Adenosine-stress dynamic myocardial volume perfusion imaging with second generation dual-source computed tomography: Concepts and first experiences

Recent research suggests that multidetector-row CT may have potential as a standalone modality for integrative imaging of coronary heart disease, including the assessment of the myocardial blood supply. However, the technical prerequisites for volumetric, time-resolved imaging of the passage of a contrast medium bolus through the myocardium have only been met with latest generation wide-detector CT scanners. Second-generation dual-source CT enables performing electrocardiographic (ECG)–synchronized dynamic myocardial perfusion imaging by a dedicated “shuttle” mode. With this acquisition mode, image data can be acquired during contrast medium infusion at 2 alternating table positions with the table shuttling back and forth between the 2 positions covering a 73-mm anatomic volume. We applied this acquisition technique for detecting differences in perfusion patterns between healthy and diseased myocardium and for quantifying myocardial blood flow under adenosine stress in 3 patients with coronary heart disease. According to our initial experience, the addition of adenosine stress volumetric dynamic CT perfusion to a cardiac CT protocol comprising coronary artery calcium quantification, prospectively ECG-triggered coronary CT angiography, and delayed acquisition appears promising for the comprehensive assessment of coronary artery luminal integrity, cardiac function, perfusion, and viability with a single modality.     

Assessment of ischemic heart disease with electron-beam CT and MR imaging

Anatomical and functional information derived from diagnostic modalities is essential in cardiac imaging. Electron-beam CT and MR imaging have played a role in the assessment of cardiac function, and recent developments in both modalities have permitted non-invasive visualization of coronary artery stenosis, which previously had been demonstrated exclusively by catheter coronary angiography. In this article, coronary artery imaging and cardiac functional imaging were reviewed by focusing on new technical developments in the screening of coronary atherosclerosis leading to acute coronary syndrome. Quantitative assessment of coronary calcifications by electron-beam CT has already become one of the most useful techniques for predicting the degree of coronary atherosclerosis and the risk of coronary events in individual patients. Electron-beam CT and MR imaging have also provided non-invasive clinical tools with which to demonstrate coronary artery stenosis. Visualization and characterization of atheromatous plaque at the coronary artery has recently been attempted with MR imaging, since this might lead to the detection of coronary artery plaque that was likely to rupture, thereby possibly predicting and preventing acute coronary syndrome in asymptomatic individuals. Although electron-beam CT and MR imaging have not been fully incorporated into routine clinical practice, each could serve as a comprehensive modality for the assessment of ischemic heart disease.     

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.     

Multidetector-row CT coronary angiographic finding of myocardial bridging

Myocardial bridging is caused by muscles overlying the intramyocardial course of an epicardial coronary artery. It is a congenital anomaly characterized by systolic compression of the tunnelled segment, commonly affecting the mid-portion of the left anterior descending coronary artery. The authors report two cases of myocardial bridging using electrocardiogram-gated multidetector-row CT coronary angiography as a reliable and non-invasive imaging technique.     

CCTA技术对冠状动脉狭窄及其钙化斑块的评估

冠状动脉CT血管成像（CCTA）是一种可无创检测冠状动脉粥样硬化性疾病的成像手段,已成为临床筛查及诊断冠心病的首要检查方法。但对于钙化严重的冠状动脉节段,CCTA的特异性及阳性预测值偏低,可导致病人过度治疗,因此限制了CCTA的临床应用。综述钙化斑块伪影对CCTA的影响,并就CCTA对冠状动脉狭窄准确评估的相关技术进展进行分析,以利于临床诊断中提高CCTA对冠状动脉狭窄率的评估。     

Reporting incidental coronary,aortic valve and cardiac calcification on non-gated thoracic computed tomography,a consensus statement from the BSCI/BSCCT and BSTI

Incidental coronary and cardiac calcification are frequent findings on non-gated thoracic CT. We recommend that the heart is reviewed on all CT scans where it is visualised. Coronary artery calcification is a marker of coronary artery disease and it is associated with an adverse prognosis on dedicated cardiac imaging and on non-gated thoracic CT performed for non-cardiac indications, both with and without contrast. We recommend that coronary artery calcification is reported on all non-gated thoracic CT using a simple patient-based score (none, mild, moderate, severe). Furthermore, we recommend that reports include recommendations for subsequent management, namely the assessment of modifiable cardiovascular risk factors and, if the patient has chest pain, assessment as per standard guidelines. In most cases, this will not necessitate additional investigations. Incidental aortic valve calcification may also be identified on non-gated thoracic CT and should be reported, along with ancillary findings such as aortic root dilation. Calcification may occur in other parts of the heart including mitral valve/annulus, pericardium and myocardium, but in many cases these are an incidental finding without clinical significance.     

