Design and implementation of multicenter pediatric and congenital studies with cardiovascular magnetic resonance: Big data in smaller bodies.

Cardiovascular magnetic resonance (CMR) has become the reference standard for quantitative and qualitative assessment of ventricular function, blood flow, and myocardial tissue characterization. There is a preponderance of large CMR studies and registries in adults; However, similarly powered studies are lacking for the pediatric and congenital heart disease (PCHD) population. To date, most CMR studies in children are limited to small single or multicenter studies, thereby limiting the conclusions that can be drawn. Within the PCHD CMR community, a collaborative effort has been successfully employed to recognize knowledge gaps with the aim to embolden the development and initiation of high-quality, large-scale multicenter research. In this publication, we highlight the underlying challenges and provide a practical guide toward the development of larger, multicenter initiatives focusing on PCHD populations, which can serve as a model for future multicenter efforts.

Cardiac Magnetic Resonance Findings of Coronavirus Disease 2019 (COVID-19) Vaccine-Associated Myopericarditis at Intermediate Follow-Up: A Comparison with Classic Myocarditis.

OBJECTIVE: To report intermediate cardiac magnetic resonance (CMR) findings of coronavirus disease 2019 (COVID-19) vaccine-associated myopericarditis (C-VAM) and compare with classic myocarditis. STUDY DESIGN: Retrospective cohort study including children diagnosed with C-VAM from May 2021 through December 2021 with early and intermediate CMR. Patients with classic myocarditis from January 2015 through December 2021 and intermediate CMR were included for comparison. RESULTS: There were 8 patients with C-VAM and 20 with classic myocarditis. Among those with C-VAM, CMR performed at a median 3 days (IQR 3, 7) revealed 2 of 8 patients with left ventricular ejection fraction <55%, 7 of 7 patients receiving contrast with late gadolinium enhancement (LGE), and 5 of 8 patients with elevated native T1 values. Borderline T2 values suggestive of myocardial edema were present in 6 of 8 patients. Follow-up CMRs performed at a median 107 days (IQR 97, 177) showed normal ventricular systolic function, T1, and T2 values; 3 of 7 patients had LGE. At intermediate follow-up, patients with C-VAM had fewer myocardial segments with LGE than patients with classic myocarditis (4/119 vs 42/340, P = .004). Patients with C-VAM also had a lower frequency of LGE (42.9 vs 75.0%) and lower percentage of left ventricular ejection fraction <55% compared with classic myocarditis (0.0 vs 30.0%), although these differences were not statistically significant. Five patients with classic myocarditis did not receive an early CMR, leading to some selection bias in study design. CONCLUSIONS: Patients with C-VAM had no evidence of active inflammation or ventricular dysfunction on intermediate CMR, although a minority had persistent LGE. Intermediate findings in C-VAM revealed less LGE burden compared with classic myocarditis.

Cardiac Magnetic Resonance Imaging to Determine Single Ventricle Function in a Pediatric Population is Feasible in a Large Trial Setting: Experience from the Single Ventricle Reconstruction Trial Longitudinal Follow up.

The Single Ventricle Reconstruction (SVR) Trial was a randomized prospective trial designed to determine survival advantage of the modified Blalock-Taussig-Thomas shunt (BTTS) vs the right ventricle to pulmonary artery conduit (RVPAS) for patients with hypoplastic left heart syndrome. The primary aim of the long-term follow-up (SVRIII) was to determine the impact of shunt type on RV function. In this work, we describe the use of CMR in a large cohort follow up from the SVR Trial as a focused study of single ventricle function. The SVRIII protocol included short axis steady-state free precession imaging to assess single ventricle systolic function and flow quantification. There were 313 eligible SVRIII participants and 237 enrolled, ages ranging from 10 to 12.5 years. 177/237 (75%) participants underwent CMR. The most common reasons for not undergoing CMR exam were requirement for anesthesia (n = 14) or ICD/pacemaker (n = 11). A total of 168/177 (94%) CMR studies were diagnostic for RVEF. Median exam time was 54 [IQR 40-74] minutes, cine function exam time 20 [IQR 14-27] minutes, and flow quantification time 18 [IQR 12-25] minutes. There were 69/177 (39%) studies noted to have intra-thoracic artifacts, most common being susceptibility artifact from intra-thoracic metal. Not all artifacts resulted in non-diagnostic exams. These data describe the use and limitations of CMR for the assessment of cardiac function in a prospective trial setting in a grade-school-aged pediatric population with congenital heart disease. Many of the limitations are expected to decrease with the continued advancement of CMR technology.

