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Objectives: To determine the prevalence of transient bacteraemia after CT colonography (CTC).Methods: Blood cultures were obtained at 5, 10 and 15 min after CTC from 100 consecutive consenting patients. Blood samples were cultured in both aerobic and anaerobic media and positive blood culture samples were analysed by a microbiologist.Results: Blood culture samples were positive for growth in sixteen patients. All positive blood culture samples were confirmed skin contaminants. There were no cases of significant bacteraemia. The estimated significant bacteraemia rate as a result of CTC is 0-3.7%, based on 95% confidence intervals around extreme results using Wilson's score method.Conclusions: American Heart Association and National Institute for Clinical Excellence guidelines advise that antibiotic prophylaxis before lower gastrointestinal endoscopy is not indicated in patients with at risk cardiac lesions (ARCL) as the risk of a transient bacteraemia leading to infective endocarditis is low. These data show that the prevalence of transient bacteraemia after CTC is also low. It follows that patients with ARCL do not require antibiotic prophylaxis before CTC. [ABSTRACT FROM AUTHOR]

Background: Cardiac Computed Tomography (CCT) is increasingly used for evaluation of congenital heart disease (CHD) in patients of all ages. Pediatric and adult congenital heart disease (ACHD) surgical programs require high quality CCT imaging as part of the multimodality imaging support expected of comprehensive care centers. Despite these expectations, there are no benchmarks or defined programmatic elements specific to the performance of CCT in patients with CHD. To address this deficit, this manuscript is written by a group of current CHD CCT practitioners and provides a collective opinion regarding the clinical components required, and essential resources needed, to deliver a comprehensive CCT CHD imaging program. Resource allocation was divided into CCT technology, imaging technologist, physician and programmatic support. The group is inclusive of pediatric and adult cardiologists and radiologists and includes practitioners from high and lower resourced programs and countries. Imaging settings are inclusive of academic and private practice, heart centers and combined radiology/cardiology service lines. Challenges and areas for future advocacy to support this growing specialty are proposed to improve performance standards that will consider the expected widespread variation in technical and staffing resources, skillsets, and practice settings for CT in CHD., Summary: High quality cardiovascular computed tomography is an essential component of pediatric and adult congenital programs and surgical centers. Program growth outpaces resource allocation in most institutions. This opinion paper outlines essential components for technical, technologist and physician resources and programmatic support to develop and maintain a successful CCT in CHD program. Although a small component of most cardiac imaging programs, it is an essential component particularly in complex cases. Institutional and imaging societal commitment is essential to support this emerging field at highest quality., Competing Interests: Declaration of competing interest There are no relevant conflicts of interest for authors of this manuscript related to the content submitted., (Copyright © 2025. Published by Elsevier Inc.)

Purpose To provide reference values for four-dimensional (4D) flow MRI in healthy fetuses and evaluate reliability of fetal 4D flow MRI hemodynamics in third trimester fetuses with normal cardiovascular development or suspected coarctation of the aorta (CoA). Materials and Methods Pregnant patients with healthy fetuses or fetuses with echocardiographic concern for CoA were prospectively recruited between May 2021 and October 2023. Doppler US-gated fetal 4D flow MRI was performed at 3 T. Repeated 4D flow (time permitting) and two-dimensional (2D) phase contrast (PC) MRI data were acquired. Net flow was quantified, and the reliability of 4D flow measurement was evaluated by using precision across adjacent measurement planes, internal consistency based on conservation of mass, comparison of net flow from 4D flow MRI versus 2D PC MRI, and repeatability of 4D flow from separate acquisitions. Results Data were obtained in 34 pregnant participants (mean maternal age, 33 years ± 5 [SD]; mean gestational age, 35 weeks ± 2; n = 22 healthy fetuses and 12 fetuses with suspected CoA). Precision was high across all vascular segments (mean within-subject coefficient of variation = 7%). For mass conservation, there was an average difference of 19% ± 12 between ductus arteriosus plus isthmus flow versus descending aorta flow ( r = 0.76). Net flow measured with 4D flow MRI correlated with that measured with 2D PC MRI ( r = 0.51) but was underestimated relative to 2D PC MRI by approximately 34%. Hemodynamic parameters quantified from repeated 4D flow acquisitions had good agreement, with an intraclass correlation coefficient of 0.94 between test and retest data. Conclusion Hemodynamic measurements derived from fetal 4D flow MRI were reliable, showing good internal consistency, precision, and repeatability; however, as expected, 4D flow MRI underestimated absolute blood flow relative to 2D PC MRI. Keywords: Fetal MRI, Cardiac, Aorta, Hemodynamics/Flow Dynamics, Pulmonary Arteries Supplemental material is available for this article. © RSNA, 2024.

