An unusual case of metastatic trophoblastic neoplasm presenting with diffuse cystic lung disease and pulmonary artery pseudoaneurysms in a teenager.

Diffuse cystic lung diseases (DCLDs) are a diverse group of lung disorders characterized by the presence of multiple air filled cysts within the lung tissue. These cysts are thin walled and surrounded by normal lung tissue. In adults, DCLD can be associated with various conditions such as lymphangioleiomyomatosis (LAM), Langerhans cell histiocytosis, cancers, and more. In children, DCLD is often linked to lung developmental abnormalities, with bronchopulmonary dysplasia being a common cause. Patients with pulmonary cysts are typically asymptomatic, but some may experience mild symptoms or pneumothorax. While DCLD in children is rarely due to malignancy, metastatic lung disease can be a cause. It is important for clinicians to be aware of the possibility of metastatic lung disease when encountering DCLD.

Imaging of Fontan-Associated Liver Disease.

ABSTRACT: The Fontan procedure is the definitive treatment for patients with single-ventricle physiology. Surgical advances have led to a growing number of patients surviving into adulthood. Fontan-associated liver disease (FALD) encompasses a spectrum of pathologic liver changes that occur secondary to altered physiology including congestion, fibrosis, and the development of liver masses. Assessment of FALD is difficult and relies on using imaging alongside of clinical, laboratory, and pathology information. Ultrasound, computed tomography, and magnetic resonance imaging are capable of demonstrating physiologic and hepatic parenchymal abnormalities commonly seen in FALD. Several novel imaging techniques including magnetic resonance elastography are under study for use as biomarkers for FALD progression. Imaging has a central role in detection and characterization of liver masses as benign or malignant. Benign FNH-like masses are commonly encountered; however, these can display atypical features and be mistaken for hepatocellular carcinoma (HCC). Fontan patients are at elevated risk for HCC, which is a feared complication and has a poor prognosis in this population. While imaging screening for HCC is widely advocated, no consensus has been reached regarding an optimal surveillance regimen.

Congenital Hepatic Fibrosis in a 2-Year-Old Child Presenting with Fever of Unknown Origin.

Congenital hepatic fibrosis is a rare, autosomal recessive, fibro-polycystic disease resulting from ductal plate malformation, leading to proliferation and fibrosis of bile ducts. Progressive hepatic fibrosis leads to portal hypertension and varices which can present with life threatening gastrointestinal hemorrhage. We report a case of congenital hepatic fibrosis in a 2-year-old child who presented with 8 days of fever without any significant medical history or physical examination findings.

Potential benefits of photon counting detector computed tomography in pediatric imaging.

Photon counting detector (PCD) CT represents the newest advance in CT technology, with improved radiation dose efficiency, increased spatial resolution, inherent spectral imaging capabilities, and the ability to eliminate electronic noise. Its design fundamentally differs from conventional energy integrating detector CT because photons are directly converted to electrical signal in a single step. Rather than converting X-rays to visible light and having an output signal that is a summation of energies, PCD directly counts each photon and records its individual energy information. The current commercially available PCD-CT utilizes a dual-source CT geometry, which allows 66 ms cardiac temporal resolution and high-pitch (up to 3.2) scanning. This can greatly benefit pediatric patients by facilitating high quality fast scanning to allow sedation-free imaging. The energy-resolving nature of the utilized PCDs allows "always-on" dual-energy imaging capabilities, such as the creation of virtual monoenergetic, virtual non-contrast, virtual non-calcium, and other material-specific images. These features may be combined with high-resolution imaging, made possible by the decreased size of individual detector elements and the absence of interelement septa. This work reviews the foundational concepts associated with PCD-CT and presents examples to highlight the benefits of PCD-CT in the pediatric population.

Normative Femoral and Tibial Lengths in a Modern Population of Twenty-First-Century U.S. Children.

