Ultrasound-estimated hepatorenal index: diagnostic performance and interobserver agreement for pediatric liver fat quantification.

BACKGROUND: Semiquantitative and quantitative sonographic techniques have the potential for screening and surveillance of children at risk of nonalcoholic fatty liver disease. OBJECTIVE: To determine diagnostic performance and interobserver agreement of hepatorenal index (HRI) for pediatric ultrasound-based liver fat quantification. MATERIALS AND METHODS: In an institutional review board (IRB)-approved retrospective study (April 2014 to April 2023), children (< 18 years) with clinically performed magnetic resonance imaging (MRI) scans for liver fat quantification were assessed. Inclusion criteria required availability of abdominal ultrasound within 3 months of quantitative MRI. Three blinded readers subjectively assessed for sonographic hepatic steatosis and calculated HRI. MRI proton density fat fraction (PDFF) was the reference standard. Interobserver agreement, correlation with PDFF, and optimal HRI (using ROC analysis) values were analyzed. The significance level was set at p < 0.05. RESULTS: A total of 41 patients (25 male) with median (interquartile range (IQR)) age of 13 (10-15) years were included. Median (IQR) MRI PDFF was 11.30% (2.70-17.95%). Hepatic steatosis distribution by MRI PDFF included grade 0 (34%), grade 1 (15%), grade 2 (22%), and grade 3 (29%) patients. Intraclass correlation coefficient for HRI among the three readers was 0.61 (95% CI 0.43-0.75) (p < 0.001). Moderate correlation was observed between manually estimated HRI and PDFF for each reader (r = 0.62, 0.67, and 0.67; p < 0.001). Optimal HRI cutoff was found to be 1.99 to diagnose hepatic steatosis (sensitivity 89%, specificity 93%). Median (IQR) HRI for each MRI grade of hepatic steatosis (0-4) was as follows: 1.2 (1.1-1.5), 2.6 (1.1-3.3), 3.6 (2.6-5.4), 5.6 (2.6-10.9), respectively (p < 0.001). CONCLUSION: Ultrasound-estimated HRI has moderate interobserver agreement and moderate correlation with MRI-derived PDFF. HRI of 1.99 maximizes accuracy for identifying pediatric liver fat.

Introduction to the COG Diagnostic Imaging Committee/SPR Oncology Committee White Papers: Rationale and methods.

Pediatric cancer is a rare disease. Because of this, many sites do not have experience providing imaging for specific tumor types. The Children's Oncology Group Diagnostic Imaging Committee and the Society for Pediatric Radiology Oncology Committee are comprised of radiologists with expertise in pediatric cancer imaging. Recently, this group endeavored to create a series of 23 White Papers designed to provide evidence-based imaging recommendations and minimum achievable imaging protocols. The purpose of this manuscript is to describe the methods employed in authoring the White Paper series.

Imaging of pediatric pancreas tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Primary pancreatic tumors in children are rare with an overall age-adjusted incidence of 0.018 new cases per 100,000 pediatric patients. The most prevalent histologic type is the solid pseudopapillary neoplasm, followed by pancreatoblastoma. This paper describes relevant imaging modalities and presents consensus-based recommendations for imaging at diagnosis and follow-up.

Imaging of pediatric thyroid tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Pediatric thyroid cancer is rare in children; however, incidence is increasing. Papillary thyroid cancer and follicular thyroid cancer are the most common subtypes, comprising about 90% and 10% of cases, respectively. This paper provides consensus imaging recommendations for evaluation of pediatric patients with thyroid cancer at diagnosis and during follow-up.

Optimizing Imaging of Pediatric Liver Lesions: Guidelines from the Pediatric LI-RADS Working Group.