Objectives: The purpose of this study is to determine if a universal 120-kV ultra-high pitch and virtual monoenergetic images (VMIs) protocol on the photon-counting computed tomography (PCCT) system can provide sufficient image quality for pediatric abdominal imaging, regardless of size, compared with protocols using a size-dependent kV and dual-source flash mode on the energy-integrating CT (EICT) system., Materials and Methods: One solid water insert and 3 iodine (2, 5, 10 mg I/mL) inserts were attached or inserted into phantoms of variable sizes, simulating the abdomens of a newborn, 5-year-old, 10-year-old, and adult-sized pediatric patients. Each phantom setting was scanned on an EICT using clinical size-specific kV dual-source protocols with a pitch of 3.0. The scans were performed with fixed scanning parameters, and the CTDI vol values of full dose were 0.30, 0.71, 1.05, and 7.40 mGy for newborn to adult size, respectively. In addition, half dose scans were acquired on EICT. Each phantom was then scanned on a PCCT (Siemens Alpha) using a universal 120-kV protocol with the same full dose and half dose as determined above on the EICT scanner. All other parameters matched to EICT settings. Virtual monoenergetic images were generated from PCCT scans between 40 and 80 keV with a 5-keV interval. Image quality metrics were compared between PCCT VMIs and EICT, including image noise (measured as standard deviation of solid water), contrast-to-noise ratio (CNR) (measured at iodine inserts with solid water as background), and noise power spectrum (measured in uniform phantom regions)., Results: Noise at a PCCT VMI of 70 keV (7.0 ± 0.6 HU for newborn, 14.7 ± 1.6 HU for adult) is comparable ( P > 0.05, t test) or significantly lower ( P < 0.05, t test) compared with EICT (7.8 ± 0.8 HU for newborn, 15.3 ± 1.5 HU for adult). Iodine CNR from PCCT VMI at 50 keV (50.8 ± 8.4 for newborn, 27.3 ± 2.8 for adult) is comparable ( P > 0.05, t test) or significantly higher ( P < 0.05, t test) to the corresponding EICT measurements (57.5 ± 6.7 for newborn, 13.8 ± 1.7 for adult). The noise power spectrum curve shape of PCCT VMI is similar to EICT, despite PCCT VMI exhibiting higher noise at low keV levels., Conclusions: The universal PCCT 120 kV with ultra-high pitch and postprocessed VMIs demonstrated equivalent or improved performance in noise (70 keV) and iodine CNR (50 keV) for pediatric abdominal CT, compared with size-specific kV images on the EICT., Competing Interests: Conflicts of interest and sources of funding: None declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: It can be challenging for children to cooperate for a magnetic resonance imaging (MRI) exam. General anesthesia is often used to ensure a high-quality image. When determining the need for general anesthesia, many institutions use a simple age cutoff. Decisions on the necessity for anesthesia are often left to schedulers who lack training on determination of patient compliance., Objective: The study aimed to evaluate whether screening questions administered by certified child life specialists (CCLS) could successfully predict which children could complete an MRI without sedation., Materials and Methods: This is a retrospective, institutional review board approved study. Data was collected as part of a quality improvement program, where a CCLS screened 4- to 12-year-old children scheduled for MRI scanning using a questionnaire. Parent responses to the screening questions, CCLS's recommendation for scheduling the MRI awake, start and end time for the MRI scan, and scan success were recorded. A predictive model for the CCLS's recommendation was developed using the child's age, estimated scan length, scan difficulty, and the parent's responses to the screening questions. The primary outcome measure was a successfully completed MRI not requiring additional imaging under anesthesia., Results: Of the 403 screened children, 317 (79%) were recommended to attempt the MRI without anesthesia. The median age of participants was 7 (IQR 4-17) years. Overall, 309 of 317 (97.5%) participants, recommended by the CCLS for the program, met the primary outcome of successful MRI completion on their first attempt. The multivariable regression model which included clinical information about the child's age, estimated scan length, scan difficulty, and four of the six parent screening questions had excellent performance (area under the curve = 0.89)., Conclusion: Information collected by the CCLS via screening along with the child's age, the estimated scan length, and difficulty can help predict which children are likely to successfully complete a non-sedate MRI., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Evaluate the use of coronary CTA as an initial assessment for determining Right Ventricle Dependent Coronary Circulation (RVDCC) in neonates with Pulmonary Atresia with Intact Ventricular Septum (PA IVS). Retrospective review of cases with coronary CTA and compare with available catheter angiography, pathology, surgical reports, and outcomes from Mar 2015 to May 2022. In our cohort of 16 patients, 3 were positive for RVDCC, confirmed by pathologic evaluation, and there was concordance for presence or absence of RVDCC with catheter angiography in 5 patients (4 negatives for RVDCC, 1 positive). Clinical follow up for the 8 patients that underwent RV decompression had no clinical evidence of myocardial ischemia. Our findings suggest that coronary CTA is reliable as first-line imaging for determination of RVDCC in neonates with PA IVS. These findings, if supported by further prospective study, may reserve invasive coronary angiography for cases with diagnostic uncertainty or at the time of necessary transcatheter interventions., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: The comprehensive evaluation of kV selection on photon-counting computed tomography (PCCT) has yet to be performed. The aim of the study is to evaluate and determine the optimal kV options for variable pediatric body sizes on the PCCT unit., Materials and Methods: In this study, 4 phantoms of variable sizes were utilized to represent abdomens of newborn, 5-year-old, 10-year-old, and adult-sized pediatric patients. One solid water and 4 solid iodine inserts with known concentrations (2, 5, 10, and 15 mg I/mL) were inserted into phantoms. Each phantom setting was scanned on a PCCT system (Siemens Alpha) with 4 kV options (70 and 90 kV under Quantum Mode, 120 and 140 kV under QuantumPlus Mode) and clinical dual-source (3.0 pitch) protocol. For each phantom setting, radiation dose (CTDIvol) was determined by clinical dose settings and matched for all kV acquisitions. Sixty percent clinical dose images were also acquired. Reconstruction was matched across all acquisitions using Qr40 kernel and QIR level 3. Virtual monoenergetic images (VMIs) between 40 and 80 keV with 10 keV interval were generated on the scanner. Low-energy and high-energy images were reconstructed from each scan and subsequently used to generate an iodine map (IM) using an image-based 2-material decomposition method. Image noise of VMIs from each kV acquisition was calculated and compared between kV options. Absolute percent error (APE) of iodine CT number accuracy in VMIs was calculated and compared. Root mean square error (RMSE) and bias of iodine quantification from IMs were compared across kV options., Results: At the newborn size and 50 keV VMI, noise is lower at low kV acquisitions (70 kV: 10.5 HU, 90 kV: 10.4 HU), compared with high kV acquisitions (120 kV: 13.8 HU, 140 kV: 13.9 HU). At the newborn size and 70 keV VMI, the image noise from different kV options is comparable (9.4 HU for 70 kV, 8.9 HU for 90 kV, 9.7 HU for 120 kV, 10.2 HU for 140 kV). For APE of VMI, high kV (120 or 140 kV) performed overall better than low kV (70 or 90 kV). At the 5-year-old size, APE of 90 kV (median: 3.6%) is significantly higher (P < 0.001, Kruskal-Wallis rank sum test with Bonferroni correction) than 140 kV (median: 1.6%). At adult size, APE of 70 kV (median: 18.0%) is significantly higher (P < 0.0001, Kruskal-Wallis rank sum test with Bonferroni correction) than 120 kV (median: 1.4%) or 140 kV (median: 0.8%). The high kV also demonstrated lower RMSE and bias than the low kV across all controlled conditions. At 10-year-old size, RMSE and bias of 120 kV are 1.4 and 0.2 mg I/mL, whereas those from 70 kV are 1.9 and 0.8 mg I/mL., Conclusions: The high kV options (120 or 140 kV) on the PCCT unit demonstrated overall better performance than the low kV options (70 or 90 kV), in terms of image quality of VMIs and IMs. Our results recommend the use of high kV for general body imaging on the PCCT., Competing Interests: Conflicts of interest and sources of funding: None declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Aortic arch measurements provide a framework for surgical decision-making in neonatal aortic coarctation, specifically in the determination of approach for arch repair by lateral thoracotomy vs median sternotomy. The purpose of this study was to evaluate our experience with transthoracic echocardiography (TTE) and computed tomography angiography (CTA) in the preoperative evaluation of infants with aortic coarctation, specifically comparing arch dimensions as a function of imaging modality., Methods: Imaging data were reviewed for all infants undergoing surgical repair of aortic coarctation at our institution from 2012 to 2022. Infants with both TTE and CTA evaluations were included. Aortic measurements were compared at predefined anatomic regions including ascending aorta, proximal arch, distal arch, and isthmus., Results: During the study period, 372 infants underwent surgical coarctation repair; 72 (19.4%) infants had TTE and CTA arch evaluations preoperatively. Significant discrepancies between imaging modalities were defined by poor correlation coefficients and absolute measurement differences and were most prominent in the proximal aortic arch (R 2  = 0.23 [-4.4 to 3.2 mm]) and isthmus regions (R 2  = 0.11 [-4.2 to 1.7 mm]). Improved correlation was demonstrated in the ascending aorta (R 2  = 0.63) and distal aortic arch (R 2  = 0.54)., Conclusions: Significant variability exists between TTE- and CTA-derived aortic measurements in infants with coarctation, with proximal arch measurements demonstrating the poorest correlation. This anatomic location represents a commonly used arch region for the determination of approach for repair of neonatal aortic coarctation. Thus, these findings have important implications for current preoperative surgical decision-making paradigms and future prospective study to minimize the risk of residual or recurrent arch obstruction., (Copyright © 2024 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Recent advances in hardware and software permit the use of cardiac MRI of late gestation fetuses, however there is a paucity of MRI-based reference values., Purpose: To provide initial data on fetal cardiac MRI-derived cardiac dimensions, volumes, ventricular function, and left ventricular longitudinal strain in healthy developing fetuses >30 weeks gestational age., Study Type: Prospective., Population: Twenty-five third trimester (34 ± 1 weeks, range of 32-37 weeks gestation) women with healthy developing fetuses., Field Strength/sequence: Studies were performed at 1.5 T and 3 T. Cardiac synchronization was achieved with a Doppler ultrasound device. The protocol included T2 single shot turbo spin echo stacks for fetal weight and ultrasound probe positioning, and multiplanar multi-slice cine balanced steady state free precession gradient echo sequences., Assessment: Primary analyses were performed by a single observer. Weight indexed right ventricular (RV) and left ventricular (LV) volumes and function were calculated from short axis (SAX) stacks. Cardiac dimensions were calculated from the four-chamber and SAX stacks. Single plane LV longitudinal strain was calculated from the four-chamber stack. Interobserver variability was assessed in 10 participants. Cardiac MRI values were compared against available published normative fetal echocardiogram data using z-scores., Statistical Tests: Mean and SDs were calculated for baseline maternal/fetal demographics, cardiac dimensions, volumes, ventricular function, and left ventricular longitudinal strain. Bland-Altman and intraclass correlation coefficient analysis was performed to test interobserver variability., Results: The mean gestational age was 34 ± 1.4 weeks. The mean RV and LV end diastolic volumes were 3.1 ± 0.6 mL/kg and 2.4 ± 0.5 mL/kg respectively. The mean RV cardiac output was 198 ± 49 mL/min/kg while the mean LV cardiac output was 173 ± 43 mL/min/kg., Data Conclusion: This paper reports initial reference values obtained by cardiac MRI in healthy developing third trimester fetuses. MRI generally resulted in slightly larger indexed values (by z-score) compared to reports in literature using fetal echocardiography., Evidence Level: 1 TECHNICAL EFFICACY: Stage 2., (© 2023 International Society for Magnetic Resonance in Medicine.)

Aim: Type 1 diabetes (T1D) increases the risk of morbidity and mortality from cardiovascular disease, and insufficient sleep is prevalent. Emerging evidence suggests a link between sleep and cardiometabolic health, but this has not been examined across the lifespan in individuals with T1D. We aimed to examine associations between sleep and cardiometabolic health in adolescents and adults with T1D in a secondary analysis of data from a 4-week double-blind, random-order, placebo-controlled crossover trial of bromocriptine quick release (BCQR) therapy with a 4-week washout in between conditions., Materials and Methods: Forty-two adults (19-60 years) and 42 adolescents (12-18 years) with T1D >9 months completed 1 week of home monitoring with wrist-worn actigraphy to estimate sleep duration and continuous glucose monitoring, anthropometrics, arterial stiffness, magnetic resonance imaging (adolescents only), and fasting laboratory testing at each treatment phase., Results: Sixty-two per cent of adolescents and 74% of adults obtained <7 h of sleep per night at baseline. After adjustment for age, sex and diabetes duration, baseline sleep <7 h per night was associated with a higher body mass index, a higher waist circumference, a higher systolic blood pressure, worse arterial stiffness and a lower estimated insulin sensitivity (all p < .05). When examined by age group, associations between sleep duration and cardiometabolic health outcomes remained significant, predominantly for adolescents. In adolescents only, wake time was significantly later (p = .027) and time in bed was significantly longer with BCQR versus placebo (p = .049)., Conclusions: Objectively measured sleep <7 h per night was prevalent in adolescents and adults with T1D and associated with poorer cardiometabolic health markers. Small changes in sleep were seen following BCQR treatment in adolescents only. Sleep may be an important and novel target for improving cardiometabolic health in individuals with T1D., (© 2024 John Wiley & Sons Ltd.)

