Naomi Strubel

Background Photon-counting detector (PCD) CT allows for reduced intravenous iodinated contrast dosing with preserved or improved image quality across anatomical regions as compared to conventional energy-integrating detector (EID) CT in adults. However, there is limited evidence to support this in pediatric CT, particularly for pediatric chest CT. Objective To compare image quality of photon-counting detector (PCD) chest CT with energy-integrating detector (EID) CT at varying iodinated contrast doses in pediatric patients. Methods and materials This retrospective observational study included 60 contrast-enhanced chest CT studies in pediatric patients. The cohort included three groups: 20 PCD CT scans with a 1.5 mL/kg weight-based iodinated contrast dose, 20 EID CT scans with a 1.5 mL/kg dose, and 20 EID CT scans with a 2.0 mL/kg dose. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were assessed through region-of-interest measurement of Hounsfield units (HU) and standard deviation (SD). Assessed locations were the lung parenchyma, thoracic aorta, main pulmonary artery, left ventricle cavity, subcutaneous tissue, and pectoralis muscle. Blinded review by three pediatric radiologists assessed overall contrast enhancement, soft tissue delineation, and streak artifact from dense contrast using 5-point Likert scales (1 – excellent to 5 – non-diagnostic). Group comparisons were analyzed using Wilcoxon signed-rank, Chi-square, and Kruskal–Wallis tests. Results Twenty patients were included for each group (60 patients total). Compared to equivalent-contrast dose EID CT at 1.5 mL/kg, PCD CT showed higher left ventricle cavity SNR (21.6 [IQR 16.3-25.1] vs 16.2 [IQR 12.3-19.3], P = 0.05) and CNR (16.0 [IQR 11.3-19.5] vs 10.3 [8.8-13.7] P = 0.05), and lower image noise in pectoralis muscle (P = 0.04) and subcutaneous fat (P < 0.01). Furthermore, objective image quality on PCD CT demonstrated improvements in lung parenchyma noise, SNR, and CNR, as well as subcutaneous fat SNR and CNR (all P < 0.01) compared with both equivalent (1.5 mL/kg) and standard (2.0 mL/kg) contrast dosing in EID CT. No significant differences between PCD CT and EID CT were observed with other objective measures of image quality. Subjective assessments favored PCD CT for overall contrast enhancement to EID CT at equivalent (1.5 mL/kg) contrast dosing (median 1, IQR 1-1 vs median 2, IQR 1-5, P = 0.02) and soft tissue delineation compared with EID CT with higher (2.0 mL/kg) contrast dosing (median 1, IQR 1-2 vs median 2, IQR 1-2, P = 0.05). Conclusion Pediatric chest CT using photon-counting detector technology enables iodinated contrast dose reduction while preserving image quality compared with conventional EID CT at standard contrast doses. Graphical Abstract

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 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 PCD CT pediatric chest CT had significantly reduced radiation exposure, improved image quality, and reduced motion artifact compared with EID CT. Graphical Abstract

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 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 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 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. Graphical abstract

Acute pancreatitis in children is usually due to infection, trauma, or anatomical abnormalities and is rarely due to obstruction from malignancy. Sporadic Burkitt lymphoma (BL) is an aggressive non-Hodgkin B-cell lymphoma that usually involves the bowel or pelvis, with isolated cases presenting as acute pancreatitis. We report a case of BL in a 12-year-old male presenting as acute pancreatitis with obstructive jaundice and a right middle cranial fossa mass invading the sphenoid bone. The common bile duct in this case was dilated to 21mm in diameter on abdominal ultrasound and to 26mm on magnetic resonance cholangiopancreatography (MRCP), significantly greater than any value reported in the literature for BL. Given the rapidly progressing nature of BL, we emphasize the importance of recognizing heterogeneous presentations of this disease to improve patient survival. We also conclude that it is important to consider malignancy in a child with acute pancreatitis, particularly in the presence of obstructive jaundice or multisystem involvement. Other Presentations. This case report has no prior publications apart from the abstract being accepted to the 2020 SIOP (International Society of Pediatric Oncology) meeting and 2020 ASPHO conference (canceled due to the COVID-19 pandemic) and subsequently published as an abstract only in Pediatric Blood and Cancer. We have also presented the abstract as a poster presentation at our institutions (NYU Langone HospitalLong Island, previously known as NYU Winthrop) annual research day conference in 2020.

Ovarian neoplasms are rare in children. Although usually asymptomatic, they sometimes present with abdominal pain, abdominal distension or palpable mass. The distribution of neoplasms in the pediatric population is different from in adults; benign mature cystic teratoma is the most common ovarian tumor in children. Radiologists should be familiar with the variable sonographic, CT and MRI findings of ovarian neoplasms. Although the less frequently encountered ovarian malignancies cannot be reliably distinguished by imaging alone, it does play an important role in workup. This review discusses the imaging and relevant clinical manifestations of the more commonly encountered pediatric ovarian neoplasms.

Magnetic resonance imaging (MRI) assessment for appendicitis is limited by exam time and patient cooperation. The radially sampled 3-dimensional (3-D) T1-weighted, gradient recalled echo sequence (radial GRE) is a free-breathing, motion robust sequence that may be useful in evaluating appendicitis in children.

Background To preserve radiology rounds in the changing health care environment, we have introduced virtual radiology rounds, an initiative enabling clinicians to remotely review imaging studies with the radiologist. Objective We describe our initial experience with virtual radiology rounds and referring provider impressions. Materials and methods Virtual radiology rounds, a web-based conference, use remote sharing of radiology workstations. Participants discuss imaging studies by speakerphone. Virtual radiology rounds were piloted with the Neonatal Intensive Care Unit (NICU) and the Congenital Cardiovascular Care Unit (CCVCU). Providers completed a survey assessing the perceived impact and overall value of virtual radiology rounds on patient care using a 10-point scale. Pediatric radiologists participating in virtual radiology rounds completed a survey assessing technical, educational and clinical aspects of this methodology. Results Sixteen providers responded to the survey; 9 NICU and 7 CCVCU staff (physicians, nurse practitioners and fellows). Virtual radiology rounds occurred 4–5 sessions/week with an average of 6.4 studies. Clinicians rated confidence in their own image interpretation with a 7.4 average rating for NICU and 7.5 average rating for CCVCU. Clinicians unanimously rated virtual radiology rounds as adding value. NICU staff preferred virtual radiology rounds to traditional rounds and CCVCU staff supported their new participation in virtual radiology rounds. Four of the five pediatric radiologists participating in virtual radiology rounds responded to the survey reporting virtual radiology rounds to be easy to facilitate (average rating: 9.3), to moderately impact interpretation of imaging studies (average rating: 6), and to provide substantial educational value for radiologists (average rating: 8.3). All pediatric radiologists felt strongly that virtual radiology rounds enable increased integration of the radiologist into the clinical care team (average rating: 8.8). Conclusion Virtual radiology rounds are a viable alternative to radiology rounds enabling improved patient care and education of providers.

Rapid and accurate diagnosis of appendicitis, particularly with respect to the presence or absence of perforation, is essential in guiding appropriate management. Although many studies have explored sonographic findings associated with acute appendicitis, few investigations discuss specific signs that can reliably differentiate perforated appendicitis from acute appendicitis prior to abscess formation.