Ultrasound imaging of bowel obstruction in infants and children.

We review the etiologies of bowel obstruction in infants and children that can be identified on ultrasound (US) including perforated appendicitis, intussusception, foreign body ingestion, colonic volvulus, intra-abdominal mass lesions, internal hernia, and stricturing inflammatory bowel disease. US can potentially identify the cause of bowel obstruction in these age groups, without the need for additional cross-sectional imaging, and can aid in patient management including interventional and surgical planning. Hence, it is important to be familiar with the sonographic imaging findings of bowel obstruction in infants and children.

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.

Impact of Focused Abdominal Ultrasound Utilization on Outcomes for Children With Midgut Volvulus.

BACKGROUND: Ultrasound (US) is gaining acceptance for the evaluation of midgut volvulus in children. However, its impact on clinical outcomes is unknown. We aim to determine whether using US as a first-line modality changes imaging mobilization, time to surgery and re-feeding, length of stay, and frequency of bowel necrosis, short bowel syndrome, and death. METHODS: An IRB-approved retrospective cohort study was performed at a tertiary pediatric institution. Eighty children with surgically confirmed midgut volvulus from 2014 to 2021 were compared before and after implementation of US as first-line imaging and based on the modality used to diagnose midgut volvulus. RESULTS: Outcomes were not statistically different pre- versus post-implementation. Compared with patients who had UGI only, those who had US only or both had significantly quicker imaging mobilization (median: -33 min; 95% CI: -61.2, -4.8; p = 0.023 and median: -31 min; 95% CI: -58.5, -3.6; p = 0.028 respectively). Patients with US only were less likely to have bowel necrosis compared with those who had UGI only (9.1% versus 43.8%, p = 0.042). Patients who had US only or both were less likely to develop short bowel syndrome compared to UGI only (4.8% US only, 0% both, 40% UGI only; p = 0.027 for US only, p = 0.005 for both). CONCLUSIONS: No statistically significant change in outcomes was found after implementation of US as first-line imaging for midgut volvulus. However, patients diagnosed with US only or US in combination with UGI had quicker imaging mobilization and decreased frequency of bowel necrosis and short bowel syndrome. Findings suggest that US has potential to improve patient outcomes. LEVEL OF EVIDENCE: III.

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.

Cancer Therapy-related Hepatic Injury in Children: Imaging Review from the Pediatric LI-RADS Working Group.

The liver is the primary organ for the metabolism of many chemotherapeutic agents. Treatment-induced liver injury is common in children undergoing cancer therapy. Hepatic injury occurs due to various mechanisms, including biochemical cytotoxicity, hepatic vascular injury, radiation-induced cytotoxicity, and direct hepatic injury through minimally invasive and invasive surgical treatments. Treatment-induced liver injury can be seen contemporaneous with therapy and months to years after therapy is complete. Patients can develop a combination of hepatic injuries manifesting during and after treatment. Acute toxic effects of cancer therapy in children include hepatitis, steatosis, steatohepatitis, cholestasis, hemosiderosis, and vascular injury. Longer-term effects of cancer therapy include hepatic fibrosis, chronic liver failure, and development of focal liver lesions. Quantitative imaging techniques can provide useful metrics for disease diagnosis and monitoring, especially in treatment-related diffuse liver injury such as hepatic steatosis and steatohepatitis, hepatic iron deposition, and hepatic fibrosis. Focal liver lesions, including those developing as a result of treatment-related vascular injury such as focal nodular hyperplasia-like lesions and hepatic perfusion anomalies, as well as hepatic infections occurring as a consequence of immune suppression, can be anxiety provoking and confused with recurrent malignancy or hepatic metastases, although there often are imaging features that help elucidate the correct diagnosis. Radiologic evaluation, in conjunction with clinical and biochemical screening, is integral to diagnosing and monitoring hepatic complications of cancer therapy in pediatric patients during therapy and after therapy completion for long-term surveillance. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material See the invited commentary by Ferraciolli and Gee in this issue.

