Management of Severe Allergic-Like Contrast Media Reactions: Pitfalls and Strategies, From the AJR Special Series on Contrast Media.

Adverse reactions to contrast media are often high-acuity events that are uncommon potentially life-threatening. Nonetheless, these events are treatable, and radiologists may be called upon to manage a contrast media reaction. However, because these events are infrequent, they are prone to management errors. This article highlights common pitfalls and practical tips for the management of acute contrast media reactions in children and adults. Recognition of frequent management errors and implementation of the mitigation strategies presented can ameliorate risk and improve patient outcomes. These measures include proper training on reaction management and medication administration, the prompt use of IM epinephrine autoinjectors whenever a severe allergic-like reaction is suspected, the use of visual aids for quick reference in the setting of a reaction, and the recognition of adverse events that are not allergic-like reactions, which commonly require only supportive care.

Reconsidering pregnancy screening policies for minors: patient-specific estimate of fetus and effective dose for potentially pregnant minors undergoing optimized dose CT of the pelvis.

BACKGROUND: Only verbal pregnancy screening is recommended for post-menarcheal females undergoing pelvic radiographs. In contrast, usually, a urine/serum pregnancy test for pelvic computed tomographic (CT) exams is required out of concern for higher radiation exposure. OBJECTIVE: To estimate patient-specific fetus absorbed dose to a potentially pregnant minor from an optimized dose CT of the pelvis for femoral version and surgical planning and provide evidence that such examinations of the pelvis can be performed with only verbal pregnancy screening. METHODS AND METHODS: A retrospective study was performed on 102 female patients between 12-18 years of age (15.4 ± 2.1 years) who underwent optimized dose CT of the pelvis for orthopedic evaluation of femoral version and surgical planning. Optimized CT exams were performed with weight-adjusted kVp and tube current modulation. Patient-specific dose from the optimized dose CT was calculated using the National Cancer Institute Dosimetry System for CT (NCICT) database by matching each patient to a phantom from the NCI non-reference phantom library based on patient sex, weight, and height. The calculated absorbed uterus dose was used as a surrogate for the fetus dose. Furthermore, patient-specific organ doses were used to estimate the effective dose. The strengths of the linear relationships between the dose metrics and patient characteristics were assessed using Pearson correlation coefficients through linear regression. RESULTS: The mean patient-specific effective dose for an optimized dose CT of the pelvis was 0.54 ± 0.20 mSv (range: 0.15-1.22 mSv). The mean estimated absorbed uterine dose was 1.57 ± 0.67 mGy (range: 0.42-4.81 mGy). Both effective dose and estimated uterine dose correlated poorly with patient physical characteristics (R = -0.26; 95% CI: [-0.43, -0.007] for age, R = 0.03; 95% CI: [-0.17, 0.22] for weight) but correlated strongly (R = 0.79, 95% CI: [0.7, 0.85]) with CTDIvol. CONCLUSION: The estimated fetus dose in case of pregnancy was significantly lower than 20 mGy for urine/serum pregnancy screening, suggesting that the pregnancy screening protocols in minors undergoing optimized dose CT require reassessment and may be safely performed by verbal attestation only.

Splenic Lymphatic Malformation With Papillary Endothelial Proliferation: A Rare Histologic Variant or a Unique Entity?

Lymphatic malformations (LMs) are congenital anomalies of the lymphatic system due to abnormalities that occur during the development of the lymphovascular system. Also known as lymphangiomas, they are usually multifocal, affect multiple organ systems, and are seen in a variety of developmental or overgrowth syndromes. Splenic lymphangiomas are uncommon and usually occur in the context of multiorgan lymphangiomatosis. Within the spleen, 7 prior cases have been reported of LMs with unusual papillary endothelial proliferations (PEPs), which can mimic more aggressive splenic lymphovascular tumors. It is not currently known if splenic LM-PEP represents a unique entity, or is simply an unusual, site-specific, morphologic variant of LM. To address this question, we conducted a retrospective, single-institutional review of this rare entity and systematically evaluated its clinical, histologic, radiologic, electron microscopical, and molecular features. In all 3 splenic LM-PEPs, the clinical course was benign, imaging demonstrated subcapsular lesions with characteristic "spoke-and-wheel" appearance, histology showed distinctive PEPs within lymphatic microcysts, immunohistochemistry confirmed a lymphatic endothelial phenotype and electron microscopy demonstrated lesional endothelial cells, rich in mitochondria and intermediate filaments with prominent cytoplasmic lumina and vacuoles and lacking Weibel-Palade granules. Occasional lymphothelial cells were situated within the cytoplasm of another lesional cell, appearing to be engulfed. Next-generation sequencing identified a PIK3CA mutation in 1 patient, while in 2 others no molecular alterations were identified. We conclude with a summary of all prior published cases and discuss key diagnostic elements that distinguish this benign entity from its more aggressive mimickers.