Cardiac Magnetic Resonance Findings after Multisystem Inflammatory Syndrome in Children.

OBJECTIVE: To describe the cardiac magnetic resonance (MR) findings of children recovered from multisystem inflammatory syndrome in children (MIS-C) longer than 3 months after acute illness. STUDY DESIGN: We performed a retrospective cohort study of children hospitalized with MIS-C at a single institution receiving cardiac MR imaging between July 2020 and May 2021. Patient demographics, echocardiogram data from diagnosis through follow-up, and cardiac MR data obtained at approximately 3 months after hospitalization were recorded. RESULTS: In total, 51 children with a median age of 11.3 years were included; 80% of patients had left ventricular ejection fraction <55%, 65% of patients developed valvular regurgitation, and 20% of patients developed coronary artery dilation during acute illness. Cardiac MR was performed at a median time of 105 days after diagnosis; 8% of patients had left ventricular ejection fraction <55%; 1 patient had residual valvular regurgitation; and 2 patients had residual coronary artery dilation. Two of 51 patients were found to have late gadolinium enhancement, T1 mapping abnormalities, and abnormal or borderline extracellular volume calculations suggesting myocardial fibrosis. No patient had T2 mapping abnormalities corresponding with edema, and no patient met the modified Lake Louise criteria for acute myocarditis; 10 of 51 patients had isolated elevated T1 values. CONCLUSIONS: At 3-5 months following diagnosis, cardiac MR reveals no evidence of acute myocarditis as described by the modified Lake Louise criteria in patients with MIS-C. Two patients were observed to have myocardial fibrosis without regional wall motion abnormalities, and 10 had isolated imaging changes (elevated T1 values) in the absence of macroscopic fibrosis.

Highlights of the Virtual Society for Cardiovascular Magnetic Resonance 2022 Scientific Conference: CMR: improving cardiovascular care around the world.

The 25th Society for Cardiovascular Magnetic Resonance (SCMR) Annual Scientific Sessions saw 1524 registered participants from more than 50 countries attending the meeting virtually. Supporting the theme "CMR: Improving Cardiovascular Care Around the World", the meeting included 179 invited talks, 52 sessions including 3 plenary sessions, 2 keynote talks, and a total of 93 cases and 416 posters. The sessions were designed so as to showcase the multifaceted role of cardiovascular magnetic resonance (CMR) in identifying and prognosticating various myocardial pathologies. Additionally, various social networking sessions as well as fun activities were organized. The major areas of focus for the future are likely to be rapid efficient and high value CMR exams, automated and quantitative acquisition and post-processing using artificial intelligence and machine learning, multi-contrast imaging and advanced vascular imaging including 4D flow.

Autologous Cardiac Stem Cell Injection in Patients with Hypoplastic Left Heart Syndrome (CHILD Study).

Mortality in infants with hypoplastic left heart syndrome (HLHS) is strongly correlated with right ventricle (RV) dysfunction. Cell therapy has demonstrated potential improvements of RV dysfunction in animal models related to HLHS, and neonatal human derived c-kit+ cardiac-derived progenitor cells (CPCs) show superior efficacy when compared to adult human cardiac-derived CPCs (aCPCs). Neonatal CPCs (nCPCs) have yet to be investigated in humans. The CHILD trial (Autologous Cardiac Stem Cell Injection in Patients with Hypoplastic Left Heart Syndrome) is a Phase I/II trial aimed at investigating intramyocardial administration of autologous nCPCs in HLHS infants by assessing the feasibility, safety, and potential efficacy of CPC therapy. Using an open-label, multicenter design, CHILD investigates nCPC safety and feasibility in the first enrollment group (Group A/Phase I). In the second enrollment group, CHILD uses a randomized, double-blinded, multicenter design (Group B/Phase II), to assess nCPC efficacy based on RV functional and structural characteristics. The study plans to enroll 32 patients across 4 institutions: Group A will enroll 10 patients, and Group B will enroll 22 patients. CHILD will provide important insights into the therapeutic potential of nCPCs in patients with HLHS.Clinical Trial Registration https://clinicaltrials.gov/ct2/home NCT03406884, First posted January 23, 2018.

