Visualization Of Coronary Arteries Research Articles

Diagnostic performance of high and ultra-high-resolution photon counting CT for detection of coronary artery disease in patients evaluated for transcatheter aortic valve implantation.

We assessed the diagnostic performance of both ultra-high-resolution (UHR) and high-resolution (HR) modes of photon-counting detector (PCD)-CT within the confines of standard pre-TAVI CT scans, as well as the performance of UHR mode adjusted specifically for coronary imaging, using quantitative coronary angiography (QCA) as the reference. We included 60 patients undergoing pre-TAVI planning CT scans. Patients were divided into 3 groups: 20 scanned in HR mode, 20 in UHR mode, and 20 in adjusted UHR mode, on a dual-source PCD-CT. The adjusted UHR mode employed a lower tube voltage (90kV vs. 120kV) and a higher image quality level (65 vs. 34) to enhance coronary artery visualization. Patients underwent invasive coronary angiography as part of clinical routine. CCTA and QCA were reviewed to assess CAD presence defined as stenosis ≥ 50% in proximal and middle coronary segments. We included 60 patients (mean age 79 ± 7 years; 39(65%) men). Mean heart rate during scanning was 72 ± 13bpm. Median coronary calcium score was 973[379-2007]. QCA identified significant CAD in 24 patients (40%): 9 patients scanned with HR mode, 10 patients with the UHR mode, and 5 patients with the UHR adjusted mode. Per-patient area under the curves were 0.57 for HR, 0.80 for UHR, and 0.80 for adjusted UHR, with no significant differences between the scan modes, and per-vessel the area under the curves were 0.73 for HR, 0.69 for UHR, and 0.87 for adjusted UHR, with significant differences between UHR and adjusted UHR (p = 0.04). UHR and adjusted UHR modes of dual source PCD-CT show potential for improved sensitivity and negative predictive value for detecting CAD in patients undergoing pre-TAVI scans, however, no statistically significant difference from HR mode was observed.

Automated Classification of Coronary Plaque on Intravascular Ultrasound by Deep Classifier Cascades.

Intravascular ultrasound (IVUS) is the gold standard modality for in vivo visualization of coronary arteries and atherosclerotic plaques. Classification of coronary plaques helps to characterize heterogeneous components and evaluate the risk of plaque rupture. Manual classification is time-consuming and labor-intensive. Several machine learning-based classification approaches have been proposed and evaluated in recent years. In the current study, we develop a novel pipeline composed of serial classifiers for distinguishing IVUS images into five categories: normal, calcified plaque, attenuated plaque, fibrous plaque, and echolucent plaque. The cascades comprise densely connected classification models and machine learning classifiers at different stages. Over 100,000 IVUS frames of five different lesion types were collected and labeled from 471 patients for model training and evaluation. The overall accuracy of the proposed classifier is 0.877, indicating that the proposed framework has the capacity to identify the nature and category of coronary plaques in IVUS images. Further, it may provide real-time assistance on plaque identification and facilitate clinical decision-making in routine practice.

Cardio-respiratory motion compensation for coronary roadmapping in fluoroscopic imaging.

Inferring the shape and position of coronary artery poses challenges when using fluoroscopic image guidance during percutaneous coronary intervention (PCI) procedure. Although angiography enables coronary artery visualization, the use of injected contrast agent raises concerns about radiation exposure and the risk of contrast-induced nephropathy. To address these issues, dynamic coronary roadmapping overlaid on fluoroscopic images can provide coronary visual feedback without contrast injection. This paper proposes a novel cardio-respiratory motion compensation method that utilizes cardiac state synchronization and catheter motion estimation to achieve coronary roadmapping in fluoroscopic images. For more accurate cardiac state synchronization, video frame interpolation is applied to increase the frame rate of the original limited angiographic images, resulting in higher framerate and more adequate roadmaps. The proposed method also incorporates a multi-length cross-correlation based adaptive electrocardiogram (ECG)matching to address irregular cardiac motion situation. Furthermore, a shape-constrained path searching method is proposed to extract catheter structure from both fluoroscopic and angiographic image. Then catheter motion is estimated using a cascaded matching approach with an outlier removal strategy, leading to a final corrected roadmap. Evaluation of the proposed method on clinical x-ray images demonstrates its effectiveness, achieving a 92.8% F1 score for catheter extraction on 589 fluoroscopic and angiographic images. Additionally, the method achieves a 5.6-pixel distance error of the coronary roadmap on 164 intraoperative fluoroscopic images. Overall, the proposed method achieves accurate coronary roadmapping in fluoroscopic images and shows potential to overlay accurate coronary roadmap on fluoroscopic image in assisting PCI.

