Proposal of an Abbreviated Noncontrast MR Enterography Protocol for Patients With Crohn Disease.

MR enterography (MRE) protocols used in patients with Crohn disease are burdened by long acquisition time, high cost, and suboptimal patient experience. For several indications, highly diagnostic MRE can be performed in five or fewer sequences, without IV contrast material or antiperistaltic medication and with an examination room time of less than 12 minutes. As such, MRE could be more patient friendly, more frequently performed, and require fewer health care resources.

Consensus Minimum MRI Protocol for the Child With Acute Recurrent or Chronic Pancreatitis.

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.

Interobserver Agreement for CT and MRI Findings of Chronic Pancreatitis in Children: A Multicenter Ancillary Study Under the INSPPIRE Consortium.

BACKGROUND. Imaging findings represent key criteria for diagnosing chronic pancreatitis in children. Understanding radiologists' agreement for imaging findings is critical to standardizing and optimizing diagnostic criteria. OBJECTIVE. The purpose of this study is to evaluate the interobserver agreement among experienced pediatric radiologists for subjective, quantitative, and semiquantitative imaging findings of chronic pancreatitis in children. METHODS. In this retrospective study, CT or MRI examinations performed in children with chronic pancreatitis were submitted by six sites participating in the INSPPIRE (International Study Group of Pediatric Pancreatitis: In Search for a Cure) Consortium. One pediatric radiologist from each of the six sites reviewed examinations; three of the radiologists independently reviewed all CT examinations, and the other three radiologists independently reviewed all MRI examinations. Reviewers recorded 13 categoric imaging findings of chronic pancreatitis and measured pancreas thickness and pancreatic duct diameter. Agreement was assessed using kappa coefficients for the categoric variables and intraclass correlation coefficients (ICCs) for the continuous variables. RESULTS. A total of 76 CT and 80 MRI examinations performed in 110 children (65 girls and 45 boys; mean age, 11.3 ± 4.6 [SD] years) were reviewed. For CT, kappa coefficients for categoric findings ranged from -0.01 to 0.81, with relatively high kappa coefficients noted for parenchymal calcifications (κ = 0.81), main pancreatic duct dilatation (κ = 0.63), and atrophy (κ = 0.52). ICCs for parenchymal thickness measurements ranged from 0.57 in the pancreas head to 0.80 in the body and tail. The ICC for duct diameter was 0.85. For MRI, kappa coefficients for categoric findings ranged from -0.01 to 0.74, with relatively high kappa coefficients noted for main duct irregularity (κ = 0.74), side branch dilatation (κ = 0.70), number of dilated side branches (κ = 0.65), and main duct dilatation (κ = 0.64); kappa coefficient for atrophy was 0.52. ICCs for parenchymal thickness measurements ranged from 0.53 for the neck and body individually to 0.68 in the tail. ICC for duct diameter was 0.77. CONCLUSION. Interobserver agreement was fair to moderate for most CT and MRI findings of chronic pancreatitis in children. CLINICAL IMPACT. This study highlights challenges for the imaging diagnosis of pediatric chronic pancreatitis. Standardized and/or objective criteria are needed given the importance of imaging in diagnosis.

The role of ultrasound in necrotizing enterocolitis.

Ultrasound has proved to be a useful modality for enhancing the diagnostic accuracy of necrotizing enterocolitis and associated complications. The standard imaging algorithm for evaluating necrotizing enterocolitis includes radiographs and clinical symptoms, the combination of which constitutes the Bell criteria. Major limitations of using the Bell criteria for diagnosing and clinically managing necrotizing enterocolitis include low diagnostic accuracy of radiographs and nonspecific symptomatology of preterm infants. In this regard, US can offer additional insights into bowel health by helping to characterize bowel motility, echogenicity, thickness, pneumatosis and perfusion. Extramural findings such as portal venous gas, nature and extent of ascites, and pneumoperitoneum can also be assessed. Recently, contrast-enhanced US was explored in a case series of preterm bowel disease and its diagnostic utility warrants further investigation. This article reviews the US features of necrotizing enterocolitis and highlights the role of US as a complement to radiographs, as well as the emerging use of contrast-enhanced US in necrotizing enterocolitis.