双源CT冠状动脉成像方法与图像质量的研究

目的探讨无需口服控制心率药物准备的双源CT冠状动脉成像的扫描技术和图像质量。方法对100例临床怀疑冠心病或冠状动脉早期病变患者进行无需口服控制心率药物准备的双源CT冠状动脉成像扫描,图像行多平面重组（MPR）、最大密度投影（MIP）、容积再现技术（VRT）重组,利用Inspace软件及Circulation软件分析,总结双源CT冠状动脉成像的扫描技术和后处理方法。将图像质量分为3级,按冠状动脉分段标准评价各个节段的图像质量。结果心率平均为82．3（56～127）L~．／min。采用尽可能使冠状动脉显示良好的最佳收缩期（BestSyst）及最佳舒张期（BestDiast）的重建方法,评价1000个冠状动脉节段,其中,图像质量为1级占96％（960／1ooo）,2级占3％（30／1000）,3级者占1％（10／1000）;图像质量为2级和3级的节段多由严重心律不齐或呼吸带来的运动伪影所致。结论双源CT冠状动脉成像在无需口服控制心率药物准备的情况下可获得非常好的冠状动脉各节段图像,心率不再是影响图像质量的关键因素,但严重心律不齐还会影响冠状动脉成像的图像质量。     

IgG4-related cardiovascular disease. The emerging role of cardiovascular imaging

Immunoglobulin 4-related disease (IgG4-related disease) is a systemic inflammatory disease that presents with increases of serum IgG4. It may affect various systems, including the cardiovascular (CV) system. Assessment of serum IgG4 levels and involved organ biopsy are necessary for diagnosis. IgG4-related disease is characterized by fibrosclerosis, lymphocytic infiltration and presence of IgG4-positive plasma cells. The disease usually responds to treatment with corticosteroids and/or immunosuppressive medication.CV involvement may manifest as cardiac pseudotumors, inflammatory periaortitis, coronary arteritis and/or pericarditis. IgG4-related cardiovascular disorders can severely affect patient prognosis. Various imaging techniques, including echocardiography, Computed Tomography (CT), 18FDG-PET, Cardiovascular Magnetic Resonance (CMR) and cardiac catheterisation, have been successfully used for early disease detection and follow-up.Echocardiography and vascular ultrasound are the most commonly used non-invasive, non-radiating imaging techniques for the evaluation of IgG4-related CV disease. Periaortitis/periarteritis can be also assessed by CT, showing a soft tissue thickening around arteries. Coronary artery aneurysms can be easily diagnosed by coronary CT. In case of active periarterial or coronary artery inflammation, 18FDG-PET will show FDG uptake at the area of the lesion.CMR, due to its capability to perform function and tissue characterisation, can offer an integrated imaging of aorta, coronary arteries and the heart, assessment of disease acuity, extent of fibrosis and guide further treatment. However, multimodality imaging may be necessary for assessment of disease activity and fibrosis extent in those cases with multifocal CV involvement.     

双源CT冠状动脉成像在老年冠心病临床诊断中的应用分析

目的 探讨在老年冠心病临床诊断中双源CT冠状动脉成像的应用价值.方法 2019年12月至2020年7月期间,从我院选取140例老年冠心病患者根据随机数字表法分为对照组和观察组,每组患者均为70例.对照组行常规冠状动脉造影方法诊断,观察组行双源CT冠脉成像方法诊断.对比2组患者检查结果,冠状动脉分支诊断效果和冠状动脉节段...     

双源CT双能量心肌血池成像的应用及研究进展

缺血性心脏病已经成为威胁人类健康的高发疾病,判断供血区心肌灌注情况以及冠脉是否有狭窄对预防、治疗缺血性心脏病有重要意义。双能量CT心肌灌注检查在临床上多用于静态评估心肌血池,用于冠心病或心肌梗死的检查。笔者将近年来双源CT双能量心肌血池成像的原理、扫描方法、图像采集及临床应用做一综述。     

负荷双能量CT心肌灌注成像在冠心病诊断中的研究进展

冠状动脉CT血管成像在评估冠状动脉狭窄程度及检测冠状动脉粥样硬化斑块有着较高的准确性,但不能提供病变血管所支配心肌区域的微循环信息。而双能量CT心肌灌注成像能够同时提供冠状动脉的解剖学信息及生理学信息,其较传统单能量CT心肌灌注有一定的优势,且具有相应的临床应用潜力。综述负荷双能量CT心肌灌注成像在冠心病诊断中的研究进展。     

Coronary artery assessment by multidetector computed tomography in patients with prosthetic heart valves

Objectives

Patients with prosthetic heart valves may require assessment for coronary artery disease. We assessed whether valve artefacts hamper coronary artery assessment by multidetector CT.

