Faculty Bibliography

OBJECTIVES/OBJECTIVE:We aimed to assess inter-radiologist agreement when interpreting pelvic MRI in children with newly diagnosed perianal Crohn's disease (CD). MATERIALS AND METHODS/METHODS:In this retrospective multi-reader study, we identified pediatric patients (< 18 years of age) who underwent a pelvic MRI examination for newly diagnosed perianal CD. Images were de-identified and uploaded to a cloud-based image platform for review by 13 fellowship-trained pediatric radiologists The reviewers assessed for the presence of a fistula and abscess, categorization of different imaging findings, and classification using the Parks and St James' University Hospital systems. Fleiss' kappa (κ) statistics and intra-class correlation coefficients (ICC) were used to measure inter-reader agreement, along with 95% confidence intervals (CI). RESULTS:Forty-six patients were included in our study (median age = 13.0 years [IQR: 10.5 to 16.0 years]); thirty-five (76.1%) were boys. Most imaging features showed fair agreement (κ = 0.21 to 0.35). There was moderate agreement for categorical fistula length (κ = 0.42 [95% CI: 0.32 to 0.53]), involvement of the genitalia (κ = 0.45 [95% CI: 0.26 to 0.63]), and presence of an abscess/collection (κ = 0.52 [95% CI: 0.31 to 0.73]). Maximum abscess/collection length had good agreement (ICC = 0.81 [95% CI: 0.41, 1.00]). There was an almost equal split (yes vs. no: 50.7% vs. 49.3%) regarding whether postcontrast T1-weighted images added value compared to T2-weighted images alone across all radiologists and examinations. CONCLUSION/CONCLUSIONS:Inter-radiologist agreement when interpreting pelvic MRI for perianal CD in children is fair for most imaging features, with fewer features demonstrating moderate or good agreement. KEY POINTS/CONCLUSIONS:Question Pelvic magnetic resonance imaging (MRI) is used for diagnosing and monitoring children with perianal Crohn's disease (CD). Limited information is known about inter-radiologist agreement. Findings Agreement between pediatric radiologists when interpreting MRI for perianal CD in children is only fair for most imaging features (κ = 0.21 to 0.35). Clinical relevance Understanding MRI inter-radiologist agreement is crucial to improve the reliability of pelvic MRI in children with perianal Crohn's disease since it may affect patient management (e.g., surgery); further radiologist education and improved imaging feature definitions may help improve inter-radiologist agreement.

BACKGROUND:Magnetic resonance cholangiopancreatography (MRCP) is used to diagnose and monitor primary sclerosing cholangitis (PSC). OBJECTIVE:To assess inter-reader agreement for the diagnosis of PSC/autoimmune sclerosing cholangitis (ASC) and for individual MRCP features of cholangiopathy in a pediatric sample. MATERIALS AND METHODS/METHODS:This was a retrospective, IRB-approved study that included MRCP examinations from patients <21 years old with known or suspected cholangiopathy. Multiple biliary and hepatic imaging features were assessed independently by nine pediatric radiologists using 2D and 3D MRCP images. Kappa (κ) statistics and intra-class correlation coefficients (ICC) with 95% confidence intervals (CI) were used to measure inter-reader agreement. RESULTS:Seventy-five patients were included (median age=16.8 [IQR 13.8-18.7] years; 48 boys); 22.7% (17/75) had PSC, 22.7% (17/75) had ASC, and 54.7% (41/75) had other diagnoses. Among observers, agreement was only slight for presence of cholangiopathy (κ=0.15 [95% CI 0.07 to 0.23]) and presence of PSC/ASC (κ=0.13 [0.06 to 0.21]). Agreement was poor for categorical intrahepatic stricture number (κ=-0.002 [(-0.16 to 0.15]) and stricture extent (κ=-0.06 [-0.09 to-0.02]). Agreement was slight for presence of intrahepatic stricturing disease (κ=0.08 [0.04 to 0.12]). Most other findings had fair agreement between readers (including intrahepatic focal dilations, intrahepatic and extrahepatic diverticula, diffuse extrahepatic dilation without stricture, bile duct mural thickening, and biliary obstruction [κ=0.22 to 0.34]). There was moderate agreement for categorical extrahepatic stricture length (κ=0.46 [-0.11 to 1]) and presence of extrahepatic biliary dilation (κ=0.53 [0.40 to 0.65]). There was excellent agreement for extrahepatic bile duct maximum diameter (ICC=0.89 [0.85 to 0.92]). CONCLUSION/CONCLUSIONS:Inter-reader agreement for interpreting MRCP in children and young adults is slight to fair for the diagnosis of PSC/ASC and for most findings of cholangiopathy.