A differential diagnosis based on a patient's age, clinical presentation, and serum α-fetoprotein level will help guide the initial imaging workup in children with a liver lesion. Children vary significantly in size, the ability to stay still, and the ability to breath hold for imaging examinations. Choosing and tailoring imaging techniques and protocols for each indication and age group is important for optimal care with minimal invasiveness. The need for sedation or anesthesia can be obviated by using techniques like feed and bundle, distraction, contrast-enhanced US, and motion-insensitive sequences for MRI. US is often the first imaging modality used in children with a suspected abdominal mass. Once a hepatic lesion is confirmed, multiphasic contrast-enhanced MRI is recommended for most lesions as the next imaging modality allowing full characterization of the lesion and assessment of the liver parenchyma. Contrast-enhanced CT can also be performed for assessment of pediatric focal liver lesions, especially in patients who have a contraindication to MRI. Contrast-enhanced US has shown promise to decrease the need for MRI or CT in some lesions such as hemangioma and focal nodular hyperplasia. Children with a history of malignancy can develop multiple types of hepatic lesions at various stages, including infections during an immunocompromised state, manifesting as focal liver lesions. Based on available limited data in the literature and the collective experiences of the Liver Imaging and Reporting Data System Pediatric Working Group, the authors provide guidelines for the imaging workup of pediatric focal liver lesions with an indication- and age-based approach and discuss the selection and performance of various imaging techniques and modalities. ©RSNA, 2022 See the invited commentary by Chojniak and Boaventura in this issue.

Prospective study of quantitative liver MRI in cystic fibrosis: feasibility and comparison to PUSH cohort ultrasound.

BACKGROUND: Pediatric radiologists can identify a liver ultrasound (US) pattern predictive of progression to advanced liver disease. However, reliably discriminating these US patterns remains difficult. Quantitative magnetic resonance imaging (MRI) may provide an objective measure of liver disease in cystic fibrosis (CF). OBJECTIVE: The purpose of this study was to determine if quantitative MRI, including MR elastography, is feasible in children with CF and to determine how quantitative MRI-derived metrics compared to a research US. MATERIALS AND METHODS: A prospective, multi-institutional trial was performed evaluating CF participants who underwent a standardized MRI. At central review, liver stiffness, fat fraction, liver volume, and spleen volume were obtained. Participants whose MRI was performed within 1 year of US were classified by US pattern as normal, homogeneous hyperechoic, heterogeneous, or nodular. Each MRI measure was compared among US grade groups using the Kruskal-Wallis test. RESULTS: Ninety-three participants (51 females [54.8%]; mean 15.6 years [range 8.1-21.7 years]) underwent MRI. MR elastography was feasible in 87 participants (93.5%). Fifty-eight participants had an US within 1 year of MRI. In these participants, a nodular liver had significantly higher stiffness (P<0.01) than normal or homogeneous hyperechoic livers. Participants with a homogeneous hyperechoic liver had a higher fat fraction (P<0.005) than others. CONCLUSION: MR elastography is feasible in children with CF. Participants with a nodular pattern had higher liver stiffness supporting the US determination of advanced liver disease. Participants with a homogeneous hyperechoic pattern had higher fat fractions supporting the diagnosis of steatosis.

Imaging Features of Hepatocellular Carcinoma in Children With and Without Underlying Risk Factors.