F. Mason Sones Jr.: The Serendipitous Discovery of Coronary Angiography and Its Lasting Impact on Cardiology.

F. Mason Sones Jr. (1918-1985) was a pioneering cardiologist whose groundbreaking work revolutionized the field of cardiology. His accidental discovery of coronary angiography in 1958 at the Cleveland Clinic provided physicians with the first clear visualization of coronary arteries in living patients, paving the way for the development of coronary artery bypass surgery and interventional cardiology. This review article explores F. Mason Sones Jr.'s life and career, and his lasting impact on the field of cardiology. Born in Noxapater, MS, in 1918, F. Mason Sones Jr.attended Western Maryland College (Westminster, MD) and the University of Maryland School of Medicine (Baltimore, MD) before completing his internship and residency at the University Hospital (Baltimore, MD) and Henry Ford Hospital (Detroit, MI), respectively. After serving in the U.S. Army Air Corps during World War II, F. Mason Sones Jr.joined the Cleveland Clinic (Cleveland, OH), in 1950, as the head of pediatric cardiology, where he combined his expertise in cardiac catheterization with his interest in congenital heart disease. F. Mason Sones Jr.'s serendipitous discovery of coronary angiography occurred during a routine cardiac catheterization procedure when he inadvertently injected contrast dye directly into the right coronary artery. Realizing that smaller amounts of dye could safely opacify the coronary arteries, F. Mason Sones Jr. refined and standardized the technique of selective coronary angiography, collaborating with engineers to improve X-ray imaging and establishing protocols that remain the standard of care today. F. Mason Sones Jr.'s work provided the foundation for the development of coronary artery bypass surgery by Dr. René Favaloro and the birth of interventional cardiology, as pioneered by Dr. Andreas Gruentzig. As the director of cardiovascular disease at the Cleveland Clinic (1966-1975), F. Mason Sones Jr. mentored and inspired a generation of cardiologists, cementing his legacy as a visionary leader in the field. Throughout his career, F. Mason Sones Jr. received numerous awards and honors, including the American Medical Association's Scientific Achievement Award and the Gairdner Foundation International Award. He co-founded and served as the first president of the Society for Cardiac Angiography (now SCAI), an organization dedicated to advancing the field of interventional cardiology. This review article pays tribute to F. Mason Sones Jr.'s enduring contributions to the field of cardiology, highlighting his role as a pioneer, innovator, and mentor. His legacy continues to inspire and guide generations of cardiologists in their pursuit of improving patient care and pushing the boundaries of cardiovascular medicine.

Motion artifact correction in cardiac CT using cross-phase temporospatial information and synergistic attention gate and spatial transformer sub-networks

Objectives. To improve quality of coronary CT angiography (CCTA) images using a generalizable motion-correction algorithm. Approach. A neural network with attention gate and spatial transformer (ATOM) was developed to correct coronary motion. Phantom and patient CCTA images (39 males, 32 females, age range 19–92, scan date 02/2020 to 10/2021) retrospectively collected from dual-source CT were used to create training, development, and testing sets corresponding to 140- and 75 ms temporal resolution, with 75 ms images as labels. To test generalizability, ATOM was deployed for locally adaptive motion-correction in both 140- and 75 ms patient images. Objective metrics were used to assess motion-corrupted and corrected phantom and patient images, including structural-similarity-index (SSIM), dice-similarity-coefficient (DSC), peak-signal-noise-ratio (PSNR), and normalized root-mean-square-error (NRMSE). In objective quality assessment, ATOM was compared with several baseline networks, including U-net, U-net plus attention gate, U-net plus spatial transformer, VDSR, and ResNet. Two cardiac radiologists independently interpreted motion-corrupted and -corrected images at 75 and 140 ms in a blinded fashion and ranked diagnostic image quality (worst to best: 1–4, no ties). Main results. ATOM improved quality metrics (p < 0.05) before/after correction: in phantom, SSIM 0.87/0.95, DSC 0.85/0.93, PSNR 19.4/22.5, NRMSE 0.38/0.27; in patient images, SSIM 0.82/0.88, DSC 0.88/0.90, PSNR 30.0/32.0, NRMSE 0.16/0.12. ATOM provided more consistent improvement of objective image quality, compared to the presented baseline networks. The motion-corrected images received better ranks than un-corrected at the same temporal resolution (p < 0.05): 140 ms images 1.65/2.25, and 75 ms images 3.1/3.2. The motion-corrected 75 ms images received the best rank in 65% of testing cases. A fair-to-good inter-reader agreement was observed (Kappa score 0.58). Significance. ATOM reduces motion artifacts, improving visualization of coronary arteries. This algorithm can be used to virtually improve temporal resolution in both single- and dual-source CT.