Diagnostic performance of artificial intelligence for pediatric pulmonary nodule detection in computed tomography of the chest.

PURPOSE: To test the performance of a commercially available adult pulmonary nodule detection artificial intelligence (AI) tool in pediatric CT chests. METHODS: 30 consecutive chest CTs with or without contrast of patients ages 12-18 were included. Images were retrospectively reconstructed at 3 mm and 1 mm slice thickness. AI for detection of lung nodules in adults (Syngo CT Lung Computer Aided Detection (CAD)) was evaluated. 3 mm axial images were retrospectively reviewed by two pediatric radiologists (reference read) who determined the location, type, and size of nodules. Lung CAD results at 3 mm and 1 mm slice thickness were compared to reference read by two other pediatric radiologists. Sensitivity (Sn) and positive predictive value (PPV) were analyzed. RESULTS: The radiologists identified 109 nodules. At 1 mm, CAD detected 70 nodules; 43 true positive (Sn = 39 %), 26 false positive (PPV = 62 %), and 1 nodule which had not been identified by radiologists. At 3 mm, CAD detected 60 nodules; 28 true positive (Sn = 26 %), 30 false positive (PPV = 48 %) and 2 nodules which had not been identified by radiologists. There were 103 solid nodules (47 measuring < 3 mm) and 6 subsolid nodules (5 measuring < 5 mm). When excluding 52 nodules (solid < 3 mm and subsolid < 5 mm) based on algorithm conditions, the Sn increased to 68 % at 1 mm and 49 % at 3 mm but there was no significant change in the PPV measuring 60 % at 1 mm and 48 % at 3 mm. CONCLUSION: The adult Lung CAD showed low sensitivity in pediatric patients, but better performance at thinner slice thickness and when smaller nodules were excluded.

Surgical Management and Outcomes of Patients with Multifocal Hepatoblastoma.

OBJECTIVE: To compare the outcomes of patients with multifocal hepatoblastoma (HB) treated at our institution with either orthotopic liver transplant (OLTx) or hepatic resection to determine outcomes and risk factors for recurrence. BACKGROUND: Multifocality in HB has been shown to be a significant prognostic factor for recurrence and worse outcome. The surgical management of this type of disease is complex and primarily involves OLTx to avoid leaving behind microscopic foci of disease in the remnant liver. METHODS: We performed a retrospective chart review on all patients <18 years of age with multifocal HB treated at our institution between 2000 and 2021. Patient demographics, operative procedure, post-operative course, pathological data, laboratory values, short- and long-term outcomes were analyzed. RESULTS: A total of 41 patients were identified as having complete radiologic and pathologic inclusion criteria. Twenty-three (56.1%) underwent OLTx and 18 (43.9%) underwent partial hepatectomy. Median length of follow-up across all patients was 3.1 years (IQR 1.1-6.6 years). Cohorts were similar in rates of PRETEXT designation status identified on standardized imaging re-review (p = .22). Three-year overall survival (OS) estimate was 76.8% (95% CI: 60.0%-87.3%). There was no difference in rates of recurrence or overall survival in patients who underwent either resection or OLTx (p = .54 and p = .92 respectively). Older patients (>72 months), patients with a positive porta hepatis margin, and patients with associated tumor thrombus experienced worse recurrence rates and survival. Histopathology demonstrating pleomorphic features independently associated with worse rates of recurrence. CONCLUSIONS: Through proper patient selection, multifocal HB was adequately treated with either partial hepatectomy or OLTx with comparable outcome results. HB with pleomorphic features, increased patient age at diagnosis, involved porta hepatis margin on pathology, and the presence of associated tumor thrombus may be associated with worse outcomes regardless of the local control surgery offered. LEVEL OF EVIDENCE: III.

Low-field 0.55 T MRI evaluation of the fetus.

Fetal magnetic resonance imaging (MRI) is an important adjunct modality for the evaluation of fetal abnormalities. Recently, low-field MRI systems at 0.55 Tesla have become available which can produce images on par with 1.5 Tesla systems but with lower power deposition, acoustic noise, and artifact. In this article, we describe a technical innovation using low-field MRI to perform diagnostic quality fetal MRI.

