Tissue engineered vascular grafts are resistant to the formation of dystrophic calcification.

Advancements in congenital heart surgery have heightened the importance of durable biomaterials for adult survivors. Dystrophic calcification poses a significant risk to the long-term viability of prosthetic biomaterials in these procedures. Herein, we describe the natural history of calcification in the most frequently used vascular conduits, expanded polytetrafluoroethylene grafts. Through a retrospective clinical study and an ovine model, we compare the degree of calcification between tissue-engineered vascular grafts and polytetrafluoroethylene grafts. Results indicate superior durability in tissue-engineered vascular grafts, displaying reduced late-term calcification in both clinical studies (p < 0.001) and animal models (p < 0.0001). Further assessments of graft compliance reveal that tissue-engineered vascular grafts maintain greater compliance (p < 0.0001) and distensibility (p < 0.001) than polytetrafluoroethylene grafts. These properties improve graft hemodynamic performance, as validated through computational fluid dynamics simulations. We demonstrate the promise of tissue engineered vascular grafts, remaining compliant and distensible while resisting long-term calcification, to enhance the long-term success of congenital heart surgeries.

Anomalous Aortic Origin of a Coronary Artery.

BACKGROUND: Although anomalous aortic origin of a coronary artery (AAOCA) is associated with risk of sudden cardiac arrest (SCA), there is a spectrum of disease, with the appropriate management for many remaining unclear. Increasing data warrant review for an updated perspective on management. METHODS: A panel of congenital cardiac surgeons, cardiologists, and imaging practitioners reviewed the current literature related to AAOCA and its management. Survey of relevant publications from 2010 to the present in PubMed was performed. RESULTS: The prevalence of AAOCA is 0.4% to 0.8%. Anomalous left coronary artery is 3 to 8 times less common than anomalous right coronary, but carries a much higher risk of SCA. Nevertheless, anomalous right coronary is not completely benign; 10% demonstrate ischemia, and it remains an important cause of SCA. Decision-making regarding which patients should be recommended for surgical intervention includes determining anatomic features associated with ischemia, evidence of ischemia on provocative testing, and concerning cardiovascular symptoms. Ischemia testing continues to prove challenging with low sensitivity and specificity, but the utility of new modalities is an active area of research. Surgical interventions focus on creating an unobstructed path for blood flow and choosing the appropriate surgical technique given the anatomy to accomplish this. Nontrivial morbidity has been reported with surgery, including new-onset ischemia. CONCLUSIONS: A proportion of patients with AAOCA demonstrate features and ischemia that warrant surgical intervention. Continued work remains to improve the ability to detect inducible ischemia, to risk stratify these patients, and to provide guidance in terms of which patients warrant surgical intervention.

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.

ACR Appropriateness Criteria® Congenital or Acquired Heart Disease.

Pediatric heart disease is a large and diverse field with an overall prevalence estimated at 6 to 13 per 1,000 live births. This document discusses appropriateness of advanced imaging for a broad range of variants. Diseases covered include tetralogy of Fallot, transposition of great arteries, congenital or acquired pediatric coronary artery abnormality, single ventricle, aortopathy, anomalous pulmonary venous return, aortopathy and aortic coarctation, with indications for advanced imaging spanning the entire natural history of the disease in children and adults, including initial diagnosis, treatment planning, treatment monitoring, and early detection of complications. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Brand ferumoxytol vs. generic ferumoxytol comparison across two dosing regimens: a cardiac MRI image quality study.

