How Reliable Is the Measurement of the Lateral Center Edge Angle on Scoliosis Radiographs for Detecting Acetabular Dysplasia?

PURPOSE: Hip dysplasia reportedly occurs in up to 12% of the general population and may be higher in patients with adolescent idiopathic scoliosis (AIS). When using lateral center edge angle (LCEA) measurements to help identify hip dysplasia, it is uncertain if this measurement can be performed reliably on scoliosis radiographs due to parallax. The purpose of this study is to evaluate the reliability of measuring LCEA on scoliosis radiographs compared with standard pelvis radiographs. METHODS: This study evaluated 40 hips on 20 patients (mean age 12.5 years ± 3.1; 50% Female) who received PA scoliosis radiographs and AP pelvis radiographs within 1 year of each other. Review was performed by 4 pediatric radiologists (2 general, 2 MSK), 2 pediatric orthopaedic surgeons, and 1 research fellow. Radiographic measurement of the LCEA for each hip was first performed on the scoliosis radiograph. After a minimum of 3 days, the LCEA was measured on a pelvis radiograph of the same individual obtained within 1 year of the scoliosis radiograph. Pearson coefficient was used to measure agreement between scoliosis and pelvis radiograph measurements. Intraclass correlation coefficient (ICC) was used to evaluate intraobserver and interobserver agreement. ICC values <0.5 were classified as poor reliability, 0.5 to 0.75 were classified moderate, 0.75 to 0.90 were classified good, and >0.9 indicated excellent reliability. RESULTS: The mean difference between scoliosis and pelvis radiographs was 54 ± 79 days. There was good-to-excellent interobserver agreement on LCEA measurements made between readers on scoliosis radiographs (ICC: 0.94, 95% CI: 0.90-0.96, P <0.001) and pelvis radiographs (ICC: 0.91, 95% CI: 0.83-0.95, P <0.001), and moderate-to-excellent intraobserver agreement for scoliosis radiographs (ICC range: 0.68 to 0.98; P <0.001) and pelvis radiographs (ICC range: 0.62 to 0.96; P <0.001). There was a strong correlation between LCEA measurements made on scoliosis and pelvis radiographs ( r2 =0.66, P <0.001), and the intermodality agreement between scoliosis and pelvis radiograph LCEA measurements were moderate to good (ICC range: 0.68 to 0.89, P <0.001). CONCLUSIONS: Overall, there was good-to-excellent agreement between readers on scoliosis and pelvis radiographs, respectively, and moderate-to-excellent intraobserver agreement between LCEA measurements made on scoliosis radiographs and pelvis radiographs, respectively. LCEA measurements made on scoliosis radiographs strongly correlated to the measurements made on pelvis radiographs, and the intermodality ICC was also considered moderate to good. Dedicated pelvis radiographs may not be necessary during scoliosis workup and follow-up surveillance, thereby decreasing radiation exposure, cost, and improving patient care workflow. LEVEL OF EVIDENCE: Level IV-diagnostic study.

Diagnostic performance of artificial intelligence for pediatric pulmonary nodule detection on chest computed tomography: comparison of simulated lower radiation doses.

The combination of low dose CT and AI performance in the pediatric population has not been explored. Understanding this relationship is relevant for pediatric patients given the potential radiation risks. Here, the objective was to determine the diagnostic performance of commercially available Computer Aided Detection (CAD) for pulmonary nodules in pediatric patients at simulated lower radiation doses. Retrospective chart review of 30 sequential patients between 12-18 years old who underwent a chest CT on the Siemens SOMATOM Force from December 20, 2021, to April 12, 2022. Simulated lower doses at 75%, 50%, and 25% were reconstructed in lung kernel at 3 mm slice thickness using ReconCT and imported to Syngo CT Lung CAD software for analysis. Two pediatric radiologists reviewed the full dose CTs to determine the reference read. Two other pediatric radiologists compared the Lung CAD results at 100% dose and each simulated lower dose level to the reference on a nodule by nodule basis. The sensitivity (Sn), positive predictive value (PPV), and McNemar test were used for comparison of Lung CAD performance based on dose. As reference standard, 109 nodules were identified by the two radiologists. At 100%, and simulated 75%, 50%, and 25% doses, lung CAD detected 60, 62, 58, and 62 nodules, respectively; 28, 28, 29, and 26 were true positive (Sn = 26%, 26%, 27%, 24%), 30, 32, 27, and 34 were false positive (PPV = 48%, 47%, 52%, 43%). No statistically significance difference of Lung CAD performance at different doses was found, with p-values of 1.0, 1.0, and 0.7 at simulated 75%, 50%, and 25% doses compared to standard dose. CONCLUSION: The Lung CAD shows low sensitivity at all simulated lower doses for the detection of pulmonary nodules in this pediatric population. However, radiation dose may be reduced from standard without further compromise to the Lung CAD performance. WHAT IS KNOWN: • High diagnostic performance of Lung CAD for detection of pulmonary nodules in adults. • Several imaging techniques are applied to reduce pediatric radiation dose. WHAT IS NEW: • Low sensitivity at all simulated lower doses for the detection of pulmonary nodules in our pediatric population. • Radiation dose may be reduced from standard without further compromise to the Lung CAD performance.