Contrast-enhanced ultrasound: a comprehensive review of safety in children.

Contrast-enhanced ultrasound (CEUS) has been increasingly used in pediatric radiology practice worldwide. For nearly two decades, CEUS applications have been performed with the off-label use of gas-containing second-generation ultrasound contrast agents (UCAs). Since 2016, the United States Food and Drug Administration (FDA) has approved the UCA Lumason for three pediatric indications: the evaluation of focal liver lesions and echocardiography via intravenous administration and the assessment of vesicoureteral reflux via intravesical application (contrast-enhanced voiding urosonography, ceVUS). Prior to the FDA approval of Lumason, numerous studies with the use of second-generation UCAs had been conducted in adults and children. Comprehensive protocols for clinical safety evaluations have demonstrated the highly favorable safety profile of UCA for intravenous, intravesical and other intracavitary uses. The safety data on CEUS continue to accumulate as this imaging modality is increasingly utilized in clinical settings worldwide. As of August 2021, 57 pediatric-only original research studies encompassing a total of 4,518 children with 4,906 intravenous CEUS examinations had been published. As in adults, there were a few adverse events; the majority of these were non-serious, although very rarely serious anaphylactic reactions were reported. In the published pediatric-only intravenous CEUS studies included in our analysis, the overall incidence rate of serious adverse events was 0.22% (10/4,518) of children and 0.20% (10/4,906) of all CEUS examinations. Non-serious adverse events from the intravenous CEUS were observed in 1.20% (54/4,518) of children and 1.10% (54/4,906) of CEUS examinations. During the same time period, 31 studies with the intravesical use of UCA were conducted in 12,362 children. A few non-serious adverse events were encountered (0.31%; 38/12,362), but these were most likely attributable to the bladder catheterization rather than the UCA. Other developing clinical applications of UCA in children, including intracavitary and intralymphatic, are ongoing. To date, no serious adverse events have been reported with these applications. This article reviews the existing pediatric CEUS literature and provides an overview of safety-related information reported from UCA uses in children.

Contrast-enhanced ultrasound of the spleen, pancreas and gallbladder in children.

Gray-scale and color/power Doppler ultrasound (US) are the first-line imaging modalities to evaluate the spleen, gallbladder and pancreas in children. The increasing use of contrast-enhanced ultrasound (CEUS) as a reliable and safe method to evaluate liver lesions in the pediatric population promises potential for imaging other internal organs. Although CEUS applications of the spleen, gallbladder and pancreas have been well described in adults, they have not been fully explored in children. In this manuscript, we present an overview of the applications of CEUS for normal variants and diseases affecting the spleen, gallbladder and pancreas. We highlight a variety of cases as examples of how CEUS can serve in the diagnosis and follow-up for such diseases in children. Our discussion includes specific examination techniques; presentation of the main imaging findings in various benign and malignant lesions of the spleen, gallbladder and pancreas in children; and acknowledgment of the limitations of CEUS for these organs.

Contrast-enhanced ultrasound of the pediatric bowel.

Contrast-enhanced ultrasound (CEUS) has emerged as a valuable modality for bowel imaging in adults and children. CEUS enables visualization of the perfusion of the bowel wall and of the associated mesentery in healthy and disease states. In addition, CEUS images can be used to make quantitative measurements of contrast kinetics, allowing for objective assessment of bowel wall enhancement. Bowel CEUS is commonly applied to evaluate inflammatory bowel disease and to monitor treatment response. It has also been applied to evaluate necrotizing enterocolitis, intussusception, appendicitis and epiploic appendagitis, although experience with these applications is more limited. In this review article, we present the current experience using CEUS to evaluate the pediatric bowel with emphasis on inflammatory bowel disease, extrapolating the established experience from adult studies. We also discuss emerging applications of CEUS as an adjunct or problem-solving tool for evaluating bowel perfusion.