Imaging findings of COPA Syndrome.

BACKGROUND: Autosomal dominant mutations in the coatomer-associated protein alpha (COPA) gene cause an immune dysregulation disorder associated with pulmonary hemorrhage, lymphoid hyperplasia, arthritis, and glomerulonephritis. OBJECTIVE: To describe the thoracic, musculoskeletal, and renal imaging findings of COPA syndrome with a focus on the evolution of the pulmonary findings. MATERIALS AND METHODS: With approval of the Institutional Review Board, consensus retrospective review of findings on chest radiography and computed tomography (CT), musculoskeletal radiography and magnetic resonance imaging (MRI), and renal ultrasound (US) was performed for pediatric COPA syndrome patients. COPA syndrome patients < 18 years of age presenting between 1992 and 2019 were identified from an institutional rheumatology registry. RESULTS: Twelve pediatric COPA syndrome patients (mean age of 6.5 years at first imaging exam; 6 females) were identified. Imaging exams available for review included 45 chest CT exams on 12 patients, 37 musculoskeletal exams on 4 patients, and 10 renal US exams on 5 patients. All 12 had abnormal chest CT exams, with findings including ground-glass opacities (12/12), cysts (8/12), septal thickening (9/12), nodules (8/12), fibrosis (7/12), crazy-paving (2/12), consolidation (1/12), hilar/mediastinal lymphadenopathy (11/12), and chest wall deformity (5/12). Nine had at least one follow-up chest CT, which showed improvement in nodules (7/9), ground-glass opacities (4/9), and lymphadenopathy (9/9), but worsening of septal thickening (3/9), cyst formation (3/9), and fibrosis (3/9). Four had musculoskeletal imaging revealing synovitis (2/4), bone erosions (1/4), tenosynovitis (1/4), enthesitis (1/4), and subcutaneous nodules (1/4). Five had at least one renal US, revealing renal size abnormalities (4/5) and cortical hyperechogenicity (3/5). CONCLUSION: The most prevalent imaging finding of COPA syndrome is diffuse lung disease related to early childhood-onset recurrent pulmonary hemorrhage and lymphoid hyperplasia that may progress to pulmonary fibrosis. Other imaging findings manifesting later in childhood or adolescence relate to arthritis and glomerulonephritis.

Imaging of pediatric liver tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Primary hepatic malignancies are relatively rare in the pediatric population, accounting for approximately 1%-2% of all pediatric tumors. Hepatoblastoma and hepatocellular carcinoma are the most common primary liver malignancies in children under the age of 5 years and over the age of 10 years, respectively. This paper provides consensus-based imaging recommendations for evaluation of patients with primary hepatic malignancies at diagnosis and follow-up during and after therapy.

Optimizing Imaging of Pediatric Liver Lesions: Guidelines from the Pediatric LI-RADS Working Group.

A differential diagnosis based on a patient's age, clinical presentation, and serum α-fetoprotein level will help guide the initial imaging workup in children with a liver lesion. Children vary significantly in size, the ability to stay still, and the ability to breath hold for imaging examinations. Choosing and tailoring imaging techniques and protocols for each indication and age group is important for optimal care with minimal invasiveness. The need for sedation or anesthesia can be obviated by using techniques like feed and bundle, distraction, contrast-enhanced US, and motion-insensitive sequences for MRI. US is often the first imaging modality used in children with a suspected abdominal mass. Once a hepatic lesion is confirmed, multiphasic contrast-enhanced MRI is recommended for most lesions as the next imaging modality allowing full characterization of the lesion and assessment of the liver parenchyma. Contrast-enhanced CT can also be performed for assessment of pediatric focal liver lesions, especially in patients who have a contraindication to MRI. Contrast-enhanced US has shown promise to decrease the need for MRI or CT in some lesions such as hemangioma and focal nodular hyperplasia. Children with a history of malignancy can develop multiple types of hepatic lesions at various stages, including infections during an immunocompromised state, manifesting as focal liver lesions. Based on available limited data in the literature and the collective experiences of the Liver Imaging and Reporting Data System Pediatric Working Group, the authors provide guidelines for the imaging workup of pediatric focal liver lesions with an indication- and age-based approach and discuss the selection and performance of various imaging techniques and modalities. ©RSNA, 2022 See the invited commentary by Chojniak and Boaventura in this issue.

