Cardiac Computed Tomography Angiography Research Articles

IntraCardiac echocardiography-guided leaflet modification for coronary protection prior to transcatheter valve-in-valve replacement.

A 79-year-old man with a failed 25-mm CE Magna Ease 3300 surgical prosthesis (Edwards Lifesciences) and of high re-operative surgical risk (STS 8%) presented with dyspnea, NYHA III. Cardiac computed tomography angiography revealed anatomy that was high risk for coronary occlusion with a short right coronary artery height of 6 mm and a valve-to-coronary distance of 2 mm.

Quantification of functional hemodynamics in aortic valve disease using cardiac computed tomography angiography

Background and Objective:Cardiac computed tomography angiography (CTA) is the preferred modality for preoperative planning in aortic valve stenosis. However, it cannot provide essential functional hemodynamic data, specifically the mean transvalvular pressure gradient (MPG). This study aims to introduce a computational fluid dynamics (CFD) approach for MPG quantification using cardiac CTA, enhancing its diagnostic value. Methods:Twenty patients underwent echocardiography, cardiac CTA, and invasive catheterization for pressure measurements. Cardiac CTA employed retrospective electrocardiographic gating to capture multi-phase data throughout the cardiac cycle. We segmented the region of interest based on mid-systolic phase cardiac CTA images. Then, we computed the average flow velocity into the aorta as the inlet boundary condition, using variations in end-diastolic and end-systolic left ventricular volume. Finally, we conducted CFD simulations using a steady-state model to obtain pressure distribution within the computational domain, allowing for the derivation of MPG. Results:The mean value of MPG, measured via invasive catheterization (MPGInv), echocardiography (MPGEcho), and cardiac CTA (MPGCT), were 51.3 ± 28.4 mmHg, 44.8 ± 19.5 mmHg, and 55.8 ± 25.6 mmHg, respectively. In comparison to MPGInv, MPGCT exhibited a higher correlation of 0.91, surpassing that of MPGEcho, which was 0.82. Moreover, the limits of agreement for MPGCT ranged from −27.7 to 18.7, outperforming MPGEcho, which ranged from −40.1 to 18.0. Conclusions:The proposed method based on cardiac CTA enables the evaluation of MPG for aortic valve stenosis patients. In future clinical practice, a single cardiac CTA examination can comprehensively assess both the anatomical and functional hemodynamic aspects of aortic valve disease.

An unusual pericardial cyst with cardiac and coronary involvement evaluated by cardiac computed tomography angiography.

An unusual pericardial cyst with cardiac and coronary involvement evaluated by cardiac computed tomography angiography.

Prognostic Impact of Left Atrial Appendage Patency After Device Closure

BACKGROUND: The prognostic impact of left atrial appendage (LAA) patency, including those with and without visible peri-device leak (PDL), post–LAA closure in patients with atrial fibrillation, remains elusive. METHODS: Patients with atrial fibrillation implanted with the WATCHMAN 2.5 device were prospectively enrolled. The device surveillance by cardiac computed tomography angiography was performed at 3 months post-procedure. Adverse events, including stroke/transient ischemic attack (TIA), major bleeding, cardiovascular death, all-cause death, and the combined major adverse events (MAEs), were compared between patients with complete closure and LAA patency. RESULTS: Among 519 patients with cardiac computed tomography angiography surveillance at 3 months post–LAA closure, 271 (52.2%) showed complete closure, and LAA patency was detected in 248 (47.8%) patients, including 196 (37.8%) with visible PDL and 52 (10.0%) without visible PDL. During a median of 1193 (787–1543) days follow-up, the presence of LAA patency was associated with increased risks of stroke/TIA (adjusted hazard ratio for baseline differences, 3.22 [95% CI, 1.17–8.83]; P =0.023) and MAEs (adjusted hazard ratio, 1.12 [95% CI, 1.06–1.17]; P =0.003). Specifically, LAA patency with visible PDL was associated with increased risks of stroke/TIA (hazard ratio, 3.66 [95% CI, 1.29–10.42]; P =0.015) and MAEs (hazard ratio, 3.71 [95% CI, 1.71–8.07]; P =0.001), although LAA patency without visible PDL showed higher risks of MAEs (hazard ratio, 3.59 [95% CI, 1.28–10.09]; P =0.015). Incidences of stroke/TIA (2.8% versus 3.0% versus 6.7% versus 22.2%; P =0.010), cardiovascular death (0.9% versus 0% versus 1.7% versus 11.1%; P =0.005), and MAEs (4.6% versus 9.0% versus 11.7% versus 22.2%; P =0.017) increased with larger PDL (0, >0 to ≤3, >3 to ≤5, or >5 mm). Older age and discontinuing antiplatelet therapy at 6 months were independent predictors of stroke/TIA and MAEs in patients with LAA patency. CONCLUSIONS: LAA patency detected by cardiac computed tomography angiography at 3 months post–LAA closure is associated with unfavorable prognosis in patients with atrial fibrillation implanted with WATCHMAN 2.5 device. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03788941.