Cardiomegaly on chest radiographs as a predictor of heart disease in the pediatric population.

BACKGROUND: Cardiomegaly on chest radiographs (CXR) in pediatric patients leads to multiple tests. We aimed to determine the positive predictive value (PPV) of cardiomegaly on CXR in predicting subsequent heart disease and to assess the utility of obtaining a B-type Natriuretic Peptide level (BNP) and/or electrocardiogram (EKG) in such patients. We hypothesized that an echocardiogram may not be appropriate in all cases of cardiomegaly on CXR, particularly in a patient with a normal EKG and BNP level. METHODS: We performed a retrospective cohort study of pediatric patients with cardiomegaly on their initial CXR between January 2015-December 2017. Patients without a subsequent echocardiogram or known congenital heart disease were excluded. A patient was deemed to have heart disease if they had structural abnormalities, functional abnormalities or a pericardial effusion on echocardiogram. The PPV of CXR and the PPV/NPV of the other tests (EKG, BNP) were calculated using contingency tables. RESULTS: Four hundred and eighty nine patients met inclusion criteria. The PPV of cardiomegaly on CXR alone without any other diagnostic testing in predicting subsequent heart disease was 15%. The PPV increased if there was either an abnormal EKG or a BNP >100 pg/ml and further increased if both of these were present. The PPV values were higher in patients <1 year of age. CONCLUSIONS: Cardiomegaly on CXR can often predict the presence of heart disease, particularly in infants. Further testing with EKG and BNP can better predict who may have heart disease, but it may not eliminate the need for echocardiography.

Cardiac Magnetic Resonance Imaging Macroscopic Fibro-Fatty Infiltration of the Myocardium in Pediatric Patients with Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia.

Background: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is an inherited, progressive form of cardiomyopathy, which is characterized by fibrofatty replacement of the myocardium. While the gold standard for diagnosis remains pathologic evaluation of biopsy, advances in noninvasive imaging, including cardiac magnetic resonance imaging (CMRI), have led to improved clinical diagnosis.Case report: We report three additional cases of pediatric patients that have pathologically confirmed ARVC/D with CMRI images, demonstrating extensive macroscopic fatty infiltration of the right and left ventricular myocardium. The identification using CMRI allowed timely transplantation and patient survival.Conclusion: Our study is designed to highlight how fibrofatty changes are minimal using CMRI in the pediatric population and how this can be a valuable tool to provide an additional method of diagnosis.

Radiation dose management for pediatric cardiac computed tomography: a report from the Image Gently 'Have-A-Heart' campaign.

Children with congenital or acquired heart disease can be exposed to relatively high lifetime cumulative doses of ionizing radiation from necessary medical imaging procedures including radiography, fluoroscopic procedures including diagnostic and interventional cardiac catheterizations, electrophysiology examinations, cardiac computed tomography (CT) studies, and nuclear cardiology examinations. Despite the clinical necessity of these imaging studies, the related ionizing radiation exposure could pose an increased lifetime attributable cancer risk. The Image Gently "Have-A-Heart" campaign is promoting the appropriate use of medical imaging studies in children with congenital or acquired heart disease while minimizing radiation exposure. The focus of this manuscript is to provide a comprehensive review of radiation dose management and CT performance in children with congenital or acquired heart disease.

Utility of cardiac MRI in paediatric myocarditis.