How Often Do Patients Presenting With Severe Adolescent Idiopathic Scoliosis Have Underlying Hip Dysplasia?

INTRODUCTION: Adolescent idiopathic scoliosis radiographic screening will often include the hips. The purpose of this study is to evaluate the prevalence of hip dysplasia by lateral center edge angle (LCEA) on scoliosis radiographs in patients presenting with severe range (>45 deg) idiopathic curves. METHODS: We reviewed 200 consecutive patients (400 hips) with idiopathic scoliosis with major coronal curves ≥45 degrees between October 2009 and October 2022. The presenting scoliosis radiograph PA were reviewed for the following variables: major coronal curve direction, coronal balance, and lateral center edge angles. An LCEA value ≤18 was considered dysplastic. To assess potential measurement variability related to parallax of the scoliosis radiographs, the intermodality intraclass correlation coefficient (ICC) was measured from a subset of 20 hip LCEA values from patients with both scoliosis and pelvis radiographs. RESULTS: A total of 200 patients [mean age: 13.6 (1.8) years; Female: 79%] were reviewed. The mean major curve (SD) was 58.6 degrees (11.4 deg). Overall 19% (37/200) patients or 11% (43/400) of hips had hip dysplasia. Of the dysplastic hips, 16% (6/43, P <0.001) were bilateral and 57% (21/43, P =0.04) were right sided. There was no association between dysplastic hip laterality and ipsilateral or contralateral coronal balance ( P =0.26) or curve direction ( P =0.49). The interobserver ICC for assessment of LCEA on scoliosis radiographs was 0.85, and the intermodality ICC between pelvic and scoliosis radiographs was 0.78. CONCLUSION: Hip dysplasia was present in 19% of patients presenting with large major curves, and many of these patients had right sided hip dysplasia. There was no association between hip dysplasia laterality and the patient's major curve direction or coronal balance. There was good intermodality reliability (ICC=0.78) between LCEA values in patients who had both scoliosis and pelvis radiographs, and good inter-rater reliability between raters. Radiographic interpretation of adolescent idiopathic scoliosis should focus not only on the description of the curve and ruling out underlying segmentation anomalies but should also include critical assessment of the hips to exclude co-existing hip dysplasia. LEVEL OF EVIDENCE: Therapeutic study-level IV.

Circulating tumor DNA sequencing of pediatric solid and brain tumor patients: An institutional feasibility study.

The potential of circulating tumor DNA (ctDNA) analysis to serve as a real-time "liquid biopsy" for children with central nervous system (CNS) and non-CNS solid tumors remains to be fully elucidated. We conducted a study to investigate the feasibility and potential clinical utility of ctDNA sequencing in pediatric patients enrolled on an institutional clinical genomics trial. A total of 240 patients had tumor DNA profiling performed during the study period. Plasma samples were collected at study enrollment from 217 patients and then longitudinally from a subset of patients. Successful cell-free DNA extraction and quantification occurred in 216 of 217 (99.5%) of these initial samples. Twenty-four patients were identified whose tumors harbored 30 unique variants that were potentially detectable on a commercially-available ctDNA panel. Twenty of these 30 mutations (67%) were successfully detected by next-generation sequencing in the ctDNA from at least one plasma sample. The rate of ctDNA mutation detection was higher in patients with non-CNS solid tumors (7/9, 78%) compared to those with CNS tumors (9/15, 60%). A higher ctDNA mutation detection rate was also observed in patients with metastatic disease (9/10, 90%) compared to non-metastatic disease (7/14, 50%), although tumor-specific variants were detected in a few patients in the absence of radiographic evidence of disease. This study illustrates the feasibility of incorporating longitudinal ctDNA analysis into the management of relapsed or refractory patients with childhood CNS or non-CNS solid tumors.