Screening, risk stratification and CT imaging for assessment of coronary artery disease

Early treatment of cardiovascular risk factors and characterization of coronary plaques is essential to collect prognostic information about coronary artery disease (CAD) and prevent cardiovascular events. Discussion of the most important risk factors of CAD, basic diagnostic of CAD, prevention, and prognostic factors of CAD with focus on cardiac computed tomography (CT). Prevalence and prognostic impact of CAD risk factors; description of specific assessment of risk profiles; estimation of pretest probability; conventional prevention of CAD; prognostic assessment of CAD using the Calcium Scoring and coronary CT angiography. Assessment of risk profiles and estimation of pretest probability for obstructive coronary stenosis necessitates athorough evaluation of medical history and laboratory values. The composition and extent of calcified and noncalcified plaques in CT exams based on the criteria of the Coronary Artery Disease-Reporting and Data System give important prognostic information about the risk of cardiovascular events, which increases with high plaque burden and vice versa. Initial imaging with CT for evaluation of CAD leads to areduction of invasive coronary angiographies and catheter-associated complications. Besides early detection of cardiovascular risk factors, the additional assessment of plaque burden and significant stenosis in CT gives further prognostic information to facilitate effective therapies to prevent cardiovascular events and in the case of low plaque burden avoid invasive coronary angiography. However, systmatic screening using Calcium Scoring is not established yet due to insufficient data, although it could potentially be used for an early risk stratification in patients with multiple risk factors.

Updating national diagnostic reference levels for computed tomography in Greece: Challenges on patient protection optimisation

The escalating use of Computed Tomography (CT) imaging necessitates establishment and periodic revision of Diagnostic Reference Levels (DRLs) to ensure patient protection optimization. This paper presents the outcomes of a national survey conducted from 2019 to 2022, focusing on revising DRLs for adult CT examinations. Dosimetric data from 127 scanners in 120 medical facilities, representing 25% of the country's CT scanners, were collected, emphasizing geographic distribution and technology representation. Τhe parameters used for DRLs were the CTDIvol and the DLP of a typical acquisition of the region of interest (scan DLP). In addition to the 7 CT examination for which the DRL values were revised, establishment of DRLs for neck, cervical spine, pelvic bones-hips, coronary artery calcium (Ca) score and cardiac computed tomography angiography (CCTA) examinations was performed.Revised DRLs exhibited a 15 % average decrease in CTDIvol and a 7 % average decrease in scan DLP from the initial DRLs. This reduction of dosimetric values is relatively low compared to other national studies. The findings revealed wide variations in dosimetric values and scan lengths among scanners, emphasizing the need for standardization and optimization. Incorporation of advanced technologies like Iterative Reconstruction (IR) showcased potential for further dose reduction, yet challenges in uniform implementation persist. The study underscores the importance of ongoing optimisation efforts, particularly in the context of increased CT utilization and evolving technology. The revised DRLs have been officially adopted in Greece, emphasizing the commitment to safe and effective CT practices.

CAR and CSTR Cardiac Computed Tomography (CT) Practice Guidelines: Part 1 Coronary CT Angiography (CCTA).