Carotid Artery Ultrasonography as a Screening Tool for Predicting Coronary Artery Disease: A Cross-sectional Study from Hilly State of Northern India

Introduction: Coronary Artery Disease (CAD) is a major cause of morbidity and mortality worldwide; therefore, early diagnosis plays a crucial role in managing patients with CAD. Multidetector Computed Tomography (MDCT) allows non invasive visualisation of coronary arteries but has limited availability, involves radiation, and is costly. Carotid artery atherosclerosis can be assessed by Ultrasound (USG) in terms of Carotid Intima-media Thickness (CIMT) and carotid plaque assessment. These carotid USG parameters are associated with CAD and can be used to predict CAD in high-risk patients. Aim: To study the association and correlation between carotid artery atherosclerosis USG parameters (CIMT and carotid plaque) and CAD, using Computed Tomography Coronary Angiography (CTCA) as a reference. Materials and Methods: A cross-sectional study was conducted from January 2020 to October 2021 in the Department of Radiodiagnosis at Indira Gandhi Medical College, Shimla, Himachal Pradesh, India. In the present study, 31 patients with suspected CAD were enrolled. All patients underwent CTCA followed by carotid artery USG within two weeks. The association and correlation between carotid artery atherosclerosis on USG and CAD on CTCA were examined. Sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), and accuracy were calculated using CTCA as the reference standard. Categorical data were analysed using the Chi-square test, with a p-value of &lt;0.05 considered statistically significant. Results: The mean age of the patients was 54.06±10.79 years. The CAD was observed in 14 (45.1%) cases, of which 13 (92.8%) had significant CAD. Nine patients had raised CIMT, of which eight had CAD. Raised CIMT and CAD showed a significant association with sensitivity, specificity, PPV, NPV, and accuracy of 57.14%, 94.12%, 88.89%, 72.73%, and 77.42%, respectively. A positive correlation was found between CIMT values and the number of vessels with significant CAD (r= +0.67). A total of 7 patients (22.5%) had the presence of carotid plaque, of which 6 (88.57%) had significant CAD. A significant association was found between CAD and the presence of carotid plaque. Carotid plaque had sensitivity, specificity, PPV, NPV, and accuracy of 50%, 100%, 100%, 70.83%, and 77.42%, respectively, in predicting CAD. A positive correlation was observed between carotid plaque burden and the number of vessels with significant CAD (r= +0.56). Conclusion: There is a significant association between carotid ultrasonography parameters (i.e., CIMT, carotid plaque) and CAD. CIMT is a more sensitive parameter than carotid plaque in predicting CAD. However, carotid plaque is more specific for predicting CAD. Carotid artery ultrasonography can be used as a screening tool for predicting CAD and should be included in the work-up of patients with suspected CAD.

Historical and current aspects of angiovisualization methods in CАD (a literature review)

The aim of the work. To summarize and expand knowledge about current methods used for visualization of coronary arteries, their evolution, capabilities, effectiveness, indications for use, safety for patients, guided by the principles of evidence-based medicine. Coronary artery disease (CАD) is an extremely common clinical cardiovascular disease, which is caused by atherosclerosis of the subepicardial coronary arteries (CAs) and can have both acute and chronic course. The incidence of CАD is increasing every year and getting younger. CАD has not only a high morbidity rate, but also a high mortality rate. In Ukraine, mortality from CАD is the main cause of population mortality. Without timely diagnosis and effective treatment, myocardial infarction or sudden cardiac death may develop. It is possible to ascertain the etiological cause of myocardial ischemia only after visualization of the СAs. A practicing physician is able to visualize the СAs using X-ray contrast coronary angiography or contrast-enhanced computed tomography of the chest. СA visualization methods have been used in clinical practice for more than half a century. The hardware and software are constantly upgraded, the diagnostic options of these methods are improved and expanded, and recommendations regarding their use in general clinical practice are updated. The main task for clinicians is to confirm or rule out the presence of a СA atherosclerotic lesion, as well as to determine its localization, extent, degree of stenosis and its significance for coronary blood flow, the presence of СA calcification, collateral pathways, plaque composition and its internal structure. Only after identifying the anatomical and physiological aspects of the atherosclerotic process in СA, it is possible to choose the right strategy for the treatment of patients by a multidisciplinary heart team including pharmacological therapy, a method of cardiac revascularization, and measures for primary or secondary prevention. Conclusions. CАD is a common disease worldwide. Today, two methods of the CА visualization are available – invasive coronary angiography and non-invasive coronary CT angiography. Further research is needed on the efficacy and safety of different СA imaging methods in CAD. Better results of the diagnostic search depend on both the capabilities of the clinic hardware component and on the optimal sequence for diagnostic processes rationally constructed by physicians.