BACKGROUND: Ferumoxytol is becoming more widely used as an off-label blood-pool contrast agent for MR angiography (MRA) and four-dimensional (4D) flow imaging in pediatric cardiovascular disease. Brand and generic versions of ferumoxytol are available with no information on relative efficacy as a contrast agent and safety profiles. OBJECTIVE: This study evaluates patient safety and image quality of comparable dosages of generic ferumoxytol (GF) versus brand ferumoxytol (BF) with the following hypotheses: (1) Reducing the contrast dosage from 3 to 2 mg/kg will not affect imaging quality and diagnostic accuracy of MRA and four-dimensional 4D flow. (2) GF and BF have similar image quality. (3) GF and BF have similar patient safety profiles. MATERIALS AND METHODS: In an IRB-approved retrospective study, changes in vitals/clinical status between baseline, during infusion, and 30 min post-infusion were analyzed in 3 groups: group 1 (3 mg/kg BF, 216 patients, age: 19.29 ± 11.71 years ranging from 2 months to 62 years), group 2 (2 mg/kg BF, 47 patients, age: 15.35 ± 8.56 years ranging from 10 days to 41 years), and group 3 (2 mg/kg GF, 127 patients, age: 17.16 ± 12.18 years ranging from 6 days to 58 years). Both pediatric and adult patients with congenital heart disease (CHD) indications were included within the study. Adverse reactions were classified as mild, moderate, or severe. Quantitative analysis of MR image quality was performed with signal-to-noise ratio (SNR) on MRA and velocity-to-noise ratio (VNR) on 4D flow. Qualitative grading of imaging features was performed by 2 experienced observers. Two-way analysis of variance (ANOVA) and chi-square tests were used for comparison with a P value of ≤ 0.05 used for significance. RESULTS: No statistical difference was found in clinical status and vital signs (P>0.05). No severe reactions were reported. 7.9% of GF patients experienced an adverse reaction compared to 2.3% with 3 mg/kg BF and 8.4% with 2 mg/kg BF. There was no statistical difference in SNR between the 3 groups (P>0.05). For 4D flow, 2 mg/kg GF demonstrated an increase in VNR compared to 2 mg/kg BF (P = 0.005). The qualitative scores for MRA and 4D flow were high (≥ 3) across all 3 groups. CONCLUSIONS: No significant difference was identified between 2 mg/kg GF and BF in terms of safety profile and image quality. Given the small sample size of this study, further studies are required to confirm these results.

Vertebral Tortuosity Is Associated With Increased Rate of Cardiovascular Events in Vascular Ehlers-Danlos Syndrome.

Background Arterial tortuosity is associated with adverse events in Marfan and Loeys-Dietz syndromes but remains understudied in Vascular Ehlers-Danlos syndrome. Methods and Results Subjects with a pathogenic COL3A1 variant diagnosed at age <50 years were included from 2 institutions and the GenTAC Registry (National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions). Height-adjusted vertebral artery tortuosity index (VTI-h) using magnetic resonance or computed tomography angiography was calculated. Associations between VTI-h and outcomes of (1) cardiovascular events (arterial dissection/rupture, aneurysm requiring intervention, stroke), or (2) hollow organ collapse/rupture at age <50 years were evaluated using receiver operator curve analysis (using outcome by age 30 years) and mixed-effects Poisson regression for incidence rate ratios. Of 65 subjects (54% male), median VTI-h was 12 (interquartile range, 8-16). Variants were missense in 46%, splice site in 31%, and null/gene deletion in 14%. Thirty-two subjects (49%) had 59 events, including 28 dissections, 5 arterial ruptures, 4 aneurysms requiring intervention, 4 strokes, 11 hollow organ ruptures, and 7 pneumothoraces. Receiver operator curve analysis suggested optimal discrimination at VTI-h ≥15.5 for cardiovascular events (sensitivity 70%, specificity 76%) and no association with noncardiovascular events (area under the curve, 0.49 [95% CI, 0.22-0.78]). By multivariable analysis, older age was associated with increased cardiovascular event rate while VTI-h ≥15.5 was not (incidence rate ratios, 1.79 [95% CI, 0.76-4.24], P=0.185). However, VTI-h ≥15.5 was associated with events among those with high-risk variants <40 years (incidence rate ratios, 4.14 [95% CI, 1.13-15.10], P=0.032), suggesting effect modification by genotype and age. Conclusions Increased arterial tortuosity is associated with a higher incidence rate of cardiovascular events in Vascular Ehlers-Danlos syndrome. Vertebral tortuosity index may be a useful biomarker for prognosis when evaluated in conjunction with genotype and age.