Background: In recent years, self-expanding technology to treat pulmonary regurgitation in the native right ventricular outflow tract became Food and Drug Administration approved in the United States and is now routinely used. The current practice for selection of patients who are candidates for these devices includes screening for "anatomic fit," performed by each of the manufacturing companies. Our study aims to validate the use of virtual reality (VR) as a tool for local physician-led screening of patients., Methods and Results: This retrospective study from Children's Hospital Colorado included patients who underwent pulmonary valve replacement and had screening for a Harmony TPV or Alterra Prestent performed between September 2020 and January 2022. The data from the commercial companies' dedicated analysis for self-expanding transcatheter pulmonary valve frames evaluation with perimeter analysis were collected. VR simulation was performed blinded by 2 congenital interventional cardiologists using Elucis VR software and an Oculus Quest 2 headset. Among the 27 evaluated cases, the use of a self-expandable valve was recommended by companies' dedicated analysis in 23 cases (85.2%), by VR assessment in 26 cases (96.3), and finally implanted in 25 cases (92.6%). Regarding the level of agreement, both modalities (manufacturer and VR) were good at screening-in patients who received a self-expanding valve (100% versus 96.1%). When it came to screening-out the patients, VR presented good capacity to accurately classify nonsuitable patients (50% versus 100%)., Conclusions: Our institutional experience with VR transcatheter pulmonary valve implantation planning accurately predicted clinical outcomes. This paves the way for routine use of VR in patient selection for self-expanding valve technologies.

Background: Mutations in the T-Box 4 (TBX4) gene are a lesser-known cause of heritable pulmonary arterial hypertension (PAH). Patients with heritable PAH typically have worse outcomes when compared with patients with idiopathic PAH, yet little is known about the phenotypical presentation of this mutation., Objective: This article reviews the pattern of chest CT findings in pediatric patients with PAH and TBX4 mutations and compares their radiographic presentation with those of age-matched patients with PAH but without TBX4 mutations., Materials and Methods: A retrospective chart review of the pulmonary arterial hypertension database was performed. Pediatric patients with PAH-confirmed TBX4 mutations and an available high CT were included. Fifteen (9 females) patients met the inclusion criteria. Fourteen (8 females) age-matched controls with diagnosed PAH but without TBX4 mutations were also evaluated. The median age at diagnosis was 7.4 years (range: 0.1-16.4 years). Demographic information and clinical outcomes were collected. CTs of the chest were reviewed for multiple airway, parenchymal, and structural abnormalities (16 imaging findings in total). Chi-square tests were used to compare the prevalence of each imaging finding in the TBX4 cohort compared to the control group., Results: Patients with TBX-4 mutations had increased presence of peripheral or subpleural irregularity (73% vs 0%, P < 0.01), cystic lucencies (67% vs 7%, P < 0.01), and linear or reticular opacity (53% vs 0%, P < 0.01) compared to the control group. Ground glass opacities, bronchiectasis, and centrilobular nodules were not significantly different between the two patient groups (P > 0.05)., Conclusion: TBX4 mutations have distinct imaging phenotypes in pediatric patients with PAH. Compared to patients without this mutation, patients with TBX-4 genes typically present with peripheral or subpleural irregularity, cystic lucencies, and linear or reticular opacity., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Imaging plays an important role in the diagnosis and follow-up of children with acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP). Consensus is lacking for a minimum MRI protocol for the child with known or suspected ARP or CP. Lack of standardization contributes to variable diagnostic performance and hampers application of uniform interpretive criteria for clinical diagnosis and multicenter research studies. We convened a working group to achieve consensus for a minimum MRI protocol for children with suspected ARP or CP. The group included eight pediatric radiologists experienced in interpreting MRI for pediatric pancreatitis and one medical pancreatologist and functioned from November 2022 to March 2023. Existing clinical protocols were summarized across sites represented by group members, and commonly used sequences guided the group's discussion. The final consensus minimum MRI protocol includes five noncontrast sequences and two postcontrast sequences (which are required only in select clinical scenarios). The working group also provides recommended acquisition parameters, sequence-specific technical suggestions, and general recommendations for optimal imaging technique. We recommend that all sites imaging children with ARP and CP for clinical care, and particularly those engaged in cooperative group trials for pancreatitis, ensure that their local protocol includes these minimum sequences.

Background: Aortic dilation is seen in pediatric/young adult patients with bicuspid aortic valve (BAV), and hemodynamic markers to predict aortic dilation are necessary for monitoring. Although promising hemodynamic metrics, such as abnormal wall shear stress (WSS) magnitude, have been proposed for adult BAV patients using four-dimensional (4D) flow cardiovascular magnetic resonance, those for pediatric BAV patients have less frequently been reported, partly due to scarcity of data to define normal WSS range. To circumvent this challenge, this study aims to investigate if a recently proposed 4D flow-based hemodynamic measurement, abnormal flow directionality, is associated with aortic dilation in pediatric/young adult BAV patients., Methods: 4D flow scans for BAV patients (<20 years old) and age-matched controls were retrospectively enrolled. Static segmentation for the aorta and pulmonary arteries was obtained to quantify peak systolic hemodynamics and diameters in the proximal aorta. In addition to peak velocity, WSS, vorticity, helicity, and viscous energy loss, direction of aortic velocity and WSS in BAV patients were compared with that of control atlas using registration technique; angle differences of >60 deg and >120 deg were defined as moderately and severely abnormal, respectively. The association between the obtained metrics and normalized diameters (Z-scores) was evaluated at the sinotubular junction, mid-ascending aorta, and distal ascending aorta., Results: Fifty-three BAV patients, including 18 with history of repaired aortic coarctation, and 17 controls were enrolled. Correlation between moderately abnormal velocity/WSS direction and aortic Z-scores was moderate to strong at the sinotubular junction and mid-ascending aorta (R = 0.62-0.81; p < 0.001) while conventional measurements exhibited weaker correlation (|R| = 0.003-0.47, p = 0.009-0.99) in all subdomains. Multivariable regression analysis found moderately abnormal velocity direction and existence of aortic regurgitation (only for isolated BAV group) were independently associated with mid-ascending aortic Z-scores., Conclusion: Abnormal velocity and WSS directionality in the proximal aorta were strongly associated with aortic Z-scores in pediatric/young adult BAV patients., Competing Interests: Declaration of competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Late gadolinium enhancement (LGE) sequences have become common in pediatric cardiovascular magnetic resonance (CMR) to assess for myocardial fibrosis. Bright-blood late gadolinium enhancement (BB-LGE) by conventional phase-sensitive inversion recovery (PSIR) is commonly utilized, but similar inversion time (TI) value of fibrosis and left ventricular (LV) blood pool can make subendocardial areas difficult to assess. A gray-blood LGE (GB-LGE) technique has been described, targeting nulling of the LV blood pool and demonstrating improvement in ischemic scar detection over BB-LGE in adult patients. We sought to evaluate the feasibility of the GB-LGE technique in a young population with congenital and acquired heart disease and compare its ability to detect subendocardial scar to conventional BB-LGE., Methods: Seventy-six consecutive patients referred for clinical CMR underwent both BB-LGE and GB-LGE on 1.5 T and 3 T scanners. Conventional PSIR sequences were obtained with TI to null the myocardium (BB-LGE) in short-axis and horizontal long-axis stacks. Same PSIR stacks were immediately repeated with TI to null the blood pool (GB-LGE). Both sequences were reviewed separately a week apart by two readers, blinded to the initial clinical interpretation. Studies were analyzed for overall image quality, confidence in scar detection, confidence in detection of LGE, LGE class, inter- and intra-observer agreement for the presence of scar, and intraclass correlation coefficient (ICC) for total scar burden., Results: Overall confidence in myocardial scar detection by BB-LGE or GB-LGE as well as grading of image quality were not statistically different [( p  = 1 and p  = 1) and ( p  = 0.53, p  = 0.18), respectively]. There was very good inter-observer agreement for the presence of scar on BB-LGE ( K  = 0.88, 95% CI 0.77-0.99) and GB-LGE ( K  = 0.84, 95% CI 0.7-0.96), as well as excellent intra-observer agreement for both readers ( K  = 0.93, 95% CI 0.87-0.99; and K  = 0.81, 95% CI 0.69-0.95). Interclass correlation coefficient for total scar burden was excellent for BB-LGE (ICC = 0.98, 95% CI 0.96-0.99) and GB-LGE (ICC = 0.94, 95% CI 0.91-0.97)., Conclusions: The GB-LGE technique is feasible in the pediatric population with congenital and acquired heart disease. It can detect subendocardial/ischemic scar similar to conventional bright-blood PSIR sequences in the pediatric population., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Gonzalez de Alba, Moghari, Browne, Friesen, Fonseca and Malone.)