Comparison of the different imaging modalities used to image pediatric oncology patients: A COG diagnostic imaging committee/SPR oncology committee white paper.

Diagnostic imaging is essential in the diagnosis and management, including surveillance, of known or suspected cancer in children. The independent and combined roles of the various modalities, consisting of radiography, fluoroscopy, ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine (NM), are both prescribed through protocols but also function in caring for complications that may occur during or subsequent to treatment such as infection, bleeding, or organ compromise. Use of a specific imaging modality may be based on situational circumstances such as a brain CT or MR for a new onset seizure, chest CT for respiratory signs or symptoms, or US for gross hematuria. However, in many situations, there are competing choices that do not easily lend themselves to a formulaic approach as options; these situations depend on the contributions of a variety of factors based on a combination of the clinical scenario and the strengths and limitations of the imaging modalities. Therefore, an improved understanding of the potential influence of the imaging decision pathways in pediatric cancer care can come from comparison among the individual diagnostic imaging modalities. The purpose of the following material to is to provide such a comparison. To do this, pediatric imaging content experts for the individual modalities of radiography and fluoroscopy, US, CT, MRI, and NM will discuss the individual modality strengths and limitations.

Is Thyroid Monitoring Warranted in Infants and Young Children After Intravascular Administration of Iodine-Based Contrast Media?

On March 30, 2022, the U.S. FDA issued a drug safety communication recommending that infants and young children through 3 years of age undergo monitoring of thyroid function within 3 weeks of intravascular administration of iodine-based contrast media. This article considers the literature that was referenced for this decision and provides an outlook on thyroid monitoring after diagnostic imaging from pediatric radiology and pediatric endocrinology perspectives.

Hip Imaging in Children With Cerebral Palsy: Estimation and Intrapatient Comparison of Patient-Specific Radiation Doses of Low-Dose CT and Radiography.

OBJECTIVES: Hip displacement is the second most common orthopedic problem affecting children with cerebral palsy (CP). Routine radiographic hip surveillance typically involves an anteroposterior (AP) pelvis radiograph. Unfortunately, this imaging protocol is limited by its projectional technique and the positioning challenges in children with CP. Alternatively, hip low-dose computed tomography (LDCT) has been advocated as a more accurate strategy for imaging surveillance as it provides biofidelic details of the hip that is independent of patient positioning. However, the tradeoff is the (presumed) higher radiation dose to the patient. The goal of this study is to estimate patient-specific radiation doses of hip LDCTs and AP pelvis radiographs in CP patients, and perform an intrapatient dose comparison. MATERIALS AND METHODS: A search of our imaging database was performed to identify children with CP who underwent hip LDCT and AP pelvis radiograph within 6 months of each other. The LDCTs were performed using weight-adjusted kVp and tube current modulation, whereas the radiographs were obtained with age-/size-adjusted kVp/mAs. The patient-specific organ and effective doses for LDCT were estimated by matching the patients to a nonreference pediatric phantom library from the National Cancer Institute Dosimetry System for Computed Tomography database with Monte Carlo-based dosimetry. The patient-specific organ and effective doses for radiograph were estimated using the National Cancer Institute Dosimetry System for Radiography and Fluoroscopy with Monte Carlo-based dose calculation. Dose conversion k-factors of dose area product for radiography and dose length product for LDCT were adapted, and the estimation results were compared with patient-specific dosimetry. RESULTS: Our study cohort consisted of 70 paired imaging studies from 67 children (age, 9.1 ± 3.3 years). The patient-specific and dose length product-based effective doses for LDCT were 0.42 ± 0.21 mSv and 0.59 ± 0.28 mSv, respectively. The patient-specific and dose area product-based effective doses for radiography were 0.14 ± 0.09 mSv and 0.08 ± 0.06 mSv, respectively. CONCLUSIONS: The radiation dose for a hip LDCT is ~4 times higher than pelvis radiograph, but it is still very low and poses minimal risk to the patient.