Early pulmonary complications related to cancer treatment in children.

In this review, we summarize early pulmonary complications related to cancer therapy in children and highlight characteristic findings on imaging that should be familiar to a radiologist reviewing imaging from pediatric cancer patients.

Late pulmonary complications related to cancer treatment in children.

As the number of childhood cancer survivors increases, a heightened awareness and recognition of therapy-related late effects is becoming more important. Pulmonary complications are the third leading cause of late mortality in cancer survivors. Diagnosis of these complications on chest imaging helps facilitate prompt treatment to mitigate adverse outcomes. In this review, we summarize the imaging of late pulmonary complications of cancer therapy in children and highlight characteristic findings that should be recognized by radiologists.

Ultrasound for Midgut Malrotation and Midgut Volvulus: AJR Expert Panel Narrative Review.

Midgut volvulus in association with malrotation is a pediatric surgical emergency. Prompt and accurate diagnosis is necessary to avoid bowel ischemia and necrosis, thereby reducing morbidity and mortality. Historically, the fluoroscopic upper gastrointestinal series has been the preferred imaging modality for the evaluation of both midgut malrotation and volvulus, although the use of ultrasound (US) is increasing. In this Narrative Review, we describe the findings of midgut malrotation and volvulus on US, including practical tips for acquisition and interpretation; discuss the advantages and challenges of both imaging modalities; and propose a path and safeguards for possible transition to the use of US as the first-line modality for diagnosis based on our experience in imaging children with midgut malrotation and volvulus.

Angiosarcoma of the Pancreas in a Pediatric Patient With an Activating KDR-Internal Tandem Duplication: A Case Report and Review of the Literature.

Pancreatic angiosarcoma is an exceedingly rare malignancy accounting for <1% of pancreatic neoplasms. A very limited number of pancreatic angiosarcomas have been reported in the literature without any cases described in children. We present the case of a 17-year-old female diagnosed with angiosarcoma of the pancreas following pancreaticoduodenectomy for a pancreatic mass, initially presumed to be a solid pseudopapillary neoplasm of the pancreas. The angiosarcoma was found to have a novel activating internal tandem duplication in the KDR gene (KDR-internal tandem duplication). We discuss the current literature on this disease process. This is the first reported case of pancreatic angiosarcoma in a pediatric patient and the first with an activating KDR-internal tandem duplication.

Integration of a dedicated management protocol in the care of pediatric liver cancer: From specialized providers to complication reduction.

INTRODUCTION: Up to a third of children undergoing partial hepatectomy for primary hepatic malignancies experience at least one perioperative complication, with a presumed deleterious effect on both short- and long-term outcomes. We implemented a multidisciplinary treatment protocol in the management of these patients in order to improve complication rates following partial hepatectomy. METHODS: A retrospective chart review was completed for all patients < 18 years of age who underwent liver resection at our institution between 2002 and 2019 for primary hepatic cancer. Demographic, intraoperative, postoperative, pathologic, and outcome data were analyzed for perioperative complications using the CLASSIC and Clavien-Dindo (CD) scales, event-free survival (EFS) and overall survival (OS). RESULTS: A total of 73 patients were included in the analysis with 33 prior-to and 40 after dedicated provider protocol implementation. Perioperative complication rates decreased from 52% to 20% (p = 0.005) with major complications going from 18% to 10% (p = 0.31). On multivariable logistic regression, protocol implementation was associated with a reduction in any (OR 0.29 [95% CI 0.09 - 0.89]) but not major complications. On multivariate cox models, post protocol implementation was associated with improved event free survival (EFS) (HR 0.19 (0.036 - 0.195). Among patients with a diagnosis of hepatoblastoma (n = 62), the occurrence of a major perioperative complication was associated with a worse EFS (HR=5.45, p = 0.03) on multivariate analysis, however this did not translate into an impact on overall survival. CONCLUSIONS: Our results demonstrate that, for children with primary liver malignancies, a dedication of patients to high-volume surgeons can improve rates of complications of liver resections and may improve the oncological outcome of hepatoblastoma.