Methods

ECG-gated or -triggered CT angiograms were selected from our PACS archive based on the presence of prosthetic heart valves. The best systolic and diastolic axial reconstructions were selected for coronary assessment. Each present coronary segment was scored for the presence of valve-related artefacts prohibiting coronary artery assessment. Scoring was performed in consensus by two observers.

Results

Eighty-two CT angiograms were performed on a 64-slice (n?=?27) or 256-slice (n?=?55) multidetector CT. Eighty-nine valves and five annuloplasty rings were present. Forty-three out of 1160 (3.7%) present coronary artery segments were non-diagnostic due to valve artefacts (14/82 patients). Valve artefacts were located in right coronary artery (15/43; 35%), left anterior descending artery (2/43; 5%), circumflex artery (14/43; 32%) and marginal obtuse (12/43; 28%) segments. All cobalt-chrome containing valves caused artefacts prohibiting coronary assessment. Biological and titanium-containing valves did not cause artefacts except for three specific valve types.

Conclusions

Most commonly implanted prosthetic heart valves do not hamper coronary assessment on multidetector CT. Cobalt-chrome containing prosthetic heart valves preclude complete coronary artery assessment because of severe valve artefacts.

Key Points

? Most commonly implanted prosthetic heart valves do not hamper coronary artery assessment ? Prosthetic heart valve composition determines the occurrence of prosthetic heart valve-related artefacts ? Bj?rk–Shiley and Sorin tilting disc valves preclude diagnostic coronary artery segment assessment     

Comparative use of radionuclide stress testing, coronary artery calcium scanning, and noninvasive coronary angiography for diagnostic and prognostic cardiac assessment

Noninvasive cardiac imaging has undergone a recent resurgence with the development of new approaches for imaging coronary atherosclerosis. Non-contrast computed tomography (CT) for imaging the extent of coronary artery calcification (CAC) and contrast CT for noninvasive coronary angiography (CTA) are developments with a growing evidence base regarding risk assessment and the diagnosis of obstructive coronary disease. This review discusses the role of CAC for risk assessment of asymptomatic individuals and for the use of coronary CTA in symptomatic patients. By comparison, gated myocardial perfusion scintigraphy (MPS) is a well-established noninvasive imaging modality that is a core element in evaluation of patients with stable chest pain syndromes. Stress MPS is the most commonly used stress imaging technique for patients with suspected or known coronary disease. In contrast to the nascent evidence noted with coronary CTA, MPS has a robust evidence base, including the support of numerous clinical guidelines. We highlight the current evidence supporting the diagnostic accuracy and risk stratification data for MPS for symptomatic patients with known or suspected coronary artery disease. It is likely that assessing the extent of atherosclerosis using CAC or coronary CTA will become an increasing part of mainstream cardiovascular imaging practices. In some patients, further ischemia testing with MPS will be required. Similarly, in some patients referred for MPS, anatomic definition of atherosclerosis using CAC by CT may be appropriate. Thus, this review also provides a synopsis of the available literature on imaging that integrates both CT and MPS in combined strategies for the assessment of atherosclerotic and obstructive coronary disease burden. We also propose possible risk-based strategies through which imaging might be used to identifying candidates for more intensive prevention and risk factor modification strategies as well as those who would benefit from referral to coronary angiography and revascularization.     

Current status of coronary multislice CT angiography

Multislice computed tomography (MSCT) is an emerging technique which has an enormous potential to improve the current practice of coronary artery imaging. This article reviews the current status of coronary MSCT angiography (MSCTA) with emphasis on the imaging techniques and clinical utilities of 16-slice CTA. Results and experiences gained from coronary MSCTA in the past few years have taught us that accurate diagnosis of coronary artery disease relies on good technical studies and can be achieved by optimizing image parameters including image timing and image reconstruction ECG-trigger delay. Current clinical applications of coronary MSCTA include: quantitative assessment of coronary artery stenosis, characterization of coronary atherosclerotic plaques, and follow-up of coronary artery stent and bypass graft. Furthermore, MSCT has brought an increasing awareness to the amount of radiation used in CT. This has prompted CT researchers and manufacturers to improve various techniques and develop new strategies to reduce radiation dose. It is anticipated that MSCT will become a sensitive and accurate tool for detecting coronary artery disease and monitoring outcomes after treatment for coronary artery disease.     