Abstract 18876: Safety and Efficacy of Coronary CT Angiography in Acute Chest Pain. A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Background: Coronary computed tomography angiography (CCTA) allows direct visualization of coronary arteries. As a result of the high accuracy, CCTA has been proposed as an initial step in patients presenting to the emergency department (ED) with acute chest pain to rule out obstructive coronary artery disease (CAD). The effect of the initial CCTA strategy on downstream testing with coronary angiogram and coronary revascularization is yet to be delineated. Objective: To investigate the safety and efficacy of CCTA in patients presenting to the ED with acute chest pain compared to standard of care (SoC). Method: We searched PubMed, Cochrane CENTRAL Register, and ClinicalTrials.gov (inception through July 1st, 2023) for randomized clinical trials evaluating the outcomes of CCTA in acute chest pain. We used a random-effect model to calculate risk ratio (RR) with a 95% confidence interval (CI). The endpoints were all-cause mortality, major adverse cardiac events (MACE), rates of coronary angiography, and length of stay (LOS). Results: A total of 17 studies comprising 9237 patients were included in the analysis. Compared to SoC, the CCTA group had a shorter length of hospitalization (RR -0.3; 95%CI -0.64- -0.13; P = 0.0005). There was no significant difference in all-cause mortality or MACE (RR 0.8; 95%CI 0.45- 1.5; P = 0.52) and (RR -1.00; 95%CI 0.76- 1.3; P = 0.98), respectively. Rates of coronary angiography did not differ between the two groups (RR 0.93; 95%CI 0.61- 1.41; P = 0.96). Conclusion: CCTA is a reliable non-invasive imaging modality that can play a significant role in evaluating acute chest pain in the emergency department and is associated with a decrease in the length of stay without an increase in MACE. There was no increase in downstream coronary angiogram or coronary revascularization in the CCTA group.

The Impact of Nitroglycerin on the Evaluation of Coronary Stenosis in Coronary-CT: Preliminary Study in 131 Patients.

The sublingual administration of short-acting nitroglycerin (NTG) before coronary computed tomography (CCT) improves the visualization of coronary arteries, causing vasodilatation. The aim of this study was to evaluate whether and how nitroglycerin can influence the concordance between radiologists and cardiologists in the evaluation of vessel stenosis measured in CCT by the former and during the following coronarography by the latter. We conducted a retrospective analysis of 131 patients who underwent CCT for cardiac symptoms in 2022, followed by coronarography performed six months later because of significant stenosis revealed by the CCT. First, the patients were divided into two groups: an NTG group who received sublingual nitroglycerin before CCT and a non-NTG group who did not because of contraindications. Second, 254 stenoses were measured by two radiologists after CCT and by two interventional cardiologists during the next coronarography; moreover, stenoses were classified on the basis of their location and plaque pattern (calcific, mixed and lipidic). Third, the strength of agreement was evaluated between the two radiologists, between the two cardiologists and finally between the radiologists and cardiologists in order to evaluate whether and how the interdisciplinary discrepancy in stenosis evaluation could change with or without the use of nitroglycerin before CCT and in relation to the different plaque pattern. In the NTG group, the use of nitroglycerine reduced the agreement between radiologists and cardiologists in calcific stenosis but did not change the concordance in the case of mixed or lipidic plaques on the same vessels. The use of sublingual nitroglycerin before CCT may lead to a radiological overestimation of calcific stenosis.

Improved Coronary Artery Visualization Using Virtual Monoenergetic Imaging from Dual-Layer Spectral Detector CT Angiography.

