Cardiac Computed Tomography Scans Research Articles

Conduit Flow Compensates for Impaired Left Atrial Passive and Booster Functions in Advanced Diastolic Dysfunction.

Quantification of left atrial (LA) conduit function and its contribution to left ventricular (LV) filling is challenging because it requires simultaneous measurements of both LA and LV volumes. The functional relationship between LA conduit function and the severity of diastolic dysfunction remains controversial. We studied the role of LA conduit function in maintaining LV filling in advanced diastolic dysfunction. We performed volumetric and flow analyses of LA function across the spectrum of LV diastolic dysfunction, derived from a set of consecutive patients undergoing multiphasic cardiac computed tomography scanning (n=489). From LA and LV time-volume curves, we calculated 3 volumetric components: (1) early passive emptying volume; (2) late active (booster) volume; and (3) conduit volume. Results were prospectively validated on a group of patients with severe aortic stenosis (n=110). The early passive filling progressively decreased with worsening diastolic function (P<0.001). The atrial booster contribution to stroke volume modestly increases with impaired relaxation (P=0.021) and declines with more advanced diastolic function (P<0.001), thus failing to compensate for the reduction in early filling. The conduit volume increased progressively (P<0.001), accounting for 75% of stroke volume (interquartile range, 63-81%) with a restrictive filling pattern, compensating for the reduction in both early and booster functions. Similar results were obtained in patients with severe aortic stenosis. The pulmonary artery systolic pressure increased in a near-linear fashion when the conduit contribution to stroke volume increased above 60%. Maximal conduit flow rate strongly correlated with mitral E-wave velocity (r=0.71; P<0.0001), indicating that the increase in mitral E wave in diastolic dysfunction represents the increased conduit flow. An increase in conduit volume contribution to stroke volume represents a compensatory mechanism to maintain LV filling in advanced diastolic dysfunction. The increase in conduit volume despite increasing LV diastolic pressures is accomplished by an increase in pulmonary venous pressure.

Jugular Approach for the Transcatheter Pacemaker Implant - Better Access for Smaller Hearts?

The Micra leadless pacemaker was developed to fit inside the right ventricle, thereby reducing overall complications by 48% compared with a historical control group. The current labeling restricts implants to the femoral approach. In this article we used 3-dimensional computer models of human hearts to demonstrate why implants can be difficult in small patients and how using the jugular approach reduces these difficulties.Methods and Results: Cardiac computed tomography scans were made of 45 pacemaker patients, 26 in the US and 19 from a single center in Japan. Dimensional measurements were taken in all 45 hearts, and these dimensions were compared between patient cohorts and between the Micra delivery tool dimension and patient heart dimensions. Hearts were smaller among patients in the Japanese than US cohort. In addition, the tool dimension exceeded heart dimensions in a larger percentage of hearts from Japanese patients. Three dimensions were identified that most likely limit navigating across the tricuspid valve to the right ventricle in smaller hearts and for which the jugular approach improved navigation. Although the femoral procedure today maintains an excellent safety profile and procedure experience for most global implants, this study provides the rationale as to why the jugular approach may improve the ease of the Micra implant in small hearts, namely by reducing the tortuosity of the navigation across the tricuspid valve.

Early-onset vs late-onset preeclampsia and risk of coronary atherosclerosis later in life: a clinical follow-up study