Background: Glomerular filtration rate (GFR) is a key measure of kidney function but often inaccurately ascertained by serum creatinine and cystatin C in pediatrics. In this pilot trial, we evaluated the relationship between GFR calculated by using phase-contrast MRI (PC-MRI) biomarkers and GFR by 125 I-iothalamate clearance in youth undergoing bone marrow transplantation (BMT)., Methods: A total of twenty-one pediatric BMT candidates (8-21 years of age) were recruited for a research kidney PC-MRI. After completion of 125 I-iothalamate clearance, same-day PC-MRI measurements were completed of the kidney circulation without a gadolinium-based contrast agent. MRI included a non-contrast balanced-SSFP-triggered angiography to position ECG-gated breath-held 2D PC-MRI flow measurements (1.2 × 1.2 × 6 mm 3 ). A multivariate model of MRI biomarkers estimating GFR (GFR-MRI) was selected using the elastic net approach., Results: The GFR-MRI variables selected by elastic net included average heart rate during imaging (bpm), peak aorta flow below the kidney artery take-offs (ml/s), average kidney artery blood flow, average peak kidney vein blood flow, and average kidney vein blood flow (ml/s). The GFR-MRI model demonstrated strong agreement with GFR by 125 I-iothalamate (R 2  = 0.65), which was stronger than what was observed with eGFR by the full age spectrum and Chronic Kidney Disease in Children under 25 (CKiD U25) approaches., Conclusion: In this pilot study, noninvasive GFR-MRI showed strong agreement with gold standard GFR in youth scheduled for BMT. Further work is needed to evaluate whether non-contrast GFR-MRI holds promise to become a superior alternative to eGFR and GFR by clearance techniques. A higher resolution version of the Graphical abstract is available as Supplementary information., (© 2022. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Background: Developmental pulmonary vein pulmonary vein stenosis in the setting of prematurity is a rare and poorly understood condition. Diagnosis can be challenging in the setting of chronic lung disease of prematurity. High-resolution non-contrast chest computed tomography (CT) is the conventional method of evaluating neonates for potential structural changes contributing to severe lung dysfunction and pulmonary hypertension but may miss pulmonary venous stenosis due to the absence of contrast and potential overlap in findings between developmental pulmonary vein pulmonary vein stenosis and lung disease of prematurity., Objective: To describe the parenchymal changes of pediatric patients with both prematurity and pulmonary vein stenosis, correlate them with venous disease and to describe the phenotypes associated with this disease., Materials and Methods: A 5-year retrospective review of chest CT angiography (CTA) imaging in patients with catheterization-confirmed pulmonary vein stenosis was performed to identify pediatric patients (< 18 years) who had a history of prematurity (< 35 weeks gestation). Demographic and clinical data associated with each patient were collected, and the patients' CTAs were re-reviewed to evaluate pulmonary veins and parenchyma. Patients with post-operative pulmonary vein stenosis and those with congenital heart disease were excluded. Data was analyzed and correlated for descriptive purposes., Results: A total of 17 patients met the inclusion criteria (12 female, 5 male). All had pulmonary hypertension. There was no correlation between mild, moderate, and severe grades of bronchopulmonary dysplasia and the degree of pulmonary vein stenosis. There was a median of 2 (range 1-4) diseased pulmonary veins per patient. In total, 41% of the diseased pulmonary veins were atretic. The right upper and left upper lobe pulmonary veins were the most frequently diseased (n = 13/17, 35%, n = 10/17, 27%, respectively). Focal ground glass opacification, interlobular septal thickening, and hilar soft tissue enlargement were always associated with the atresia of an ipsilateral vein., Conclusion: Recognition of the focal parenchymal changes that imply pulmonary vein stenosis, rather than chronic lung disease of prematurity changes, may improve the detection of a potentially treatable source of pulmonary hypertension, particularly where nonangiographic studies result in a limited direct venous assessment., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Modern CT scanners with lower radiation doses have resulted in large numbers of cardiac CTs being performed in children. As seen in adults, pediatric cardiac CT has the potential to demonstrate extracardiac variants and pathology that can occur in conjunction with congenital heart disease (CHD). Prior publications demonstrated a high incidence of extracardiac findings in various locations but the prevalence of urgent unexpected extracardiac findings in children is unknown., Objective: The purpose of this study was to describe the incidence, distribution and clinical significance of the extracardiac findings on pediatric cardiac CT at a tertiary referral center., Materials and Methods: We reviewed all reports (n = 648) for 554 children through young adults who received a cardiac CT study between Jan. 2, 2018, and March 10, 2020, at our tertiary referral pediatric hospital. We interrogated CT reports for extracardiac findings and categorized them by system (airway, pulmonary, abdomen, malpositioned lines and musculoskeletal). We then subclassified each of these findings by level of clinical importance based upon the need for intervention or treatment into low, medium or high importance. High-importance findings were confirmed with a focused chart review. If a patient had more than one CT with a persistent extracardiac finding, the finding was only counted once., Results: We identified 562 individual extracardiac findings, with one or more extracardiac findings present in 91% of the study population. Extracardiac findings with high clinical importance, requiring urgent attention or intervention, were present in 10% (57/554) of cases. The most common location of extracardiac findings was pulmonary (50%; 280/562), followed by airway (22%; 125/562) and abdomen (9%; 52/562)., Conclusion: Unexpected highly important extracardiac findings were found in 10% of patients. Therefore, extracardiac structures should be scrutinized for the timely identification of potentially highly important findings., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: The presence of vascular dysfunction is a well-recognized feature in youth with type 1 diabetes (T1D), accentuating their lifetime risk of cardiovascular events. Therapeutic strategies to mitigate vascular dysfunction are a high clinical priority. In the bromocriptine quick release T1D study (BCQR-T1D), we tested the hypothesis that BCQR would improve vascular health in youth with T1D., Methods: BCQR-T1D was a placebo-controlled, random-order, double-blinded, cross-over study investigating the cardiovascular and metabolic impact of BCQR in T1D. Adolescents in the BCQR-T1D study were randomized 1:1 to phase-1: 4 weeks of BCQR or placebo after which blood pressure and central aortic stiffness measurements by pulse wave velocity, relative area change, and distensibility from phase-contrast magnetic resonance imaging were performed. Following a 4-week washout period, phase 2 was performed in identical fashion with the alternate treatment., Results: Thirty-four adolescents (mean age 15.9±2.6 years, hemoglobin A1c 8.6±1.1%, body mass index percentile 71.4±26.1, median T1D duration 5.8 years) with T1D were enrolled and had magnetic resonance imaging data available. Compared with placebo, BCQR therapy decreased systolic (∆=-5 mmHg [95% CI, -3 to -7]; P <0.001) and diastolic blood pressure (∆=-2 mmHg [95% CI, -4 to 0]; P =0.039). BCQR reduced ascending aortic pulse wave velocity (∆=-0.4 m/s; P =0.018) and increased relative area change (∆=-2.6%, P =0.083) and distensibility (∆=0.08%/mmHg; P =0.017). In the thoraco-abdominal aorta, BCQR decreased pulse wave velocity (∆=-0.2 m/s; P =0.007) and increased distensibility (∆=0.05 %/mmHg; P =0.013)., Conclusions: BCQR improved blood pressure and central and peripheral aortic stiffness and pressure hemodynamics in adolescents with T1D over 4 weeks versus placebo. BCQR may improve aortic stiffness in youth with T1D, supporting future longer-term studies.