Coronary artery imaging during preoperative CT staging: preliminary experience with 64-slice multidetector CT in 99 consecutive patients

The purpose of this study was to evaluate the clinical feasibility of coronary artery imaging during routine preoperative 64-slice MDCT scans of the chest. Ninety-nine consecutive patients in sinus rhythm underwent a biphasic multidetector-row spiral CT examination of the chest without the administration of beta-blockers, including an ECG-gated acquisition over the cardiac cavities, followed by a non-gated examination of the upper third of the thorax. Data were reconstructed to evaluate coronary arteries and to obtain presurgical staging of the underlying disease. The percentage of assessable segments ranged from 65.4% (972/1,485) when considering all coronary artery segments to 88% (613/693) for the proximal and mid segments, reaching 98% (387/396) for proximal coronary artery segments. The 387 interpretable proximal segments included 97 (97%) LM, 99 (100%) LAD, 96 (97%) LCX and 95 (96%) RCA with a mean attenuation of 280.70±52.93 HU. The mean percentage of assessable segments was significantly higher in patients with a heart rate ≤80 bpm (n=48) than in patients with a heart rate greater than 80 bpm (n=35) (80±11% vs. 72±13%; P=0.0008). Diagnostic image quality was achieved in all patients for preoperative staging of the underlying disorder. The mean estimated effective dose was 12.06±3.25 mSv for ECG-gated scans and 13.88±3.49 mSv for complete chest examinations. Proximal and mid-coronary artery segments can be adequately evaluated during presurgical CT examinations of the chest obtained with 64-slice MDCT without the administration of β-blockers.     

Applications of multislice computed tomography in coronary artery disease

Multislice computed tomography (MSCT) provides high accuracy for noninvasive assessment of coronary artery disease (CAD). The introduction of the latest computed tomography (CT) technology allows comprehensive evaluation of various aspects of CAD, including the coronary calcium score, coronary artery stenoses, bypass patency, and myocardial function. Other applications, such as plaque characterization, first-pass perfusion imaging, and viability imaging using delayed contrast enhancement, are still under development and may demonstrate clinical utility in the future. Further improvements in CT hardware and imaging protocols are expected that may result in improved coronary artery imaging, new applications, and a significant reduction of radiation dose.     

Cardiac hybrid imaging: state-of-the-art

The field of noninvasive cardiac imaging has experienced enormous advances including computerized tomography coronary angiography (CTCA). Invasive angiography remains the anatomic standard of reference but it is associated with a non-negligible peri-procedural morbidity and mortality which suggests confining its use to patients who will benefit from a revascularization procedure. Many factors that are beyond the simple quantification of diameter narrowing and therefore cannot be fully assessed with luminology will eventually determine whether or not a given lesion produces stress-induced ischemia. Myocardial perfusion scintigraphy by single photon emission computerized tomography (SPECT) is one of the most widely used and well established noninvasive tools for the diagnosis of ischemic heart disease. Although positron emission tomography (PET) offers a higher accuracy than SPECT its use is often limited to large centers. This article explains the great potential of cardiac hybrid imaging which allows a comprehensive evaluation of coronary artery disease as it combines both morphological and functional information by fusing either SPECT or PET with CTCA. SPECT/CT and PET/CT hybrid imaging can provide entirely noninvasively unique information which helps improving diagnostic assessment and risk stratification and also impacts decision making with regard to revascularization in patients with coronary artery disease. The University Hospital Zurich holds a research contract with GE Healthcare (Milwaukee, WI, USA).     

What nuclear cardiology can learn from nuclear oncology

Conclusion  Combining PET and CT imaging technology to determine regional myocardial perfusion, perfusion reserve, ventricular function, coronary angiographic results, coronary calcification, and coronary artery inflammation offers an opportunity to bring together a constellation of important measurements to characterize coronary heart disease. These images can be recorded in an outpatient environment, providing information that can be added to data available from blood tests of inflammation, such as high-sensitivity C-reactive protein, and patient performance on exercise testing. Addition of the focal assessment of coronary vascular inflammation should provide a key assessment, identifying coronary lesions at high risk of rupture or erosion. These considerations suggest that applying the technology now used in nuclear oncology offers great potential for nuclear cardiology.     

Coronary artery bypass grafts and MDCT imaging: what to know and what to look for

Multi-detector row CT (MDCT) scanners with high spatial and temporal resolutions are now available and are increasingly used for non-invasive assessment of vascular disease, including coronary arteries and coronary artery bypass grafts (CABG). Follow-up of patients who have previously undergone surgical revascularization for coronary artery disease is nowadays one of the main applications of MDCT. Thanks to the continuous technical evolution of the CT scanners, it is now possible to scan the heart and the full anatomic extent of grafts with sub-millimeter slice-thickness within a single breath-hold. In the evaluation of these patients, it is important for the radiologist to be familiar with the different types of grafts and surgical techniques to know the main characteristics of each graft type and what to look for in the assessment of a patient who has undergone coronary artery surgical revascularization. This review summarizes some surgical aspects, the biological characteristics of conduits, and the main technical MDCT features, and describes the CABG anatomy together with some typical CT findings.     

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.