, specificity, accuracy and positive and negative predictive values for MPI to detect clinically relevant coronary artery stenoses (> or =50%) at conventional coronary angiography were 83%, 87%, 86%, 56% and 96%, respectively. CONCLUSIONS: Non-invasive dobutamine MPI reliably identifies patients at risk for subsequent cardiac events in cases of CAV, with a high negative predictive value of 98% and an accuracy of 87%.     

Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320-MDCT: the CT angiography and perfusion methods of the CORE320 multicenter multinational diagnostic study

OBJECTIVE: Coronary MDCT angiography has been shown to be an accurate noninvasive tool for the diagnosis of obstructive coronary artery disease (CAD). Its sensitivity and negative predictive value for diagnosing percentage of stenosis are unsurpassed compared with those of other noninvasive testing methods. However, in its current form, it provides no information regarding the physiologic impact of CAD and is a poor predictor of myocardial ischemia. CORE320 is a multicenter multinational diagnostic study with the primary objective to evaluate the diagnostic accuracy of 320-MDCT for detecting coronary artery luminal stenosis and corresponding myocardial perfusion deficits in patients with suspected CAD compared with the reference standard of conventional coronary angiography and SPECT myocardial perfusion imaging. CONCLUSION: We aim to describe the CT acquisition, reconstruction, and analysis methods of the CORE320 study.     

Acute chest pain with normal coronary angiogram: role of contrast-enhanced multidetector computed tomography in the differential diagnosis between myocarditis and myocardial infarction

OBJECTIVE: To evaluate the accuracy of delayed-enhanced multidetector computed tomography (MSCT) for differentiating between myocarditis and myocardial infarction in patients with normal x-ray coronary angiography. METHODS: Twelve consecutive patients referred for acute chest pain and normal coronary arteries on x-ray coronary angiography were involved in this study. Delayed-enhanced MSCT and postgadolinium delayed-enhanced magnetic resonance imaging (MRI) examinations were performed within 36 hours and 4 days, respectively, after patient admission. Comparison between delayed-enhanced MSCT and MRI was performed by 3 independent blinded observers in term of final diagnosis, number of involved segments, and transmural extent. RESULTS: Final diagnosis between myocarditis and myocardial infarction was identical for delayed-enhanced MSCT and MRI with a significant agreement for number of involved segments and transmural extension. Interobserver reproducibility was good for both techniques. CONCLUSIONS: We demonstrated that delayed-enhanced MSCT allows differentiation between myocardial infarction and myocarditis with the same accuracy at acute phase compared with MRI.     

MRI in coronary artery disease

Diagnosis of coronary artery disease (CAD) is a major challenge for medical imaging, because CAD is the leading cause of death in developed nations. Several non-invasive tests are used in clinical routine for the detection of CAD. However, due to limited sensitivity and specificity, the reliable diagnosis as well as the exclusion of CAD can only be established by catheter angiography. In patients with known CAD, therapeutic decisions require accurate information on myocardial function, ischemia and viability. Recently, magnetic resonance (MR) imaging has emerged as a non-invasive cardiac imaging technique that provides information on cardiac morphology, cardiac function, myocardial viablitiy, and coronary morphology. This review discusses technical aspects and the clinical impact of different MR techniques.     

Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320 row detector computed tomography: design and implementation of the CORE320 multicenter, multinational diagnostic study

Multidetector coronary computed tomography angiography (CTA) is a promising modality for widespread clinical application because of its noninvasive nature and high diagnostic accuracy as found in previous studies using 64 to 320 simultaneous detector rows. It is, however, limited in its ability to detect myocardial ischemia. In this article, we describe the design of the CORE320 study ("Combined coronary atherosclerosis and myocardial perfusion evaluation using 320 detector row computed tomography"). This prospective, multicenter, multinational study is unique in that it is designed to assess the diagnostic performance of combined 320-row CTA and myocardial CT perfusion imaging (CTP) in comparison with the combination of invasive coronary angiography and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). The trial is being performed at 16 medical centers located in 8 countries worldwide. CT has the potential to assess both anatomy and physiology in a single imaging session. The co-primary aim of the CORE320 study is to define the per-patient diagnostic accuracy of the combination of coronary CTA and myocardial CTP to detect physiologically significant coronary artery disease compared with (1) the combination of conventional coronary angiography and SPECT-MPI and (2) conventional coronary angiography alone. If successful, the technology could revolutionize the management of patients with symptomatic CAD.     

Double right coronary artery diagnosed by computed tomographic angiography: A case report and systematic review of the literature

Double right coronary artery (RCA) is an extremely uncommon anomaly that is mostly detected incidentally in patients undergoing coronary angiography. It can be a benign and isolated anomaly or associated with other congenital abnormalities, mostly other coronary anomalies. Although atherosclerosis and myocardial ischemia have been frequently reported in patients with double RCA, this likely reflects that the patients were evaluated for chest pain rather than the predisposition to atherosclerosis in double RCA. Paralleling the increased awareness of this entity and the availability of non-invasive and cost-effective imaging of the coronary arteries, the diagnosis of double RCA has increased recently. Here, we present a case of double RCA diagnosed by coronary computed tomographic angiography, and provide a mini-review on the demography, anatomic variants, and clinical significance of double RCA.     

静息心肌灌注显像判断梗塞相关动脉的作用

目的　评价静息心肌显像的缺血缺损部位对于判断梗塞相关动脉 (IRA)的价值。方法对 44例心肌梗死患者进行99Tcm 甲氧基异丁基异腈 (MIBI)静息心肌断层显像和冠状动脉造影(CAG)。结果　CAG提示IRA 44支 ,其中左前降支 (LAD) 2 7支 ,左旋支 (LCX) 9支 ,右冠脉 (RCA) 8支。当IRA是LAD时出现间壁受累 ,IRA是LCX时出现侧壁受累和IRA是RCA时表现下后壁受累的意义较大 (χ2 =8.98和 8.96 ,P均 <0 .0 5 ;χ2 =43.82 ,P <0 .0 0 5 )。前壁、心尖部、间壁和广泛前壁稀疏缺损对于判断IRA LAD的灵敏度较高 ,分别是 89% ,86 % ,80 %和 89% ;特异性以间壁最高 ,达 80 % ;侧壁和后侧壁判断IRA LCX的灵敏度和特异性分别是 75 % ,6 7%和 85 % ,83% ;下后壁病变判断IRA RCA的灵敏度和特异性分别是 71%和 91%。结论　心肌灌注显像对于判断心肌梗死的IRA有一定价值     

冠状动脉CTA诊断心肌桥的临床价值

目的:探讨冠状动脉CTA诊断心肌桥的临床价值。材料和方法:使用16排螺旋CT对56例患者行CTA检查,根据CTA上冠状动脉的走行部位,诊断12例心肌桥,其中7例行X线冠状动脉造影,10例使用3D屏气FIESTA序列行冠状动脉MRA检查,比较CTA、MRA和X线冠状动脉造影显示心肌桥的效率。结果:CT显示12例心肌桥共13支壁血管在心肌内走行,其中4例可以被X线冠状动脉造影显示,MRA不能可靠显示心肌桥,仅3例提示心肌桥可能。结论:冠状动脉CTA可以准确显示心肌桥,为临床提供判断心肌缺血的可能原因。