BACKGROUND: The diagnostic role of cardiac MRI in myocarditis is evolving, however with extremely limited data in paediatrics. The goal of this study was to assess the utility of cardiac MRI in paediatric myocarditis and present a new prognostic score for risk stratification. METHOD: The present study is a retrospective investigation of children with a clinical diagnosis of myocarditis, including analysis of demographics, clinical presentation, diagnostic studies, including cardiac MRI, and outcomes. RESULTS: A total of 44 patients met the inclusion criteria, of whom 20 had undergone cardiac MRI. Patients who underwent cardiac MRI were older (median 15.6 versus 11.1 years, p=0.004), had a shorter length of hospital stay (median 4.0 versus 12.5 days, p=0.004), had overall less-severe illness at presentation as evidenced by a higher left-ventricular ejection fraction on echocardiography, had lower peak brain-type natriuretic peptide, were less likely to require advanced mechanical support, and were less likely to experience cardiac death or transplant. In patients who had undergone cardiac MRI, the most common findings were increased early gadolinium enhancement (n=9) or late gadolinium enhancement (n=9). Cardiac MRI findings did not predict a worse outcome. Independent predictors of the need for heart-failure medications at 1-year follow-up included inotrope requirement, extracorporeal membrane oxygenator requirement, and antiarrhythmic requirement at presentation (p<0.05). CONCLUSION: In paediatric myocarditis, cardiac MRI is not used uniformly, has a low yield, and does not predict worse outcomes. Future research should evaluate clinical decision-making and the cost-benefit analysis of cardiac MRI in the diagnosis of paediatric myocarditis.

A Method for In Vitro TCPC Compliance Verification.

The Fontan procedure is a common palliative intervention for sufferers of single ventricle congenital heart defects that results in an anastomosis of the venous return to the pulmonary arteries called the total cavopulmonary connection (TCPC). Local TCPC and global Fontan circulation hemodynamics are studied with in vitro circulatory models because of hemodynamic ties to Fontan patient long-term complications. The majority of in vitro studies, to date, employ a rigid TCPC model. Recently, a few studies have incorporated flexible TCPC models, but provide no justification for the model material properties. The method set forth in this study successfully utilizes patient-specific flow and pressure data from phase contrast magnetic resonance images (PCMRI) (n = 1) and retrospective pulse-pressure data from an age-matched patient cohort (n = 10) to verify the compliance of an in vitro TCPC model. These data were analyzed, and the target compliance was determined as 1.36 ± 0.78 mL/mm Hg. A method of in vitro compliance testing and computational simulations was employed to determine the in vitro flexible TCPC model material properties and then use those material properties to estimate the wall thickness necessary to match the patient-specific target compliance. The resulting in vitro TCPC model compliance was 1.37 ± 0.1 mL/mm Hg-a value within 1% of the patient-specific compliance. The presented method is useful to verify in vitro model accuracy of patient-specific TCPC compliance and thus improve patient-specific hemodynamic modeling.

Improved high-resolution pediatric vascular cardiovascular magnetic resonance with gadofosveset-enhanced 3D respiratory navigated, inversion recovery prepared gradient echo readout imaging compared to 3D balanced steady-state free precession readout imaging.

BACKGROUND: Improved delineation of vascular structures is a common indication for cardiovascular magnetic resonance (CMR) in children and requires high spatial resolution. Currently, pre-contrast 3D, respiratory navigated, T2-prepared, fat saturated imaging with a bSSFP readout (3D bSSFP) is commonly used; however, these images can be limited by blood pool inhomogeneity and exaggeration of metal artifact. We compared image quality of pediatric vasculature obtained using standard 3D bSSFP to 3D, respiratory navigated, inversion recovery prepared imaging with a gradient echo readout (3D IR GRE) performed after administration of gadofosveset trisodium (GT), a blood pool contrast agent. METHODS: For both sequences, VCG triggering was used with acquisition during a quiescent period of the cardiac cycle. 3D bSSFP imaging was performed pre-contrast, and 3D IR GRE imaging was performed 5 min after GT administration. We devised a vascular imaging quality score (VIQS) with subscores for coronary arteries, pulmonary arteries and veins, blood pool homogeneity, and metal artifact. Scoring was performed on axial reconstructions of isotropic datasets by two independent readers and differences were adjudicated. Signal- and contrast-to-noise (SNR and CNR) calculations were performed on each dataset. RESULTS: Thirty-five patients had both 3D bSSFP and 3D IR GRE imaging performed. 3D IR GRE imaging showed improved overall vascular imaging compared to 3D bSSFP when comparing all-patient VIQS scores (n = 35, median 14 (IQR 11-15), vs 6 (4-10), p < 0.0001), and when analyzing the subset of patients with intrathoracic metal (n = 17, 16 (14-17) vs. 5 (2-9), p < 0.0001). 3D IR GRE showed significantly improved VIQS subscores for imaging the RCA, pulmonary arteries, pulmonary veins, and blood pool homogeneity. In addition, 3D IR GRE imaging showed reduced variability in both all-patient and metal VIQS scores compared to 3D bSSFP (p < 0.05). SNR and CNR were higher with 3D IR GRE in the left ventricle and left atrium, but not the pulmonary arteries. CONCLUSIONS: Respiratory navigated 3D IR GRE imaging after GT administration provides improved vascular CMR in pediatric patients compared to pre-contrast 3D bSSFP imaging, as well as improved imaging in patients with intrathoracic metal. It is an excellent alternative in this challenging patient population when high spatial resolution vascular imaging is needed.