Imaging of Right Lower Quadrant Pain in Children and Adolescents: AJR Expert Panel Narrative Review.

Right lower quadrant (RLQ) pain is a common clinical presentation in children, and accurate clinical diagnosis remains challenging given that this nonspecific presentation is associated with numerous surgical and nonsurgical conditions. The broad differential diagnosis varies by patient age and sex. Important considerations in the selection of a diagnostic imaging strategy include the sequencing, performance, and cost of tests. This article provides a comprehensive narrative review of the diagnostic imaging of RLQ pain in children and adolescents, including a discussion of the complementary roles of ultrasound, CT, and MRI; description of key imaging findings based on available evidence; and presentation of salient differential diagnoses. Subspecialized pediatric emergency medicine and surgical perspectives are also provided as further clinical insight into this common, but often challenging, scenario. Finally, the current status of imaging of RLQ pain in children and adolescents is summarized on the basis of expert consensus.

Diagnostic challenges with central venous catheter studies.

A central venous catheter is typically made of silicone rubber or polyurethane and inserted into a large central vein to provide prolonged and direct access to central venous circulation. These catheters provide a safe and effective method to administer intravenous medications, nutritional supplements, fluids and blood products. However, a myriad of complications is associated with central venous catheters, including, but not limited to, mechanical malfunction or fracture, kinking, erroneous placement, line infection, fibrin sheath formation and venous thrombosis. Following clinical and radiographic evaluation, contrast-enhanced line studies constitute the next best diagnostic tool to assess the functionality of central venous catheters. However, there is a lack of standardization in the literature outlining how these studies should be performed. In addition, the interpretation of these studies can be problematic for general pediatric radiologists, many of whom are often not familiar with placement or manipulation of these catheters. In this pictorial review, we highlight the challenges associated with performing and interpreting fluoroscopically guided contrast injection studies, using case studies drawn from a large tertiary children's hospital database for illustration. Revealing these challenges and understanding their causative mechanisms can improve the performance of these line studies.

Triple gallbladder with heterotopic gastric mucosa: a case report.

BACKGROUND: Triple gallbladder is a rare congenital anomaly of the biliary tract that can be associated with heterotopic tissue. Gallbladder triplication results from the failure of rudimentary bile ducts to regress during embryological development, and can be difficult to distinguish from Todani type II choledochal cysts and biliary duplication cysts. CASE PRESENTATION: A 2-year-old patient presented to our institution with intermittent abdominal pain for 1 year. She had elevated transaminases with imaging concerning for a choledochal cyst. After assessment with magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography, she was diagnosed with a gallbladder multiplication and a common bile duct stricture. She underwent laparoscopic cholecystectomy, which confirmed the diagnosis of triple gallbladder. One of the three gallbladders demonstrated heterotopic gastric mucosa on final pathology, including at the cystic duct margin. Follow up testing with a technetium 99 m scan demonstrated a subtle focus of increased activity in the right upper abdomen at the expected location of the common bile duct, concerning for the presence of residual gastric mucosa. The patient remains well without abdominal pain. CONCLUSIONS: We describe the first case of heterotopic gastric mucosa in a triple gallbladder in a young patient presenting with chronic abdominal pain. We also demonstrate the safety and feasibility of laparoscopic cholecystectomy in young children with triple gallbladder. Finally, we propose an interdisciplinary approach to the management of common bile duct strictures in the setting of ectopic acid secretion, involving a combination of medical management, endoscopic intervention, and possible salvage laparoscopic Roux-en-Y hepaticojejunostomy.

Longitudinal changes in glucose during pregnancy in women with gestational diabetes risk factors.