Ensuring Adequate Development and Appropriate Use of Artificial Intelligence in Pediatric Medical Imaging.

Of over 100 FDA-cleared artificial intelligence (AI) tools for triage, detection, or diagnosis in medical imaging, only one is cleared for use in children. Thus, children may be unable to benefit from the advances that AI provides to adults. Furthermore, dataset demographics are frequently absent from the publicly available FDA documents, and it is not apparent that the software is unsuitable for use in pediatric patients. Herein, recommendations for change are proposed.

Gastrointestinal Symptoms Profile in Pediatric Patients With Gastroparesis Compared to Healthy Controls.

OBJECTIVES: The primary objective was to compare the patient-reported gastrointestinal symptoms profiles of pediatric patients with gastroparesis to matched healthy controls using the Pediatric Quality of Life Inventory™ (PedsQL™) Gastrointestinal Symptoms Scales. The secondary objectives were to compare pediatric patients with gastroparesis to pediatric patients with gastroparesis-like symptoms and normal gastric emptying and to compare pediatric patients with gastroparesis-like symptoms and normal gastric emptying to matched healthy controls. METHODS: The PedsQL™ Gastrointestinal Symptoms Scales were completed by 64 pediatric patients with gastroparesis, 59 pediatric patients with gastroparesis-like symptoms and normal gastric emptying, and 200 age, gender, and race/ethnicity matched healthy controls. The PedsQL™ Gastrointestinal Symptoms Scales encompass 10 individual multi-item scales which measure stomach pain, stomach discomfort when eating, food and drink limits, trouble swallowing, heartburn and reflux, nausea and vomiting, gas and bloating, constipation, blood in poop, and diarrhea/fecal incontinence. Based on gastric emptying scintigraphy testing, those with abnormal gastric retention were classified as having gastroparesis. RESULTS: The gastrointestinal symptoms profile analysis identified large differences between those with gastroparesis compared to healthy controls (most P <0.001), with the largest effect sizes for upper gastrointestinal symptoms including stomach pain, stomach discomfort when eating, food and drink limits, nausea, and vomiting. Those with gastroparesis self-reported similar gastrointestinal symptoms to those with normal gastric emptying, except for increased constipation. CONCLUSIONS: Pediatric patients with gastroparesis self-reported broad multidimensional gastrointestinal symptoms profiles in comparison to healthy controls with large differences, indicating the critical need for more highly efficacious interventions to bring patient functioning within the normal range of healthy functioning.

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.

Acute appendicitis and SARS-CoV-2 in children: imaging findings at a tertiary children's hospital during the COVID-19 pandemic.

BACKGROUND: Evidence suggests severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may be associated with appendicitis or clinical symptoms that mimic appendicitis, but it is not clear if the findings or utility of imaging in pediatric patients with suspected appendicitis have changed since the onset of the coronavirus disease 2019 (COVID-19) pandemic. OBJECTIVE: To evaluate for potential differences in SARS-CoV-2 positive and SARS-CoV-2 negative pediatric patients imaged for suspected appendicitis to determine the reliability of the existing medical imaging approach for appendicitis in a population that contains both SARS-CoV-2 positive and SARS-CoV-2 negative pediatric patients. MATERIALS AND METHODS: Patients imaged for suspected appendicitis Apr. 1, 2020, to Dec. 31, 2020, were identified via an electronic medical records search. Differences in ultrasound (US) diagnostic performance, use of computed tomography (CT) following US, rates of appendicitis, imaging findings of appendicitis and perforation were compared between SARS-CoV-2 positive and SARS-CoV-2 negative tested patients, using pathology and surgery as reference standards for appendicitis and perforation, respectively. Fisher exact test and Student's t-test were used for statistical analysis. RESULTS: One thousand, six hundred and ninety-three patients < 18 years old met inclusion criteria, with 46% (772/1,693) female, 11 imaged with only CT and 1,682 with US. Comparing SARS-CoV-2 positive and SARS-CoV-2 negative patients, no statistically significant differences in sensitivity or specificity of US (P = 1 and P = 1, respectively), or in the US (P-values ranging from 0.1 to 1.0) or CT imaging findings (P-values ranging from 0.2 to 1.0) in appendicitis were found. Perforation rates were similar between SARS-CoV-2 positive (20/57, 35.1% perforated) and SARS-CoV-2 negative (359/785, 45.7% perforated) patients with appendicitis (P = 0.13). Use of CT following first-line US was similar, with 7/125 (5.6%) of SARS-CoV-2 positive imaged with CT after US and 127/1,557 (8.2%) of SARS-CoV-2 negative imaged with CT after US (P = 0.39). CONCLUSION: In pediatric patients with suspected appendicitis, no significant difference was found in the diagnostic performance of US, CT usage or perforation rates between SARS-CoV-2 positive and SARS-CoV-2 negative patients.