Contrast-enhanced ultrasound of benign and malignant liver lesions in children.

Contrast-enhanced ultrasound (CEUS) is increasingly being used in children. One of the most common referrals for CEUS performance is characterization of indeterminate focal liver lesions and follow-up of known liver lesions. In this setting, CEUS is performed with intravenous administration of ultrasound contrast agents (UCAs). When injected into a vein, UCA microbubbles remain confined within the vascular network until they dissipate. Therefore, visualization of UCA within the tissues and lesions corresponds to true blood flow. CEUS enables continuous, real-time observation of the enhancement pattern of a focal liver lesion, allowing in most cases for a definite diagnosis and obviating the need for further cross-sectional imaging or other interventional procedures. The recent approval of Lumason (Bracco Diagnostics, Monroe Township, NJ) for pediatric liver CEUS applications has spurred the widespread use of CEUS. In this review article we describe the role of CEUS in pediatric liver applications, focusing on the examination technique and interpretation of main imaging findings of the most commonly encountered benign and malignant focal liver lesions. We also compare the diagnostic performance of CEUS with other imaging modalities for accurate characterization of focal liver lesions.

RADIAL: leveraging a learning management system to support radiology education.

Increasing volume and complexity of cases in academic radiology and the drive toward pediatric sub-specialization have threatened knowledge assimilation for radiologists. There is a clear need for a system that retrieves vetted information from the excess available on the internet. Partnered with an interdisciplinary team from the Graduate School of Education, the authors created the first comprehensive learning management system (LMS) for radiology, implemented in the reading room to augment image interpretation and point-of-care education. The LMS supports quantitative analysis using a robust analytics platform to evaluate user statistics, facilitating improved quality of patient care by revolutionizing the way radiologists assimilate knowledge. This integration promises to enhance workflow and point-of-care teaching and to support the highest quality of care.

Current State of Imaging of Pediatric Pancreatitis: AJR Expert Panel Narrative Review.

Pancreatitis is as common in children as it is in adults, though causes and accepted imaging strategies differ in children. In this narrative review we discuss the epidemiology of childhood pancreatitis and key imaging features for pediatric acute, acute recurrent, and chronic pancreatitis. We rely heavily on our collective experience in discussing advantages and disadvantages of different imaging modalities; practical tips for optimization of ultrasound, CT, and MRI with MRCP in children; and image interpretation pearls. Challenges and considerations unique to imaging pediatric pancreatitis are discussed, including timing of imaging, role of secretin-enhanced MRCP, utility of urgent MRI, severity prediction, autoimmune pancreatitis, and best methods for serial imaging. We suggest a methodical approach to pancreatic MRI interpretation in children and have included a sample structured report, and we provide consensus statements according to our experience imaging children with pancreatitis.

State of the Art MR Enterography Technique.

ABSTRACT: Magnetic resonance enterography (MRE) is a well-established imaging technique that is commonly used for evaluating a variety of bowel diseases, most commonly inflammatory bowel disease which is increasing in prevalence. Inflammatory bowel disease is composed of 2 related, but distinct disease entities: Crohn disease (CD) and ulcerative colitis. In ulcerative colitis, inflammation is generally limited to the mucosa and invariably involves the rectum, and often the more proximal colon. CD is typified by transmural inflammation with skip lesions occurring anywhere from the mouth to anus, but characteristically involves the terminal ileum. The transmural involvement of CD may lead to debilitating ulceration and, ultimately, development of sinus tracts, which can be associated with abscesses and fistulae as extraenteric manifestations of the disease. Because much of the small bowel and extraenteric disease cannot be adequately assessed with conventional endoscopy, imaging plays a crucial role in initial diagnosis and follow-up. MRE does not use ionizing radiation which is important for these patients, many of which present earlier in life and may require multiple imaging examinations. In this article, we review the clinical indications, patient preparation, and optimal technique for MRE. We also discuss the role and proper selection of intravenous gadolinium-based contrast material, oral contrast material, and antiperistaltic agents, including pediatric considerations. Finally, we review the recommended and optional pulse sequence selection, including discussion of a "time-efficient" protocol, reviewing their utility, advantages, and limitations. Our hope is to aid the radiologist seeking to develop a robust MRE imaging program for the evaluation of bowel disease.

