Govind B. Chavhan

To assess whether multi-echo T2* MRI can differentiate neonatal hemochromatosis (NH) from other causes of neonatal liver failure (NLF) by evaluating siderosis in the liver and extrahepatic organs. This retrospective study evaluated 26 infants ≤ 20 weeks of age, who underwent MRI with Gradient-Recalled (GRE) multi-echo T2* sequence for liver failure. Two radiologists noted the degree of siderosis in the liver, pancreas, thyroid, spleen and renal cortex using a semiquantitative scale. Kendall's tau was used to assess the correlation between siderosis grades and final diagnosis. Consensus review by hepatologist, neonatologist, and pathologist using integrated clinical, biochemical, imaging and histopathologic data served as the reference standard for the final diagnosis. Of 26 patients, 7 had NH and 19 had other causes of NLF. Interobserver agreement was highest for liver (κ = 0.97), followed by kidney (κ = 0.87), spleen (κ = 0.84), thyroid (κ = 0.80), and pancreas (κ = 0.73). Significant positive correlations between siderosis grades and NH diagnosis were found for thyroid (Kendall's tau = 0.70, p < 0.01), pancreas (Kendall's tau = 0.67, p < 0.01), and liver (Kendall's tau = 0.42, p = 0.03), while spleen showed a significant negative correlation (Kendall's tau = -0.51, p < 0.01). MRI demonstrated 100% sensitivity, 89.5% specificity, 77.8% positive predictive value, 100% negative predictive value, and 92.3% overall accuracy for NH diagnosis. There were significant differences among groups in R2* values for the pancreas, thyroid and spleen, with no differences in the liver. Multi-echo T2* MRI reliably distinguishes NH from other causes of NLF by revealing significant siderosis in the thyroid and pancreas, with relative sparing of the spleen. Question Neonatal hemochromatosis (NH) is a rare but often fatal condition causing neonatal liver failure (NLF), and differentiating it from other causes of NLF is challenging. Finding Pancreatic and thyroid iron deposition, as seen on MRI, strongly correlated with NH, and splenic iron deposition correlated inversely with NH. Clinical relevance Multi-echo T2* MRI is a highly accurate, non-invasive technique for early differentiation of neonatal hemochromatosis from other liver failure causes, potentially enabling earlier diagnosis of NH and guiding crucial management decisions in affected neonates.

INTRODUCTION: Radioimmunoassay (RIA)-serum trypsin serves as a pancreas function biomarker because its blood concentration correlates with duodenal trypsin output. With the unavailability of RIA tests and global availability of dried blood spot immunoreactive trypsin (DBS-IRT) testing as part of cystic fibrosis newborn-screening programs, IRT can be made accessible for routine clinical use. We aimed to validate DBS-IRT for its use as a biomarker of exocrine pancreas function in children older than the newborn age group. METHODS: Analytical accuracy of DBS-IRT was evaluated in 28 children (mean [SD] age: 13 [4.5] years) with known pancreas function status and simultaneous RIA-based serum trypsin testing. Reference ranges were established based on 134 metabolically stable children. Clinical validation was performed in 164 children with well-established pancreas phenotypes. Available cross-sectional imaging was reviewed to assess for pancreas atrophy to measure acinar cell loss. RESULTS: Total imprecision of DBS-IRT ranged from 7.1% to 16.4%; samples were stable samples at −20C for 28 days and showed excellent correlation to RIA-serum trypsin (r = 0.95, P < 0.001). A reference range of 6.9–21.2 ng/mL was newly established. DBS-IRT replicated serum trypsin in discriminating exocrine pancreatic insufficiency (EPI) in the cystic fibrosis group with high sensitivity (90.7%; 95% CI: 79.7%–96.9%) and specificity (94.7%; 95% CI: 73.9%–99.8%). Children with pancreatitis and EPI had significantly lower median DBS-IRT level compared with those without EPI ( P = 0.01). Low DBS-IRT was associated with pancreas atrophy ( P = 0.001). DISCUSSION: DBS-IRT was successfully validated as a biomarker of exocrine pancreas function which allows its use in clinical setting, in addition to fecal elastase to determine pancreas function.

We present the case of a 3-week-old girl with multiple cutaneous vascular lesions, melena, hematemesis, severe anemia (hemoglobin 4.4 g/dL), and thrombocytopenia (72 × 10³/µL), with clinical features consistent with multifocal lymphangioendotheliomatosis with thrombocytopenia (MLT). Upper gastrointestinal endoscopy revealed numerous actively bleeding angiomatous lesions, measuring 1–3 mm in diameter. Homeostasis was successfully achieved using argon plasma coagulation (APC). To our knowledge, this is among the few reports describing the effective use of APC in managing life-threatening gastric hemorrhage in an infant with MLT. While gastrointestinal perforation has been previously reported as a complication of endoscopic therapy in this context, our findings suggest that APC may be a viable option for refractory bleeding, provided that surgical support is immediately accessible.