BACKGROUND: The Green-Anderson (GA) leg-length data remain the gold standard for the age-based assessment of leg lengths in children despite their methodologic weaknesses. We aimed to summarize current growth trends among a cross-sectional cohort of modern U.S. children using quantile regression methods and to compare the median femoral and tibial lengths of the modern U.S. children with those of the GA cohort. METHODS: A retrospective review of scanograms and upright slot-scanning radiographs obtained in otherwise healthy children between 2008 and 2020 was completed. A search of a radiology registry revealed 3,508 unique patients between the ages of 2 and 18 years for whom a standard-of-care scanogram or slot-scanning radiograph had been made. All patients with systemic illness, genetic conditions, or generalized diseases that may affect height were excluded. Measurements from a single leg at a single time point per subject were included, and the latest available time point was used for children who had multiple scanograms made. Quantile regression analysis was used to fit the lengths of the tibia and femur and overall leg length separately for male patients and female patients. RESULTS: Seven hundred patients (328 female and 372 male) met the inclusion criteria. On average, the reported 50th percentile tibial lengths from the GA study at each time point were shorter than the lengths in this study by 2.2 cm (range, 1.4 to 3.3 cm) for boys and 2 cm (range, 1.1 to 3.1 cm) for girls. The reported 50th percentile femoral lengths from the GA study at each time point were shorter than the lengths in this study by 1.8 cm (range, 1.1 to 2.5 cm) for boys and 1.7 cm (range, 0.8 to 2.3 cm) shorter for girls. CONCLUSIONS: This study developed new growth charts for femoral and tibial lengths in a modern U.S. population of children. The new femoral and tibial lengths at nearly all time points are 1 to 3 cm longer than traditional GA data. The use of GA data for epiphysiodesis could result in underestimation of expected childhood growth. LEVEL OF EVIDENCE: Prognostic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Pilot study to determine whether reduced-dose photon-counting detector chest computed tomography can reliably display Brody II score imaging findings for children with cystic fibrosis at radiation doses that approximate radiographs.

BACKGROUND: The Brody II score uses chest CT to guide therapeutic changes in children with cystic fibrosis; however, patients and providers are often reticent to undergo chest CT given concerns about radiation. OBJECTIVE: We sought to determine the ability of a reduced-dose photon-counting detector (PCD) chest CT protocol to reproducibly display pulmonary disease severity using the Brody II score for children with cystic fibrosis (CF) scanned at radiation doses similar to those of a chest radiograph. MATERIALS AND METHODS: Pediatric patients with CF underwent non-contrast reduced-dose chest PCD-CT. Volumetric inspiratory and expiratory scans were obtained without sedation or anesthesia. Three pediatric radiologists with Certificates of Added Qualification scored each scan on an ordinal scale and assigned a Brody II score to grade bronchiectasis, peribronchial thickening, parenchymal opacity, air trapping and mucus plugging. We report image-quality metrics using descriptive statistics. To calculate inter-rater agreement for Brody II scoring, we used the Krippendorff alpha and intraclass correlation coefficient (ICC). RESULTS: Fifteen children with CF underwent reduced-dose PCD chest CT in both inspiration and expiration (mean age 8.9 years, range, 2.5-17.5 years; 4 girls). Mean volumetric CT dose index (CTDIvol) was 0.07 ± 0.03 mGy per scan. Mean effective dose was 0.12 ± 0.04 mSv for the total examination. All three readers graded spatial resolution and noise as interpretable on lung windows. The average Brody II score was 12.5 (range 4-19), with moderate inter-reader reliability (ICC of 0.61 [95% CI=0.27, 0.84]). Inter-rater reliability was moderate to substantial for bronchiectasis (0.52), peribronchial thickening (0.55), presence of opacity (0.62) and air trapping (0.70) and poor for mucus plugging (0.09). CONCLUSION: Reduced-dose PCD-CT permits diagnostic image quality and reproducible identification of Brody II scoring imaging findings at radiation doses similar to those for chest radiography.

Imaging of pre- and post-cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pediatric intraperitoneal malignancy.

Although rare, pediatric peritoneal carcinomatosis does occur in primary abdominopelvic tumors. Additionally, peritoneal carcinomatosis has been described to occur as metastatic disease where the primary tumor is outside the abdominopelvic cavity. Where amenable, cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) can be beneficial in disease management. However, favorable outcomes are predicated on specific tumor histology as well as proper patient selection, which significantly relies on preoperative imaging. This review gives a comprehensive, up-to-date summary on pediatric peritoneal carcinomatosis pre-surgical evaluation; where imaging is beneficial and limited; pediatric radiologists' role in helping to quantify disease; and how we, as pediatric radiologists, can help the surgeons and oncologists in the selection of patients for cytoreductive surgery and HIPEC.

Performing chest computed tomography on pediatric patients on extracorporeal membrane oxygenation (ECMO): a stepwise approach.

Chest CT in pediatric patients on extracorporeal membrane oxygenation (ECMO) can be done safely and provide valuable high-quality diagnostic images to help guide patient management. An understanding of the basics of the ECMO circuit, cannula locations, where and how to inject contrast media, and how to time image acquisition is vital for the radiologist. Additionally, understanding the precautions associated with performing these exams is essential to ensure the safety of the child. This article provides a brief review of pediatric ECMO and its challenges and considerations, as well as a stepwise approach to perform and optimize these exams safely.