BackgroundYounger women with previous preeclampsia have an increased risk of coronary atherosclerosis. It is unknown if this risk is associated with the time of onset of preeclampsia. ObjectivesThe aim of the study was to investigate if women with early-onset preeclampsia have a higher risk of coronary atherosclerosis compared to women with late-onset preeclampsia, independent of other perinatal risk factors. Study DesignA total of 911 women with previous preeclampsia aged 35-55 years participated in a clinical follow-up study, including clinical examination, comprehensive questionnaires, and cardiac computed tomography scan 13 years (range 0-28) after index pregnancy. Early-onset preeclampsia versus late-onset preeclampsia was defined as gestational age at delivery < versus ≥ 34+0 gestational weeks, respectively. The primary outcome of the study was the presence of coronary atherosclerosis on the cardiac computed tomography. A logistic regression analysis was performed to investigate the association between time of onset of preeclampsia, perinatal risk factors and the primary outcome. ResultsWomen with early-onset preeclampsia (N=139) were older (46.2±5.7 vs. 44.4±5.5 years, P<0.001), more likely to have hypertension (51.1% vs. 35.1%, P=<0.001), and had a higher body mass index (27.9±6.3 vs. 26.9±5.5 kg/m2, P=0.051) compared to women with late-onset preeclampsia (N=772) at follow-up. The prevalence of the primary outcome coronary atherosclerosis on the cardiac computed tomography was 28.8% vs. 22.2% (P=0.088) with an adjusted OR=1.74, 95% CI (1.01-3.01), P=0.045 after adjustment for maternal age at index pregnancy, pre-pregnancy body mass index, parity, diabetes in pregnancy, smoking in pregnancy, offspring birth weight and sex, and follow-up length. ConclusionsWomen with early-onset preeclampsia had a slightly higher risk of coronary atherosclerosis compared to women with late-onset preeclampsia. However, based on the current evidence it does not seem indicated to limit screening, diagnostic and preventive measures for cardiovascular disease only to women with early-onset preeclampsia.

Estimate and compensate head motion in non-contrast head CT scans using partial angle reconstruction and deep learning.

Patient head motion is a common source of image artifacts in computed tomography (CT) of the head, leading to degraded image quality and potentially incorrect diagnoses. The partial angle reconstruction (PAR) means dividing the CT projection into several consecutive angular segments and reconstructing each segment individually. Although motion estimation and compensation using PAR has been developed and investigated in cardiac CT scans, its potential for reducing motion artifacts in head CT scans remains unexplored. To develop a deep learning (DL) model capable of directly estimating head motion from PAR images of head CT scans and to integrate the estimated motion into an iterative reconstruction process to compensate for the motion. Head motion is considered as a rigid transformation described by six time-variant variables, including the three variables for translation and three variables for rotation. Each motion variable is modeled using a B-spline defined by five control points (CP) along time. We split the full projections from 360° into 25 consecutive PARs and subsequently input them into a convolutional neural network (CNN) that outputs the estimated CPs for each motion variable. The estimated CPs are used to calculate the object motion in each projection, which are incorporated into the forward and backprojection of an iterative reconstruction algorithm to reconstruct the motion-compensated image. The performance of our DL model is evaluated through both simulation and phantom studies. The DL model achieved high accuracy in estimating head motion, as demonstrated in both the simulation study (mean absolute error (MAE) ranging from 0.28 to 0.45mm or degree across different motion variables) and the phantom study (MAE ranging from 0.40 to 0.48mm or degree). The resulting motion-corrected image, , exhibited a significant reduction in motion artifacts when compared to the traditional filtered back-projection reconstructions, which is evidenced both in the simulation study (image MAE drops from 178 33HU to 37 9HU, structural similarity index (SSIM) increases from 0.60 0.06 to 0.98 0.01) and the phantom study (image MAE drops from 117 17HU to 42 19HU, SSIM increases from 0.83 0.04 to 0.98 0.02). We demonstrate that using PAR and our proposed deep learning model enables accurate estimation of patient head motion and effectively reduces motion artifacts in the resulting head CT images.

Standardization and validation of neoLVOT assessment using three-dimensional trans-esophageal echocardiography before trans-catheter mitral valve replacement.