Quantitative Assessment of Ventricular Septal Contour for Estimation of Right Ventricular Pressure.

BACKGROUND: Qualitative assessment of ventricular septal flattening is commonly used in pediatric patients with pulmonary hypertension (PH) who lack adequate tricuspid regurgitation (TR) Doppler signal. We sought to determine the relation between quantitative measures of septal flattening including the eccentricity index (EIs) and a novel marker, the septal flattening angle (SFA) with right ventricular systolic pressure (RVSP). METHODS: Subjects (≤18 years) with an anatomically normal heart, an adequate TR signal to obtain a peak velocity, and a simultaneous systemic systolic blood pressure (SBP) was included. RVSP was derived using TR gradient. Eccentricity index (EIs) and the SFA in systole were measured offline and correlated with RVSP/SBP. RESULTS: Of the 108 subjects, RVSP/SBP was < 50% in 77 and ≥ 50% in 31. In those with RVSP/SBP ≥50%, the median SFA was significantly lower (7.4° vs. 22°, p < 0.0001), and the median EIs was higher (1.61 vs. 1.07, p < 0.0001). SFA and EIs had a significant correlation with RVSP/SBP (rs = -0.70 and 0.61, respectively). Area under the curve was higher for SFA compared to EIs (0.92 and 0.85, respectively). The sensitivity and specificity of SFA for predicting an RVSP/SBP ≥ 50% using a cut point of 16° was 84% and 95% and for an EIs cut point of 1.35 was 74.2% and 96.1%, respectively. CONCLUSION: Septal flattening angle and EIs are quantitative measures of ventricular septal flattening that correlate well with RVSP/SBP and should be considered more routinely in clinical practice, especially in patients with inadequate TR Doppler signal.

Safety of Magnetic Resonance Imaging After Implantation of Stainless Steel Embolization Coils.

Stainless steel embolization coils (SSEC) have been used for over four decades for vascular occlusion. Recently, the safety of these coils in a magnetic resonance environment has been called into question, with important ramifications for thousands of patients with existing coils in place. We performed a retrospective chart review at five tertiary care pediatric centers evaluating all children and young adults with implanted SSEC who underwent magnetic resonance imaging (MRI). Data reviewed included demographics, coil implantation, MRI studies, and follow-up evaluations. Complications such as heating, discomfort, or device migration were specifically sought. Two hundred and ninety-seven patients with implanted SSEC underwent 539 MRI examinations. The median age at SSEC implantation was 2.3 years (1 week-23.2 years). The MRI studies were performed a median of 7.4 years (4 days-23.1 years) after implantation. No patients experienced any reported complications associated with their MRI examinations during the study or at median follow-up post-MRI of 4.8 years (1 day-23 years). In this large, retrospective review of patients with implanted SSEC undergoing MRI, there were no reported adverse events. These findings support the recent change by Cook Medical Inc. of their standard embolization coils from a designation of magnetic resonance unsafe to conditional.

Zic3 is required in the extra-cardiac perinodal region of the lateral plate mesoderm for left-right patterning and heart development.