Imaging the heart is one of the most technically challenging applications of Computed Tomography (CT) due to the presence of cardiac motion limiting optimal visualization of small structures such as the coronary arteries. Electrocardiographic gating during CT data acquisition facilitates motion free imaging of the coronary arteries. Since publishing the first version of the Canadian Association of Radiologists (CAR) cardiac CT guidelines, many technological advances in CT hardware and software have emerged necessitating an update. The goal of these cardiac CT practice guidelines is to present an overview of the current evidence supporting the use of cardiac CT in various clinical scenarios and to outline standards of practice for patient safety and quality of care when establishing a cardiac CT program in Canada.

CAR and CSTR Cardiac Computed Tomography (CT) Practice Guidelines: Part 2-Non-Coronary Imaging.

The cardiac computed tomography (CT) practice guidelines provide an updated review of the technological improvements since the publication of the first Canadian Association of Radiologists (CAR) cardiac CT practice guidelines in 2009. An overview of the current evidence supporting the use of cardiac CT in the most common clinical scenarios, standards of practice to optimize patient preparation and safety as well as image quality are described. Coronary CT angiography (CCTA) is the focus of Part I. In Part II, an overview of cardiac CT for non-coronary indications that include valvular and pericardial imaging, tumour and mass evaluation, pulmonary vein imaging, and imaging of congenital heart disease for diagnosis and treatment monitoring are discussed. The guidelines are intended to be relevant for community hospitals and large academic centres with established cardiac CT imaging programs.

Assessing breast arterial calcification in mammograms and its implications for atherosclerotic cardiovascular disease risk

PurposeBreast arterial calcifications (BAC) are incidentally observed on mammograms, yet their implications remain unclear. We investigated lifestyle, reproductive, and cardiovascular determinants of BAC in women undergoing mammography screening. Further, we investigated the relationship between BAC, coronary arterial calcifications (CAC) and estimated 10-year atherosclerotic cardiovascular (ASCVD) risk. MethodsIn this cross-sectional study, we obtained reproductive history and CVD risk factors from 215 women aged 18 or older who underwent mammography and cardiac computed tomographic angiography (CCTA) within a 2-year period between 2007 and 2017 at hospital. BAC was categorized as binary (present/absent) and semi-quantitatively (mild, moderate, severe). CAC was determined using the Agatston method and recorded as binary (present/absent). Adjusted odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated, accounting for age as a confounding factor. ASCVD risk over a 10-year period was calculated using the Pooled Cohort Risk Equations. ResultsOlder age, systolic and diastolic blood pressures, higher parity, and younger age at first birth (≤28 years) were significantly associated with greater odds of BAC. Women with both BAC and CAC had the highest estimated 10-year risk of ASCVD (13.30 %). Those with only BAC (8.80 %), only CAC (5.80 %), and no BAC or CAC (4.40 %) had lower estimated 10-year risks of ASCVD. No association was detected between presence of BAC and CAC. ConclusionsThese findings support the hypothesis that BAC on a screening mammogram may help to identify women at potentially increased risk of future cardiovascular disease without additional cost and radiation exposure.

Cardiac computed tomography angiography-derived pulmonary vein volumetry as a predictor for atrial fibrillation recurrence after catheter ablation.