Background: To evaluate if coronary CT angiography (CCTA) monoenergetic reconstructions, obtained with a dual-layer spectral detector computed tomography (DLCT) system, offer improved image quality compared with 120 kVp conventional images without affecting the quantitative assessment of coronary stenoses. Methods: Fifty CCTA datasets (30 men; mean age: 61.6 ± 12.3 years) acquired with a DLCT system were reconstructed using virtual monoenergetic images (VMI) from 40 to 100 keV with 10 keV increment and compared with conventional images. An analysis of objective image quality was performed, evaluating the signal- and contrast-to-noise ratio. For the subjective assessment, two readers used a 5-point Likert scoring system to evaluate sharpness, noise, demarcation of coronary plaques, vascular contrast, and an overall score. Furthermore, coronary stenoses were analyzed for each vessel to describe the diagnostic agreement between monoenergetic images and conventional images. Results: The objective image analysis showed that all reconstructions from 70 keV to 40 keV show higher SNR (from 61.33 ± 12.46 to 154.22 ± 42.91, respectively) and CNR (from 51.45 ± 11.19 to 135.63 ± 39.38, respectively) compared with conventional images (all p < 0.001). The 40 keV monoenergetic images obtained the best average score for sharpness, vascular contrast, and for the overall impression (all with p < 0.001). The detection and grading of stenoses of the coronary arteries with conventional and monoenergetic images at 70 keV and 40 keV showed an overall excellent interobserver agreement (k= 0.81 [0.72-0.91]). Conclusions: The 40 keV virtual monoenergetic images obtained with a DLCT system allow the objective and subjective image quality of coronary CT angiography to be improved.

Clinical quantitative coronary artery stenosis and coronary atherosclerosis imaging: a Consensus Statement from the Quantitative Cardiovascular Imaging Study Group.

The detection and characterization of coronary artery stenosis and atherosclerosis using imaging tools are key for clinical decision-making in patients with known or suspected coronary artery disease. In this regard, imaging-based quantification can be improved by choosing the most appropriate imaging modality for diagnosis, treatment and procedural planning. In this Consensus Statement, we provide clinical consensus recommendations on the optimal use of different imaging techniques in various patient populations and describe the advances in imaging technology. Clinical consensus recommendations on the appropriateness of each imaging technique for direct coronary artery visualization were derived through a three-step, real-time Delphi process that took place before, during and after the Second International Quantitative Cardiovascular Imaging Meeting in September 2022. According to the Delphi survey answers, CT is the method of choice to rule out obstructive stenosis in patients with an intermediate pre-test probability of coronary artery disease and enables quantitative assessment of coronary plaque with respect to dimensions, composition, location and related risk of future cardiovascular events, whereas MRI facilitates the visualization of coronary plaque and can be used in experienced centres as a radiation-free, second-line option for non-invasive coronary angiography. PET has the greatest potential for quantifying inflammation in coronary plaque but SPECT currently has a limited role in clinical coronary artery stenosis and atherosclerosis imaging. Invasive coronary angiography is the reference standard for stenosis assessment but cannot characterize coronary plaques. Finally, intravascular ultrasonography and optical coherence tomography are the most important invasive imaging modalities for the identification of plaques at high risk of rupture. The recommendations made in this Consensus Statement will help clinicians to choose the most appropriate imaging modality on the basis of the specific clinical scenario, individual patient characteristics and the availability of each imaging modality.

Addition of gadolinium contrast to three-dimensional SSFP MR sequences improves the visibility of coronary artery anatomy in young children.

This study aims to compare the value of a gadolinium contrast-enhanced 1.5-T three-dimensional (3D) steady-state free precession (SSFP) sequence with that of a noncontrast 3D SSFP sequence for magnetic resonance coronary angiography in a pediatric population. Seventy-nine patients from 1 month to 18 years old participated in this study. A 3D SSFP coronary MRA at 1.5-T was applied before and after gadolinium-diethylenetriaminepentaaceticacid (DTPA) injection. The detection rates of coronary arteries and side branches were assessed by McNemar's χ2 test. The image quality, vessel length, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the coronary arteries were analyzed by the Wilcoxon signed-rank test. The intra- and interobserver agreements were evaluated with a weighted kappa test or an intraclass correlation efficient test. A contrast-enhanced scan detected more coronary arteries than a noncontrast-enhanced scan in patients under 2 years old (P < 0.05). The SSFP sequence with contrast media detected more coronary artery side branches in patients younger than 5 years (P < 0.05). The image quality of all the coronary arteries was better after the injection of gadolinium-DTPA in children younger than 2 years (P < 0.05) but not significantly improved in children older than 2 years (P > 0.05). The contrast-enhanced 3D SSFP protocol detected longer lengths for the left anterior descending coronary artery in children younger than 2 years and the left circumflex coronary artery (LCX) in children younger than 5 years (P < 0.05). SNR and CNR of all the coronary arteries in children younger than 5 years and the LCX and right coronary artery in children older than 5 years enhanced after the injection of gadolinium-DTPA (P < 0.05). The intra- and interobserver agreements were high (0.803-0.998) for image quality, length, SNR, and CNR of the coronary arteries in both pre- and postcontrast groups. The use of gadolinium contrast in combination with the 3D SSFP sequence is necessary for coronary imaging in children under 2 years of age and may be helpful in children between 2 and 5 years. Coronary artery visualization is not significantly improved in children older than 5 years.