Increasing Engagement of Imaging Professionals in Quality Improvement Using an Encounter-specific Quality-reporting Tool.

The involvement of pediatric imaging professionals in quality improvement (QI) in our department was low, with few available informatics tools to report issues or suggest improvement opportunities in a timely and efficient manner. We aimed to increase QI engagement in radiology by creating a real-time, encounter-specific reporting tool embedded into the clinical imaging workflow. Methods: A multidisciplinary team outlined requirements for a new electronic quality-reporting tool, including point-of-care access during imaging workflow and simultaneous automatic capture of encounter-specific clinical information from the hospital information system. Information system experts created a user-friendly interface for categories based on stages of imaging workflow (Planning, Acquisition, Processing, Interpretation, Communication, and Data Collection). Team members trained all department staff. Quality coordinators sorted entries and monitored personnel engagement for two 36-week periods: immediately after launch and 3 years later. Descriptive statistics were used to analyze proposed and completed QI projects during these periods. Results: There were 1,498 entries during the first 36 weeks. Ninety-three percent of radiologists and 56% of technologists participated. Three years later, there were 1,251 entries in 36 weeks. Data collection entries for established QI projects increased from 380 (25%) to 487(39%). The engagement continued among radiologists but decreased among technologists over time. Submissions for QI projects increased from baseline. The project completion rate increased. Conclusion: We created a QI reporting tool embedded into the clinical imaging workflow, which improved the participation of our imaging professionals and increased the number of completed QI projects.

Anomalous Aortic Origin of Coronary Arteries in Children: Postoperative High-risk Anatomic Features.

BACKGROUND: This study aimed to assess postoperative presumed high-risk anatomic features (HRAFs) by using computed tomographic angiography (CTA) in patients with anomalous aortic origin of a coronary artery (AAOCA) after surgical unroofing vs transection and reimplantation (TAR) if unroofing was thought to provide unsatisfactory results. METHODS: The study included 62 children with postoperative CTA performed at a median of 3 months (interquartile range, 3-4 months) after unroofing (n = 45) and TAR (n = 17). HRAFs included slitlike ostium, intramural course, acute angle takeoff (<45o), interarterial course, proximal stenosis >50%, or course through a thickened intercoronary pillar. RESULTS: Median age at surgery was 13.8 years (interquartile range, 10.5-15.8 years). None of the patients had a slitlike ostium or an intramural course on postoperative CTA. Acute takeoff was seen in 100% after unroofing and in 2 of 17 (12%) after TAR (P < .001). After unroofing, the interarterial course improved to 35 of 45 (78%) from 43 of 45 (96%) (P = .003), and a thickened intercoronary pillar improved to 10 of 45 (22%) from 22 of 45 (49%) (P = .0001), compared with none seen after TAR. Preoperative intramural length <5 mm was associated with a postoperative thickened intercoronary pillar in right AAOCA after unroofing (P = .0004). Severe coronary stenosis occurred in 2 of 17 (12%) after TAR, and both patients needed urgent revision procedures. All patients except 2 (97%) returned to exercise activities at a median follow-up of 4.9 years (range, 0.6-9.2 years). CONCLUSIONS: The slitlike ostium and intramural course resolved in all patients. Residual acute angle takeoff, an interarterial course, and mild coronary narrowing related to a thickened intercoronary pillar were common after unroofing. TAR allows resolution of all HRAFs, although severe narrowing requiring surgical revision happened only in TAR. Long-term studies are needed to understand the clinical significance of these residual presumed HRAFs.

Dynamic Volumetric Computed Tomography Angiography is an Effective Method to Evaluate Tracheomalacia in Children.

