Coronary CTA assessment of coronary anomalies

Coronary anomalies occur in <1% of the general population and can range from a benign incidental finding to the cause of sudden cardiac death. The coronary anomalies are classified here according to the traditional grouping into those of origin and course, intrinsic arterial anatomy, and termination. Classic coronary anomalies of origin and course include those in which a coronary artery originates from the contralateral aortic sinus or the pulmonary artery with anomalous course. Single coronary artery anomalies, in which single coronary artery branches to supply the entire coronary tree, are also included in this category. Anomalies of intrinsic arterial anatomy are a broad class that includes myocardial bridges, coronary ectasia and aneurysms, subendocardial coursing arteries, and coronary artery duplication. Coronary anomalies of termination are those in which a coronary artery terminates in a fistulous connection to a great vessel or cardiac chamber. In the case of those anomalies associated with a risk of sudden cardiac death, the relevant imaging features on CT angiography (CTA) associated with poorer prognosis are reviewed. Recent guidelines and appropriateness criteria favor the use of coronary CTA for the evaluation of coronary anomalies. Although invasive angiography has historically been used to diagnose coronary anomalies, multidetector CT imaging techniques have now become an accurate noninvasive alternative. Cardiac CTA provides excellent spatial and temporal resolution, allowing accurate anatomical assessment of these anomalies.     

Coronary artery anomalies diagnosed by magnetic resonance angiography

Coronary artery anomalies are uncommon entities that may be associated with sudden death. Because of its 2-D projection imaging nature, conventional X-ray coronary angiography may not accurately delineate the origins and course of aberrant coronary arteries with respect to the great vessels. Non-invasive, cross-sectional imaging techniques such as coronary CT angiography and magnetic resonance angiography are increasingly used in clinical practice to diagnose coronary artery anomalies. Although this study reviews coronary artery anatomy and selected anomalies as seen with true fast imaging with steady-state precession magnetic resonance angiography, the information provided is equally applicable to electrocardiogram-gated coronary CT angiography.     

Coronary CT angiography: current status and continuing challenges

Coronary CT angiography has been increasingly used in the diagnosis of coronary artery disease owing to rapid technological developments, which are reflected in the improved spatial and temporal resolution of the images. High diagnostic accuracy has been achieved with multislice CT scanners (64 slice and higher), and in selected patients coronary CT angiography is regarded as a reliable alternative to invasive coronary angiography. With high-quality coronary CT imaging increasingly being performed, patients can benefit from an imaging modality that provides a rapid and accurate diagnosis while avoiding an invasive procedure. Despite the tremendous contributions of coronary CT angiography to cardiac imaging, study results reported in the literature should be interpreted with caution as there are some limitations existing within the study design or related to patient risk factors. In addition, some attention must be given to the potential health risks associated with the ionising radiation received during cardiac CT examinations. Radiation dose associated with coronary CT angiography has raised serious concerns in the literature, as the risk of developing malignancy is not negligible. Various dose-saving strategies have been implemented, with some of the strategies resulting in significant dose reduction. The aim of this review is to present an overview of the role of coronary CT angiography on cardiac imaging, with focus on coronary artery disease in terms of the diagnostic and prognostic value of coronary CT angiography. Various approaches for dose reduction commonly recommended in the literature are discussed. Limitations of coronary CT angiography are identified. Finally, future directions and challenges with the use of coronary CT angiography are highlighted.     