Improving diagnostic assessments in the ever-changing landscape of atherosclerosis.

As our understanding of atherosclerotic vascular injury continues to evolve, so should our diagnostic approaches. Emerging data have recently challenged our basic understanding in linking ischemia to its adverse outcomes as well as the need for invasive testing for both diagnosis and treatment. The advent of coronary computed tomography in providing improved visualization of coronary arteries has led to the identification of both subclinical atherosclerosis and high-risk coronary lesions. Recognition of asymptomatic coronary artery disease (CAD) with objective localization of subclinical coronary atherosclerosis improves atherosclerotic cardiovascular risk assessment and allows healthcare providers to take effective primary prevention measures. Therefore, reshaping the diagnostic landscape in proposing new testing modalities would be highly dependent on local resource availability and the reading expertise of each clinical practice and medical institution. The main objective of this Review is to propose a potentially new diagnostic approach of simply using noninvasive stress testing or coronary angiography in the routine assessment of CAD.

A U-Shaped Network Based on Multi-level Feature and Dual-Attention Coordination Mechanism for Coronary Artery Segmentation of CCTA Images.

Computed tomography coronary angiography (CCTA) images provide optimal visualization of coronary arteries to aid in diagnosing coronary heart disease (CHD). With the deep convolutional neural network, this work aims to develop an intelligent and lightweight coronary artery segmentation algorithm that can be deployed in hospital systems to assist clinicians in quantitatively analyzing CHD. With the multi-level feature fusion, we proposed Dual-Attention Coordination U-Net (DAC-UNet) that achieves automated coronary artery segmentation in 2D CCTA images. The coronary artery occupies a small region, and the foreground and background are extremely unbalanced. For this reason, the more original information can be retained by fusing related features between adjacent layers, which is conducive to recovering the small coronary artery area. The dual-attention coordination mechanism can select valid information and filter redundant information. Moreover, the complementation and coordination of double attention factors can enhance the integrity of features of coronary arteries, reduce the interference of non-coronary arteries, and prevent over-learning. With gradual learning, the balanced character of double attention factors promotes the generalization ability of the model to enhance coronary artery localization and contour detail segmentation. Compared with existing related segmentation methods, our method achieves a certain degree of improvement in 2D CCTA images for the segmentation accuracy of coronary arteries with a mean Dice index of 0.7920. Furthermore, the method can obtain relatively accurate results even in a small sample dataset and is easy to implement and deploy, which is promising. The code is available at: https://github.com/windfly666/Segmentation . Our method can capture the coronary artery structure end-to-end, which can be used as a fundamental means for automatic detection of coronary artery stenosis, blood flow reserve fraction analysis, and assisting clinicians in diagnosing CHD.

Feasibility of 3.0 T balanced fast field echo non-contrast-enhanced whole-heart coronary magnetic resonance angiography.