Objectives: Flow through the proximal pulmonary arteries (PAs) of patients with repaired Tetralogy of Fallot (TOF) is known to be highly disordered and associated with significant regurgitation. The purpose of this study was to evaluate 4D-Flow MRI-derived viscous energy loss [Formula: see text])-as a result of non-efficient flow propagation, and relate this parameter to standard right ventricular (RV) size and function markers in patients with repaired TOF., Methods: Thirty-five patients with TOF and 14 controls underwent comprehensive 4D-Flow MRI evaluation for qualitative flow analysis and to calculate [Formula: see text] in the main and right pulmonary arteries. Sampled [Formula: see text] indices were correlated with the MRI-derived RV size and functional indices., Results: All patients with TOF exhibited abnormal, supra-physiologic helical/vortical formations in the PAs. Patients with TOF had significantly increased peak systolic [Formula: see text] (8.0 vs 0.5 mW, p < 0.001), time-averaged [Formula: see text] (2.5 vs. 0.2 mW, p < 0.001), and peak systolic [Formula: see text] indexed to stroke volume (0.082 vs. 0.012 mW/mL, p < 0.001). [Formula: see text] indexed to stroke volume correlated with the RV end-diastolic volume (R = 0.68, p < 0.001), end-systolic volume (R = 0.62, p < 0.001), ejection fraction (R = -0.45, p = 0.002), and cardiac index (R = 0.45, p = 0.002). The mean estimated energy loss due to [Formula: see text] with regard to input RV mechanical power was 4.7%., Conclusion: This study demonstrates that patients with repaired TOF have highly abnormal flow conduction through the PAs which result into extensive viscous energy loss. This significant flow-mediated energy loss is associated with the RV volume and function, and might represent considerable loss of mechanical power generated by each cardiac cycle. Future studies are required to assess whether the abnormal flow conduction adds to the RV afterload and remodeling., Key Points: • Abnormal flow patterns through proximal pulmonary arteries in patients with TOF are associated with excessive viscous energy loss. • Inefficient flow conduction is associated with the RV dilation and reduced function and might contribute to the RV adaptive remodeling., (© 2022. The Author(s), under exclusive licence to European Society of Radiology.)

Successful neuronal regeneration requires the reestablishment of synaptic connectivity. This process requires the reconstitution of presynaptic neurotransmitter release, which we investigate here in a model of entirely natural regeneration. After toxin-induced injury, olfactory sensory neurons in the adult mouse olfactory epithelium can regenerate fully, sending axons via the olfactory nerve to reestablish synaptic contact with postsynaptic partners in the olfactory bulb. Using electrophysiological recordings in acute slices, we find that, after initial recontact, functional connectivity in this system is rapidly established. Reconnecting presynaptic terminals have almost mature functional properties, including high release probability and strong capacity for presynaptic inhibition. Release probability then matures quickly, rendering reestablished terminals functionally indistinguishable from controls just 1 week after initial contact. These data show that successful synaptic regeneration in the adult mammalian brain is almost a "plug-and-play" process, with presynaptic terminals undergoing a rapid phase of functional maturation as they reintegrate into target networks., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: To develop and validate a non-contrast free-breathing whole-heart 3D cine steady-state free precession (SSFP) sequence with a novel 3D radial leaf trajectory., Methods: We used a respiratory navigator to trigger acquisition of 3D cine data at end-expiration to minimize respiratory motion in our 3D cine SSFP sequence. We developed a novel 3D radial leaf trajectory to reduce gradient jumps and associated eddy-current artifacts. We then reconstructed the 3D cine images with a resolution of 2.0mm 3 using an iterative nonlinear optimization algorithm. Prospective validation was performed by comparing ventricular volumetric measurements from a conventional breath-hold 2D cine ventricular short-axis stack against the non-contrast free-breathing whole-heart 3D cine dataset in each patient (n = 13)., Results: All 3D cine SSFP acquisitions were successful and mean scan time was 07:09 ± 01:31 min. End-diastolic ventricular volumes for left ventricle (LV) and right ventricle (RV) measured from the 3D datasets were smaller than those from 2D (LV: 159.99 ± 42.99 vs. 173.16 ± 47.42; RV: 180.35 ± 46.08 vs. 193.13 ± 49.38; p-value≤0.044; bias<8%), whereas ventricular end-systolic volumes were more comparable (LV: 79.12 ± 26.78 vs. 78.46 ± 25.35; RV: 97.18 ± 32.35 vs. 102.42 ± 32.53; p-value≥0.190, bias<6%). The 3D cine data had a lower subjective image quality score., Conclusion: Our non-contrast free-breathing whole-heart 3D cine sequence with novel leaf trajectory was robust and yielded smaller ventricular end-diastolic volumes compared to 2D cine imaging. It has the potential to make examinations easier and more comfortable for patients., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Imaging the coronary arteries of children, with their faster heart rates, small vessel size and common inability to lie still or breath-hold, has been a major challenge. With numerous advances in technology, CT examinations can now be performed quickly, often with children free-breathing and with much lower radiation doses than previously. This has led to increased use in children. Care must be taken with technique and choice of electrocardiogram (ECG)-gating technique to obtain adequate imaging for a diagnosis while keeping radiation dose as low as reasonably achievable (ALARA). In this paper, we discuss techniques and tips for CT imaging of the coronary arteries in children, including use of dual-source- and ultrawide-detector CT scanners., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Competing Interests: Conflict of interest: None declared.

Background: Conventional chest and abdominal MRI require breath-holds to reduce motion artifacts. Neonates and infants require general anesthesia with intubation to enable breath-held acquisitions., Objective: We aimed to validate a free-breathing approach to reduce general anesthesia using a motion-insensitive radial acquisition with respiratory gating., Materials and Methods: We retrospectively enrolled children <3 years old who were referred for MRI of the chest or abdomen. They were divided into two groups according to MRI protocol: (1) breath-held scans under general anesthesia with T2-weighted single-shot fast spin-echo (SSFSE) and contrast-enhanced T1-weighted modified Dixon, and (2) free-breathing scans using radial sequences (T2-W MultiVane XD and contrast-enhanced T1-W three-dimensional [3-D] Vane XD). Two readers graded image quality and motion artifacts., Results: We included 23 studies in the free-breathing cohort and 22 in the breath-hold cohort. The overall imaging scores for the free-breathing radial T2-W sequence were similar to the scores for the breath-held T2-W SSFSE sequence (chest, 3.6 vs. 3.2, P=0.07; abdomen, 3.9 vs. 3.7, P=0.66). The free-breathing 3-D radial T1-W sequence also had image quality scores that were similar to the breath-held T1-W sequence (chest, 4.0 vs. 3.0, P=0.06; abdomen, 3.7 vs. 3.9, P=0.15). Increased motion was seen in the abdomen on the radial T2-W sequence (P<0.001), but increased motion was not different in the chest (P=0.73) or in contrast-enhanced T1-W sequences (chest, P=0.39; abdomen, P=0.15). The mean total sequence time was longer in free-breathing compared to breath-held exams (P<0.01); however, this did not translate to longer overall exam times (P=0.94)., Conclusion: Motion-insensitive radial sequences used for infants and neonates were of similar image quality to breath-held sequences and had decreased sedation and intubation., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Automated segmentation using convolutional neural networks (CNNs) have been developed using four-dimensional (4D) flow magnetic resonance imaging (MRI). To broaden usability for congenital heart disease (CHD), training with multi-institution data is necessary. However, the performance impact of heterogeneous multi-site and multi-vendor data on CNNs is unclear., Purpose: To investigate multi-site CNN segmentation of 4D flow MRI for pediatric blood flow measurement., Study Type: Retrospective., Population: A total of 174 subjects across two sites (female: 46%; N = 38 healthy controls, N = 136 CHD patients). Participants from site 1 (N = 100), site 2 (N = 74), and both sites (N = 174) were divided into subgroups to conduct 10-fold cross validation (10% for testing, 90% for training)., Field Strength/sequence: 3 T/1.5 T; retrospectively gated gradient recalled echo-based 4D flow MRI., Assessment: Accuracy of the 3D CNN segmentations trained on data from single site (single-site CNNs) and data across both sites (multi-site CNN) were evaluated by geometrical similarity (Dice score, human segmentation as ground truth) and net flow quantification at the ascending aorta (Qs), main pulmonary artery (Qp), and their balance (Qp/Qs), between human observers, single-site and multi-site CNNs., Statistical Tests: Kruskal-Wallis test, Wilcoxon rank-sum test, and Bland-Altman analysis. A P-value <0.05 was considered statistically significant., Results: No difference existed between single-site and multi-site CNNs for geometrical similarity in the aorta by Dice score (site 1: 0.916 vs. 0.915, P = 0.55; site 2: 0.906 vs. 0.904, P = 0.69) and for the pulmonary arteries (site 1: 0.894 vs. 0.895, P = 0.64; site 2: 0.870 vs. 0.869, P = 0.96). Qs site-1 medians were 51.0-51.3 mL/cycle (P = 0.81) and site-2 medians were 66.7-69.4 mL/cycle (P = 0.84). Qp site-1 medians were 46.8-48.0 mL/cycle (P = 0.97) and site-2 medians were 76.0-77.4 mL/cycle (P = 0.98). Qp/Qs site-1 medians were 0.87-0.88 (P = 0.97) and site-2 medians were 1.01-1.03 (P = 0.43). Bland-Altman analysis for flow quantification found equivalent performance., Data Conclusion: Multi-site CNN-based segmentation and blood flow measurement are feasible for pediatric 4D flow MRI and maintain performance of single-site CNNs., Level of Evidence: 3 TECHNICAL EFFICACY: Stage 2., (© 2021 International Society for Magnetic Resonance in Medicine.)