Whole-body magnetic resonance imaging in the evaluation of children with fever without a focus.

BACKGROUND: Fever without a focus is defined as a temperature of 38° C or higher as the single presenting symptom. After extensive investigation, a large percentage (12-67%) of cases remain undiagnosed. OBJECTIVE: To assess the diagnostic value of whole-body magnetic resonance imaging (WB-MRI) in children with fever without a focus. MATERIALS AND METHODS: A retrospective study was performed to identify children who underwent WB-MRI for fever without a focus. Ninety-two children, 50 boys, with a mean age of 6.1 years were included. A multidisciplinary team of physicians completed in consensus a medical record review that included: 1) immune status, 2) underlying chronic conditions, 3) hospitalization status at onset of fever, and 4) results of tissue, body fluid cultures and biopsies. Original MRI reports were evaluated. WB-MRI studies were categorized into helpful WB-MRI and not helpful WB-MRI. RESULTS: A final diagnosis for the cause of the fever was available for 68/92 cases (73.9%), which were determined to be infectious in 33/68 (48.5%), oncological in 3/68 (4.4%), rheumatological etiologies in 23/68 (33.8%) and miscellaneous in 9/68 (13.2%) cases. WB-MRI was found to be helpful in 62/92 cases (67.4%) and not helpful in 30/92 cases (32.6%). WB-MRI was 10.2 times less likely to be helpful in immunosuppressed children and almost 5.7 times less likely to be helpful in cases of prolonged fever (>3 weeks) at the time of MRI (P≤0.01). CONCLUSION: WB-MRI provides helpful information in approximately 2/3 of children with fever without a focus. In most cases, it was helpful to exclude the need of further investigation.

North American Society for Pediatric Gastroenterology, Hepatology and Nutrition and the Society for Pediatric Radiology Joint Position Paper on Noninvasive Imaging of Pediatric Pancreatitis: Literature Summary and Recommendations.

ABSTRACT: The reported incidence of pediatric pancreatitis is increasing. Noninvasive imaging, including ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), play important roles in the diagnosis, staging, follow-up, and management of pancreatitis in children. In this position paper, generated by members of the Pancreas Committee of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) and the Abdominal Imaging Committee of The Society for Pediatric Radiology (SPR), we review the roles of noninvasive imaging in pediatric acute, acute recurrent, and chronic pancreatitis. We discuss available evidence related to noninvasive imaging, highlighting evidence specific to pediatric populations, and we make joint recommendations for use of noninvasive imaging. Further, we highlight the need for research to define the performance and role of noninvasive imaging in pediatric pancreatitis.

Contrast-enhanced US in Pediatric Patients: Overview of Bowel Applications.

Contrast material-enhanced US is a technique that is approved by the U.S. Food and Drug Administration for the characterization of liver lesions and intravesicular applications in children; however, contrast-enhanced US has several other pediatric applications in clinical practice. The most common application is for patients with inflammatory bowel disease (IBD). Contrast-enhanced US can be used to diagnose IBD, distinguish regions of active or chronic inflammation of the bowel wall, and evaluate associated complications such as abscesses, fistulas, and strictures. Dynamic contrast material evaluation provides qualitative and quantitative information about mural and mesenteric blood flow, which is essential in the determination of disease activity in these patients. It also has the potential to provide a means of monitoring the response to therapy beyond endoscopy or MR enterography. In addition to its use for IBD, contrast-enhanced US can be used to assess for bowel perfusion when problem solving in patients with necrotizing enterocolitis, neonatal bowel infarction, or intussusception. It is a useful imaging technique to fortify diagnoses that may otherwise be indeterminate, such as appendicitis, epiploic appendagitis, intraluminal bowel masses, and complex cysts. Finally, innovative applications such as shear-wave elastography have the potential to provide information about the stiffness of the bowel wall. Online supplemental material is available for this article. ©RSNA, 2020 See discussion on this article by Watson and Humphries.