BACKGROUND. Pediatric hepatocellular carcinoma (HCC) is an aggressive malignancy for which imaging findings remain poorly described. In comparison with adult HCC, pediatric HCC more commonly occurs without underlying risk factors, and standardized surveillance guidelines for those with predispositions are lacking. OBJECTIVE. The purpose of this article was to evaluate imaging findings of nonfibrolamellar pediatric HCC and to identify associations between these imaging findings and the presence of predisposing factors. METHODS. This retrospective study included children (≤ 18 years) with histologically confirmed nonfibrolamellar HCC who underwent multiphase CT or MRI at one of four academic children's hospitals between July 2009 and April 2019. Surveillance regimens in children with predispositions were at the discretion of treating physicians. Clinical characteristics were recorded. Scan indications were classified as surveillance versus clinical signs and symptoms. Images from all sites were submitted to a cloud-based server. Two radiologists independently assessed imaging features of HCC, including tumor size, tumor in vein, Pre-Treatment Extent of Tumor (PRETEXT) stage, and LI-RADS major features of adult HCC. Imaging findings were compared between patients with and without predispositions. RESULTS. The study included 39 patients: 17 with predispositions (mean age, 10.5 ± 4.5 years; nine boys, eight girls) and 22 without predispositions (mean age, 11.3 ± 5.1 years; 12 boys, 10 girls). Scan indication was surveillance in 14/17 patients with predispositions versus 0/22 patients without predispositions (p < .001). Patients with versus those without predispositions had smaller tumor size (reader 1: 6.0 vs 11.9 cm [p = .003]; reader 2: 6.0 vs 12.9 cm [p < .001]) and less frequent tumor in vein (reader 1: 0% vs 41% [p = .002]; reader 2: 0% vs 36% [p = .006]). PRETEXT stage IV disease was observed in 18% (both readers) of patients with predispositions versus 50-55% of patients without predispositions. No LI-RADS major feature of adult HCC showed a significant difference in frequency between patients with and without predispositions for either reader (all p > .05). CONCLUSION. Among children with HCC, those with predispositions exhibited smaller and lower-stage tumors and less frequent tumor in vein, likely because of surveillance imaging. CLINICAL IMPACT. The study supports the role of routine surveillance imaging in children with HCC predispositions to facilitate earlier detection. Standardization of surveillance guidelines remains needed.

Pediatric Hepatic Cystic Lesions: Differential Diagnosis and Multimodality Imaging Approach.

When a pediatric hepatic cystic lesion is identified at imaging, the differential diagnosis may be broad, including developmental, infectious, neoplastic, and posttraumatic or iatrogenic causes. The location of a cystic lesion and its number, size, composition, and relationship to the biliary system are features that help in narrowing the differential diagnosis. An incidentally detected simple hepatic cyst is the most commonly encountered. Ciliated foregut cysts are typically located in hepatic segment IVa. The presence of multiple cysts should raise suspicion for fibropolycystic liver disease, a group of related lesions-including biliary hamartoma and choledochal cyst-caused by abnormal embryologic development of the ductal plate. Communication of the cystic lesion with the biliary tree can confirm the diagnosis of choledochal cyst. In a neonate with jaundice, a cystic lesion at the porta hepatis should raise suspicion for choledochal cyst versus cystic biliary atresia. Hepatic abscess can appear cystlike, though typically with internal contents. In an immunocompromised child, multiple cystlike lesions should raise concern for fungal microabscesses. A complex cystic mass in a young child should raise suspicion for mesenchymal hamartoma, which can evolve into undifferentiated embryonal sarcoma if untreated. Hepatic hematoma and biloma can appear cystlike in children with a history of trauma or recent intervention. In neonates with an umbilical vein catheter (UVC), an intrahepatic cyst along the course of the UVC should raise concern for infusate extravasation. Familiarity with imaging findings and clinical features is essential for achieving accurate diagnosis of pediatric hepatic cystic lesions, which in turn can guide appropriate clinical management. Online supplemental material is available for this article. ©RSNA, 2022.

Signal intensity patterns in health and disease: basics of abdominal magnetic resonance imaging in children.

Magnetic resonance imaging (MRI) is playing an increasing role in pediatric abdominal imaging, especially in the evaluation of diffuse parenchymal disease where other imaging modalities might be less sensitive. While quantitative imaging is slowly being incorporated into clinical imaging, qualitative assessment of visceral signal intensity should be part of the routine clinical workflow of all radiologists. Based on their T1 and T2 weighting, the liver, spleen, kidneys and pancreas have characteristic signal intensity patterns with respect to one another and to skeletal muscle. It is important to recognize normal signal intensity patterns of viscera and their evolution with patient age to be able to identify age-related variations and accurately identify diffuse parenchymal disease. Knowledge of normal signal intensity patterns can also help identify ectopic locations of normal tissue such as splenic rests and splenosis. In this review, we discuss normal signal intensity patterns of upper abdominal viscera and their variations on commonly used sequences in pediatric abdominal MRI. We also review normal variations in the perinatal period. Knowledge of these patterns can help pediatric radiologists become more astute in their interpretation of diffuse parenchymal disease in the abdomen.