Temperature management is an essential element of cardiopulmonary bypass (CPB), as indicated in the Guide to Good Practice in Clinical Perfusion, 'The safe conduct of CPB requires the clinical perfusionist to measure and control. . . blood temperature. . . during the period of bypass'. To review current practice, we have conducted a research survey into the management of temperature on CPB. Surveys were distributed to each centre in Great Britain and the Republic of Ireland, investigating numerous temperature management practices, to elucidate current practice and assess if recent research into temperature management marry routine clinical practice. Our results demonstrate that nasopharyngeal temperature is the most common (52%) temperature site used across the many centres, which correlates with previous research as a routine site for cerebral temperature management. The arterial outlet of the oxygenator temperature was used in 33% of centres, however, all centres lacked the knowledge to maintain this temperature below 37°C. There was significant variation between all centres, especially regarding rewarming times (20-40 minutes), demonstrating a lack of uniformity among perfusion centres. Interestingly, most centres have been using the same protocol that has been in place over the previous 10 years.To conclude, the practice of temperature management is changing with the awareness of new research. Lower target temperatures are recommended for rewarming, ensuring a lower temperature gradient and a longer mean rewarming time.

Background: The purpose of this study was to determine whether aortic biomechanical properties are abnormal in children with repaired truncus arteriosus (TA) and to concurrently evaluate left ventricular (LV) function post-repair utilizing a novel platform for regional ventricular function., Methods: Cardiac magnetic resonance (CMR) studies from 26 children (mean age: 15.6 ± 7.2 years) post-TA repair were compared with 20 normal controls (mean age: 14.7 ± 2.6 years). Parameters of aortic stiffness (pulse wave velocity and relative area change) were measured. Flow hemodynamic metrics (aortic regurgitant fraction, peak systolic flow, and peak systolic velocity) and LV function (volumetric data, ejection fraction, regional wall strain) were also compared., Results: Ascending aortic pulse wave velocity was elevated and relative area change was decreased in TA patients compared with controls. Patients post-TA repair demonstrated elevated end diastolic and end systolic volumes in addition to decreased regional wall strain and increased mechanical dyssynchrony. LV functional changes were independent of aortic biomechanical properties., Conclusions: Children with repaired TA have increased ascending aortic stiffness and altered LV function as measured by CMR imaging. Longitudinal studies and advanced CMR assessments are warranted to better determine the long-term potential for late aortic complications and to optimize both the medical and surgical management of these patients after TA repair., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Lithium button battery ingestions have been increasing in frequency since the early 2000s and can develop severe and sometimes fatal complications from caustic injury even after rapid battery removal. To aid in clinical decision-making, we began obtaining magnetic resonance imaging (MRI)/MR angiography in these patients., Objective: Our goal was to review MRI/MR angiography imaging in button battery ingestion cases and compare with other imaging, clinical data and outcomes in these patients., Materials and Methods: In this retrospective institutional-review-board-approved study, we reviewed all button battery ingestion cases with MRI from April 2012 to September 2018. Clinical data, endoscopic findings and all imaging studies were rereviewed. MRIs were evaluated for inflammation, blooming artifact and complications including vascular injury, tracheoesophageal fistula, esophageal perforation and spondylodiscitis, and compared to endoscopy, esophagram and bronchoscopy., Results: Twenty-three patients with button battery ingestions had a total of 51 MRI/MR angiograms. Seventy percent of the cohort was male with a median age of 2 years (range: 0.94-17 years). Severe complications were found in 48% of patients (11/23), including esophageal perforation (n=11), tracheoesophageal fistula (n=3) and spondylodiscitis (n=1). No patients had vascular injury. Cervical location of the battery was significantly associated with severe complications (10/11 cases). The length of the blooming artifact was greater than 2 cm in those with severe complications and, in most cases, <2 cm in those without severe complications. All complications were seen on initial screening MR exam with serial exams showing decreased inflammation., Conclusion: MRI/MR angiography can provide valuable information about complications, including esophageal perforation, tracheoesophageal fistula and spondylodiscitis. Decreasing inflammation surrounding the esophagus and vasculature is believed to be clinically reassuring and aids in managing button battery ingestion patients., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Little is known about the impact of sarcopenia (reduced muscle mass and function) in pediatric chronic liver disease. We compared psoas muscle surface area (PMSA), measured at the 4th lumbar vertebrae, in children listed for liver transplantation (LT) to that of healthy controls and studied the impact of sarcopenia on transplant-associated outcomes. The effect of PMSA (raw value and z score) on survival was studied using multivariable proportional hazards, whereas the impact of PMSA on other transplant-associated outcomes was assessed by multivariable linear or logistic regression. The correlation of PMSA with anthropometric values and markers of disease severity was studied using Spearman's rank-order correlation. Mean PMSA was significantly lower in LT candidates (n = 57, 699.4 ± 591.9 mm 2 [mean ± SD]) than controls (n = 53, 1052.9 ± 960.7 mm 2 ; P = 0.02). For LT candidates, there was an increased risk of death (either while on the waiting list or following transplantation) with lower PMSA (hazard ratio [HR], 1.6 per 100 mm 2 [P = 0.03]; 95% confidence interval [CI], 1.1-2.8), amounting to a 4.9 times higher risk of death for every 1 unit decrease in PMSA z score (HR, 4.9 [P = 0.05], 95% CI, 1.2-34.5), adjusting for age and sex. PMSA did not correlate with posttransplant length of intubation, hospital length of stay, or perioperative complications. PMSA also did not correlate with calculated (r = 0.10, P = 0.60) or appealed Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease scores (r = 0.10, P = 0.69). Pediatric LT candidates have a significant reduction in muscle compared with controls. LT candidates with lower PMSA experience significant increases in mortality. As such, sarcopenia may provide a novel indicator of disease severity in children with chronic liver disease., (Copyright © 2021 by the American Association for the Study of Liver Diseases.)

Background: Conventional pediatric volumetric MRI acquisitions of a short-axis stack typically require multiple breath-holds under anesthesia., Objective: Here, we aimed to validate a vendor-optimized compressed-sensing approach to reduce scan time during short-axis balanced steady-state free precession (bSSFP) cine imaging., Materials and Methods: Imaging was performed in 28 patients (16±9 years) in this study on a commercial 3-tesla (T) scanner using retrospective electrocardiogram-gated cine bSSFP. Cine short-axis images covering both ventricles were acquired with conventional parallel imaging and a vendor-optimized parallel imaging/compressed-sensing approach. Qualitative Likert scoring for blood-myocardial contrast, edge definition, and presence of artifact was performed by two experienced radiologists. Quantitative comparisons were performed including biventricular size and function. A paired t-test was used to detect significant differences (P<0.05)., Results: Scan duration was 7±2 s/slice for conventional imaging (147±33 s total) vs. 4±2 s/slice for compressed sensing (83±28 s total). No significant differences were found with qualitative image scores for blood-myocardial contrast, edge definition, and presence of artifact. No significant differences were found in volumetric analysis between the two sequences. The number of breath-holds was 10±4 for conventional imaging and 5±3 for compressed sensing., Conclusion: Compressed sensing allowed for a 50% reduction in the number of breath-holds and a 43% reduction in the total scan time without differences in the qualitative or quantitative measurements as compared to the conventional technique.

Background Pulmonary arterial hypertension (PAH) manifests with progressive right ventricular (RV) dysfunction, which eventually impairs the left ventricular function. We hypothesized that 4-dimensional-flow magnetic resonance imaging can detect flow hemodynamic changes associated with efficient intracardiac flow during noninvasive inhaled nitric oxide (iNO) challenge in children with PAH. Methods and Results Children with PAH (n=10) underwent 2 same-day separate iNO challenge tests using: (1) 4-dimensional-flow magnetic resonance imaging and (2) standard catheterization hemodynamics. Intracardiac flow was evaluated using the particle tracking 4-flow component analysis technique evaluating the direct flow , retained inflow , delayed ejection flow , and residual volume . Respective flow hemodynamic changes were compared with the corresponding catheterization iNO challenge results. The RV analysis revealed decreased direct flow in patients with PAH when compared with controls ( P <0.001) and increase in residual volume ( P <0.001). Similarly, the left ventricular analysis revealed decreased direct flow in patients with PAH when compared with controls ( P =0.004) and increased proportion of the residual volume ( P =0.014). There was an increase in the RV direct flow during iNO delivery ( P =0.009), with parallel decrease in the residual volume ( P =0.008). Conclusions Children with PAH have abnormal biventricular flow associated with impaired diastolic filling. The flow efficiency is significantly improved in the RV on iNO administration with no change in the left ventricle. The changes in the RV flow have occurred despite the minimal change in catheterization hemodynamics, suggesting that flow hemodynamic evaluation might provide more quantitative insights into vasoreactivity testing in PAH.