There is an increasing evidence that pulmonary vein (PV) enlargement is associated with atrial fibrillation (AF); however, the predictive value of PV enlargement in AF recurrence remains unclear. This study sought to evaluate whether PV volume quantification derived from cardiac computed tomographic angiography (CCTA) could serve as a predictive indicator of the success of the catheter ablation (CA) procedure. The data of 160 patients diagnosed with AF who underwent both CCTA and CA treatments from January to June 2020 were retrospectively examined; the CCTA was conducted before the CA surgery. The study focused on documenting the PV structure, and the volume of the PV and left atrium (LA). The clinical, CCTA, and echocardiographic predictors of the recurrence and no-recurrence groups were compared. A multivariable logistic regression analysis was performed to adjust for confounders. Receiver operating characteristic (ROC) curves were analyzed to assess the predictive performance of the predictors of AF recurrence. Of the 160 patients [55.6% male, 62.00 (55.25-68.00) years, 23.1% with persistent AF], 45 (28.1%) experienced AF recurrence within a one-year period. Notably, patients with AF recurrence had elevated CHADS2 scores (P=0.020) and increased LA and PV volumes (P<0.05). Patients with persistent AF (n=37) had significantly larger LA volume indexes (P<0.001) than those with paroxysmal AF, but there was no difference between the two groups in terms of the PV maximum volume index (P=0.200). Moreover, the PV maximum volume index [odds ratio (OR): 1.244, 95% confidence interval (CI): 1.008-1.536, P=0.042] and the LA minimum volume index (OR: 1.026, 95% CI: 1.001-1.052, P=0.038) were found to be significant predictors of AF recurrence. The ROC curves revealed that the PV maximum volume index threshold for predicting AF recurrence was 7.13 mL/m2, with a sensitivity of 84.4% and a specificity of 34.8% [area under the curve (AUC): 0.635, 95% CI: 0.540-0.730, P=0.008], and the LA minimum volume index threshold for predicting AF recurrence was 46.16 mL/m2, with a sensitivity of 88.9% and a specificity of 31.3% (AUC: 0.629, 95% CI: 0.534-0.723, P=0.012). A sub-analysis of patients with a lower left atrial dimension (LAD ≤38 mm in females, LAD ≤40 mm in males, n=120) demonstrated that the PV maximum volume index was a noteworthy indicator of AF recurrence (OR: 1.443: 95% CI: 1.145-1.820, P=0.002). Conversely, no significant correlation between AF recurrence and the LA volume index was found. The AUC value for the PV maximum volume index predictive of recurrent AF was 0.680 (95% CI: 0.577-0.781, P=0.003), with a sensitivity of 75.8%, specificity of 54%, and the cut-off value of the maximum AUC was 7.89 mL/m2. PV volume, derived from CCTA, may help to predict the recurrence of AF after CA, and is superior to the LA size in patients with less pronounced LA enlargement.

Non-electrocardiography-gated dual-energy cardiac CT angiography for assessment of left atrial appendage thrombus

ObjectiveTo explore the diagnosis value of a low dose, dual-energy cardiac computed tomography angiography (CTA) with non-electrocardiography-gated (non-ECG-gated) in detecting left atrial appendage thrombus. MethodsConsecutive patients with atrial fibrillation who underwent cardiac CTA protocol (dual-energy scan for arterial phase and conventional scan for delayed phase) were prospectively enrolled. LAA lesions were proved by clinical comprehensive diagnosis, the final study included 18 cases with LAA thrombus and 48 cases with circulatory stasis. Quantitative parameters derived from dual-energy images were measured for the LAA lesions, including the conventional CT attenuation value (CT value), iodine concentration (IC), normalized iodine concentration (NIC), effective atomic number values (Zeff) and energy spectrum curve slope (Slope). The differences between LAA thrombus group and circulatory stasis group were compared by independent t-test or Wilcoxon rank sum test regarding to the normality test. The diagnosis performance of the dual-energy parameters was assessed using receiver operating characteristic (ROC) curve analysis and area under curve (AUC). ResultsAll the dual-energy parameters were demonstrated significantly difference between LAA thrombus and circulatory stasis group (P＜0.05), and showed better diagnostic performance than the conventional CT value. ROC analysis revealed IC was the most predictive parameter with AUC equal to 0.836. The radiation dose in the arterial phase was (2.64 ​± ​0.66) mSv. ConclusionDual-energy CTA scanning shows convincing diagnostic performance in detecting left atrial appendage thrombus with lower radiation dose, and may help reduce the need for delayed phase scan.

Prevalence of major embolic findings and incidental findings on early cardiac CT in patients with suspected ischemic stroke