Esophageal discoid foreign body detection and classification using artificial intelligence.

BACKGROUND: Early and accurate radiographic diagnosis is required for the management of children with radio-opaque esophageal foreign bodies. Button batteries are some of the most dangerous esophageal foreign bodies and coins are among the most common. We hypothesized that artificial intelligence could be used to triage radiographs with esophageal button batteries and coins. OBJECTIVE: Our primary objective was to train an object detector to detect esophageal foreign bodies, whether button battery or coin. Our secondary objective was to train an image classifier to classify the detected foreign body as either a button battery or a coin. MATERIALS AND METHODS: We trained an object detector to detect button batteries and coins. The training data set for the object detector was 57 radiographs, consisting of 3 groups of 19 images each with either an esophageal button battery, esophageal coin or no foreign body. The foreign bodies were endoscopically confirmed, and the groups were age and gender matched. We then trained an image classifier to classify the detected foreign body as either a button battery or a coin. The training data set for the image classifier consisted of 19 radiographs of button batteries and 19 of coins, cropped from the object detector training data set. The object detector and image classifier were then tested on 103 radiographs with an esophageal foreign body, and 103 radiographs without a foreign body. RESULTS: The object detector was 100% sensitive and specific for detecting an esophageal foreign body. The image classifier accurately classified all 6/6 (100%) button batteries in the testing data set and 93/95 (97.9%) of the coins. The remaining two coins were incorrectly classified as button batteries. In addition to these images with a single button battery or coin, there were two unique cases in the testing data set: a stacked button battery and coin, and two stacked coins, both of which were classified as coins. CONCLUSION: Artificial intelligence models show promise in detecting and classifying esophageal discoid foreign bodies and could potentially be used to triage radiographs for radiologist interpretation.

Working from home during the COVID-19 pandemic: surveys of the Society for Pediatric Radiology and the Society of Chiefs of Radiology at Children's Hospitals.

BACKGROUND: Due to the COVID-19 pandemic, some pediatric radiologists have shifted to working from home; the long-term ramifications for pediatric radiologists and departments have not yet been defined. OBJECTIVE: To characterize experiences of working from home associated with the COVID-19 pandemic and guide expectations after the pandemic is controlled, via separate surveys of Society for Pediatric Radiology (SPR) and Society of Chiefs of Radiology at Children's Hospitals (SCORCH) members. MATERIALS AND METHODS: Two separate surveys were conducted. In the first, SPR members were surveyed Jan. 11 through Feb. 8, 2021. The response rate was 17.0% (255 of 1,501). Survey questions included demographics, information on the ability to work from home and subjective experiences ranked on a scale of 0 to 10. The survey enabled segregation and comparison of responses between those with and without home PACS. In the second survey, SCORCH members were surveyed Dec. 8, 2020, through Jan. 8, 2021. The response rate was 51.5% (51/99). Survey questions included the logistics of working from home, technical specifications and the expectations on clinical duties performed from home. The Wilcoxon rank test was used to determine statistical significance of compared variables between respondents with and without home PACS in SPR members, and expectations between SPR and SCORCH members. Descriptive statistics summarized demographic questions and free text responses. RESULTS: The majority of member respondents (81.2%, 207/255) had a home PACS and most departments provided home PACS to faculty (94.1%, 48/51). Overall, radiologists who could work from home were satisfied with their ability to work from home (mean rating: 8.3/10) and were significantly more satisfied than predicted by those without home PACS (5.9/10, P<0.0001). Respondents overwhelmingly indicated they were less able to teach trainees (mean rating: 2.7/10) and had decreased emotional engagement (mean rating: 4.4/10), but had improved research productivity and cognitive ability for research when working from home (mean rating for both: 5.3/10). Regarding the expectations of the ability to work from home after no longer needing to address the pandemic, department chairs generally favored fewer rotations from home, with 97.9% (47/48) indicating working from home should be 60% or fewer assignments, compared with 84.1% (164/195) of individual radiologists (P=0.071). CONCLUSIONS: Due to the COVID-19 pandemic, there has been a shift to working from home using PACS. Results of these SPR and SCORCH member surveys can help inform future decisions regarding pediatric radiologists working from home once the pandemic has been controlled.