OBJECTIVE: Standard methods to evaluate tracheal pathology in children, including bronchoscopy, may require general anesthesia. Conventional dynamic proximal airway imaging in noncooperative children requires endotracheal intubation and/or medically induced apnea, which may affect airway mechanics and diagnostic performance. We describe a technique for unsedated dynamic volumetric computed tomography angiography (DV-CTA) of the proximal airway and surrounding vasculature in children and evaluate its performance compared to the reference-standard of rigid bronchoscopy. METHODS: Children who had undergone DV-CTA and bronchoscopy in one-year were retrospectively identified. Imaging studies were reviewed by an expert reader blinded to the bronchoscopy findings of primary or secondary tracheomalacia. Airway narrowing, if present, was characterized as static and/or dynamic, with tracheomalacia defined as >50% collapse of the tracheal cross-sectional area in exhalation. Pearson correlation was used for comparison. RESULTS: Over a 19-month period, we identified 32 children (median age 8 months, range 3-14 months) who had undergone DV-CTA and bronchoscopy within a 90-day period of each other. All studies were unsedated and free-breathing. The primary reasons for evaluation included noisy breathing, stridor, and screening for tracheomalacia. There was excellent agreement between DV-CTA and bronchoscopy for diagnosis of tracheomalacia (κ = 0.81, p < 0.001), which improved if children (n = 25) had the studies within 30 days of each other (κ = 0.91, p < 0.001). CTA provided incremental information on severity, and cause of secondary tracheomalacia. CONCLUSION: For most children, DV-CTA requires no sedation or respiratory manipulation and correlates strongly with bronchoscopy for the diagnosis of tracheomalacia. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:410-416, 2023.

Workflow Interruptions and Effect on Study Interpretation Efficiency.

BACKGROUND: Interruptions have been shown to adversely impact efficiency, accuracy, and patient safety. OBJECTIVE: To analyze the frequency and types of interruptions and effect on report interpretation efficiency. MATERIALS AND METHODS: A business process improvement team was consulted to make detailed recordings of the activities of the radiologists. Activities were categorized as interpreting studies, active interruptions initiated by the radiologist, and passive interruptions initiated by an external source. RESULTS: Thirteen board-certified, pediatric radiologists were observed for 61 hours. Radiologists spent 52% of their time interpreting studies, 29% on active interruptions, and 18% on passive interruptions. Approximately 50% of non-interpretive time involved in-person conversations or consults and 16% involved phone calls of which 67% were incoming. The longest time period without an interruption was 20 minutes. 85% of the time, an interruption came within 3 minutes of beginning an interpretation and lasted 1 minute or less 70% of the time. Interruptions increased the time a radiologist needed to read a study by 1 minute for radiographs, 2 minutes for ultrasounds, 6 minutes for CTs, and 10 minutes for magnetic resonance imaging. CONCLUSION: Total interruption time nearly equaled the total time interpreting studies for radiologists, and interruptions decreased efficiency and increased report interpretation times for all modalities studied. This study highlights the type and extent of interruptions in radiology and examines the effect on report interpretation times. With the frequency of interruptions and impact on efficiency, there is a need to dedicate resources to manage the radiologist workflow. Strategic interventions may ultimately improve outcomes, efficiency, and the overall work environment.

SCMR expert consensus statement for cardiovascular magnetic resonance of acquired and non-structural pediatric heart disease.

Cardiovascular magnetic resonance (CMR) is widely used for diagnostic imaging in the pediatric population. In addition to structural congenital heart disease (CHD), for which published guidelines are available, CMR is also performed for non-structural pediatric heart disease, for which guidelines are not available. This article provides guidelines for the performance and reporting of CMR in the pediatric population for non-structural ("non-congenital") heart disease, including cardiomyopathies, myocarditis, Kawasaki disease and systemic vasculitides, cardiac tumors, pericardial disease, pulmonary hypertension, heart transplant, and aortopathies. Given important differences in disease pathophysiology and clinical manifestations as well as unique technical challenges related to body size, heart rate, and sedation needs, these guidelines focus on optimization of the CMR examination in infants and children compared to adults. Disease states are discussed, including the goals of CMR examination, disease-specific protocols, and limitations and pitfalls, as well as newer techniques that remain under development.

Tissue engineered vascular grafts transform into autologous neovessels capable of native function and growth.