PurposeThe purpose of this study was to assess the type and prevalence of stroke and non-stroke-related findings diagnosed on early cardiac computed tomography (CT) in patients with suspected stroke. The secondary objective was to assess the clinical consequences on the management of patients with non-stroke-related conditions identified by early cardiac CT. Materials and methodsThis single-center, retrospective, observational study included 1111 consecutive patients with suspected ischemic stroke between November 2018 and March 2020 who underwent cardiac CT examination in addition to the usual brain CT protocol (i.e., non-enhanced brain CT, perfusion brain CT when needed, aortic arch and supra-aortic CT angiography, and post contrast brain CT). There were 562 women and 549 men with a median age of 74 years (range: 60–85 years). Of these, 415 (415/1111; 37.4%) patients had ischemic stroke and 692 (692/1111; 62.3%) had no stroke. Cardiac CT examinations were retrospectively reviewed for cardiac CT findings at high embolic risk and clinically significant extracardiac incidental findings. ResultsAmong 1111 included patients, 89 (89/1111; 8.0%) had a stroke-related condition identified on early cardiac CT. This was significantly more frequent in patients with ischemic stroke (66/415; 15.9%) by comparison with those without ischemic stroke (23/696; 3.3%) (P < 0.001), with 41 patients (41/415; 9.9%) diagnosed with left atrial thrombus. Cardiac CT revealed a clinically significant non-stroke-related finding in 173 patients (173/1111; 15.6%), including 17 pulmonary embolisms (1.5%), seven suspicious pulmonary lesions (0.6%), and three breast lesions suspected to be malignant (0.3%). Twenty out of 173 patients (20/173; 11.5%) with incidental findings on early cardiac CT had a change in their management. ConclusionThis study shows that adding early cardiac CT to brain CT during the acute phase of an ischemic stroke leads to a higher rate of etiological diagnoses and highlights the major interest of looking at the bigger picture.

Long-Term Efficacy Analysis of Surgical Resection of 70 Primary Right Heart Tumors

Introduction: The aim of the study was to investigate the clinical characteristics, surgical treatment, and long-term efficacy of primary right heart tumors. Methods: This study is retrospective analysis of the clinical data of 70 patients with primary right heart tumors admitted to our department between 1980 and 2022 (observation group) and 70 patients with left heart tumors during the same period (control group). The surgical treatment was performed under cardiopulmonary bypass after differential diagnosis by echocardiography, cardiac CTA, and PET-CT before the surgery. The perioperative characteristics, recurrence rate, and long-term survival rates of right heart tumor versus left heart tumor were compared. Results: The most common pathological types of right heart tumors were myxoma (60%), lipoma (8.57%), and papillary elastofibroma (7.14%). During the perioperative period, there were 1 case of systemic embolism in the observation group, compared with 6 in the control group (p = 0.026), 13 cases of malignant tumor in the observation group versus 1 in the control group (p = 0.01). During the follow-up period, there were 15 cases of tumor recurrence and 17 cases of death in the observation group versus 4 (p = 0.002) and 7 in the control group (p = 0.006), comparatively. Conclusion: Compared with left heart tumors, primary right heart tumors had a higher incidence of malignant tumors and a lower risk of systemic embolism during perioperative period. During the follow-up period, primary right heart tumors had a higher rate of tumor recurrence and a lower long-term survival rate.

The impact of contrast retention on thrombus formation risks in patients with atrial fibrillation: A numerical study

BackgroundContrast retention (CR) is an important predictor of left atrial appendage thrombus (LAAT) and stroke in patients with non-valvular atrial fibrillation (AF). We sought to explore the underlying mechanisms of CR using computational fluid dynamic (CFD) simulations. MethodsA total of 12 patients with AF who underwent both cardiac computed tomography angiography (CTA) and transesophageal echocardiography (TEE) before left atrial appendage occlusion (LAAO) were included in the study. The patients were allocated into the CR group or non-CR group based on left atrial appendage (LAA) angiography. Patient-specific models were reconstructed to evaluate time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and endothelial cell activation potential (ECAP). Additionally, the incidence of thrombosis was predicted using residence time (RT) at different time-points. ResultsTAWSS was lower [median (Interquartile Range) 0.27 (0.19–0.47) vs 1.35 (0.92–1.79), p < 0.001] in LAA compared to left atrium. In contrast, RRT [1438 (409.70–13869) vs 2.23 (1.81–3.14), p < 0.001] and ECAP [122.70 (30.01–625.70) vs 0.19 (0.16–0.27), p < 0.001)] was higher in the LAA. The patients in the CR group had significantly higher RRT [(mean ± SD) 16274 ± 11797 vs 639.70 ± 595.20, p = 0.009] and ECAP [610.80 ± 365.30 vs 54.26 ± 54.38, p = 0.004] in the LAA compared to the non-CR group. Additionally, patients with CR had a wider range of thrombus-prone regions [0.44(0.27–0.66)% vs 0.05(0.03–0.27)%, p = 0.009] at the end of the 15th cardiac cycle. ConclusionsThese findings suggest that CR might be an indicator of high-risk thrombus formation in the LAA. And CT-based CFD simulation may be a feasible substitute for the evaluation of LAA thrombotic risk in patients with AF, especially in patients with CR.