Normal Liver Stiffness Measured with MR Elastography in Children.

Background Stiffness thresholds for liver MR elastography in children vary between studies and may differ from thresholds in adults. Normative liver stiffness data are needed to optimize diagnostic thresholds for children. Purpose To determine normal liver stiffness, and associated normal ranges for children, as measured with MR elastography across vendors and field strengths. Materials and Methods This was a prospective multicenter cohort study (ClinicalTrials.gov identifier: NCT03235414). Volunteers aged 7-17.9 years without a known history of liver disease were recruited at four sites for a research MRI and blood draw between February 2018 and October 2019. MRI was performed on three vendor platforms and at two field strengths (1.5 T and 3.0 T). All MRI scans were centrally analyzed; stiffness, proton density fat fraction (PDFF), and R2* values were expressed as means of means. Mean and 95% confidence intervals (CIs) for liver stiffness were calculated. Pearson correlation coefficient (r), two-sample t test, or analysis of variance was used to assess univariable associations. Results Seventy-one volunteers had complete data and no documented exclusion criterion (median age, 12 years; interquartile range [IQR], 10-15 years; 39 female participants). Median body mass index percentile was 54% (IQR, 32.5%-69.5%). Mean liver stiffness was 2.1 kPa (95% CI: 2.0, 2.2 kPa) with mean ± 1.96 kPa standard deviation of 1.5-2.8 kPa. Median liver PDFF was 2.0% (IQR, 1.7%-2.6%). There was no association between liver stiffness and any patient variable or MRI scanner factor. Conclusion Mean liver stiffness measured with MR elastography in children without liver disease was 2.1 kPa (similar to that in adults). The 95th percentile of normal liver stiffness was 2.8 kPa. Liver stiffness was independent of sex, age, or body mass index and did not vary with MRI scanner vendor or field strength. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Yin in this issue.

Diagnostic performance and role of the contrast enema for low intestinal obstruction in neonates.

PURPOSE: We aim to evaluate the diagnostic performance and relationship between clinical characteristics, imaging findings, and final diagnosis for the neonatal contrast enema (CE). METHODS: Retrospective 10-year review of all neonatal CEs including imaging findings, clinical information, indication, and final diagnosis from discharge summaries, surgical reports, and pathology (reference standard). Two blinded pediatric radiologists reinterpreted 366 CEs for obstruction, microcolon, rectosigmoid index (RSI), serrations, meconium, ileal cut-off, transition zone, diagnosis, and level of confidence. CE diagnostic performance was calculated versus reference standard. RESULTS: Diagnoses included Hirschsprung disease (HD) (15.8%), small left colon syndrome (14.8%), small intestinal atresia/colonic atresia (SIA/CA) (12.6%), meconium ileus (MI) (4.4%), and normal (48.9%). CE had a moderate specificity (87.7%) and low sensitivity (65.5%) for HD; abnormal RSI and serrations showed high specificities (90.3%, 97.4%) but low sensitivities (46.6%, 17.2%). CE showed high specificity (97.4%) and low sensitivity (56.3%) for MI blinded to cystic fibrosis status. Microcolon was specific (96.6%) but not sensitive (68.8%) for MI. CE showed highest PPV (73.1%) (specificity 95.6%, sensitivity 82.6%) for SIA/CA. Microcolon with an abrupt cut-off was specific (99.1%) but not sensitive (41.3%) for atresias. CONCLUSION: Neonatal CE demonstrates high specificities and low to moderate sensitivities across all diagnoses, with lowest performance in HD. CLINICAL TRIAL REGISTRATION: None.