Diagnostic Performance of LI-RADS Version 2018 for Evaluation of Pediatric Hepatocellular Carcinoma.

Background The Liver Imaging Reporting and Data System (LI-RADS) has standardized the evaluation of adult but not pediatric hepatocellular carcinoma (HCC). Purpose To evaluate the performance of LI-RADS version 2018 for diagnosis of pediatric HCC. Materials and Methods This multi-institution retrospective study evaluated all available dynamic CT and/or MRI scans of pediatric (≤18 years) HCC from five institutions between July 2009 and April 2019. The control group included an equal number of other enhancing hepatic lesions. Blinded to final diagnosis, three radiologists independently applied LI-RADS version 2018 criteria. The reference standard was pathologic examination or more than 1 year follow-up. Sensitivity and specificity of LI-RADS were computed using a dichotomous classification of LR-1, LR-2, or LR-3 versus LR-4, LR-5, LR-TIV (tumor in vein), or LR-M (probably or definitely malignant but not HCC-specific) for predicting hepatic malignancy in the entire cohort and in patients at risk for HCC. Results The cohort consisted of 116 children: 58 with HCC (mean age, 12 years ± 5; 31 girls) and 58 with other enhancing hepatic masses (mean age, 12 years ± 5; 42 girls). Frequencies of major criteria in classic HCC for the three readers were as follows: nonrim arterial phase hyperenhancement, 49%-62% (19-24 of 39 patients); nonperipheral "washout," 36%-59% (14-23 of 39 patients); and enhancing "capsule," 28%-38% (11-15 of 39 patients). For the full cohort, the sensitivity of LR-4, LR-5, LR-TIV, or LR-M for malignancy among the three readers ranged from 85% (95% CI: 76, 94) to 88% (95% CI: 80, 96); specificity of LR-1, LR-2, or LR-3 for benignity ranged from 54% (95% CI: 40, 68) to 70% (95% CI: 57, 83). In the at-risk subgroup, sensitivity ranged from 58% (95% CI: 36, 80) to 68% (95% CI: 48, 89); specificity ranged from 56% (95% CI: 37, 74) to 63% (95% CI: 45, 81). All lesions categorized as LR-TIV (n = 10-13) were HCCs. Conclusion Liver Imaging Reporting and Data System version 2018 had moderate sensitivity but low specificity for the diagnosis of pediatric hepatocellular carcinoma (HCC), which had low frequencies of the major criteria used for adult HCC diagnosis. © RSNA, 2021 See also the editorial by Paltiel in this issue.

Chest radiograph features of multisystem inflammatory syndrome in children (MIS-C) compared to pediatric COVID-19.