A Novel Reconstruction Technique to Reduce Stair-Step Artifacts in Sequential Mode Coronary CT Angiography.

Prospective electrocardiography-triggering is one of the most commonly used cardiac computed tomography (CT) scan modes but can be susceptible to stair-step artifacts in the transition areas of an acquisition over multiple cardiac cycles. We evaluated a novel reconstruction algorithm to reduce the occurrence and severity of such artifacts in sequential coronary CT angiography. In this institutional review board-approved, retrospective study, 50 consecutive patients (16 females; mean age, 58.9 ± 15.2) were included who underwent coronary CT angiography on a dual-source photon-counting detector CT in the sequential ultra-high-resolution mode with a detector collimation of 120 × 0.2 mm. Each scan was reconstructed without (hereafter called standard reconstruction) and with the novel ZeeFree reconstruction algorithm, which aims to minimize stair-step artifacts. The presence and extent of stair-step artifacts were rated by 2 independent, blinded readers on a 4-point discrete visual scale. The relationship between the occurrences of artifacts was correlated with the average and variability of heart rate and with patient characteristics. A total of 504 coronary segments were included into the analyses. In standard reconstructions, reader 1 reported stair-step artifacts in 40/504 (7.9%) segments, from which 12/504 led to nondiagnostic image quality (2.4% of all segments). Reader 2 reported 56/504 (11.1%) stair-step artifacts, from which 11/504 lead to nondiagnostic image quality (2.2% of all segments). With the ZeeFree algorithm, 9/12 (75%) and 8/11 (73%) of the nondiagnostic segments improved to a diagnostic quality for readers 1 and 2, respectively. The ZeeFree reconstruction algorithm significantly reduced the frequency and extent of stair-step artifacts compared with standard reconstructions for both readers (P < 0.001, each). Heart rate variability and body mass index were significantly related to the occurrence of stair-step artifacts (P < 0.05). Our study demonstrates the feasibility and effectiveness of a novel reconstruction algorithm leading to a significant reduction of stair-step artifacts and, hence, a reduction of coronary segments with a nondiagnostic image quality in sequential ultra-high-resolution coronary photon-counting detector CT angiography.

Cardiac Computed Tomography Angiography in Infants and Young Children Without Sedation.

Cardiac computed tomography (CT) imaging plays a pivotal role in the diagnosis and management of infants and young children with congenital heart disease (CHD). While the benefits of CT imaging are well-established, the challenge lies in adapting these procedures to the unique requirements of infants and young children. Traditionally, sedation has been a common practice to ensure cooperation and motion control during imaging. However, using sedation introduces its challenges including potential risks, limitations, and cost implications. In this study, authors explore the feasibility, safety, and diagnostic accuracy of unsedated cardiac CT examinations in infants and young children. This study proves cardiac CT can be performed in India without sedation using simple restraining techniques. This approach aligns with the cultural and familial dynamics prevalent in the country and holds the potential to address economic and infrastructure challenges.

Cardiac computed tomography angiography for assessment of endothelial insufficiency of left atrial appendage disc-like occluder.