Trans-catheter mitral valve replacement (TMVR) procedures had emerged as an alternative solution for patients who are at high risk for mitral valve surgery. Although cardiac computed tomography (CT) remains the standard method for procedural planning, there is no full agreement on the best systolic phase for quantitation of the neoLVOT. Furthermore, a new three-dimensional trans-esophageal echocardiography (3DTEE) based software was developed to serve as filter and or an alternative for patients who cannot have CT due to any contraindication. To determine the systolic phase of the cardiac cycle that shows the narrowest NeoLVOT area in order to standardize the way of using these software and then to validate the 3DTEE-based software against the CT-based one as a gold standard, in mitral valve annulus (MA) and NeoLVOT assessment. A single center, observational, retrospective study. Initially, a sample of 20 patients (age 62±4 years, 70% men) had CT-based analysis at mid-diastole (80%), early-systole (10%), mid-systole (20%), late-systole (30%-40%), in order to detect the best systolic phase at which the neoLVOT area is the narrowest after TMVR. Then, the end systolic phase was standardized for the analysis of 49 patients (age 57±6 years, 60% men), using both the commercially available CT-based software and the newly available 3DTEE-based software (3mensio Structural Heart, Pie Medical Imaging, The Netherlands). The 3DTEE derived parameters were compared with the gold standard CT-based measurements. The neoLVOT area was significantly narrower at end-systole (224±62 mm2), compared to early-systole (299±70 mm2) and mid-systole (261±75 mm2), (p=.005). Excellent correlation was found between 3DTEE and CT measurements for MA AP diameter (r=.96), IC diameter (r=.92), MA area (r=.96), MA perimeter (r=.94) and NeoLVOT area (r=.96), (all p-values<.0001). Virtual valve sizing was based on annulus measurement and was identical between CT and 3DTEE. Interobserver and intraobserver agreements were excellent for all the measurements with ICCs>.80. End-systole is the phase that shows the narrowest neoLVOT and hence should be the standard phase used during the analysis. The 3DTEE based analysis using this new software is reliable compared to the CT-based analysis and can be serve as an alternative analysis tool in patients who cannot have CT for any clinical contraindication or as a screening test and/or filter for all patients before proceeding to a detailed CT scan.

Left atrial appendage filling defect in exclusive early-phase scanning of dual-phase cardiac computed tomography: An indicator for elevated thromboembolic risk.

Dual-phase cardiac computed tomography (CCT) has been applied to detect left atrial appendage (LAA) thrombosis, which is characterized as the presence of left atrial appendage filling defects (LAADF) in both early- and delayed-phase scanning. However, the clinical implication of LAAFD in exclusive early-phase scanning (LAAFD-EEpS) of CCT in patients with atrial fibrillation (AF) is unclear. The baseline clinical data and dual-phase CCT findings in 1183 AF patients (62.1 ± 11.6 years, 59.9% male) was collected and analyzed. A further analysis of CCT and transesophageal echocardiography (TEE) data (within 5 days) in a subgroup of 687 patients was performed. LAAFD-EEpS was defined as LAAFD present in early-phase and absent in delayed-phase scanning of dual-phase CCT. A total of 133 (11.2%) patients were detected with LAAFD-EEpS. Patients with LAAFD-EEpS had a higher prevalence of ischemic stroke or transient ischemic attack (TIA) (p < 0.001) and a higher predefined thromboembolic risk (p < 0.001). In multivariate analysis, a history of ischemic stroke or TIA was independently associated with LAAFD-EEpS (odds ratio [OR] 11.412, 95% confidence interval [CI] 6.561-19.851, p < 0.001). When spontaneous echo contrast in TEE was used as the reference standard, the sensitivity, specificity, positive predictive value, and negative predictive value of LAAFD-EEpS was 77.0% (95% CI 66.5-87.6%), 89.0% (95% CI 86.5-91.4%), 40.5% (95% CI 31.6-49.5%), 97.5% (96.3-98.8%), respectively. In AF patients, LAAFD-EEpS is not an uncommon finding in dual-phase CCT scanning, and is associated with elevated thromboembolic risk.

Airway Tree Caliber and Susceptibility to Pollution-associated Emphysema: MESA Air and Lung Studies.

Airway tree morphology varies in the general population and may modify the distribution and uptake of inhaled pollutants. We hypothesized that smaller airway caliber would be associated with emphysema progression and would increase susceptibility to air pollutant-associated emphysema progression. The Multi-Ethnic Study of Atherosclerosis (MESA) is a general population cohort of adults 45-84 years old from six U.S. communities. Airway tree caliber was quantified as the mean of airway lumen diameters measured from baseline cardiac computed tomography (CT) (2000-02). Percent emphysema, defined as percentage of lung pixels below -950 Hounsfield units, was assessed up to 5 times per participant via cardiac CT scan (2000-07) and equivalent regions on lung CT scan (2010-18). Long-term outdoor air pollutant concentrations (PM2.5, NOx, O3) were estimated at residential address with validated spatio-temporal models. Linear mixed models estimated the association between airway tree caliber and emphysema progression; modification of pollutant-associated emphysema progression was assessed using multiplicative interaction terms. Among 6,793 participants (mean±SD age: 62±10 years), baseline airway tree caliber was 3.95±1.1 mm and median (interquartile range) of percent emphysema was 2.88 (1.21-5.68). In adjusted analyses, 10-year emphysema progression rate was 0.75 percentage points (95%CI 0.54-0.96%) higher in the smallest compared to largest airway tree caliber quartile. Airway tree caliber also modified air pollutant-associated emphysema progression. Smaller airway tree caliber was associated with accelerated emphysema progression and modified air pollutant-associated emphysema progression. A better understanding of mechanisms of airway-alveolar homeostasis and air pollutant deposition are needed.