NUT carcinoma of the thorax in a 7-year-old child.

We present a rare case of NUT midline carcinoma of the thorax in a 7-year-old-male who presented with nonspecific abdominal pain. The patient was initially evaluated with an abdominal ultrasound, which was negative, followed by an abdominopelvic CT that demonstrated a partially visualized infiltrative mediastinal mass. Subsequent, chest CT showed a large, aggressive appearing heterogenous middle mediastinal mass with pulmonary parenchyma, hilar, and posterior mediastinal invasion. Given its epicenter in the middle mediastinum and its irregular and invasive appearance, the primary consideration was NUT midline carcinoma, subsequently confirmed on biopsy.

Cellular variant of kaposiform lymphangiomatosis: a report of three cases, expanding the morphologic and molecular genetic spectrum of this rare entity.

Kaposiform lymphangiomatosis (KLA) is a very rare form of generalized lymphatic anomaly, consisting of a diffuse proliferation of abnormal, dilated lymphatics, and small fascicles of hemosiderin-laden spindled lymphatic endothelial cells. KLA occurs in children and young adults and may present with multicentric disease, pleural and pericardial effusions, and life-threatening coagulopathy. Genetically, KLA most often harbors somatic activating mutations in NRAS. We recently encountered 3 cases of KLA with cellular features, resembling kaposiform hemangioendothelioma (KHE), and studied their clinicopathologic, radiologic, and molecular genetic features. The patients (1 male, 2 females; aged 2 years, 2 months, 4 years) presented with multicentric disease involving skin, soft tissue, bone, and spleen and thrombocytopenia/coagulopathy. Advanced imaging studies confirmed multicentric disease. Biopsies (skin, soft tissue, bone, and spleen) demonstrated both conventional KLA and much more cellular foci, consisting of sheets, nodules, glomeruloid structures, and sieve-like arrays of lymphatic endothelial cells (positive for CD31 and D2-40). Cellular areas superficially resembled KHE but displayed more epithelioid cytology and lacked surrounding hyaline fibrosis and minute platelet aggregates. Molecular genetic studies demonstrated NRAS c.181C > A p.Q61K (Gln61Lys) in 2 specimens from one patient and HRAS p.A59_Q61delinsGGSIL in another. Two patients were treated with sirolimus; all are currently alive with stable disease. We conclude that cellular morphology in KLA, a previously undescribed feature, does not appear to be associated with clinical features, site of disease, mutation type, response to sirolimus, or outcome. Although cellular KLA may mimic KHE, there are sufficient clinical, morphologic, and genetic differences such that these are likely unrelated diseases.

Can the use of deception be justified in medical education research? A point/counterpoint and case study.

Deception is a common feature of behavioral research design, although not commonly employed in the medical literature. It can promote scientific validity but is ethically controversial because it compromises subject autonomy and incurs additional costs.  In this Point/Counterpoint monograph, we review the nature of deception in research and present arguments for and against its ethical use as a research methodology in behavioral studies.  We describe the necessary guidelines, safeguards, and oversight, when deceptive methodology is considered, and report our experiences and lessons learned from conducting a multi-institutional audit study that relied upon deception of academic radiology faculty.

Pediatric Abdominal Masses: Imaging Guidelines and Recommendations.

Pediatric abdominal masses are commonly encountered in the pediatric population, with a broad differential diagnosis that encompasses benign and malignant entities. The primary role of abdominal imaging in the setting of a suspected pediatric abdominal mass is to establish its presence, as nonneoplastic entities can mimic an abdominal mass, and to identify characteristic imaging features that narrow the differential diagnosis. In the setting of a neoplasm, various imaging modalities play an important role to characterize the mass, stage extent of disease, and assist in presurgical planning. The purpose of this article is to discuss a practical imaging algorithm for suspected pediatric abdominal masses and to describe typical radiological findings of the commonly encountered abdominal masses in neonates and children with emphasis on imaging guidelines and recommendations.

Neonatal and Pediatric Bowel Obstruction: Imaging Guidelines and Recommendations.

Pediatric bowel obstructions are one of the most common surgical emergencies in children, and imaging plays a vital role in the evaluation and diagnosis. An evidence-based and practical imaging approach to diagnosing and localizing pediatric bowel obstructions is essential for optimal pediatric patient care. This article discusses an up-to-date practical diagnostic imaging algorithm for pediatric bowel obstructions and presents the imaging spectrum of pediatric bowel obstructions and their underlying causes.

Chylolymphatic mesenteric cyst with midgut volvulus in an adolescent: a peculiar presentation.