BACKGROUND:Ultrasound (US) is increasingly used as the first-line imaging modality for the diagnosis of midgut volvulus, but may be non-diagnostic in some cases. OBJECTIVE:To determine the frequency and factors associated with non-diagnostic US for each midgut volvulus and malrotation in a multi-institutional sample. MATERIALS AND METHODS/METHODS:We conducted a retrospective multi-institutional study of children (age 0-18 years) who underwent US to evaluate for midgut volvulus and malrotation between January 1, 2018, and June 30, 2021, and had an available reference standard of one of the following: upper GI series, CT/MRI, surgery, or, for volvulus, clinical follow-up at 30 days or greater. Blinded review of US images was performed by a single radiologist at each institution. When available, radiographs acquired ≤3 h from the US were reviewed for bowel gas pattern. After blinded review, original ultrasound reports were classified as diagnostic or non-diagnostic for midgut volvulus and malrotation. Stepwise logistic regression identified the most important predictors of non-diagnostic US. RESULTS:In total, 637 patients were imaged for midgut volvulus and 311 for malrotation. Based on original report review, non-diagnostic proportions of examinations for volvulus and malrotation were 13.5% (86/637) and 25.7% (80/311), respectively. Based on blinded review, non-diagnostic proportions of examinations for volvulus and malrotation were 17.3% (110/637) and 37.6% (117/311), respectively. Of the patients with US considered non-diagnostic for volvulus by original reports, 2.3% (2/86) were subsequently found to have volvulus. Among patients with non-diagnostic US for volvulus by blinded review (n=110), none was found to have volvulus. Gaseous dilation with elongation of bowel on radiography was the single best predictor of a non-diagnostic US in blinded interpretation for volvulus and malrotation (OR=8.2 and 9.2; 95%CI 3.7-19.8 and 1.7-89.4, respectively) and in original radiology reports for volvulus (OR=4.5; 95%CI 2.2-9.5). CONCLUSION/CONCLUSIONS:A small fraction of a multi-institutional sample of US for midgut volvulus was non-diagnostic; however, assessment of malrotation without volvulus is associated with a higher frequency of non-diagnostic examinations. Dilated bowel gas pattern on radiography is the strongest predictor for a non-diagnostic US, although it does not necessarily preclude a diagnostic exam.

Endometriosis, a chronic condition that often starts in adolescence, can have a significant impact on quality of life due to symptoms of dysmenorrhea and pelvic pain. Although laparoscopy with direct visualization and pathologic correlation is the reference standard for the diagnosis of endometriosis, some authors have called for a greater emphasis on clinical diagnosis - including imaging. Magnetic resonance imaging (MRI) provides highly reproducible, large field of view, multiplanar, and multiparametric imaging of pelvic endometriosis and is well tolerated in adolescent patients. As such, pediatric radiologists need to be familiar with the manifestations of endometriosis on MRI and how these findings may differ from those seen in adult populations.