This study was performed to explore the diagnostic value of cardiac computed tomography angiography (CCTA) for endothelial insufficiency (EIS) of a left atrial appendage (LAA) disc-like occluder. Fifty-nine patients with nonvalvular atrial fibrillation who underwent placement of an LAA disc-like occluder (LAmbre; Lifetech Scientific) in our hospital were retrospectively analyzed. Patients who were found to have contrast agent entering the LAA at the 3-month postoperative CCTA examination underwent Hounsfield unit (HU) measurement of the LAA and construction of a three-dimensional(3D) model of the device for preliminary discernment between peri-device leakage (PDL) and EIS. These patients were then further examined by transesophageal echocardiography (TEE) to check for concordance with the computed tomography (CT) findings. According to the CT and TEE results, all patients were divided into the PDL group, total endothelialization group, and EIS group. The endothelial conditions and other implantation-related results were also tracked at the 6-month follow-up. All 59 patients underwent successful implantation of the LAmbre LAA closure device with no severe adverse events during the procedure. Thirty-five patients were found to have contrast agent entering the LAA at the 3-month postoperative CCTA follow-up. Based on the CT HU measurement and the 3D construction analysis results, these 35 patients were divided into the PDL group (19 patients) and the EIS group (16 patients). In the PDL group, the contrast agent infiltrated from the shoulder along the periphery of the occluder on two-dimensional (2D)CT images, and the 3D model showed a gap between the LAA and the device cover. However, the CCTA images of the other 16 patients in the EIS group showed that the contrast agent in the occluder on the 2D CTA images and 3D construction model confirmed the absence of a gap between the LAA and the device cover. TEE confirmed all of the CT results. The 6-month follow-up results showed that 14 of 19 patients in the EIS group achieved total endothelialization, whereas this number in the PDL group was only five of 19 patients. CCTA can replace TEE for examination of the endothelialization status, and patients with EIS have a higher chance of endothelialization than patients with PDL.

TTN: Topological Transformer Network for Automated Coronary Artery Branch Labeling in Cardiac CT Angiography

TTN: Topological Transformer Network for Automated Coronary Artery Branch Labeling in Cardiac CT Angiography

Multimodality Imaging Diagnosis in Infective Endocarditis.

Imaging is an important tool in the diagnosis and management of infective endocarditis (IE). Echocardiography is an essential examination, especially in native valve endocarditis (NVE), but its diagnostic accuracy is reduced in prosthetic valve endocarditis (PVE). The diagnostic ability is superior for transoesophageal echocardiography (TEE), but a negative test cannot exclude PVE. Both transthoracic echocardiography (TTE) and TEE can provide normal or inconclusive findings in up to 30% of cases, especially in patients with prosthetic devices. New advanced non-invasive imaging tests are increasingly used in the diagnosis of IE. Nuclear medicine imaging techniques have demonstrated their superiority over TEE for the diagnosis of PVE and cardiac implantable electronic device infective endocarditis (CIED-IE). Cardiac computed tomography angiography imaging is useful in PVE cases with inconclusive TTE and TEE investigations and for the evaluation of paravalvular complications. In the present review, imaging tools are described with their values and limitations for improving diagnosis in NVE, PVE and CIED-IE. Current knowledge about multimodality imaging approaches in IE and imaging methods to assess the local and distant complications of IE is also reviewed. Furthermore, a potential diagnostic work-up for different clinical scenarios is described. However, further studies are essential for refining diagnostic and management approaches in infective endocarditis, addressing limitations and optimizing advanced imaging techniques across different clinical scenarios.

Coronary stenosis quantification in cardiac computed tomography angiography: multi-factorial optimization of image quality and radiation dose.

The accuracy and variability of quantification in computed tomography angiography (CTA) are affected by the interplay of imaging parameters and patient attributes. The assessment of these combined effects has been an open engineering challenge. In this study, we developed a framework that optimizes imaging parameters for accurate and consistent coronary stenosis quantification in cardiac CTA while accounting for patient-specific variables. The framework utilizes a task-specific image quality index, the estimability index (), approximated by a surrogate estimability polynomial function (EPF) capable of finding the optimal protocol that (1)maximizes image quality with an upper bound for desired radiation dose or (2)minimizes the dose level with a lower bound of acceptable image quality. The optimization process was formulated with the decision variables being subject to a set of constraints. The methodology was verified using CTA data from a prior clinical trial (prospective multi-center imaging study for evaluation of chest pain) by assessing the concordance of its prediction with the trial results. Further, the framework was used to derive an optimum protocol for each case based on the patient attributes, gauging how much improvement would have been possible if the derived optimized protocol would have been deployed. The framework produced results consistent with imaging physics principles with approximated EPFs of 97% accuracy. The feature importance evaluation demonstrated a close match with earlier studies. The verification study found scores closely predicting the cardiologist scores to within 95% in terms of the area under the receiver operating characteristic curve and predicting potential for either an average of fourfold increase in within a targeted dose or a reduction in radiation dose by an average of 57% without reducing the image quality. The protocol optimization framework provides means to assess and optimize CTA in terms of either image quality or radiation dose objectives with its results predicting prior clinical trial findings.