Accuracy of Transthoracic Echocardiography in Detecting Persistent Left Superior Vena Cava against the Cardiac Computed Tomography Scan

Abstract Introduction: Detection of the persistent left superior vena cava (LSVC) is essential to diagnosing pediatric congenital heart diseases (CHDs). Transthoracic echocardiography is the most commonly used diagnostic tool for CHDs. This study compares transthoracic echocardiography and cardiac computed tomography (CT) to detect LSVC. Methods: Retrospective review of 49 pediatrics patients with CHDs who underwent echocardiography and cardiac CT. Results: Forty-nine pediatric patients with CHDs who underwent CT scans were included. In acyanotic CHD patients, CT identified four with bilateral superior vena cava (SVC), while echocardiography picked up three and missed one. In the remaining 16 patients with acyanotic CHDs, CT found single right-sided SVC; however, two of these were misidentified as having bilateral SVC during echocardiography. In the cyanotic CHD group, four patients had bilateral SVC. All four were picked up by echocardiography as well. However, echocardiography diagnosed one additional patient as having bilateral SVC, while the patient actually had a single SVC on CT scan. Conclusion: Transthoracic echocardiography can reasonably detect persistent LSVC in pediatric CHD patients.

Fatal Hemoptysis Secondary to Severe Pulmonary Veins Stenosis and Fibrosing Mediastinitis following Radiofrequency Ablation for Atrial Fibrillation: A Case Report and Review of the Literature

Fatal hemoptysis secondary to severe pulmonary veins stenosis and fibrosing mediastinitis is an exceptional late complication of radiofrequency ablation for atrial fibrillation. We report the case of a 53-year-old male with a history of atrial fibrillation treated by radiofrequency ablation and admitted in our center 6 months after the procedure because of aggravating dyspnea and fatigability. Transthoracic echocardiography showed moderate dilation of right heart cavities, severe pulmonary hypertension and a turbulent flow in superior pulmonary veins. The cardiologist suspected pulmonary vein(s) stenosis and so cardiac computed tomography (CT) angiography was performed, with findings of severe stenosis of the right superior, right inferior and left inferior pulmonary veins, near-occlusion of the left superior pulmonary vein and the vein draining the apical segment of the right lower lobe. The CT scan also revealed soft tissue attenuation of the mediastinum posterior to the left atrium suggesting fibrosing mediastinitis together with parenchymal findings consistent with pulmonary veno-oclusive disease and an area of hemorrhagic infarction. Fatal hemoptysis occurred 3 days later, before treatment was attempted. In conclusion, severe pulmonary vein stenosis and fibrosing mediastinitis are rare but devastating complications of radiofrequency ablation. Prevention and early diagnosis are the key elements as these entities are potentially life-threatening.

Coronary artery disease in atrial fibrillation ablation: impact on arrhythmic outcomes.