Background: Tissue-engineered vascular grafts (TEVGs) have the potential to advance the surgical management of infants and children requiring congenital heart surgery by creating functional vascular conduits with growth capacity. Methods: Herein, we used an integrative computational-experimental approach to elucidate the natural history of neovessel formation in a large animal preclinical model; combining an in vitro accelerated degradation study with mechanical testing, large animal implantation studies with in vivo imaging and histology, and data-informed computational growth and remodeling models. Results: Our findings demonstrate that the structural integrity of the polymeric scaffold is lost over the first 26 weeks in vivo, while polymeric fragments persist for up to 52 weeks. Our models predict that early neotissue accumulation is driven primarily by inflammatory processes in response to the implanted polymeric scaffold, but that turnover becomes progressively mechano-mediated as the scaffold degrades. Using a lamb model, we confirm that early neotissue formation results primarily from the foreign body reaction induced by the scaffold, resulting in an early period of dynamic remodeling characterized by transient TEVG narrowing. As the scaffold degrades, mechano-mediated neotissue remodeling becomes dominant around 26 weeks. After the scaffold degrades completely, the resulting neovessel undergoes growth and remodeling that mimicks native vessel behavior, including biological growth capacity, further supported by fluid-structure interaction simulations providing detailed hemodynamic and wall stress information. Conclusions: These findings provide insights into TEVG remodeling, and have important implications for clinical use and future development of TEVGs for children with congenital heart disease.

ACR Appropriateness Criteria® Dyspnea-Suspected Cardiac Origin (Ischemia Already Excluded): 2021 Update.

Dyspnea is the symptom of perceived breathing discomfort and is commonly encountered in a variety of clinical settings. Cardiac etiologies of dyspnea are an important consideration; among these, valvular heart disease (Variant 1), arrhythmia (Variant 2), and pericardial disease (Variant 3) are reviewed in this document. Imaging plays an important role in the clinical assessment of these suspected abnormalities, with usually appropriate procedures including resting transthoracic echocardiography in all three variants, radiography for Variants 1 and 3, MRI heart function and morphology in Variants 2 and 3, and CT heart function and morphology with intravenous contrast for Variant 3. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Validation of automated bone age analysis from hand radiographs in a North American pediatric population.

BACKGROUND: Radiographic bone age assessment by automated software is precise and instantaneous. OBJECTIVE: The aim of this study was to evaluate the accuracy of an automated tool for bone age assessment. MATERIALS AND METHODS: We compared a total of 586 bone age radiographs from 451 patients, which had been assessed by three radiologists from 2013 to 2018, with bone age analysis by BoneXpert, using the Greulich and Pyle method. We made bone age comparisons in different patient groups based on gender, diagnosis and race, and in a subset with repeated bone age studies. We calculated Spearman correlation (r) and accuracy (root mean square error, or R2). RESULTS: Bone age analyses by automated and manual assessments showed a strong correlation (r=0.98; R2=0.96; P<0.0001), with the mean bone age difference of 0.12±0.76 years. Bone age comparisons by the two methods remained strongly correlated (P<0.0001) when stratified by gender, common endocrine conditions including growth disorders and early/precocious puberty, and race. In the longitudinal analysis, we also found a strong correlation between the automated software and manual bone age over time (r=0.7852; R2=0.63; P<0.01). CONCLUSION: Automated bone age assessment was found to be reliable and accurate in a large cohort of pediatric patients in a clinical practice setting in North America.

Flow Dynamics in Anomalous Aortic Origin of a Coronary Artery in Children: Importance of the Intramural Segment.