Mutations in ZIC3 cause human X-linked heterotaxy and isolated cardiovascular malformations. A mouse model with targeted deletion of Zic3 demonstrates an early role for Zic3 in gastrulation, CNS, cardiac and left-right axial development. The observation of multiple malformations in Zic3(null) mice and the relatively broad expression pattern of Zic3 suggest its important roles in multiple developmental processes. Here, we report that Zic3 is primarily required in epiblast derivatives to affect left-right patterning and its expression in epiblast is necessary for proper transcriptional control of embryonic cardiac development. However, cardiac malformations in Zic3 deficiency occur not because Zic3 is intrinsically required in the heart but rather because it functions early in the establishment of left-right body axis. In addition, we provide evidence supporting a role for Zic3 specifically in the perinodal region of the posterior lateral plate mesoderm for the establishment of laterality. These data delineate the spatial requirement of Zic3 during left-right patterning in the mammalian embryo, and provide basis for further understanding the molecular mechanisms underlying the complex interaction of Zic3 with signaling pathways involved in the early establishment of laterality.

Nitric-oxide supplementation for treatment of long-term complications in argininosuccinic aciduria.

Argininosuccinate lyase (ASL) is required for the synthesis and channeling of L-arginine to nitric oxide synthase (NOS) for nitric oxide (NO) production. Congenital ASL deficiency causes argininosuccinic aciduria (ASA), the second most common urea-cycle disorder, and leads to deficiency of both ureagenesis and NO production. Subjects with ASA have been reported to develop long-term complications such as hypertension and neurocognitive deficits despite early initiation of therapy and the absence of documented hyperammonemia. In order to distinguish the relative contributions of the hepatic urea-cycle defect from those of the NO deficiency to the phenotype, we performed liver-directed gene therapy in a mouse model of ASA. Whereas the gene therapy corrected the ureagenesis defect, the systemic hypertension in mice could be corrected by treatment with an exogenous NO source. In an ASA subject with severe hypertension refractory to antihypertensive medications, monotherapy with NO supplements resulted in the long-term control of hypertension and a decrease in cardiac hypertrophy. In addition, the NO therapy was associated with an improvement in some neuropsychological parameters pertaining to verbal memory and nonverbal problem solving. Our data show that ASA, in addition to being a classical urea-cycle disorder, is also a model of congenital human NO deficiency and that ASA subjects could potentially benefit from NO supplementation. Hence, NO supplementation should be investigated for the long-term treatment of this condition.

Surgical Modulation of Pulmonary Artery Shear Stress: A Patient-Specific CFD Analysis of the Norwood Procedure.

PURPOSR: This study created 3D CFD models of the Norwood procedure for hypoplastic left heart syndrome (HLHS) using standard angiography and echocardiogram data to investigate the impact of shunt characteristics on pulmonary artery (PA) hemodynamics. Leveraging routine clinical data offers advantages such as availability and cost-effectiveness without subjecting patients to additional invasive procedures. METHODS: Patient-specific geometries of the intrathoracic arteries of two Norwood patients were generated from biplane cineangiograms. "Virtual surgery" was then performed to simulate the hemodynamics of alternative PA shunt configurations, including shunt type (modified Blalock-Thomas-Taussig shunt (mBTTS) vs. right ventricle-to-pulmonary artery shunt (RVPAS)), shunt diameter, and pulmonary artery anastomosis angle. Left-right pulmonary flow differential, Qp/Qs, time-averaged wall shear stress (TAWSS), and oscillatory shear index (OSI) were evaluated. RESULTS: There was strong agreement between clinically measured data and CFD model output throughout the patient-specific models. Geometries with a RVPAS tended toward more balanced left-right pulmonary flow, lower Qp/Qs, and greater TAWSS and OSI than models with a mBTTS. For both shunt types, larger shunts resulted in a higher Qp/Qs and higher TAWSS, with minimal effect on OSI. Low TAWSS areas correlated with regions of low flow and changing the PA-shunt anastomosis angle to face toward low TAWSS regions increased TAWSS. CONCLUSION: Excellent correlation between clinically measured and CFD model data shows that 3D CFD models of HLHS Norwood can be developed using standard angiography and echocardiographic data. The CFD analysis also revealed consistent changes in PA TAWSS, flow differential, and OSI as a function of shunt characteristics.

A Deep Learning Pipeline for Assessing Ventricular Volumes from a Cardiac MRI Registry of Patients with Single Ventricle Physiology.