Catheter ablation (CA) is an established treatment for atrial fibrillation (AF). A computed tomography (CT) may be performed before ablation to evaluate the anatomy of pulmonary veins. The aim of this study is to investigate the prevalence of patients with coronary artery disease (CAD) detected by cardiac CT scan pre-ablation and to evaluate the impact of CAD and revascularization on outcomes after AF ablation. All consecutive patients with AF diagnosis, hospitalized at Universitair Ziekenhuis Brussel, Belgium, between 2015 and 2019, were prospectively screened for enrolment in the study. Inclusion criteria were (i) AF diagnosis, (ii) first procedure of AF ablation with cryoballoon CA, and (iii) contrast CT scan performed pre-ablation. A total of 576 consecutive patients were prospectively included and analysed in this study. At CT scan, 122 patients (21.2%) were diagnosed with CAD, of whom 41 patients (7.1%) with critical CAD. At survival analysis, critical CAD at CT scan was a predictor of atrial tachyarrhythmia (AT) recurrence during the follow-up, only in Cox univariate analysis [hazard ratio (HR) = 1.79] but was not an independent predictor in Cox multivariate analysis. At Cox multivariate analysis, independent predictors of AT recurrence were as follows: persistent AF (HR = 2.93) and left atrium volume index (HR = 1.04). In patients undergoing CT scan before AF ablation, critical CAD was diagnosed in 7.1% of patients. Coronary artery disease and revascularization were not independent predictors of recurrence; thus, in this patient population, AF ablation should not be denied and can be performed together with CAD treatment.

Innovative advances in pediatric radiology: computed tomography reconstruction techniques, photon-counting detector computed tomography, and beyond.

In pediatric radiology, balancing diagnostic accuracy with reduced radiation exposure is paramount due to the heightened vulnerability of younger patients to radiation. Technological advancements in computed tomography (CT) reconstruction techniques, especially model-based iterative reconstruction and deep learning image reconstruction, have enabled significant reductions in radiation doses without compromising image quality. Deep learning image reconstruction, powered by deep learning algorithms, has demonstrated superiority over traditional techniques like filtered back projection, providing enhanced image quality, especially in pediatric head and cardiac CT scans. Photon-counting detector CT has emerged as another groundbreaking technology, allowing for high-resolution images while substantially reducing radiation doses, proving highly beneficial for pediatric patients requiring frequent imaging. Furthermore, cloud-based dose tracking software focuses on monitoring radiation exposure, ensuring adherence to safety standards. However, the deployment of these technologies presents challenges, including the need for large datasets, computational demands, and potential data privacy issues. This article provides a comprehensive exploration of these technological advancements, their clinical implications, and the ongoing efforts to enhance pediatric radiology's safety and effectiveness.

TT U-Net: Temporal Transformer U-Net for Motion Artifact Reduction Using PAD (Pseudo All-Phase Clinical-Dataset) in Cardiac CT.

Involuntary motion of the heart remains a challenge for cardiac computed tomography (CT) imaging. Although the electrocardiogram (ECG) gating strategy is widely adopted to perform CT scans at the quasi-quiescent cardiac phase, motion-induced artifacts are still unavoidable for patients with high heart rates or irregular rhythms. Dynamic cardiac CT, which provides functional information of the heart, suffers even more severe motion artifacts. In this paper, we develop a deep learning based framework for motion artifact reduction in dynamic cardiac CT. First, we build a PAD (Pseudo All-phase clinical-Dataset) based on a whole-heart motion model and single-phase cardiac CT images. This dataset provides dynamic CT images with realistic-looking motion artifacts that help to develop data-driven approaches. Second, we formulate the problem of motion artifact reduction as a video deblurring task according to its dynamic nature. A novel TT U-Net (Temporal Transformer U-Net) is proposed to excavate the spatiotemporal features for better motion artifact reduction. The self-attention mechanism along the temporal dimension effectively encodes motion information and thus aids image recovery. Experiments show that the TT U-Net trained on the proposed PAD performs well on clinical CT scans, which substantiates the effectiveness and fine generalization ability of our method. The source code, trained models, and dynamic demo will be available at https://github.com/ivy9092111111/TT-U-Net.

Deformation of transcatheter heart valves with mitral valve-in-valve.