This study aims to assess the differences in pressure, fractional flow reserve (FFR) and coronary flow (with increasing pressure) of the proximal coronary artery in patients with anomalous aortic origin of a coronary artery with a confirmed ischemic event, without ischemic events, and before and after unroofing surgery, and compare to a patient with normal coronary arteries. Patient-specific flow models were 3D printed for 3 subjects with anomalous right coronary arteries with intramural course, 2 of them had documented ischemia, and compared with a patient with normal coronaries. The models were placed in the aortic position of a pulse duplicator and precise measurements to quantify FFR and coronary flow rate were performed from the aortic to the mediastinal segment of the anomalous right coronary artery. In an ischemic model, a gradual FFR drop (emulating that of pressure) was shown from the ostium location (∼1.0) to the distal intramural course (0.48). In nonischemic and normal patient models, FFR for all locations did not drop below 0.9. In a second ischemic model prior to repair, a drop to 0.44 was encountered at the intramural and mediastinal intersection, improving to 0.86 postrepair. There is a difference in instantaneous coronary flow rate with increasing aortic pressure in the ischemic models (slope 0.2846), compared to the postrepair and normal models (slope >0.53). These observations on patient models support a biomechanical basis for ischemia and potentially sudden cardiac death in aortic origin of a coronary artery, with a drop in pressure and FFR in the intramural segment, and a decrease in coronary flow rate with increasing aortic pressure, with both improving after corrective surgery.

Advanced imaging use and payment trends in a large pediatric accountable care organization.

BACKGROUND: Pediatric imaging use and payment trends in accountable care organizations (ACOs) are seldom studied but are important for health policy decisions and resource allocation. OBJECTIVE: To evaluate patterns of advanced imaging use and associated payments over a 7-year period at a large ACO in the USA serving a Medicaid population. MATERIALS AND METHODS: We reviewed paid claims data from 2011 through 2017 from an ACO, analyzing the MRI, CT and US use trends and payments from emergency department (ED) and outpatient encounters. We defined "utilization rate" as the number of advanced imaging procedures per 100 enrolled children per calendar year. Average yearly utilization and payments trends were analyzed using Pearson correlation. RESULTS: Across 7 years, 186,552 advanced imaging procedures were performed. The average overall utilization rate was 6.99 (95% confidence interval [CI]: 6.9-7.1). In the ED this was 2.7 (95% CI: 2.6-2.8) and in outpatients 4.3 (95% CI: 4.2-4.3). The overall utilization rate grew by 0.7% yearly (P=0.077), with US growing the most at 4.0% annually (P=0.0005), especially in the ED in the US, where it grew 10.8% annually (P=0.000019). The overall payments were stable from 2011 to 2017, with outpatient MRI seeing the largest payment decrease at 1.8% (P=0.24) and ED US showing the most growth at 3.3% (P=0.00016). Head CT and abdominal US were the two most common procedures. CONCLUSION: Over the study period, advanced imaging utilization at this large pediatric ACO serving the Medicaid population increased, especially with US use in the ED. Overall payments related to advanced imaging remained stable over this period.

Pediatric Emergency Imaging Studies in Academic Radiology Departments: A Nationwide Survey of Staffing Practices.

OBJECTIVE: Particularly for pediatric patients presenting with acute conditions or challenging diagnoses, identifying variation in emergency radiology staffing models is essential in establishing a standard of care. We conducted a cross-sectional survey among radiology departments at academic pediatric hospitals to evaluate staffing models for providing imaging interpretation for emergency department imaging requests. METHODS: We conducted an anonymous telephone survey of academic pediatric hospitals affiliated with an accredited radiology residency program across the United States. We queried the timing, location, and experience of reporting radiologists for initial and final interpretations of emergency department imaging studies, during weekday, overnight, and weekend hours. We compared weekday with overnight, and weekday with weekend, using Fisher's exact test and an α of 0.05. RESULTS: Surveying 42 of 47 freestanding academic pediatric hospitals (89%), we found statistically significant differences for initial reporting radiologist, final reporting radiologist, and final report timing between weekday and overnight. We found statistically significant differences for initial reporting radiologist and final report timing between weekday and weekend. Attending radiologist involvement in initial reports was 100% during daytime, but only 33.3% and 69.0% during overnight and weekends. For initial interpretation during overnight and weekend, 38.1% and 28.6% use resident radiologists without attending radiologists, and 28.6% and 2.4% use teleradiology. All finalized reports as soon as possible during weekdays, but only 52.4% and 78.6% during overnight and weekend. DISCUSSION: A minority of hospitals use 24-hour in-house radiology attending radiologist coverage. During overnight periods, the majority of academic pediatric emergency departments rely on resident radiologists without attending radiologist supervision or outside teleradiology services to provide initial reports. During weekend periods, over a quarter rely on resident radiologists without attending radiologist supervision for initial reporting. This demonstrates significant variation in staffing practices at academic pediatric hospitals. Future studies should look to determine whether this variation has any impact on standard of care.