Mesenteric cysts are rare intra-abdominal masses in the pediatric population, with the chylolymphatic variant comprising only 7.3% of all abdominal cysts. These cysts can have a varied clinical presentation, ranging from asymptomatic cystic masses to intestinal obstruction. We report a 16-year-old female, who presented with acute abdominal pain and vomiting, and was diagnosed with an intra-abdominal cystic mass with midgut volvulus accompanied by the classical "whirlpool sign" on imaging. She underwent laparoscopic abdominal exploration, which revealed a large chylolymphatic mesenteric cyst associated with feeder lymph vessels. This cyst had resulted in volvulus of the small bowel. The bowel was detorsed and found to be viable, and the cyst was removed en bloc after suction evacuation with ligation of the lymphatic feeder vessels. Midgut volvulus in the pediatric population is usually secondary to malrotation, but in this case the patient's small intestine was not found to be malrotated, and hence we present this case and urge physicians to consider a diagnosis of midgut volvulus even in the absence of malrotation in a child with a cystic abdominal mass presenting as intestinal obstruction.

Perianal magnetic resonance imaging findings and their potential impact on outcome in children with perianal fistulizing Crohn disease.

BACKGROUND: Children with perianal fistulizing Crohn disease require intensive medical management but also have a higher risk for subsequent surgical interventions. OBJECTIVE: We performed a retrospective study to identify patient factors and perianal anatomical features by pelvic MR that are associated with surgical interventions in these children. MATERIALS AND METHODS: We included children with Crohn disease and perianal fistula who underwent pelvic MR with available, archived images and collected demographic, clinical and laboratory data. Radiologists reviewed pelvic MR exams and identified Park classification and additional anatomical features of perianal fistulas, including fistula branching, horseshoe ramifications, abscess, inflammatory mass, supralevator extension, anal sphincter damage, proctitis and posterior anal space involvement. We performed univariate and subsequent multivariate analysis to determine features associated with subsequent surgical intervention. RESULTS: Ninety-nine children with Crohn disease underwent pelvic MR. In this cohort, 69 children had no surgical interventions prior to baseline MRI, with subsequent median clinical follow-up of 5.5 years. Univariate analysis demonstrated that branching (P=0.009), supralevator extension (P=0.015) and anal sphincter damage (P=0.031) were significantly associated with subsequent surgical intervention. Age at baseline MRI was also associated with intervention (hazard ratio [HR] every 5 years: 2.13; 95% confidence interval [CI]: 1.18-3.83; P=0.012). A multivariable model identified only fistula branching (HR: 2.31; 95% CI: 1.28-4.15; P=0.005) and age (HR: 5.18; CI: 1.57-17.14; P=0.007) as independent predictors of subsequent surgery. No demographic, clinical or laboratory parameter predicted subsequent surgical intervention. CONCLUSION: Age and anatomical MR features indicating fistula complexity (branching, supralevator extension) and sphincter damage confer a higher risk of subsequent surgical intervention in children with perianal Crohn disease.

Factors Influential in the Selection of Radiology Residents in the Post-Step 1 World: A Discrete Choice Experiment.

OBJECTIVES: Reporting of United States Medical Licensing Examination Step 1 results will transition from a numerical score to a pass or fail result. We sought an objective analysis to determine changes in the relative importance of resident application attributes when numerical Step 1 results are replaced. METHODS: A discrete choice experiment was designed to model radiology resident selection and determine the relative weights of various application factors when paired with a numerical or pass or fail Step 1 result. Faculty involved in resident selection at 14 US radiology programs chose between hypothetical pairs of applicant profiles between August and November 2020. A conditional logistic regression model assessed the relative weights of the attributes, and odds ratios (ORs) were calculated. RESULTS: There were 212 participants. When a numerical Step 1 score was provided, the most influential attributes were medical school (OR: 2.35, 95% confidence interval [CI]: 2.07-2.67), Black or Hispanic race or ethnicity (OR: 2.04, 95% CI: 1.79-2.38), and Step 1 score (OR: 1.8, 95% CI: 1.69-1.95). When Step 1 was reported as pass, the applicant's medical school grew in influence (OR: 2.78, 95% CI: 2.42-3.18), and there was a significant increase in influence of Step 2 scores (OR: 1.31, 95% CI: 1.23-1.40 versus OR 1.57, 95% CI: 1.46-1.69). There was little change in the relative influence of race or ethnicity, gender, class rank, or clerkship honors. DISCUSSION: When Step 1 reporting transitions to pass or fail, medical school prestige gains outsized influence and Step 2 scores partly fill the gap left by Step 1 examination as a single metric of decisive importance in application decisions.