Ileocolic intussusception in pediatric SARS-CoV-2 patients: experience at a tertiary pediatric center.

PURPOSE: COVID-19 disease can manifest with intussusception in pediatric patients, but prevalence of abnormalities on ultrasounds performed for intussusception is uncertain. We aim to report our experience in children with COVID-19 presenting with suspected intussusception imaged with ultrasound. METHODS: Children under 18 years who had an ultrasound for possible intussusception underwent retrospective analysis and were tested for COVID-19 between April 1 and December 14, 2020. Patients' demographic, clinical, radiological and surgical characteristics were reviewed. RESULTS: Twenty-four COVID-19-positive patients were identified; 19 boys with mean age 3 years (range: 3 months-18 years). Ultrasound was abnormal in 11 patients (11/24, 46%). Sonographic features of enterocolitis were documented in seven children (7/24, 29%). Three boys (3/24, 13%) were found to have ileocolic intussusception on ultrasound and underwent air enema with failed reduction (3/3, 100%), precipitating surgical reductions, all with favorable outcomes. One patient (1/24, 4%) was found to have a long segment of persistent small bowel-small bowel intussusception which was surgically repaired. CONCLUSION: Given the known association between failed reduction at air enema and delayed presentation, heightened awareness for intussusception in the setting of COVID-19 should be maintained, though more often, the etiology was attributed to other GI manifestations of COVID-19.

Meal-Induced Symptoms in Children with Dyspepsia-Relationships to Sex and the Presence of Gastroparesis.

OBJECTIVES: To test the hypothesis that in children with dyspepsia, prospective symptom severity following ingestion of a meal would correlate with percent gastric retention, and those ultimately diagnosed with gastroparesis would report worse symptoms. STUDY DESIGN: Prospective, single-center study with 104 children with dyspepsia completing a prospective dyspepsia symptom questionnaire before and after eating a standardized Tougas meal during gastric emptying scintigraphy. Main outcomes included correlation between gastric retention and symptoms and comparison of symptom severity between those with and without gastroparesis. RESULTS: Fifty-two children (50%) had gastroparesis (gastroparesis: 12.5 ± 2.9 years, 65% female; nongastroparesis: 13.0 ± 2.9 years, 60% female; all P > .05). Bloating was the only symptom significantly worse in youth with gastroparesis. For the entire cohort, bloating and fullness correlated with percent retention. However, in those with gastroparesis, only nausea correlated with retention (4 hours.; rs = 0.275, P < .05). Girls with gastroparesis had significantly worse symptoms (except satiety) when compared with boys with gastroparesis (P < .05). CONCLUSIONS: Overall in children, there is little difference in symptom severity between children with gastroparesis vs normal emptying based on current standards. However, girls with gastroparesis have worse symptoms vs boys with gastroparesis, underscoring a need for further studies into the role of sex in gastroparesis symptoms. In all children, both bloating and fullness correlated modestly with gastric retention, and nausea correlated in those with gastroparesis.

Prospective cost implications with a clinical decision support system for pediatric emergency head computed tomography.