AIMS/HYPOTHESIS: Despite recommendations to screen women with diabetes risk factors for hyperglycaemia in the first trimester, criteria for normal glucose values in early pregnancy have not been firmly established. We aimed to compare glucose levels in early pregnancy with those later in gestation and outside of pregnancy in women with diabetes risk factors. METHODS: In pregnant women (N = 123) followed longitudinally through the postpartum period, and a separate cohort of non-pregnant women (N = 65), we performed 75 g oral glucose tolerance tests. All participants had one or more risk factors for diabetes. Using linear regression, we tested for differences in glucose levels between non-pregnant and pregnant women at early (7-15 weeks) and mid-late (24-32 weeks) gestation as well as postpartum, with adjustment for maternal age, parity, marital status and BMI. In a longitudinal analysis using mixed-effects models, we tested for differences in glucose levels across early and mid-late pregnancy compared with postpartum. Differences are expressed as ß (95% CI). RESULTS: Fasting glucose was lower in pregnant compared with non-pregnant women by 0.34 (0.18, 0.51) mmol/l (p < 0.0001) in early pregnancy and by 0.45 (0.29, 0.61) mmol/l (p < 0.0001) in mid-late pregnancy. In longitudinal models, fasting glucose was lower by 0.13 (0.04, 0.21) mmol/l (p = 0.003) in early pregnancy and by 0.16 (0.08, 0.25) mmol/l (p = 0.0003) in mid-late pregnancy compared with the same women postpartum. Early pregnancy post-load glucose levels did not differ from those in non-pregnant women or the same women postpartum. In mid-late pregnancy, compared with non-pregnant women, elevations in 1 h post-load glucose level (0.60 [-0.12, 1.33] mmol/l, p = 0.10) and 2 h post-load glucose (0.49 [-0.21, 1.19] mmol/l, p = 0.17) were not statistically significant. However, in longitudinal analyses, 1 h and 2 h post-load glucose levels were higher in mid-late pregnancy (by 0.78 [0.35, 1.21] mmol/l, p = 0.0004, and 0.67 [0.30, 1.04] mmol/l, p = 0.0005, respectively) when compared with postpartum. CONCLUSIONS/INTERPRETATION: In women with diabetes risk factors, fasting glucose declines in the first trimester. Post-load glucose increases later in pregnancy. These findings may inform criteria for diagnosing hyperglycaemia early in pregnancy.

Radiographic assessment of traction-induced esophageal growth and traction-related complications of the Foker process for treatment of long-gap esophageal atresia.

BACKGROUND: Radiographic assessment of esophageal growth in long-gap esophageal atresia while on traction and associated traction-related complications have not been described. OBJECTIVE: To demonstrate how chest radiography can estimate esophageal position while on traction and to evaluate radiography's utility in diagnosing certain traction system complications. MATERIALS AND METHODS: In this retrospective evaluation of portable chest radiographs obtained in infants with long-gap esophageal atresia who underwent the Foker process between 2014 and 2020, we assessed distances between the opposing trailing clips (esophageal gap) and the leading and trailing clips for each esophageal segment on serial radiographs. Growth during traction was estimated using longitudinal random-effects regression analysis to account for multiple chest radiograph measurements from the same child. RESULTS: Forty-three infants (25 male) had a median esophageal gap of 4.5 cm. Median traction time was 14 days. Median daily radiographic esophageal growth rate for both segments was 2.2 mm and median cumulative growth was 23.6 mm. Traction-related complications occurred in 13 (30%) children with median time of 8 days from traction initiation. Daily change >12% in leading-to trailing clip distance demonstrated 86% sensitivity and 92% specificity for indicating traction-related complications (area under the curve [AUC] 0.853). Cumulative change >30% in leading- to trailing-clip distance during traction was 85% sensitive and 85% specific for indicating traction complications (AUC 0.874). CONCLUSION: Portable chest radiograph measurements can serve as a quantitative surrogate for esophageal segment position in long-gap esophageal atresia. An increase of >12% between two sequential chest radiographs or >30% increase over the traction period in leading- to trailing-clip distance is highly associated with traction system complications.

Should I irradiate with computed tomography or sedate for magnetic resonance imaging?

In the context of pediatric cross-sectional imaging, the risk of ionizing radiation for CT and the potential adverse effects associated with sedation/anesthesia for MRI continue to provoke lively discussions in the pediatric literature and lay press. This is particularly true for issues relating to the risks of ionizing radiation for CT, which has been a topic of discussion for nearly two decades. In addition to understanding these potential risks and the importance of minimizing individual pediatric patient exposure to ionizing radiation, it is equally important for radiologists to be able to frame these risks with respect to the potential for adverse outcomes associated with the use of anesthesia for cross-sectional imaging in the pediatric population. Notably, before such risks can be estimated and compared, one should always consider the potential utility of each imaging modality for a given diagnosis. If one cross-sectional imaging modality is likely to be far superior to the other for a specific clinical question, every effort must be made to safely image the child, even if sedation/anesthesia is required.

Assessing and conveying risks and benefits of imaging in neonates using ionizing radiation and sedation/anesthesia.