CT of coronary artery disease

The socioeconomic importance of heart disease provides considerable motivation for development of radiologic tools for noninvasive imaging of the coronary arteries. Current computed tomographic (CT) techniques combine high speed and spatial resolution with sophisticated electrocardiographic synchronization and robustness of use. Application of these modalities for evaluation of coronary artery disease is a topic of active current research. Coronary artery calcium measurements with different CT techniques have been used for determining the risk of coronary events, but the exact role of this marker for cardiac risk stratification remains unclear pending results of population-based studies. Contrast material-enhanced CT coronary angiography has become an established clinical indication for some scenarios (eg, coronary artery anomalies, bypass patency, surgical planning). With current technology, the accuracy of CT coronary angiography for detection of coronary artery stenoses appears promising enough to warrant pursuit of this application, but sensitivity is still not high enough for routine diagnostic needs. The high negative predictive value of a normal CT coronary angiogram, however, may be useful for reliable exclusion of coronary artery stenosis. The cross-sectional nature of CT may allow noninvasive assessment of the coronary artery wall. Use of contrast-enhanced CT coronary angiography for detection, characterization, and quantification of atherosclerotic changes and total disease burden in coronary arteries as a potential tool for cardiac risk stratification is currently being investigated.     

64MSCTA对冠状动脉变异的诊断及临床评价

目的评价64层螺旋CT冠状动脉血管成像（CTCA）对冠状动脉变异的诊断价值及临床评价。方法回顾性分析3529例临床疑为心肌缺血患者及常规体查者冠状动脉CTA影像检查结果并对发现的变异冠状动脉进行分类。结果3529例冠状动脉CTA受检者中,共检出冠状动脉变异42例（1．19％,42／3529）,MIP、VRT、CPR重建图像均明确显示其开口及走行;其中右冠状动脉起自主动脉左冠状窦者9例,左冠状动脉起自主动脉右冠状窦者2例,左回旋支异位开口于右冠窦1例,冠状动脉高位开口于升主动脉壁者6例．并行左主干3例（前降支、旋支分别开口于左冠窦）,左主干开口于肺动脉伴右冠状动脉瘤1例,左旋支-冠状静脉瘘者2例,副冠状动脉9例,右冠状动脉-左心室瘘合并右冠状动脉瘤l例。冠状动脉发育不良8例。结论冠状动脉CTA能准确显示各种类型冠状动脉变异,可作为无创性诊断冠状动脉变异的首选方法。     

64排容积CT对成人冠状动脉起源异常的诊断价值

 目的 探讨64排容积CT对成人冠状动脉起源异常的诊断价值.方法 回顾分析3 030例成人冠状动脉CTA检查资料. 结果 3 030例冠脉CTA中,检查出冠状动脉起源异常70例,检出率为2.3%,其中冠状动脉起源于对侧冠状窦及窦外27例(38.5%);冠状动脉高位开口23例(32.8%);前降支、回旋支均开口于左冠状窦17例(24.3%);单一冠脉2例(均为单一左冠,其中1例合并左主干高开口,2.8%),回旋支开口于对角支及窦房结支开口于右冠状窦各1例(1.4%).结论 64排容积CT诊断冠状动脉起源异常是一种无创、安全、准确、经济的检查方法 .     

Coronary CT angiography: How should physicians use it wisely and when do physicians request it appropriately?

Coronary CT angiography has been increasingly used in the diagnosis of coronary artery disease due to rapid technological developments, which are reflected in the improved spatial and temporal resolution of the images. High diagnostic accuracy has been achieved with 64- and more slice CT scanners and in selected patients, coronary CT angiography is regarded as a reliable alternative to invasive coronary angiography. Although the tremendous contributions of coronary CT angiography to cardiac imaging are acknowledged, appropriate use of cardiac CT as the first line technique by physicians has not been well established. Optimal selection of cardiac CT is essential to ensure acquisition of valuable diagnostic information and avoid unnecessary invasive procedures. This is of paramount importance since cardiac CT not only involves patient risk assessment, prediction of major cardiac events, but also impacts physician decision-making on patient management. Applications of CT in cardiac imaging include coronary artery calcium scoring for predicting the patient risk of developing major cardiac events, followed by coronary CT angiography which is commonly used to determine the diagnostic and prognostic accuracy in the coronary artery disease. This review presents an overview of the applications of CT in cardiac imaging in terms of coronary calcium scoring and coronary CT angiography. Judicious use of both cardiac CT tools will be discussed with regard to their value in different patient risk groups with the aim of identifying the appropriate criteria for choosing a cardiac CT modality. An effective diagnostic pathway is finally recommended to physicians for appropriate selection of cardiac CT in clinical practice.     