BACKGROUND: Unnecessary imaging is a potential cost driver in the United States health care system. OBJECTIVE: Using a clinical decision support tool, we determined the percentage of low-utility non-contrast head computed tomography (CT) examinations on emergency patients and calculated the prospective cost implications of providing low-value imaging using time-driven activity-based costing at an academic quaternary pediatric hospital. MATERIALS AND METHODS: A clinical decision support tool for imaging, CareSelect (National Decision Support Co., Madison, WI), was integrated in silent mode into the electronic health record from September 2018 through August 2019. Each non-contrast head CT order received a score from the clinical decision support tool based on the American College of Radiology Appropriateness Criteria. Descriptive statistics for all levels of appropriateness scores were compiled with an emphasis on low-utility exams. A micro-costing assessment was conducted using time-driven activity-based costing on head CT without contrast examinations. RESULTS: Within the 11-month time period, 3,186 head CT examinations without contrast were ordered for emergency center patients. Among these orders, 28% (896/3,186) were classified as low-utility studies. The base case CT pathway time was 43 min and base case total cost was $193.35. The base case opportunity cost of these low-utility exams extrapolated annually amounts to $188,902 for our institution. CONCLUSION: Silent mode implementation of a clinical decision support tool resulted in 28% of head CT non-contrast exams on emergency patients being graded as low-utility studies. Prospective cost implications resulted in an annual base case cost of $188,902 to Texas Children's Hospital.

Implementation of a Software Distribution Intervention to Improve Workload Balance in an Academic Pediatric Radiology Department.

In our pediatric radiology department, radiographs (XR) are the shared responsibility of the body section and interpreted in addition to modality or site-specific assignments. Given an unequal contribution amongst radiologists to the XR workload, a software solution was developed to distribute radiographs and improve workload balance. Metrics to evaluate the intervention's effectiveness were compared before and after the intervention. Data was retrieved from the radiology analytics platform, scheduling software, and the peer learning database. Metrics were compared 12 months pre (March 2018-February 2019) and 6 months post (March 2019-August 2019) intervention on non-holiday weekdays, 7 am-5 pm. To evaluate the intervention's effectiveness, variance between radiologists' contributions to XR volume was assessed using Levene's and Fisher's tests. Changes in turnaround times (TATs) and error rates pre- and post-intervention were evaluated as secondary metrics. Following the intervention, the average number of XR interpreted on target rotations increased by 8.9% (p = 0.011) while the departmental volume of radiographs increased only 4.5%. The variance between radiologists' daily XR contribution was 21.3% (p < 0.0001) higher prior to the intervention. Days where target rotations read fewer than 5 XR decreased from 17.8 to 1.1% (p < 0.0001) after the intervention. Days in which more than 75% of all XR had a TAT less than 60 min improved from 26.8 to 39.7% (p = 0.017) after the intervention. There was no statistically significant difference in error frequency (error rate 2.49% pre and 2.72% post, p = 0.636). In conclusion, the software intervention improved XR workload contribution with decreased variability. Despite increased volumes, there was an improvement in turnaround times with no effect on error rates.

Response to the COVID-19 Pandemic: Practical Guide to Rapidly Deploying Home Workstations to Guarantee Radiology Services During Quarantine, Social Distancing, and Stay Home Orders.

OBJECTIVE. The purpose of this article is to share an experience in the rapid deployment of home workstations that illustrates a creative solution that transcended typical administrative barriers. CONCLUSION. In response to the global coronavirus disease (COVID-19) pandemic, radiology departments need to rapidly deploy home PACS workstations to facilitate physical distancing and to guarantee radiologic expertise despite possible home quarantining or stay home, work safe orders.

Current trends in pediatric nuclear medicine: a Society for Pediatric Radiology membership survey.