Neonates represent a unique subset of the pediatric population that requires special attention and careful thought when implementing advanced cross-sectional imaging with CT or MRI. The ionizing radiation associated with CT and the sedation/anesthesia occasionally required for MRI present risks that must be balanced against the perceived benefit of the imaging examination in the unique and particularly susceptible neonatal population. We review the perceived risks of ionizing radiation and the more concrete risks of sedation/anesthesia in term and preterm neonates in the context of an imaging paradigm. When the expected diagnostic yield from CT and MRI is similar, and sedation is required for MRI but not for CT, CT likely has the higher benefit-to-risk ratio in the neonate. However, despite the risks, the most appropriate imaging modality should always be chosen after thoughtful consideration is given to each unique patient and informed discussions including radiology, anesthesia, neonatology and the parents/caregivers are pursued.

The impact of social distancing during the COVID-19 pandemic on rates of pediatric idiopathic intussusception.

BACKGROUND: The causes of idiopathic ileocolic intussusception are unknown, with infection as the most likely culprit. Recently, social distancing measures were implemented during the coronavirus disease 2019 (COVID-19) pandemic to decrease transmissible infectious diseases, creating an opportune setting to study the role of infection on the pathogenesis of intussusception on a population level. OBJECTIVE: To investigate the impact of social distancing on intussusception. MATERIALS AND METHODS: We retrospectively reviewed air contrast enemas and pylorus ultrasounds performed between March 2010 and March 2021 to identify cases of ileocolic intussusception and hypertrophic pyloric stenosis (HPS), using the latter as a negative control. The study time frame was divided into two periods: pre-pandemic (March 2010-February 2020) and pandemic (April 2020-March 2021). The number of cases that occurred in these two time periods were compared using the Poisson regression model. RESULTS: Of the 407 cases of idiopathic ileocolic intussusception identified, 396 occurred in the pre-pandemic time period (mean = 39.6 per 12-month period) and 11 occurred in the 12-month pandemic time period. The mean monthly number of intussusceptions showed a decline of 72% (95% confidence interval [CI] 49-85%) between the pre-pandemic and pandemic time periods (3.3 vs. 0.9 monthly cases; P < 0.001). In contrast, the mean monthly number of HPS did not differ significantly (P = 0.19). CONCLUSION: Social distancing-imposed to curb the spread of infection during the COVID-19 pandemic-resulted in a significant decline in ileocolic intussusception, lending strong support to the theory that infection is the dominant cause of intussusception.

The pediatric stomach - congenital abnormalities.

Diagnostic imaging of the pediatric stomach often provides a challenge for practicing radiologists. Radiologists should be aware of relatively unusual congenital pathology, especially when imaging very young children with gastrointestinal symptoms. We review congenital pathology of the pediatric stomach.

Sequencing Cell-free Fetal DNA in Pregnant Women With GCK-MODY.

CONTEXT: Individuals with monogenic diabetes due to inactivating glucokinase (GCK) variants typically do not require treatment, except potentially during pregnancy. In pregnancy, fetal GCK genotype determines whether treatment is indicated, but noninvasive methods are not clinically available. OBJECTIVE: This work aims to develop a method to determine fetal GCK genotype noninvasively using maternal cell-free fetal DNA. METHODS: This was a proof-of-concept study involving 3 pregnant women with a causal GCK variant that used information from 1) massive parallel sequencing of maternal plasma cell-free DNA, 2) direct haplotype sequences of maternal genomic DNA, and 3) the paternal genotypes to estimate relative haplotype dosage of the pathogenic variant-linked haplotype. Statistical testing of variant inheritance was performed using a sequential probability ratio test (SPRT). RESULTS: In each of the 3 cases, plasma cell-free DNA was extracted once between gestational weeks 24 and 36. The fetal fraction of cell-free DNA ranged from 21.8% to 23.0%. Paternal homozygous alleles that were identical to the maternal GCK variant-linked allele were not overrepresented in the cell-free DNA. Paternal homozygous alleles that were identical to the maternal wild-type-linked allele were significantly overrepresented. Based on the SPRT, we predicted that all 3 cases did not inherit the GCK variant. Postnatal infant genotyping confirmed our prediction in each case. CONCLUSION: We have successfully implemented a noninvasive method to predict fetal GCK genotype using cell-free DNA in 3 pregnant women carrying an inactivating GCK variant. This method could guide tailoring of hyperglycemia treatment in pregnancies of women with GCK monogenic diabetes.

Acute pancreatitis in children: a review with clinical perspectives to enhance imaging interpretation.