Accuracy of computed tomography angiography and structured reporting of high-risk morphology in anomalous aortic origin of coronary artery: comparison with surgery.

BACKGROUND: Morphological features including interarterial course, intramural course, high ostial location and slit-like ostium are presumed risk factors for sudden cardiac death in children with anomalous aortic origin of the coronary artery (AAOCA). To facilitate clinical risk stratification, the diagnostic accuracy of CT angiography for individual risk factors in the setting of AAOCA must be established. OBJECTIVE: We assessed diagnostic accuracy of standardized CT angiography interpretation for morphological characteristics that might determine risk in children with AAOCA by comparing them to surgical findings. MATERIALS AND METHODS: We created a standardized protocol for CT angiography of AAOCA and retrospectively evaluated diagnostic performance in 25 consecutive surgical patients. Relevant morphological variables in AAOCA were assessed by three independent blinded readers, with surgery as the reference standard. We used Cohen kappa coefficients and accuracies to assess agreement between readers and surgical findings, and we calculated intraclass correlation coefficients to compare length of the intramural course. RESULTS: CT angiography correctly identified AAOCA in all patients. For the three readers, accuracies for detecting ostial stenosis were 84%, 94% and 96%; for high ostial origin, accuracies were 76%, 78% 82%; for intramurality using the peri-coronary fat sign, accuracies were 98%, 96% and 92%; and for intramurality using oval shape of coronary artery, accuracies were 98%, 94% and 92%. The intraclass correlation coefficients (ICCs) for predicting intramural length among the three readers were 0.67, 0.75 and 0.81 using peri-coronary fat, and 0.69, 0.50 and 0.81 using oval shape, respectively. CONCLUSION: CT angiography reliably identified AAOCA in all children and detected the presence of intramurality with high accuracy.

Assessment of transfer of morphological characteristics of Anomalous Aortic Origin of a Coronary Artery from imaging to patient specific 3D Printed models: A feasibility study.

BACKGROUND AND OBJECTIVE: This study aims to determine the accuracy of patient specific 3D printed models in capturing pathological anatomical characteristics derived from CT angiography (CTA) in children with anomalous aortic origin of a coronary artery (AAOCA). METHODS & MATERIALS: Following institutional regulatory approval, a standardized protocol for CTA of AAOCA was utilized for imaging. Blood volume of the aorta and coronaries were segmented from the DICOM images. A total of 10 models from 8 AAOCA patients were created, including 2 post-operative models. Mechanical properties of Agilus30 a flexible photopolymer coated with a thin layer of parylene, polyurethane (PU) and silicone and native aortic tissue from a postmortem specimen were compared. AAOCA models with wall thicknesses of 2mm aorta and 1.5mm coronaries were 3D printed in Agilus30 and coated with PU. CT of the printed models was performed, and 3D virtual models were generated. Transfer of anatomical characteristics and geometric accuracy were compared between the patient model virtual models. RESULTS: Dynamic modulus of Agilus30 at 2mm thickness was found to be close to native aortic tissue. Structured reporting of anatomical characteristics by imaging experts showed good concordance between patient and model CTA Comparative patient and virtual model measurements showed Pearson's correlation (r) of 0.9959 for aorta (n=70) and 0.9538 for coronaries (n=60) linear, and 0.9949 for aorta (n=30) and 0.9538 for coronaries (n=30) cross-sectional, dimensions. Surface contour map mean difference was 0.08 ± 0.29mm. CONCLUSIONS: Geometrically accurate AAOCA models preserving morphological characteristics, essential for risk stratification and decision-making, can be 3D printed from a patient's CTA.