Coronary artery disease (CAD) is one of the most common diseases seriously harmful to human health caused by atherosclerosis. Besides coronary computed tomography angiography (CCTA) and invasive coronary angiography (ICA), coronary magnetic resonance angiography (CMRA) has become an alternative examination. The purpose of this study was to prospectively evaluate the feasibility of 3.0 T free-breathing whole-heart non-contrast-enhanced coronary magnetic resonance angiography (NCE-CMRA). After Institutional Review Board approval, the NCE-CMRA data sets of 29 patients acquired successfully at 3.0 T were evaluated independently by two blinded readers for visualization and image quality of coronary arteries using the subjective quality grade. The acquisition times were recorded in the meantime. A part of the patients had undergone CCTA, we represented stenosis by scores and used the Kappa to evaluate the consistency between CCTA and NCE-CMRA. Six patients did not get diagnostic image quality because of severe artifacts. The image quality score assessed by both radiologists is 3.2±0.7, which means the NCE-CMRA can show the coronary arteries excellently. The main vessels of the coronary artery on NCE-CMRA images are considered reliably assessable. The acquisition time of NCE-CMRA, is 8.8±1.2 min. The Kappa of CCTA and NCE-CMRA on detecting stenosis is 0.842 (P<0.001). The NCE-CMRA results in reliable image quality and visualization parameters of coronary arteries within a short scan time. The NCE-CMRA and CCTA have a good agreement for detecting stenosis.

Electroanatomic visualization of coronary arteries: a case series to elicit safety, feasibility, and diagnostic value in complex ablation procedures.

The goal of this case series was to evaluate the feasibility, safety, and advantages of a wire-based approach for the live visualization of coronary arteries (CAs) in an electroanatomic mapping (EAM) system and to assess its diagnostic information. For this single-centre case series, we included procedures in which close proximity of a possible ablation site to any epicardial vessel was suspected. An uncoated-tip guidewire was introduced into the relevant CAs after exclusion of critical CA stenosis by coronary angiography. By connecting this wire to the EAM system using a clip and pin connection, mapping and live visualization of the wire tip is possible, as well as the assessment of the local electrograms within the respective CAs. Procedural wire insertion and intracoronary mapping was performed by EP specialists and was assisted to judge the relevance of CA disease by an interventional cardiologist. A total of nine procedures in nine patients were included in this case series, four ventricular tachycardia ablation procedures and five procedures for the ablation of premature ventricular contractions. The left CAs were mapped in eight cases and the right CA was mapped in one case. In two cases, epicardial mapping was combined with visualization of the right or left CAs. There were no complications attributed to coronary wiring and mapping in this case. We demonstrated the feasibility and safety of CA visualization and integration in an EAM. The live visualization of the CAs added valuable information without the need for preprocedural planning or the purchase of separate software. Electroanatomic visualization was achieved intraprocedurally in a safe and straightforward manner, adding critical diagnostic information without excessive costs or risks.

Theoretical comparison of energy-resolved and digital-subtraction angiography.

X-ray coronary angiography is a sub-optimal vascular imaging technique because it cannot suppress un-enhanced anatomy that may obscure the visualization of coronary arterydisease. The purpose of this paper is to evaluate the theoretical image quality of energy-resolved x-ray angiography (ERA) implemented with spectroscopic x-ray detectors (SXDs), which may overcome limitations of x-ray coronaryangiography. We modeled the large-area signal-difference-to-noise (SDNR) of contrast-enhanced vasculature in ERA images and compared with that of digital-subtraction angiography (DSA), which served as a gold standard vascular imaging technique. To this end, we used calibrated numerical models of the response of cadmium telluride SXDs including the effects of charge sharing, electronic noise, and energy thresholding. Our models assumed zero scatter, no pulse pile up and small signals such that image contrast is approximately linear in the area density of contrast agents. For DSA, we similarly modeled x-ray detection by cesium iodide energy-integrating detectors using validated numerical models. For ERA, we investigated iodine and gadolinium (Gd) contrast agents, two-material and three-material decompositions, analog charge summing for charge sharing correction, and optimized image quality with respect to the tube voltage and energy thresholds assuming cadmium telluride SXDs with three energybins. Our analysis reveals that a three-material decomposition using iodine contrast agents will require x-ray exposures that are approximately 400 times those of DSA to achieve the same SDNR as DSA in coronary applications, and is therefore not feasible in a clinical setting. However, three-material decompositions with Gd contrast agents have the potential to provide SDNR that is ∼45% of that of DSA for matched patient air kerma. For two-material decompositions that suppress soft-tissue, ERA has the potential to produce images with SDNR that is 50%-75% of that of DSA for matched patient air kermas but lower levels of tube loading. Achieving these SDNR levels will require the use of analog charge summing for charge sharing correction, which increased SDNR by up to a factor of 1.7 depending on the contrast agent and whether or not a two-material or three-material decomposition wasassumed. We conclude that three-material ERA implemented with Gd contrast agents and two-material ERA implemented with either iodine or Gd contrast agents, should be investigated as alternatives to DSA in situations where motion artifacts preclude the use of DSA, such as in coronaryimaging.