The use of oversizing in mitral valve-in-valve (MViV) procedures can lead to non-uniform expansion of transcatheter heart valves (THV). This may have implications for THV durability. The objective of this study was to assess the extent and predictors of THV deformation in MViV procedures. We examined 33 patients who underwent MViV with SAPIEN prostheses. The extent of THV deformation (deformation index, eccentricity, neosinus volume, asymmetric leaflet expansion and vertical deformation) and hypoattenuating leaflet thickening (HALT) were assessed using cardiac computed tomography (CT), performed prospectively at 30 days post-procedure. For descriptive purposes, the THV deformation index was calculated, with values >1.00 representing a more hourglass shape. Non-uniform underexpansion of THV was common after MViV implantation, with a median expansion area of 74.0% (interquartile range 68.1-84.1) at the narrowest level and a THV deformation index of 1.21 (1.13-1.29), but circularity was maintained with eccentricity ranging from 0.24 to 0.28. The degree of oversizing was a key factor associated with greater underexpansion and a higher deformation index (β=-0.634; p<0.001; β=0.594; p<0.001, respectively). Overall, the incidence of HALT on the 30-day postprocedural CT was 27.3% (9 of 33). Most patients (32 of 33) were on anticoagulation therapy, but the prothrombin time and international normalised ratio (PT-INR) at the time of the CT scan was <2.5 in 23 of 32 patients. Among patients with a PT-INR of <2.5, HALT was predominantly observed with a high THV deformation index of ≥1.18. THV deformation, i.e., underexpansion and an hourglass shape, commonly occurs after MViV implantation and is negatively affected by excessive oversizing. Optimising THV expansion during MViV could potentially prevent HALT.

Anomalous Origin of Left Circumflex Artery from the Right Sinus of Valsalva in Cardiac Computed Tomography in a Group of 16,680 Patients—Radiologic and Clinical Characteristics

Background: Anomalous aortic origin of a coronary artery (AAOCA) is the most prevalent form of coronary anomaly. One variant of AAOCA is the anomalous origin of the left circumflex artery from the right sinus of Valsalva, which can be detected using cardiac computed tomography (CT). However, limited data are available regarding the natural history of this anomaly, its impact on myocardial function, and associated symptoms. Methods: We conducted a retrospective analysis of 16,680 CT exams (cardiac and chest) performed between 2015 and 2022 at our Heart Imaging Department, utilising a dual-source 128-slice CT scanner (SOMATOM Definition Flash, Siemens Healthineers, Forchheim, Germany). A registry of patients with anomalous origin of the circumflex artery from the right sinus of Valsalva (RCx) was established. The study included 56 cases of RCx (0.33%). Clinical information was obtained from medical records. RCx was defined as a circumflex artery originating from the right sinus of Valsalva (type I or II) or the right coronary artery (type III). Two researchers independently reevaluated each CT exam in our study group to ensure accurate radiologic descriptions and provide additional precise radiologic information regarding the anomaly, including high-risk features. Results: Our study comprised 56 patients, with approximately equal distribution between males (n = 30, 54%) and females (n = 26, 46%), and with a median age of 59 years. Coronary heart disease (CAD) was known in 23% of patients (n = 13), while 11% (n = 6) were obese (defined as a BMI &gt; 30 kg/m2), and 13% (n = 7) were diagnosed with type 2 diabetes. Only 9% of patients (n = 5) were smokers. Dyslipidemia was the most prevalent atherosclerotic risk factor, affecting approximately one third of patients (n = 17, 30%). In 14% (n = 8) of patients, heart failure was observed, while 13% (n = 7) were diagnosed with atrial fibrillation. Type I RCx was the most common subtype, identified in 48% of patients (n = 27) with this anomaly. Type II and Type III were found in 25% (n = 14) and 27% (n = 15) of patients, respectively. Conclusions: Our findings suggest that RCx is frequently encountered as an incidental finding, and we did not identify a consistent clinical characteristic in all patients with this type of anomaly. Furthermore, no gender predominance was associated with RCx. The natural history of this anomaly and its clinical implications seem benign. Further research is warranted to better understand this anomaly’s natural course and clinical implications.

Sex-Specific Morphometric Analysis of Ascending Aorta and Aortic Arch for Planning Thoracic Endovascular Aortic Repair: A Retrospective Cohort Study.