BACKGROUND: Although the radiographic features of coronavirus disease 2019 (COVID-19) in children have been described, the distinguishing features of multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 are not well characterized. OBJECTIVE: We compared the chest radiographic findings of MIS-C with those of COVID-19 and described other distinguishing imaging features of MIS-C. MATERIALS AND METHODS: We performed a retrospective case series review of children ages 0 to 18 years who were hospitalized at Children's Healthcare of Atlanta from March to May 2020 and who either met the Centers for Disease Control and Prevention (CDC) case definition for MIS-C (n=11) or who had symptomatic, laboratory-confirmed COVID-19 (n=16). Two radiologists reviewed the most severe chest radiographs for each patient. The type and distribution of pulmonary opacities and presence or absence of pleural effusions were recorded. The chest radiographs were categorized based on potential COVID-19 imaging findings as typical, indeterminate, atypical or negative. An imaging severity score was also assigned using a simplified version of the Radiographic Assessment of Lung Edema Score. Findings were statistically compared between patients with MIS-C and those with COVID-19. Additional imaging findings of MIS-C were also described. RESULTS: Radiographic features of MIS-C included pleural effusions (82% [9/11]), pulmonary consolidations (73% [8/11]) and ground glass opacities (91% [10/11]). All of the lung opacities (100% [10/10]) were bilateral, and the majority of the pleural effusions (67% [6/9]) were bilateral. Compared to children with COVID-19, children with MIS-C were significantly more likely to develop pleural effusions on chest radiograph (82% [9/11] vs. 0% [0/0], P-value <0.01) and a lower zone predominance of pulmonary opacifications (100% [10/10] vs. 38% [5/13], P-value <0.01). Children with MIS-C who also had abdominal imaging had intra-abdominal inflammatory changes. CONCLUSION: Key chest radiographic features of MIS-C versus those of COVID-19 were pleural effusions and lower zone pulmonary opacifications as well as intra-abdominal inflammation. Elucidating the distinguishing radiographic features of MIS-C may help refine the case definition and expedite diagnosis and treatment.

Serial MRI Findings After Endoscopic Removal of Button Battery From the Esophagus.

OBJECTIVE. The purpose of this study was to evaluate findings at serial MRI after endoscopic removal of a button battery from the esophagus in a series of pediatric patients. MATERIALS AND METHODS. Serial MRI examinations after removal of a button battery from the esophagus were reviewed retrospectively for the presence of mediastinal edema; imaging characteristics of the aorta and arteries; imaging characteristics of the trachea; and imaging characteristics of the esophageal wall at the level of injury. RESULTS. A total of 48 MRI examinations were performed on 19 patients, 89% (17/19) in the first 48 hours after battery removal. Serial MRI was performed for 84% (16/19) of patients. Initial MRI showed extensive mediastinal edema in all 17 patients who underwent MRI in the first 48 hours. Edema directly abutted major arteries in all 17 patients and abutted the airway in all 10 patients with proximal esophageal injury. Arterial vascular changes were seen in 30% (3/10) of patients with proximal esophageal injury and 57% (4/7) of patients with mid or distalesophageal injury. Airway changes were seen in 80% (8/10) of patients with proximal esophageal injury. Serial MRI showed improvement of airway changes in all patients and improvement in vessel wall changes in all but one (25%, 1/4) of the patients who had mid or distal esophageal injury. Four patients (21% [4/19]) had contained esophageal leak on esophagrams. No patients in our series developed a tracheoesophageal or vascular-enteric fistula. CONCLUSION. Our case series provides important information on natural history of MRI findings in children after endoscopic removal of a button battery from the esophagus. Further studies are needed to determine the imaging findings most sensitive and specific for severe complications, such as tracheoesophageal fistula and vascular-enteric fistula.

Gemcitabine/nab-paclitaxel for pediatric relapsed/refractory sarcomas.