Primary immunodeficiency disorders (PIDs), which are humoral, combined, and innate defects of the immune system, are relatively uncommon and may go undiagnosed in patients experiencing recurrent infections, resulting in increased morbidity and mortality. PIDs are clinically characterized by a broad spectrum of disorders, including repeated infections, autoimmune disorders, lymphoproliferative diseases, congenital anomalies, and increased risk of malignancy. Cardiothoracic imaging plays a crucial role in the diagnosis of PIDs owing to the high rates of repeated respiratory infections leading to bronchiectasis and other forms of chronic lung disease. Although PIDs as a group may seem similar in terms of radiologic features and clinical manifestations, there are specific entities that are pertinent to each PID on an individual level. For example, patients with common variable immunodeficiency may develop a unique granulomatous lymphocytic interstitial lung disease, and Good syndrome is associated with thymoma. Familiarity with the imaging characteristics of these disorders may expedite diagnosis and prognostication, and better direct therapy. Reviewing the thoracic manifestations of all PIDs is beyond the scope of this article; thus, the focus herein is on discussing the thoracic manifestations of the most common PIDs and their imaging features. © RSNA, 2021An earlier incorrect version appeared online. This article was corrected on March 25, 2021., Competing Interests: Disclosures of Conflicts of Interest: J.A.R. disclosed no relevant relationships. T.J.B. disclosed no relevant relationships. C.S.R. disclosed no relevant relationships. D.B.G. disclosed no relevant relationships. L.P.B. disclosed no relevant relationships. D.V. disclosed no relevant relationships., (2021 by the Radiological Society of North America, Inc.)

Can alterations in experience trigger different plastic modifications in neuronal structure and function, and if so, how do they integrate at the cellular level? To address this question, we interrogated circuitry in the mouse olfactory bulb responsible for the earliest steps in odor processing. We induced experience-dependent plasticity in mice of either sex by blocking one nostril for one day, a minimally invasive manipulation that leaves the sensory organ undamaged and is akin to the natural transient blockage suffered during common mild rhinal infections. We found that such brief sensory deprivation produced structural and functional plasticity in one highly specialized bulbar cell type: axon-bearing dopaminergic neurons in the glomerular layer. After 24 h naris occlusion, the axon initial segment (AIS) in bulbar dopaminergic neurons became significantly shorter, a structural modification that was also associated with a decrease in intrinsic excitability. These effects were specific to the AIS-positive dopaminergic subpopulation because no experience-dependent alterations in intrinsic excitability were observed in AIS-negative dopaminergic cells. Moreover, 24 h naris occlusion produced no structural changes at the AIS of bulbar excitatory neurons, mitral/tufted and external tufted cells, nor did it alter their intrinsic excitability. By targeting excitability in one specialized dopaminergic subpopulation, experience-dependent plasticity in early olfactory networks might act to fine-tune sensory processing in the face of continually fluctuating inputs. SIGNIFICANCE STATEMENT Sensory networks need to be plastic so they can adapt to changes in incoming stimuli. To see how cells in mouse olfactory circuits can change in response to sensory challenges, we blocked a nostril for just one day, a naturally relevant manipulation akin to the deprivation that occurs with a mild cold. We found that this brief deprivation induces forms of axonal and intrinsic functional plasticity in one specific olfactory bulb cell subtype: axon-bearing dopaminergic interneurons. In contrast, intrinsic properties of axon-lacking bulbar dopaminergic neurons and neighboring excitatory neurons remained unchanged. Within the same sensory circuits, specific cell types can therefore make distinct plastic changes in response to an ever-changing external landscape., (Copyright © 2021 Galliano et al.)

Cardiac angiosarcoma (AS) is an extremely rare, malignant vascular tumor with <10 cases reported in the pediatric literature. Prognosis is dismal with overall survival often <1 year from initial diagnosis. In this report, we present the case of a 10-year-old boy with metastatic cardiac AS who is currently alive and is the longest pediatric survivor of metastatic cardiac AS reported in the literature. This is the only published pediatric case to successfully use a combination of surgical resection, conventional chemotherapy, radiation and targeted therapies including bevacizumab and pazopanib for metastatic cardiac AS., Competing Interests: The authors declare no conflict of interest., (Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Elevated systemic afterload in patients with Fontan circulation may lead to impaired single ventricular function. Wave intensity analysis (WIA) enables evaluation of compression and expansion waves traveling through vasculature. We aimed to investigate the unfavorable wave propagation causing excessive afterload may be an important contributor to the overall single ventricle function and to the limited functional capacity in this patient population., Methods: Patients with hypoplastic left heart syndrome (HLHS) (n = 25), single left ventricle (SLV) (n = 24), and normal controls (n = 10) underwent phase-contrast MRI based WIA analysis evaluated in the ascending aorta. Forward compression wave (FCW) representing dP/dt, backward compression wave (BCW) reflecting vascular stiffness, and forward decompression wave (FDW) representing LV relaxation were recorded and indexed to each other., Results: FCW was lowest in HLHS patients (1098 mm 5 /s), and higher in the SLV group (1457 mm5/s), and controls (6457 mm5/s) (P < 0.001). BCW/FCW was increased in HLHS (0.22) and SLV (0.14) groups compared to controls (0.08) (P = 0.003). Peak VO2 correlated with FCW (R = 0.50, P = 0.015), stroke volume (R = 0.72, P < 0.001), and cardiac output (R = 0.44, P = 0.034)., Conclusions: Patients with HLHS and SLV have unfavorable aortic WIA patterns with increased BCW/FCW ratio indicating increased systemic afterload due to retrograde compression waves. Reduced FCW and systolic MRI indices correlated with peak VO2 suggesting that abnormal systolic wave propagation may play a role in exercise intolerance for Fontan patients., Competing Interests: Declaration of Competing Interest The authors report no relationships that could be construed as a conflict of interest, (Copyright © 2020 Elsevier B.V. All rights reserved.)

We present a rare case of iatrogenic type B aortic dissection due to ductal cannulation during stage 1 Norwood procedure.

Background: Left ventricular intracavitary flow (LVICF) characteristics reflect diastolic function. Right ventricular (RV) volume overload due to pulmonary regurgitation (PR) adversely impacts interventricular interactions and left ventricular (LV) function. This aimed to determine whether patients with PR and mild to moderate RV dilation after repair of tetralogy of Fallot (TOF) repair have abnormal LVICF, and to determine whether RV dilation and biventricular function correlate with LVICF abnormalities., Methods: Patients with repaired TOF with PR (n = 11) and controls (n = 11) underwent LVICF analysis. LV end-diastolic volume was partitioned into 4 flow components: direct flow, retained inflow, delayed ejection flow, and residual volume. Flow components were correlated with indexed biventricular size, function, and LV strain., Results: The TOF patients had reduced direct flow (35% vs 25%; P = .004) and increased residual volume (15% vs 24%; P = .026) compared with controls. Retained inflow and delayed ejection flow did not differ. Reduced direct flow correlated with increased RV end-diastolic volume index (R = 0.44; P = .042), RV end-systolic volume index (R = -0.46; P = .032), reduced RV ejection fraction (R = 0.45; P = .036), and reduced LV circumferential strain (R = 0.52; P = .014). Increased residual volume correlated with increased RV end-systolic volume index (R = 0.52; P = .013), reduced LV ejection fraction (R = -0.54; P = .010), and reduced LV circumferential strain (R = -0.44; P = .040)., Conclusions: Patients with repaired TOF with mild to moderate RV dilation have abnormal LV diastolic direct flow and increased recirculating residual volume. These changes correlate with the degree of RV dilation and impaired LV function., (Copyright © 2019 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Background: As CT technology has advanced, techniques for pediatric cardiac CT in congenital heart disease have evolved from retrospective electrocardiography (ECG)-gating with relatively high radiation doses to lower-dose prospective ECG-gating and even single-beat gated scans. Despite these advances, coronary artery imaging in children remains challenging because of their small vessel size and high heart rates, often necessitating retrospective gating., Objective: Evaluate coronary artery visualization in pediatric patients (<20 years) who underwent low-dose high-pitch ECG-triggered scans and stratify the probability of coronary artery visualization based upon heart rate and body surface area (BSA)., Materials and Methods: Two hundred eleven high-pitch ECG-triggered studies from April 2014 to November 2017 were reviewed by two pediatric cardiac imagers in this retrospective study. Patient age, gender, BSA, average heart rate, heart rate variability and use of general anesthesia were recorded as well as dose-length product (DLP) and volumetric CT dose index (CTDI vol ). We assessed the coronary artery score using a 5-point scale, with score of ≥3 considered of diagnostic quality. We performed multivariate statistical analysis including logistic regression to analyze effects of heart rate and BSA., Results: Patient age range was 1 day to 19 years (median age 3 years). Heart rate range was 49-188 beats per minute (bpm; median 122 bpm) and BSA range was 0.15-2.07 m 2 (median 0.53 m 2 ). The origin and proximal coronary arteries were confidently seen (score ≥3) in 61% of studies in this cohort. Coronary artery visualization scores further increased with increased BSA (P<0.002) and with decreased heart rate (P<0.001). At heart rates <100 bpm or in patients with BSA>0.58, adequate coronary artery visualization was present 72% of the time., Conclusion: While in many patients the coronary artery origins are visualized using high-pitch ECG-triggered technique, the importance of coronary artery visualization needs to be weighed with the radiation dose penalty in individual patients to achieve optimal imaging.