Purpose To develop an end-to-end deep learning (DL) pipeline for automated ventricular segmentation of cardiac MRI data from a multicenter registry of patients with Fontan circulation (Fontan Outcomes Registry Using CMR Examinations [FORCE]). Materials and Methods This retrospective study used 250 cardiac MRI examinations (November 2007-December 2022) from 13 institutions for training, validation, and testing. The pipeline contained three DL models: a classifier to identify short-axis cine stacks and two U-Net 3+ models for image cropping and segmentation. The automated segmentations were evaluated on the test set (n = 50) by using the Dice score. Volumetric and functional metrics derived from DL and ground truth manual segmentations were compared using Bland-Altman and intraclass correlation analysis. The pipeline was further qualitatively evaluated on 475 unseen examinations. Results There were acceptable limits of agreement (LOA) and minimal biases between the ground truth and DL end-diastolic volume (EDV) (bias: -0.6 mL/m2, LOA: -20.6 to 19.5 mL/m2) and end-systolic volume (ESV) (bias: -1.1 mL/m2, LOA: -18.1 to 15.9 mL/m2), with high intraclass correlation coefficients (ICCs > 0.97) and Dice scores (EDV, 0.91 and ESV, 0.86). There was moderate agreement for ventricular mass (bias: -1.9 g/m2, LOA: -17.3 to 13.5 g/m2) and an ICC of 0.94. There was also acceptable agreement for stroke volume (bias: 0.6 mL/m2, LOA: -17.2 to 18.3 mL/m2) and ejection fraction (bias: 0.6%, LOA: -12.2% to 13.4%), with high ICCs (>0.81). The pipeline achieved satisfactory segmentation in 68% of the 475 unseen examinations, while 26% needed minor adjustments, 5% needed major adjustments, and in 0.4%, the cropping model failed. Conclusion The DL pipeline can provide fast standardized segmentation for patients with single ventricle physiology across multiple centers. This pipeline can be applied to all cardiac MRI examinations in the FORCE registry. Keywords: Cardiac, Adults and Pediatrics, MR Imaging, Congenital, Volume Analysis, Segmentation, Quantification Supplemental material is available for this article. © RSNA, 2023.

Diagnostic Approach to Recurrent Intracardiac Masses That Present With Systemic Symptoms.

Cardiac masses are difficult to diagnose in the pediatric population, especially in the setting of systemic symptoms. Although multiple imaging modalities are available to characterize cardiac masses, it is important to consider a different diagnostic approach in the setting of recurrent cardiac masses and nonspecific systemic symptoms. We present a case involving a previously healthy adolescent with multiple hospitalizations because of persistent fevers, cachexia, and recurrent cardiac masses. Echocardiography and cardiac computed tomography imaging suggested endocarditis, but the patient failed to respond to multiple intravenous antibiotic treatments. He developed recurrent cardiac masses in the right atrium and right ventricle that were debulked and biopsied. The biopsy did not yield a conclusive diagnosis. The patient returned to the hospital with hemoptysis and large pulmonary pseudoaneurysms that had to be occluded during cardiac catheterization. Given his constellation of symptoms and improvement with steroids during surgical procedures, he was ultimately diagnosed with a variant of Behcet's disease known as Hughes-Stovin syndrome. His symptoms resolved completely with steroids and immunosuppression therapy. Our report reveals the limitations of the standard diagnostic approach toward cardiac masses and the importance of considering response to treatment as a clue to the etiology of an unusual cardiac mass.

Recommendations for Cardiac Point-of-Care Ultrasound in Children: A Report from the American Society of Echocardiography.

Cardiac point-of-care ultrasound has the potential to improve patient care, but its application to children requires consideration of anatomic and physiologic differences from adult populations, and corresponding technical aspects of performance. This document is the product of an American Society of Echocardiography task force composed of representatives from pediatric cardiology, pediatric critical care medicine, pediatric emergency medicine, pediatric anesthesiology, and others, assembled to provide expert guidance. This diverse group aimed to identify common considerations across disciplines to guide evolution of indications, and to identify common requirements and infrastructure necessary for optimal performance, training, and quality assurance in the practice of cardiac point-of-care ultrasound in children. The recommendations presented are intended to facilitate collaboration among subspecialties and with pediatric echocardiography laboratories by identifying key considerations regarding (1) indications, (2) imaging recommendations, (3) training and competency assessment, and (4) quality assurance.