BACKGROUND: Pediatric patients with relapsed/refractory sarcomas have poor outcomes and need novel therapies that provide disease control while maintaining an acceptable quality of life. The activity and toxicity of gemcitabine and nab-paclitaxel in combination has not been reported in pediatrics. PROCEDURE: We reviewed the records of fifteen relapsed/refractory patients and one treatment-naïve patient who received gemcitabine/nab-paclitaxel at our institution. RESULTS: Sixteen patients (median age 13.5 years, range 3-19 years) received 53 cycles of gemcitabine/nab-paclitaxel. Twenty-nine cycles (55%) resulted in ≥Grade 3 toxicity, with nonhematologic Grade ≥3 toxicities occurring in only eight of 53 cycles (15%). Patients received red blood cell and platelet transfusions in 23% and 4% of cycles, respectively. Grade ≥3 infectious toxicities occurred in 4% of cycles. Of 14 patients with measurable disease, there were no complete responses (CR), one partial response (PR; 7%), and six patients (43%) with stable disease (SD; median SD: 4.5 months, range: 2-19 months). In total, 31% of the patients derived clinical benefit (CR + PR + SD ≥ 4 months). Median time to progression was 72 days with a 4-month progression-free survival of 31% ± 12% and 1-year overall survival of 19% ± 10%. With a median follow-up for all 16 patients of 21 months from the first treatment with gemcitabine/nab-paclitaxel, one (6%) remains alive with disease. CONCLUSIONS: Gemcitabine/nab-paclitaxel is a relatively safe regimen with mainly hematologic toxicities. It offers a well-tolerated, palliative option providing clinical benefit in a subset of patients. A phase I trial of this combination is underway.

Updates in Diagnosis, Management, and Treatment of Neuroblastoma.

Neuroblastoma is an embryonic tumor of the peripheral sympathetic nervous system. It is the most common extracranial solid tumor of childhood and accounts for up to 15% of all pediatric cancer fatalities. The manifestation of neuroblastoma is variable depending on the location of the tumor and on the presence or absence of paraneoplastic syndromes. The prognosis of neuroblastoma is also highly variable, ranging from spontaneous regression to widespread metastatic disease that is unresponsive to treatment. The age of the patient, stage of disease, histopathologic results, and multiple biologic factors contribute to the presurgical and pretreatment risk stratification of a patient with neuroblastoma. Multimodality anatomic imaging with ultrasonography, computed tomography, and magnetic resonance imaging, as well as functional or metabolic nuclear imaging, are essential to determining the risk status of a patient with neuroblastoma. Patients at low risk of metastasis or death receive minimal intervention and those at high risk receive multimodality treatment. New immunotherapeutic techniques and nuclear medicine-targeted therapies have emerged and are demonstrating promising response rates for patients at high risk. This article reviews updates in the diagnosis, management, and treatment of neuroblastoma that have evolved over the past 2 decades, including emphasis on presurgical risk stratification, genetic evaluation of tumors, and the use of modern, high-quality, advanced imaging modalities. ©RSNA, 2018.

A survey of pediatric diagnostic radiologists in North America: current practices in fetal magnetic resonance imaging.

BACKGROUND: Fetal magnetic resonance imaging (MRI) is an imaging examination in evolution. Rapid developments over recent decades have led to better image quality, an increased number of examinations and greater impact on patient care. OBJECTIVE: To gather data regarding current practices among established programs in North America and provide information to radiologists interested in implementing or growing a fetal MRI service. MATERIALS AND METHODS: An electronic survey containing 15 questions relevant to the use of fetal MRI was submitted to pediatric radiologists and neuroradiologists. Items regarded scheduling and reporting logistics, magnet strength, patient positioning and patient preparation. Answers and comments were collected, and descriptive statistics were summarized. RESULTS: One hundred and six survey responses were evaluated. Of the survey responses, 62/106 (58.5%) allow fetal MR scheduling any time during the day and 72/105 (68.6%) exclusively use 1.5-T strength platforms for fetal MRI, while only 7/105 (6.7%) use exclusively 3 T. Patient positioning is variable: supine, 40/106 (37.8%); left lateral decubitus, 22/106 (20.8%), and, patient's choice, 43/106 (40.6%). Of the centers responding, 51/104 (49.0%) require no particular fasting instructions, while 20/104 (19.2%) request the patient avoid caffeine before the scanning. CONCLUSION: Logistical trends in performing fetal MRI may supplement the American College of Radiology's published technical standards and offer guidance to radiologists new to the field.