In many studies on aortic disease, women are underrepresented. The present study aims to assess sex-specific morphometric differences and gain more insight into endovascular treatment of the ascending aorta (AA) and arch. Electrocardiogram-gated cardiac computed tomography scans of 116 consecutive patients who were evaluated for transcatheter aortic valve replacement were retrospectively reviewed. Measurements of the AA and aortic arch were made in multiplanar views, perpendicular to the semi-automatic centerline. Multiple linear regression analysis was performed to identify predictors affecting AA and aortic arch diameter in men and women. Propensity score matching was used to investigate whether sex influences aortic morphology. In both sexes, body surface area (BSA) was identified as a positive predictor and diabetes as a negative predictor for aortic diameters. In men, age was identified as a positive predictor and smoking as a negative predictor for aortic diameters. Propensity score matching identified 40 pairs. Systolic and diastolic mean diameters and AA length were significantly wider in men. On average, male aortas were 7.4% wider than female aortas, both in systole and diastole. The present analysis demonstrates that, in women, increased BSA is associated with increased aortic arch diameters, while diabetes is associated with decreased AA and arch diameters. In men, increased BSA and age are associated with increased AA and arch diameters, while smoking and diabetes are associated with decreased AA and arch diameters. Men were confirmed to have 7.4% greater AA and arch diameters than women. Men had 7.4% greater ascending aorta and arch diameters than women in a retrospective cohort, gated computed tomography-based study of 116 patients. Sex-specific differences in ascending aortic and arch size should be considered by aortic endovascular device manufacturers and physicians when developing ascending and arch endografts and planning aortic interventions.

Abstract 14789: Atrial Anatomical Variations Between Atrial Fibrillation Patients Compared to Other Subjects Without Atrial Fibrillation

Introduction: In this study, we evaluated the anatomical atrial variations using gated cardiac computed tomography (CCT) between patients with and without atrial fibrillation (AF). Hypothesis: The aim of the study is to evaluate if there are specific anatomical characteristics that are associated with poor clinical outcomes following ablation in patients with AF. Methods: We retrospectively included 502 CCT scans of patients with AF prior to their pulmonary vein isolation procedure, and 1058 CCT scans of patients without AF performed to evaluate pulmonary vein anatomy and to rule out coronary artery disease between 2014 to 2017. Anatomical variations of the atria and interatrial septum included the Bachman bundle shunt (BBS - defined as a vascular channel crossing between the atria through the Bachman bundle), and atrial diverticulae. Results: Five-hundred and two patients with AF were older (67±14 vs. 63±13 years, P = 0.039), had a higher prevalence of diabetes mellitus (24.4% vs 14.7%, p = 0.006), and cerebrovascular disease (3.8% vs. 0.9%, p = 0.044) compared to patients without AF. Furthermore, CCTs analysis of AF patients demonstrated a significantly higher prevalence of BBS: (11% vs 4.1%, p &lt;0.0001, left atrial diverticula (19% vs 7.7%), p &lt;0.0001, and right atrial diverticula (9.8% vs 2.1%), P &lt;0.0001 compared to patients without AF. Conclusions: This study is the first to analyze BBS and atrial diverticular prevalence in patients using CCT. We found that patients with AF are associated with a higher prevalence of structural atrial abnormalities including BBS, left and right atrial diverticula in comparison to individuals with no previous history of AF. Whether these anatomical variations influence AF incidence or AF recurrence after catheter ablation is yet to be determined.

Coronary Artery Calcium Identified on Non-Gated Chest CT Scans: A Wasted Opportunity for Preventive Cardiological Care

Coronary artery calcium (CAC) evaluated on dedicated cardiac computed tomography (CT) is an independent predictor of cardiovascular events. This study aimed to evaluate the correlation between CAC detected on non-gated standard chest CT and coronary lesions on coronary angiography (CAG) and determine its impact on prognosis. Consecutive patients who underwent CAG due to acute coronary syndrome and had prior non-contrasted non-gated chest CT were included and retrospectively evaluated. Coronary artery calcium was evaluated by quantitative (Agatston score) and qualitative (visual assessment) assessment. A total of 114 patients were included in this study. The mean time difference between chest CT and CAG was 23 months. Coronary artery calcium was visually classified as mild, moderate, and severe in 31%, 33%, and 16% of patients, respectively. Moderate or severe CAC was an independent predictor of significant lesions on CAG (OR 22; 95% CI 8-61; p<0.001) and all-cause mortality (OR 4; 95% CI 2-9; p=0.001). Quantitative CAC evaluation accurately predicted significant lesions on CAG (AUC 0.81; p<0.001). While significant CAC was identified in 80% of chest CTs, formal reporting was 25%. Coronary artery calcium evaluation with chest CT was feasible and strongly associated with severity of coronary disease on CAG and mortality. Although the identification of CAC on chest CT represents a unique opportunity for cardiovascular risk stratification for preventive care, CAC underreporting is frequent.