Color Doppler visualization of fetal coronary arteries is enhanced by high resolution and Radiantflow.

Color Doppler visualization of fetal coronary arteries is enhanced by high resolution and Radiantflow.

Non-electrocardiography- and electrocardiography-gated computed tomography angiography for the evaluation of feline coronary arteries.

ObjectivesFew studies have directly compared the clinical feasibility of electrocardiography-gated and non-electrocardiography-gated multidetector computed tomography for evaluating coronary arteries in veterinary medicine. We aimed to characterize and visualize feline coronary arteries using these two imaging modalities. We hypothesed that ECG-gated MDCT is superior to or advantageous to the non-ECG gated.MethodsThis prospective, controlled, comparative pilot study examined six client-owned cats (five clinically normal and one with hypertrophic cardiomyopathy) using non-electrocardiography-gated and retrospective electrocardiography-gated scans. Optimal non-electrocardiography scan timing or electrocardiography-gated R-R reconstruction interval for coronary artery visualization was determined. The degree of opacification and sharpness of proximal coronary branches was subjectively graded; coronary dominance, left coronary artery branching types, and the diameter and length of coronary artery branches were also assessed.ResultsNon-electrocardiography-gated images provided the least information on the bilateral coronary artery ostium and proximal segments, while electrocardiography-gated images clarified the detailed course of the main coronary branches at diastole in all cats. The degree of opacification and sharpness of the coronary arteries was subjectively evaluated as good/excellent in all cats. Coronary dominance (left: four; right: two) and left coronary artery branching types (three different patterns, two additional tortuous branches) varied. Body weight and sex were not significantly associated with coronary artery length or diameter. Vertebral heart score positively correlated with the right coronary artery and negatively correlated with the left main coronary artery.Clinical significanceElectrocardiography-gated multidetector computed tomography provides images with adequate resolution to identify the anatomy of feline coronary arteries. Detailed morphological knowledge of feline coronary vessels will enable novel diagnostic and therapeutic methods in veterinary medicine.

Electroanatomic visualization of coronary arteries: a case series to elicit safety, feasibility and diagnostic value in complex ablation procedures

Abstract Funding Acknowledgements Type of funding sources: None. Background Although three dimensional (3D) electroanatomic mapping systems allow detailed assessment of anatomy and substrates, ablation still carries substantial risk when close proximity to coronary arteries is suspected. 3D integration of coronary anatomy in mapping systems is still cumbersome, highlighting the need for an option of ad hoc acquirement of coronary artery anatomy. The goal of this case series was to evaluate the feasibility of a wire-based approach to the live visualization of coronary arteries and to assess its diagnostic information regarding procedure guiding. Methods For this single center case series, we included procedures in which close proximity of an ablation site to an epicardial vessel had to be suspected. An uninsulated-tip wire was then introduced into the relevant coronaries via diagnostic catheters after exclusion of critical stenosis by coronary angiography. The wire was connected to an impedance based 3D mapping system using a clamp and standard pin connection. Integrating this setup in the mapping system allows for live visualization of the wire tip, as well as the assessment of local electrograms within the respective vessel. Results We included a total of 9 procedures (4 ventricular tachycardia (VT) ablation procedures and 5 procedures for the ablation of premature ventricular contractions (PVCs)). The left coronary arteries were mapped in 8 cases, the right coronary artery was mapped in one case. In the majority of cases, the arrhythmogenic substrate was found in the left ventricle (5/9) or left ventricular summit area and the distal coronary sinus respectively (3/9). In two cases, epicardial mapping was performed combined with visualization of the right or left coronary arteries, respectively. There were no complications attributed to coronary wiring and mapping in this case series. In two cases, the diagnostic information from mapping of the coronary arteries could be used to rule out an epicardial origin of arrhythmia. In the majority of cases, coronary visualization was used to ascertain a proper distance between the ablation site and the vessel. Discussion In this case series, we could demonstrate the feasibility and safety of coronary artery visualization and its integration in a 3D mapping system. The data obtained was used for diagnostic, as well as safety aspects. The electrograms from the wire were used to quickly assess relative timing of arrhythmias, thus allowing for an estimation of possible epicardial origin. Conclusion Applying the same caveats as for any other wiring of coronary arteries, their electroanatomic visualization is achieved in a safe and straightforward manner, with minimal technical requirements. Mapping of the coronary arteries adds critical diagnostic information and their real-time visualization is feasible without exceeding costs or risks