Pathologic correlation with near infrared-indocyanine green guided surgery for pediatric liver cancer.

PURPOSE: Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the most common primary malignant tumors of childhood. Intraoperative indocyanine green (ICG) administration with near-infrared imaging (NIR) has emerged as a surgical technology that can be used to assist with localization of pulmonary metastases secondary to HB; however, there has been limited application as an adjunct for resection of the primary liver tumor and assessment of extrahepatic disease. METHODS: We present 14 patients treated for HB, HCC, and malignant rhabdoid tumor at our institution with the use of intraoperative NIR-ICG guidance. All patients were treated with 0.2-0.75 mg/kg IV ICG, 48-96 h prior to surgery. Intraoperative NIR-ICG guided imaging was performed with several commercial devices. RESULTS: Intraoperative NIR-ICG guidance allowed pulmonary metastasectomy in five patients using thoracoscopy or thoracotomy allowing for visualization of multiple nodules not seen on preoperative imaging most of which were positive for malignancy. NIR-ICG guidance allowed for assessment of extrahepatic extension in three patients; an HCC patient with extrahepatic lymph node extension of disease, an HB patient with extrapulmonary thoracic recurrence in the diaphragm and chest wall, and a patient with tumor rupture at diagnosis with peritoneal nodules at the time of surgery. This technique was used to guide partial hepatectomy in 11 patients for which the technique enabled successful identification of tumor and tumor margins. Three patients had nonspecific staining of the liver secondary to decreased timing from ICG injection to surgery or biliary obstruction. NIR-ICG enabled resection of satellite HB lesions in three multifocal patients and confirmed a benign satellite lesion in two additional patients. CONCLUSIONS: Intraoperative use of NIR-ICG imaging during partial hepatectomy enabled enhanced identification and guidance for surgical resection of extrahepatic disease and multifocal liver tumors for the treatment of children with primary liver cancer.

Ultrasound for the diagnosis of malrotation and volvulus in children and adolescents: a systematic review and meta-analysis.

CONTEXT: Despite the advantages of ultrasound (US), upper gastrointestinal contrast series (UGI) remains the first-line diagnostic modality in the diagnosis of midgut malrotation and volvulus in children. OBJECTIVE: Evaluate the diagnostic accuracy of US in the diagnosis of malrotation with or without volvulus in children and adolescents aged 0-21 years, compared with the reference standard (diagnosis by surgery, UGI, CT, MRI, and clinical follow-up individually or as a composite). DATA SOURCES: We searched the electronic databases Ovid-MEDLINE, Embase, Scopus, CINAHL, and the Cochrane library in October 2019 and updated on 18 August 2020. STUDY SELECTION: Studies evaluating the diagnostic performance of US for diagnosis of midgut malrotation with or without volvulus in children (0-21 years). DATA EXTRACTION AND SYNTHESIS: The data were extracted independently by two authors and a bivariate model was used for synthesis. RESULTS: Meta-analysis of 17 cohort or cross-sectional studies and 2257 participants estimated a summary sensitivity of 94% (95% CI 89% to 97%) and summary specificity of 100% (95% CI 97% to 100%) (moderate certainty evidence) for the use of US for the diagnosis of malrotation with or without midgut volvulus compared with the reference standard. Subgroup analysis and meta-regression revealed better diagnostic accuracy in malrotation not complicated by volvulus, in the neonatal population and enteric fluid administration before US. CONCLUSIONS: Moderate certainty evidence suggests excellent diagnostic accuracy and coupled with the advantages, a strong case exists for the use of abdominal US as the first-line diagnostic test for suspected midgut malrotation with or without volvulus in children and adolescents.