Pediatric acute pancreatitis has distinct etiologic, clinical and prognostic characteristics in contrast to the adult form of the disease. This review offers a comprehensive imaging update that emphasizes the importance of recognizing specific findings that are relevant from the clinical standpoint. Knowledge of these features facilitates communication among multidisciplinary team members and ultimately could lead to the improved care of pediatric acute pancreatitis patients.

Relationship between carbohydrate intake and oral glucose tolerance test results among pregnant women.

AIMS: Evaluate the relationship between self-reported carbohydrate intake and oral glucose tolerance test (OGTT) results in pregnancy. METHODS: We measured carbohydrate intake using 24-hour dietary recall and performed a 2-hour 75-gram OGTT in 95 pregnant women with risk factors for gestational diabetes (GDM) at a median of 26 weeks' gestation. We tested for associations between carbohydrate intake in the 24 hours preceding the OGTT and 60-minute OGTT glucose, glucose at other timepoints, and glucose area under the curve (AUC) using linear regression, with adjustment for potential confounders. RESULTS: We observed an inverse linear relationship between carbohydrate intake (median 237 grams [interquartile range: 196, 303]) and 60-minute OGTT glucose. For every 50 gram reduction in carbohydrate intake, there was an 8.9 mg/dl increase in 60-minute OGTT glucose (P < 0.01) in an adjusted model. Lower carbohydrate intake was also associated with higher 30-minute (adjusted ß = -6.5 mg/dl, P < 0.01) and 120-minute OGTT glucose (adjusted ß = -8.1 mg/dl, P = 0.01) and AUC (adjusted ß = -767, P < 0.01). CONCLUSIONS: Carbohydrate intake in the day preceding an OGTT in pregnancy is associated with post-load glucose values, with lower carbohydrate intake predicting higher glucose levels and higher carbohydrate intake predicting lower glucose levels. Carbohydrate restriction or excess before an OGTT may affect GDM diagnosis.

Free-breathing radial stack-of-stars three-dimensional Dixon gradient echo sequence in abdominal magnetic resonance imaging in sedated pediatric patients.

BACKGROUND: There is a strong need for improvements in motion robust T1-weighted abdominal imaging sequences in children to enable high-quality, free-breathing imaging. OBJECTIVE: To compare imaging time and quality of a radial stack-of-stars, free-breathing T1-weighted gradient echo acquisition (volumetric interpolated breath-hold examination [VIBE]) three-dimensional (3-D) Dixon sequence in sedated pediatric patients undergoing abdominal magnetic resonance imaging (MRI) against conventional Cartesian T1-weighed sequences. MATERIALS AND METHODS: This study was approved by the institutional review board with informed consent obtained from all subjects. Study subjects included 31 pediatric patients (19 male, 12 female; median age: 5 years; interquartile range: 5 years) undergoing abdominal MRI at 3 tesla with a free-breathing T1-weighted radial stack-of-stars 3-D VIBE Dixon prototype sequence, StarVIBE Dixon (radial technique), between October 2018 and June 2019 with previous abdominal MR imaging using conventional Cartesian T1-weighed imaging (traditional technique). MRI component times were recorded as well as the total number of non-contrast T1-weighted sequences. Two radiologists independently rated images for quality using a scale from 1 to 5 according to the following metrics: overall image quality, hepatic edge sharpness, hepatic vessel clarity and respiratory motion robustness. Scores were compared between the groups. RESULTS: Mean T1-weighted imaging times for all subjects were 3.63 min for radial exams and 8.01 min for traditional exams (P<0.001), and total non-contrast imaging time was 32.7 min vs. 43.9 min (P=0.002). Adjusted mean total MRI time for all subjects was 60.2 min for radial exams and 65.7 min for traditional exams (P=0.387). The mean number of non-contrast T1-weighted sequences performed in radial MRI exams was 1.0 compared to 1.9 (range: 0-6) in traditional exams (P<0.001). StarVIBE Dixon outperformed Cartesian methods in all quality metrics. The mean overall image quality (scale 1-5) was 3.95 for radial exams and 3.31 for traditional exams (P<0.001). CONCLUSION: Radial stack-of-stars 3-D VIBE Dixon during free-breathing abdominal MRI in pediatric patients offers improved image quality compared to Cartesian T1-weighted imaging techniques with decreased T1-weighted and total non-contrast imaging time. This has important implications for children undergoing sedation for imaging.