Detection of malignant right coronary artery anomaly by multi-slice CT coronary angiography

Coronary artery anomalies occur in 0.3-0.8% of the population and infer a high risk for sudden cardiac death in young adults. Diagnosis is usually established during coronary angiography, which is hampered by poor spatial visualization. Magnetic resonance imaging is an alternative, but it is not feasible in the presence of metal objects or claustrophobia. In this report, a 15-year-old boy experienced ventricular fibrillation and was successfully resuscitated. Cardiac catheterization was inconclusive, and pacemaker implantation prohibited the use of MR imaging. Multi-slice CT coronary angiography revealed a malignant anomalous right coronary artery.     

Congenital anomalies of coronary arteries: Diagnosis with 64 slice multidetector CT

Objective

Congenital coronary artery anomalies are generally incidental, uncommon and asymptomatic. Some can cause severe potentially life threatening symptoms. The common mode of studying the coronary arteries is Conventional Coronary Angiogram. ECG-gated-multidetector CT is a non invasive modality. The objective of our study was to identify rare congenital coronary artery anomalies and discuss their clinical significance.

Material and methods

A total number of 900 MDCT coronary angiograms were carried out at our institution between the period of April 2006 and October 2010. Patients with coronary artery anomaly constituted the subject of study.

Results

The incidence of anomalous anatomical origin and course of the coronary arteries in our study was 1.55%. Hemodynamical significance was seen in five patients. 3 cases of single coronary artery originating from right coronary sinus were seen. 1 case of anomalous left coronary artery arising from main pulmonary artery was seen. 4 cases of anomalous RCA arising from left aortic cusp, 6 cases of absent LMCA with separate origin of LAD and LCX were seen.

Conclusion

Multidetector row CT is a noninvasive modality in cardiac imaging. It provides superior resolution of coronary tree and its variant. No projectional vascular overlap is seen. Various postprocessing techniques outclass catheter angiography imaging. Definition of ostia and proximal course of the coronary arteries by Multidetector CT is better than catheter angiography.     

64层CT冠状动脉成像检测冠状动脉畸形价值初探

目的:探讨64层CT冠状动脉成像检测冠状动脉畸形的方法和诊断价值.方法:采用容积再现(VR)、最大密度投影(MIP)以及多平面重组(MPR)等方法分析2672例64层CT冠状动脉成像资料,总结冠状动脉畸形的发生率和CT表现.结果:2672例中发现冠状动脉起源异常18例(0.67%),其中发生于右冠11例(61.11%),左冠7例(38.89%);发现冠状动脉瘘7例(0.26%).结论:64层CT冠状动脉成像能够准确全面地显示冠状动脉的异常起源、走行和终止.     

Coronary artery anomalies: incidence, pathophysiology, clinical relevance and role of diagnostic imaging

Conventional coronary angiography is the gold standard for the diagnosis of coronary artery anomalies. Coronary anomalies are relatively rare findings in patients undergoing conventional coronary angiography for suspected obstructive coronary artery disease. Recently, the increasing performance of diagnostic techniques, such as electron beam tomography (EBT), magnetic resonance (MR) and, more recently, multislice computed tomography (MSCT), has enabled their application to cardiac imaging. MSCT, in particular, has a prominent role in coronary imaging due to its spatial and temporal resolution and three-dimensional capabilities. We report the incidence and pathophysiology of coronary artery anomalies based on the capabilities of recent diagnostic tools with the aim of improving an accurate and noninvasive diagnostic approach.     