BACKGROUND:Photon counting detector (PCD) CT benefits from reduced noise compared with conventional energy-integrating detector (EID) CT, which should translate to improved image quality and reduced radiation exposure for pediatric patients undergoing chest CT with IV contrast. OBJECTIVE:To determine the differences in radiation exposure and image quality of PCD CT and EID CT in pediatric chest CT with intravenous (IV) contrast. MATERIALS AND METHODS/METHODS:In this institutional review board-approved retrospective observational study, 20 scan pairs (20 PCD CT; 20 EID CT) for children who underwent chest CT with IV contrast on both a PCD CT (Siemens NAEOTOM Alpha) and an EID CT (Siemens SOMATOM Definition Edge or Force) within 12 months were reviewed independently by three pediatric radiologists for three subjective quality features on 5-point Likert scales: overall quality, small structure delineation, and motion artifact. Objective measures of image quality (image noise, signal-to-noise ratio, and contrast-to-noise ratio) were assessed by a single radiologist in several locations in the chest through region of interest measurement of Hounsfield units (HU) and standard deviation. Patient-related and radiation exposure parameters were collected for each scan and summarized with median and interquartile range (IQR). The Wilcoxon rank-sum test was utilized to compare groups. A P < 0.05 indicated statistical significance. Inter-observer agreement of subjective image quality metrics was analyzed using weighted kappa. RESULTS:Age (14.2 years vs 13.8 years, P= 0.15), height (P= 0.13), weight (P= 0.21), and BMI (P = 0.24) did not significantly differ between groups. There were 10 male and 3 female patients. Compared to EID CT, PCD CT showed lower radiation exposure parameters including volumetric CT dose index, 1.7 mGy (IQR 1.1-2.4 mGy) vs 3.8 mGy (IQR 2.0-4.7 mGy) (P< 0.01), and size-specific dose estimate, 2.6 mGy (IQR 1.8-3.1 mGy) vs 5.0 mGy (IQR 3.3-6.2 mGy) (P< 0.01). Objective image quality of lung parenchyma was improved on the PCD CT scanner, including image noise 119.5 HU (IQR 95.4-135.7 HU) vs 143.1 HU (IQR 125.4-169.8 HU) (P < 0.01), signal-to-noise ratio (SNR) -6.1 (IQR -8.4 to -4.8) vs -4.9 (IQR -5.6 to -3.8) (P= 0.01), and contrast-to-noise ratio -63.9 (-84.1 to -57.5) vs -60.5 (-76.3 to -52.5) (P = 0.01). Motion artifact was improved on the PCD CT scanner (P< 0.01). No significant differences in overall image quality or small structure delineation were identified (P= 0.06 and P= 0.31). CONCLUSION/CONCLUSIONS:PCD CT pediatric chest CT had significantly reduced radiation exposure, improved image quality, and reduced motion artifact compared with EID CT.

BACKGROUND:Few reports explore the frequency and factors associated with diagnostic ultrasound (US) for midgut volvulus. OBJECTIVE:To evaluate predictive factors for diagnostic US for midgut volvulus and clinical outcomes of patients with non-diagnostic US. MATERIALS AND METHODS/METHODS:This retrospective study included infants imaged for midgut volvulus with US. Exams were rated as diagnostic (midgut volvulus present or absent) or non-diagnostic by a pediatric radiologist, and in cases of disagreement with the original report, an additional pediatric radiologist was the tie-breaker. For each exam, the following were recorded: age, weight, respiratory support, exam indication, sonographer experience, and gaseous dilated bowel loops on radiography. Logistic regression models with "stepwise" variable selection were used to investigate the association of diagnostic US for midgut volvulus with each of the independent variables. RESULTS:One hundred nineteen patients were imaged. US was diagnostic in 74% (88/119) of patients. In subsets of patients presenting with bilious emesis or age <28 days, US was diagnostic in 92% (22/24) and 90% (53/59), respectively. Logistic regression suggested that symptom type (bilious vs other) was the best predictor of diagnostic US (type 3 P=0.02). Out of 26 patients with available radiographs, US was diagnostic in 92% (12/13) of patients without bowel dilation on radiographs compared to 62% (8/13) of patients with bowel dilation (P=0.16). Weight, respiratory support, and sonographer experience did not differ between groups. Two sick neonates, ages 2 days and 30 days, in whom the primary clinical concern was dropping hematocrit and sepsis, respectively, had non-diagnostic ultrasounds in the setting of bowel dilation on radiography. Both were found to have midgut volvulus at surgery and both expired. CONCLUSION/CONCLUSIONS:US was most frequently diagnostic in patients with bilious emesis or age less than 28 days. Non-diagnostic US for midgut volvulus must prompt a predetermined follow-up strategy, such as an additional imaging study (e.g., upper GI series), particularly in a sick child, as non-diagnostic US may miss midgut volvulus.

Choledochal cysts are rare cystic dilations of the biliary tree that typically involve the extrahepatic bile duct and more infrequently, the intrahepatic bile ducts. Todani's classification of choledochal cysts is the most referenced system in which five types of choledochal cysts are described. Several new variants have been reported including dilations of the cystic duct and a double common bile duct. We describe a never reported variant involving dilation of the common bile duct, dilation of the cystic duct and an accessory right hepatic duct.

Ovarian tumors in children are uncommon. Like those arising in the adult population, they may be broadly divided into germ cell, sex cord, and surface epithelium subtypes; however, germ cell tumors comprise the majority of lesions in children, whereas tumors of surface epithelial origin predominate in adults. Diagnostic workup, including the use of imaging, requires an approach that often differs from that required in an adult. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary ovarian malignancy at diagnosis and during follow-up.