BACKGROUND: Pediatric nuclear medicine is evolving, and its practice patterns are uncertain. Knowledge of the current trends in pediatric nuclear medicine might be helpful to direct local decisions, including expectations for patient care, needs for capital acquisitions, and staffing recruitment strategies. OBJECTIVE: To provide data regarding the current practice of pediatric nuclear medicine via a Society for Pediatric Radiology (SPR) membership survey. MATERIALS AND METHODS: The SPR emailed our 25-question survey to all 1,847 SPR members in August 2018 and we accepted responses until April 2019. Questions focused on nuclear medicine staffing, positron emission tomography (PET) utilization, and radiotherapy availability. Respondents could indicate their affiliated hospital, which we used for data cataloguing only. Analysis of survey responses was blinded to reported institution. We analyzed response data using contingency tables. Independence testing between categorical variables based on proportions of physicians with additional nuclear medicine board certification was performed on a subset of questions regarding PET and therapy practices. RESULTS: Sixty-seven people from at least 29 hospitals responded to the survey, including all 10 of the 2018-2019 U.S. News & World Report best children's hospitals. The majority (48/67, 71.6%) of respondents indicated that pediatric nuclear medicine examinations were interpreted in the pediatric radiology department by pediatric radiologists and that most physicians interpreting the exams (43/67, 64.2%) did not have subspecialty certification in nuclear medicine or nuclear radiology. Most facilities offered PET/CT (57/67, 85.1%); few offered PET/MRI (12/67, 17.9%). Most facilities offered radiotherapies (57/67, 85.1%) but at most of these facilities (30/57, 52.6%), fewer than half the physicians who cover nuclear medicine were approved to administer therapies. In the subset analyses based on proportion of physicians with additional nuclear medicine board certification, there were statistically significant differences between the groups in availability of PET/MRI, lutetium-177 dotatate therapy programs, and percentages of physicians approved to administer therapies. CONCLUSION: Pediatric nuclear medicine is largely practiced by pediatric radiologists without subspecialty certification. Staffing, PET practices and therapies vary among practices, in part associated with the number of radiologists with nuclear medicine board certification.

Assessment of Sequential PET/MRI in Comparison With PET/CT of Pediatric Lymphoma: A Prospective Study.

OBJECTIVE: The objective of our study was to compare the diagnostic performance of sequential (18)F-FDG PET/MRI (PET/MRI) and (18)F-FDG PET/CT (PET/CT) in a pediatric cohort with lymphoma for lesion detection, lesion classification, and disease staging; quantification of FDG uptake; and radiation dose. SUBJECTS AND METHODS: For this prospective study of 25 pediatric patients with lymphoma, 40 PET/CT and PET/MRI examinations were performed after a single-injection dual-time-point imaging protocol. Lesions detected, lesion classification, Ann Arbor stage, and radiation dose were tabulated for each examination, and statistical evaluations were performed to compare the modalities. Quantification of standardized uptake values (SUVs) was performed for all lesions. All available examinations and clinical history were used as the reference standard. RESULTS: No statistically significant differences between PET/MRI and PET/CT were observed in lesion detection rates, lesion classification, or Ann Arbor staging. Fifty-four regions of focal uptake were observed on PET/MRI compared with 55 on PET/CT. Both modalities accurately classified 82% of the lesions relative to the reference standard. Disease staging based on PET/MRI was correct for 35 of the 40 studies, and disease staging based on PET/CT was correct for 35 of the 40 studies; there was substantial agreement between the modalities for disease staging (κ = 0.684; p < 0.001). PET SUVs were strongly correlated between PET/CT and PET/MRI (ρ > 0.72), although PET/MRI showed systematically lower SUV measurements. PET/MRI offered an average 45% reduction in radiation dose relative to PET/CT. CONCLUSION: In a pediatric cohort with lymphoma, sequential PET/MRI showed lesion detection, lesion classification, and Ann Arbor staging comparable to PET/CT. PET/MRI quantification of FDG uptake strongly correlated with PET/CT, but the SUVs were not interchangeable. PET/MRI significantly reduced radiation exposure and is a promising new alternative in the care of pediatric lymphoma patients.

Ultrasound imaging of bowel obstruction in neonates.

Bowel obstruction (BO) in children has a wide differential diagnosis, ranging from non-urgent conditions to surgical emergencies. Abdominal radiographs are most often used as the first imaging modality for the evaluation of obstruction. However, for some indications, ultrasound can be the primary imaging modality. Therefore, it is incumbent on radiologists to recognize the types of bowel obstruction that can be recognized with US. Key sonographic features of BO include differential dilation of bowel loops, bowel wall thickening, and free fluid. "Do Not Miss" findings that indicate need for emergent treatment include volvulus, pneumoperitoneum, and/or signs of ischemia (bowel wall thinning and/or absent perfusion). The aim of this pictorial essay is to provide guidance on the sonographic technique and findings that enable identification of BO on US. Examples of neonatal BO on US, including common and less frequently encountered etiologies, are illustrated in this pictorial essay.