Anomalous coronary arteries in adults: depiction at multi-detector row CT angiography

PURPOSE: To retrospectively determine the imaging features of anomalous coronary arteries depicted at multi-detector row computed tomographic (CT) angiography in 18 patients seen at four institutions. MATERIALS AND METHODS: Eighteen patients underwent imaging with a four- or 16-section multi-detector row CT unit by using retrospective electrocardiographic (ECG) gating after infusion of 120-150 mL of intravenous contrast material. Section thicknesses of 0.8-3.0 mm were achieved during breath holding, and images were reconstructed with a 50% overlap. Volumetric reconstructions were obtained for each patient. Each study was assessed retrospectively for the origin and course of the anomalous coronary artery by two thoracic radiologists; decisions were made in consensus. Institutional review board exemption and informed consent waiver was granted at each institution. The study was compliant with the Health Insurance Portability and Accountability Act. RESULTS: Seventeen patients were referred because of equivocal findings at cardiac catheterization or echocardiography; in one, the anomalous coronary artery was incidental. A total of 20 anomalous vessels were found. Twelve patients with 14 variant vessels had an anomalous origin of a left coronary artery (right cusp, 13; noncoronary cusp, one). In four patients, an anomalous right coronary artery originated from the left side; one patient had a single coronary artery arising from the right cusp. In one patient, a left coronary artery-to-vein fistula was observed. In 10 patients, the anomalous vessel passed between the aorta and the main pulmonary artery or right ventricular outflow track. In each case, the origin of the anomalous coronary artery and its course in relationship to the great vessels were unequivocally demonstrated. Volumetric images were useful for showing the three-dimensional orientation of the anomalous coronary artery with respect to the great vessels and cardiac chambers. CONCLUSION: Multi-detector row CT angiography provided accurate depiction of vessel origin and course in this review of 20 anomalous coronary arteries. The results of this study suggest that CT is a viable noninvasive modality for delineating coronary arterial anomalies, particularly if findings at coronary angiography are equivocal.     

Coronary anomalies encountered in the acute setting: an imaging review

A broad spectrum of congenital coronary anomalies may be discovered on imaging and sometimes in the emergency setting on computed tomography (CT). Most coronary artery anomalies are of academic interest; however, a minority can cause morbidity and mortality and symptoms such as angina, myocardial infarction, or arrhythmias. These anomalies are usually discovered as an incidental finding on CT examinations as part of the diagnostic workup for other pathology or on dedicated coronary computed tomography angiography (CCTA) as part of the evaluation for a coronary cause of chest pain. The purpose of this pictorial review is to demonstrate the types of coronary anomalies and to enhance the clinicians’ understanding of the imaging classifications and clinical implications.     

Coronary CT angiography in asymptomatic middle‐aged athletes with ST segment anomalies during maximal exercise test

The clinical significance of ST segment anomalies occurring during exercise test in asymptomatic subjects is still debated. We designed a cross‐sectional study to evaluate if the presence of these exercise test abnormalities were related with coronary CT angiography findings. Nine hundred forty athletes (range 30 to 60 years old), performed a maximal exercise test for sport eligibility. Forty‐six subjects (4.9%) showing ST abnormalities during exercise and/or the recovery phase were referred to a 64‐slice coronary computed tomography (CT) angiography. Among 44 subjects who underwent coronary CT angiography, 23 had an equivocal while 21 had a positive exercise test. Coronary CT angiography found, six and eight subjects with significant and not significant coronary artery disease, respectively. Further, seven patients demonstrated origin and course coronary anomalies. The positive predictive value for significant coronary artery disease of the exercise test was 13.6%. Our data suggest the referral to coronary CT angiography even of patients with equivocal repolarization anomalies during exercise and its recovery phase. Although the positive predictive value of a maximal exercise test in asymptomatic athletes appears lower than what observed in patients at high risk for coronary artery disease, about half of athletes with equivocal or positive exercise test demonstrated some coronary abnormalities.     

Coronary artery anomalies: Role of contrast enhanced MDCT coronary angiography

Objective

The purpose of this study is to evaluate the role of MDCT in the depiction of coronary artery anomalies.

Patients and methods

Sixteen patients were included in this study. Retrospectively gated coronary CT angiography was performed in 11 patients and prospectively gated CT coronary angiography was performed in 5 patients. Post-processing techniques as maximum-intensity projection, curved multiplanar reconstruction, and volume rendering were applied to assess the origin and course of the coronary vessels.