Background Hepatocellular adenomas (HCAs) are rare, benign hepatic tumors in children, with limited imaging data available for pediatric cases. Objective To describe the magnetic resonance imaging (MRI) and clinical features of histologically proven HCAs in children. Materials and methods Single-center retrospective review of pathology-proven HCA from January 2004 to February 2024. Patients with available pre-intervention imaging in our PACS were included. Two independent readers reviewed the imaging studies. The features were summarized using descriptive statistics and inter-reader agreement was assessed using Cohen’s kappa. Results This study included 11 children (6 boys and 5 girls; median age 15 years) with 13 pathologically proven HCAs. Three patients had type 1a glycogen storage disease. Five patients had a single lesion, while six had multiple lesions. The lesions were well-defined with a median average diameter of 3.6 cm. Most were homogenously T1 iso-intense (61.5%) and mildly hyperintense (76.9%) on T2-w fat saturated images. The atoll sign was present in two lesions. Intralesional fat was observed in 69.2% of cases: microscopic in eight lesions and macroscopic in one. Hemorrhage occurred in three (23.07%) lesions and necrosis in one (7.7%). Nine out of 10 (90%) lesions showed arterial phase hyperenhancement, and only 3/10 (30%) lesions retained contrast on hepatobiliary phase. In total, 6/13 (46.1%) lesions showed washout, and all received hepatobiliary agent. One lesion ruptured with the hemoperitoneum. Of the 11, 63.6% of patients underwent percutaneous biopsy and 36.4% underwent surgical resection. Conclusion MR imaging features are nonspecific, but homogenous slight T2 hyperintensity, arterial phase hyperenhancement, and intralesional fat content are common features. Hepatobiliary contrast uptake is variable. Graphical Abstract

The neonatal liver may be affected by a variety of congenital and acquired diseases, and imaging has an important role in the workup and management of many neonatal hepatic abnormalities.

Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is a rare entity reported in adults, frequently mimicking inflammatory bowel disease (IBD). We report the first case of intestinal ischemia secondary to IMHMV presenting as IBD in a pediatric patient with Down syndrome. Chronic intestinal ischemia is rare in children, and this case emphasizes the need to consider this in the differential, when histopathology is suggestive. Clinical findings and colonoscopy in these patients may mimic IBD. The mucosal biopsies do not show classic features of IBD. Instead, there can be variable extent of mucosal changes such as dilated small capillaries in the lamina propria, edema, and early fibrosis. These changes may in fact represent early chronic ischemia. These findings should alert for vascular imaging and a full‐thickness biopsy to assess submucosal and subserosal larger vessels since medium‐ and large‐caliber veins in the colonic wall and mesentery are affected in IMHMV.

Background Angiosarcomas are rare malignant vascular tumors and there is scarcity of data on their imaging features. Objective To review and illustrate the imaging, clinical, and pathologic features of angiosarcoma in children. Materials and methods A list of pathologically proven angiosarcoma seen between Nov 1992 and Jan 2023 was obtained from a pathology database and picture archiving and communication system. Those with pre-treatment imaging available on our PACS were included in the study. Imaging studies were reviewed by two readers in consensus. Results A total of six children (two males and four females; median age of 8.8 years; range 2.9 years to 15.5 years) had angiosarcoma during the study period. Organ of origin included breast (n = 2), liver (n = 2), spleen (n = 1), and paranasal sinuses (n = 1). The patient with splenic angiosarcoma had Li-Fraumeni syndrome. Five patients had a single lesion while one had multifocal lesions. The tumors were large with a median diameter of 12.9 cm (range 2.7 cm to 24 cm). Most tumors were heterogeneous on T2-weighted imaging with hemorrhage and necrosis and showed heterogeneous enhancement. Three had well-defined borders and three had infiltrative borders. None of the tumors showed calcifications. Two tumors in the liver showed gradual non-centripetal progressive diffuse enhancement on dynamic imaging. One patient had metastases at presentation and four patients subsequently developed metastases on follow-up. Five patients underwent surgical resection and chemotherapy; one patient with a liver lesion underwent arterial embolization followed by liver transplant. Three patients died at the last follow-up. Conclusion The imaging features of angiosarcomas are nonspecific, but the tumors are large heterogeneously enhancing masses with hemorrhage and necrosis. Hepatic angiosarcomas may show non-centripetal progressive and heterogeneous enhancement on dynamic imaging.

Background Confident diagnosis of hepatic hemangioma on imaging can avoid biopsy in early infancy and helps guide conservative management. Purpose This article aims to determine if dynamic contrast-enhanced magnetic resonance imaging (MRI) can be used to differentiate liver hemangioma from other lesions in infants ≤ 100 days and to determine association of MRI features with hepatic lesions. Methods MRI performed for liver lesions were retrospectively reviewed to note imaging characteristics and the MRI diagnosis. Final diagnosis was assigned based on pathology in available cases and by corroborative standard of reference including overall clinical features, lab findings, and follow-up. Results Of 30 infants (18 boys, 12 girls; average age 42.2 days) included, 18 had solitary and 12 had multifocal lesions. Diagnoses in total 33 lesions included hemangiomas (23), hepatoblastoma (6), arteriovenous malformation (2), neuroblastoma metastases (1), and infarction (1). MRI and final diagnosis matched in 94% lesions with almost perfect agreement (kappa 0.86) for reader 1, and matched in 88% lesions with substantial agreement (kappa 0.71) for reader 2. Interobserver agreement for MRI diagnosis was substantial (kappa 0.62). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MRI in differentiating hemangioma from other lesions were 100, 90, 96, 100, and 97%, respectively. Centripetal (16/23) or flash (5/23) filling were only seen with hemangioma. There was no significant difference in alpha-fetoprotein elevation (p 0.08), average size (p 0.35), multifocality (p 0.38), and intralesional hemorrhage (p 1) between hemangioma and hepatoblastoma. Conclusion Centripetal filling on dynamic imaging and absence of washout are characteristic MRI features of hepatic hemangioma that can help to differentiate it from other lesions in early infancy.