The Fontan circulation is characterized as a nonpulsatile flow propagation without a pressure-generating ventricle. However, flow through the Fontan circulation still exhibits oscillatory waves as a result of pressure changes generated by the systemic single ventricle. Identification of discrete flow patterns through the Fontan circuit may be important to understand single ventricle performance. Ninety-seven patients with Fontan circulation underwent phase-contrast MRI of the right pulmonary artery, yielding subject-specific flow waveforms. Principal component (PC) analysis was performed on preprocessed flow waveforms. Principal components were then correlated with standard MRI indices of function, volume, and aortopulmonary collateral flow. The first principal component (PC) described systolic versus diastolic-dominant flow through the Fontan circulation, accounting for 31.3% of the variance in all waveforms. The first PC correlated with end-diastolic volume ( R  = 0.34, P = 0.001), and end-systolic volume ( R  = 0.30, P = 0.003), cardiac index ( R  = 0.51, P < 0.001), and the amount of aortopulmonary collateral flow ( R  = 0.25, P = 0.027)-lower ventricular volumes and a smaller volume of collateral flow-were associated with diastolic-dominant cavopulmonary flow. The second PC accounted for 19.5% of variance and described late diastolic acceleration versus deceleration and correlated with ejection fraction-diastolic deceleration was associated with higher ejection fraction. Principal components describing the diastolic flow variations in pulmonary arteries are related to the single ventricle function and volumes. Particularly, diastolic-dominant flow without late acceleration appears to be related to preserved ventricular volume and function, respectively. NEW & NOTEWORTHY The exact physiological significance of flow oscillations of phasic and temporal flow variations in Fontan circulation is unknown. With the use of principal component analysis, we discovered that flow variations in the right pulmonary artery of Fontan patients are related to the single ventricle function and volumes. Particularly, diastolic-dominant flow without late acceleration appears to be related to more ideal ventricular volume and systolic function, respectively.

Aortopathy is a recognized comorbidity of Tetralogy of Fallot (TOF). Aortic flow in children with repaired TOF is abnormal despite normal aortic valve anatomy and early surgical repair that results in aortic size normalization. The purpose of this study was to investigate the flow hemodynamics inside the left ventricle (LV) of children with repaired TOF using 4D-Flow MRI derived vorticity. Vorticity is the spatial derivative of flow velocity and is sensitive to anatomic and geometric variations. Vorticity was calculated inside the LV of children with repaired TOF having normal aortic size (n = 14) and normal controls (n = 10) during systolic ejection phase. All subjects underwent comprehensive biventricular analysis including the MRI based feature-tracking based LV strain analysis and mechanical dyssynchrony. Right ventricular (RV) volumetric indices along with LV mechanical indices were correlated with LV vorticity. All TOF patients had supraphysiologic helical flow in the ascending aorta. The generated peak systolic vorticity integrated over the LV volume was elevated in TOF group compared to control (median: 1344 vs. 858 s -1 , P < 0.001). TOF patients had increased LV mechanical dyssynchrony (47 ± 11 vs. 32 ± 7 ms, P < 0.001) and reduced LV global circumferential strain (19 ± 2 vs. 21 ± 2%, P = 0.020). In the TOF group, LV systolic vorticity was independent of RV size and LV mechanical indices. Pathologic aortic flow in children with repaired TOF is associated with abnormal ejection flow patterns inside the LV. Increased systolic vorticity was not associated with LV mechanical dyssynchrony and RV dilation, suggesting that systolic flow inside the LV is independent of impaired LV contractile mechanics and inter-ventricular interactions.

Objectives: Aortopathy in tetralogy of Fallot (TOF) is characterized by increased aortic stiffness, dilation and reduced left ventricular (LV) function. Repair in infancy normalizes aortic dimensions in early childhood. Our prior work demonstrated that early TOF repair does not normalize aortic compliance and that abnormal ascending aortic flow patterns are prevalent. The objectives of this study were to: (i) determine whether proximal aortic flow-mediated viscous energy loss (EL') is elevated in patients with early TOF repair compared with healthy controls, and (ii) determine whether the degree of EL' is associated with LV function., Methods: Forty-one patients post TOF repair with normalized aortic size and 15 healthy controls underwent 4-dimenisonal-flow magnetic resonance imaging flow analysis and EL' assessment. Correlations between EL', aortic size, and LV function were assessed., Results: The TOF group had increased peak systolic thoracic aorta EL' (3.8 vs 1.5 mW, P = 0.004) and increased averaged EL' throughout the cardiac cycle (1.2 vs 0.5 mW, P = 0.003). Peak and mean systolic EL' in the ascending aorta was increased 2-fold in the TOF group compared with control (peak: 2.0 vs 0.9 mW, P = 0.007). Peak EL' measured along the entire thoracic aortic length correlated with LV ejection fraction (R = -0.45, P = 0.009), indexed LV end-systolic volume (R = -0.40, P = 0.010), and right ventricular end-systolic volume (R = -0.37, P = 0.034)., Conclusions: Patients with repaired TOF exhibit abnormal aortic flow associated with increased EL' in the thoracic aorta. The magnitude of EL' is associated with LV function and volumes. Increased aortic EL' in TOF is likely due to inherently abnormal LV outflow geometry and or right ventricular interaction. Reduced aortic flow efficiency in TOF increases cardiac work and may be an important factor in long-term cardiac performance., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Adverse ventricle-ventricle interaction and resultant left ventricular (LV) dysfunction are a recognized pathophysiological component of disease progression in pulmonary arterial hypertension (PAH) and can be associated with electrical and mechanical dyssynchrony. The purpose of this study was to investigate the clinical and mechanistic implications of LV electromechanical dyssynchrony in children with PAH by using novel systolic stretch and diastolic relaxation discoordination indexes derived noninvasively from cardiac MRI (CMR). In children with PAH referred for CMR ( n = 64) and healthy controls ( n = 20), we calculated two novel markers of ventricular discoordination, systolic stretch fraction (SSF) and diastolic relaxation fraction (DRF). SSF and DRF were evaluated with respect to 1 ) electrical dyssynchrony, 2 ) functional status, and 3 ) composite clinical outcomes. SSF was increased in patients with PAH compared with controls ( P = 0.004). There was no difference in DRF between PAH and control groups. There were no differences between groups in standard mechanical dyssynchrony and LV global circumferential strain. Increased SSF was associated with greater electrical dyssynchrony (QRS duration) as well as worse WHO functional class. SSF, DRF, mechanical dyssynchrony, and right ventricular (RV) volumes were prognostic for worse clinical outcomes. LV dyssynchrony indexes are altered in pediatric patients with PAH compared with controls in proportion with greater degrees of RV dilation. Patients with PAH with greater dyssynchrony have worse clinical outcomes. RV-induced increased LV electromechanical dyssynchrony therefore may be an important link in the causal pathway from PAH to clinically significant LV dysfunction. Since dyssynchrony could precede overt LV dysfunction, addition of ventricular synchrony analysis to CMR postprocessing protocols may be of clinical benefit. NEW & NOTEWORTHY We demonstrate that left ventricular discoordination indexes are altered in pediatric patients with pulmonary arterial hypertension compared with controls and pediatric patients with pulmonary arterial hypertension with greater dyssynchrony have worse clinical outcomes. Furthermore, there is evidence for the mechanism of right ventricular-induced left ventricular discoordination to include a combination of delayed early systolic electromechanical activation, late-systolic septal shift, and prolonged, postsystolic septal thickening.