Results

Origin and course anomalies of the central coronary artery segments were seen in 11 patients (67%), anomalies of only coronary artery origin in 2 patients (13%), origin and course anomalies of the peripheral coronary segments in 2 patients (13%) and coronary arterio-venous fistula in one patient (7%). The origin and course anomalies of the central coronary artery segment were more common in the left coronary artery involving 8 patients (73%). Malignant inter-arterial course between aortic root and pulmonary artery or the right ventricle outflow tract was seen in 3 anomalous arteries.

Conclusion

MDCT coronary angiography can precisely depict the origin and course coronary artery anomalies and is recommended in young patients and before cardiac intervention or surgery to prevent possible complications.     

成年人先天性冠状动脉变异的多层螺旋CT诊断

目的探讨多层螺旋CT（MSCT）在成年人先天性冠状动脉变异诊断中的临床应用价值。资料与方法回顾性分析331例成年人患者的冠状动脉MSCT造影资料,判断各种先天性冠状动脉变异。结果331例MSCT冠状动脉造影中检出冠状动脉变异14例,包括冠状动脉开口起源异常4例,单支冠状动脉1例,左回旋支缺如1例;冠状动脉心肌桥8例。结论MSCT是一种无创、准确、可重复性强的诊断先天性冠状动脉变异的重要手段。     

MSCT对冠状动脉变异的诊断价值

目的 :分析多层螺旋CT(MSCT)对冠状动脉变异的诊断价值。方法 :回顾性分析总结 9例患者的MSCT冠状动脉成像资料。结果 :9例冠状动脉变异患者中冠状动脉开口起源异常 4例 ,单一冠状动脉 1例 ,右冠状动脉发育不良1例 ,左回旋支缺如 1例 ,冠状动脉分支起源异常 2例。结论 :MSCT可无创性准确诊断各种冠状动脉变异。     

64层螺旋CT诊断先天性冠状动脉变异

目的:探讨多层螺旋CT(MSCT)在成年人先天性冠状动脉变异诊断中的临床应用价值。方法:回顾性分析726例成年人患者的冠状动脉MSCT造影资料,判断各种先天性冠状动脉变异。结果:726例MSCT冠状动脉造影中检出冠状动脉变异39例,包括冠状动脉开口起源异常11例,单支冠状动脉1例,冠状动脉瘤2例,冠状动脉分支起源异常11例,冠状动脉发育不良13例,冠脉开口处急性扭转走行异常1例。结论:MSCT是一种无创、准确、可重复性强的诊断先天性冠状动脉变异的重要手段。     

Evaluation with 64-slice CT of the prevalence of coronary artery variants and congenital anomalies: a retrospective study of 3,236 patients

Purpose

This study retrospectively evaluated the prevalence of anatomical coronary artery variants and congenital anomalies in 3,236 patients imaged with 64-slice computed tomography (CT).

Materials and methods

Over a period of 4 years, 3,236 patients underwent CT coronary angiography performed with the standard protocol. We assessed coronary artery dominance, presence of the intermediate branch, presence and number of diagonal and marginal branches and coronary anomalies subdivided into anomalies of origin and course, intrinsic anomalies and termination anomalies.

Results

Coronary dominance was right-sided in 88.1% of patients; the intermediate branch was present in 21.3%, the number of diagonal and marginal branches was one to two in >90%, and the number of coronary anomalies was 224 (89 of origin and course, 129 intrinsic anomalies and six termination anomalies).

Conclusions

Sixty-four-slice CT coronary angiography provides accurate three-dimensional evaluation of the coronary artery tree with correct visualisation of any coronary anomalies, a relatively common finding that had a prevalence of 5.7% in our study population.     

Duplicated right coronary artery: multidetector CT angiographic findings

Multidetector CT is becoming an alternative method for the diagnosis of coronary artery anomalies. We present the multidetector coronary CT angiography findings from a patient with right coronary artery duplication. Two separate right coronary arteries originating from the right aortic sinus were observed. Their anatomical course was well depicted, and atherosclerosis was excluded based on the CT angiography findings.