Co-registration of OPM-MCG signals with CT using optical scanning

Magnetocardiography (MCG) can be used to noninvasively measure the electrophysiological activity of myocardial cells. The high spatial resolution of magnetic source localization can precisely determine the location of cardiomyopathy, which is of great significance for the diagnosis and treatment of cardiovascular disease. To perform magnetic source localization, MCG data must be co-registered with anatomical images. We propose a co-registration method that can be applied to OPM-MCG systems. In this method, the sensor array and the trunk of the subject are scanned using structured light-scanning technology, and the scan results are registered with the reconstructed structure using computed tomography (CT). This can increase the number of effective cloud points acquired and reduce the interference from respiratory motion. The scanning bed of the OPM-MCG system was modified to be consistent with the CT device, ensuring that the state of the body remains consistent between the cardiac magnetometry measurements and CT scans.

Semi-Automatic Graphical Tool for Measuring Coronary Artery Spatially Weighted Calcium Score from Gated Cardiac Computed Tomography Images.

The current standard for measuring coronary artery calcification to determine the extent of atherosclerosis is by calculating the Agatston score from computed tomography (CT). However, the Agatston score disregards pixel values less than 130 Hounsfield Units (HU) and calcium regions less than 1 mm2. Due to this thresholding, the score is not sensitive to small, weakly attenuating regions of calcium deposition and may not detect nascent micro-calcification. A recently proposed metric called the spatially weighted calcium score (SWCS) also utilizes CT but does not include a threshold for HU and does not require elevated signals in contiguous pixels. Thus, the SWCS is sensitive to weakly attenuating, smaller calcium deposits and may improve the measurement of coronary heart disease risk. Currently, the SWCS is underutilized owing to the added computational complexity. To promote translation of the SWCS into clinical research and reliable, repeatable computation of the score, the aim of this study was to develop a semi-automatic graphical tool that calculates both the SWCS and the Agatston score. The program requires gated cardiac CT scans with a calcium hydroxyapatite phantom in the field of view. The phantom allows for deriving a weighting function, from which each pixel's weight is adjusted, allowing for the mitigation of signal variations and variability between scans. With all three anatomical views visible simultaneously, the user traces the course of the four main coronary arteries by placing points or regions of interest. Features such as scroll-to-zoom, double-click to delete, and brightness/contrast adjustment, along with written guidance at every step, make the program user-friendly and easy to use. Once tracing the arteries is complete, the program generates reports, which include the scores and snapshots of any visible calcium. The SWCS may reveal the presence of subclinical disease, which may be used for early intervention and lifestyle changes.

The Impact of Pulmonary Vein Anatomy on P-Wave Appearance during Sinus Rhythm: Cardiac Computed Tomography Study.

Electrocardigraphy remains a first-line evaluation method for cardiac electrical activity, recorded from the body surface. Since atrial activation is seen on the ECG as a P-wave, several factors are known to impact the appearance of the P-wave, such as the direction of electric impulse, conduction abnormalities, and anatomical characteristics of the atria. This retrospective study aimed to find statistically significant associations between the anatomy of pulmonary veins (PVs) observed in cardiac computed tomography (CT) and P-wave appearance during sinus rhythm on resting ECG. For each patient, a resting 12-lead ECG was recorded, and the field of analysis was P-wave-its duration, morphology, and axis. The evaluation of the CT scan recordings was performed by creating 3D models of the left atrium and analyzing the anatomy of the PVs and left atrial appendages (LAA). Noteworthy correlations were found: anatomy of the left PVs showed an association with LAA volume, LAA morphology, and P-wave notching in lead II. The right PVs demonstrated a relation with the P-wave axis and amplitude. Although these correlations cannot be classified as strong, the results not only expand understanding about discussed variables but also suggest the presence of a subtle and complex relationship, that warrants further exploration.