Pediatric Radiology最新文献

Background: In vivo placental volume derived from magnetic resonance imaging (MRI) is a novel imaging tool to evaluate the placenta during pregnancy, as the placenta is difficult to access throughout gestation. There is a paucity of established standardized normative raw values and Z-scores for in vivo placental volume based on MRI.

Objective: To establish normative references for in vivo placental MRI-based volumes derived from a large cohort of healthy pregnant women carrying healthy fetuses throughout gestation.

Materials and methods: Healthy pregnant women with healthy singleton pregnancies greater than 16 weeks gestation were enrolled in a longitudinal, prospective observational study. In total, 313 placental MRIs were analyzed from 209 pregnant women. In-vivo placentas were manually segmented to derive volumes and Z-scores. Means, standard deviations, and percentiles for normative reference raw values were calculated using weekly gestational age (GA) bins. Placental volume Z-scores were calculated based on 2-week GA bins using means and standard deviations.

Results: Normative reference placental volumes from 209 subjects (313 scans) with median GA 31.43 [8.86] weeks are presented in weekly and bi-weekly GA bins. Using 2-week GA intervals, 95% of placental volume Z-scores were within ±2 standard deviations of the population mean.

Conclusion: This data provides established normative in vivo raw and Z-score values derived from placental MRI. The value of accessing the placenta in vivo through MRI has become increasingly recognized, as the importance of the placenta in fetal and postnatal health is now more widely known. Establishing normative reference values for the in vivo placenta throughout gestation benefits both the clinical and scientific communities.

This report presents the prenatal imaging findings and short-term clinical outcome of a rare case of fetal cerebral sinovenous thrombosis, along with a brief review of the literature. A 31-year-old pregnant Afghan woman at 34 weeks of gestation (gravida 3, para 0, abortion 2) presented to the hospital with complaints of decreased fetal movement. Fetal cranial ultrasonography revealed a thick-walled, avascular, hypoechoic, mass-like lesion (17×18×18 mm) extending from the left foramen of Monro to the superior aspect of the thalamus and displacing the body of the left lateral ventricle. Fetal cranial magnetic resonance imaging (MRI) suggested subacute hemorrhage and demonstrated hyperintensity in the left transverse venous sinus, indicative of thrombosis. Serial follow-up revealed stability of the lesion; however, at 36 weeks, an emergency cesarean section was performed due to fetal distress. Postnatal cranial MRI and magnetic resonance venography (MRV) confirmed left transverse venous sinus thrombosis with subacute hemorrhage. The newborn received enoxaparin therapy for 3 months, remained clinically stable, and had no neurological deficits at the 4-month follow-up. Fetal intracranial hemorrhage has a broad differential diagnosis, and accurate identification of the underlying etiology is critical for prognosis and management. Fetal cerebral sinovenous thrombosis should be considered in the differential diagnosis when mass-like hemorrhagic lesions are detected on prenatal imaging. While short-term outcomes may be favorable in the absence of additional cranial pathology, the long-term prognosis remains uncertain.

Neuroleukemiosis, leukemic infiltration of the peripheral nerves, is exceedingly rare. We report a child with neuroleukemiosis affecting multiple peripheral nerves, presenting 2 months after stem cell transplant for acute myeloid leukemia. We discuss this unusual entity and highlight the ultrasonographic and magnetic resonance imaging findings that facilitated biopsy confirmation. Recognition of this entity is critical as it may be the sole sign of primary disease or relapse.

Background: Most commercially available artificial intelligence (AI) tools in radiology are trained and approved for adult use, creating an access gap for pediatric patients. Intracranial hemorrhage (ICH) detection is a common adult AI application without pediatric FDA clearance.

Objective: To evaluate the performance of an FDA-cleared, adult-trained AI tool for ICH detection on non-contrast head CT (NCHCT) in pediatric patients aged 6-17 years.

Materials and methods: This retrospective, multi-institution study analyzed consecutive pediatric NCHCTs performed between January 2017 and November 2022 across 21 sites. Inclusion criteria were patient age 6-17 years and adequate imaging quality. Radiology reports were classified as ICH-positive or ICH-negative using a validated natural language processing (NLP) tool. The AI tool analyzed DICOM images independently. Discordant AI-NLP cases underwent blinded adjudication by three radiologists to establish ground truth. Performance metrics includingsensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated with Wilson 95% confidence intervals (CIs).

Results: The cohort included 1,996 NCHCTs (768 females, 1,223 males, 5 unknown). ICH prevalence was 8.6% (172/1,996). Compared with ground truth, AI achieved 94.2% sensitivity (162/172, 95% CI, 89.6-97.2%), 94.7% specificity (1,727/1,824, 95% CI, 93.6-95.7%), 94.6% accuracy (1,889/1,996, 95% CI, 93.6-95.6%), 62.5% PPV (162/259, 95% CI, 57.8-67.0%), and 99.4% NPV (1,727/1,737, 95% CI, 99.0-99.7%). AI correctly identified ICH in cases missed by radiologists, but false positives were common, most often due to streak artifact (21.6%) and misclassified anatomy (18.6%). Interrater agreement for ground truth adjudication was substantial (κ=0.683).

Conclusion: An adult-trained AI tool demonstrated high sensitivity, specificity, and accuracy for ICH detection in pediatric patients aged 6-17 years, comparable to its adult performance. Selective adaptation of adult-trained AI tools could expand access to AI-assisted triage for certain pediatric populations, potentially reducing delays in critical imaging interpretation. However, prospective validation is required before clinical deployment.

Chronic nonbacterial osteitis (CNO), including its multifocal form, chronic recurrent multifocal osteomyelitis (CRMO), is an autoinflammatory sterile bone disorder with protean imaging features across the appendicular and axial skeletons in children and adolescents. Magnetic resonance imaging (MRI)-particularly whole-body MRI (WBMRI)-is pivotal for diagnostic imaging, mapping total inflammatory burden, demonstrating multifocality, and monitoring treatment response. Radiographs are frequently normal early in the disease. Beyond the classic metaphyseal pattern, we demonstrate atypical presentations that often mimic other conditions, such as infection or malignancy: progressive collapsing vertebral disease with vertebra plana, hip arthritis due to involvement of intra-articular metaphyseal equivalents, myositis not related to areas of active osteitis, extensive periosteal new bone in long bones, pseudotumoral lesions of flat bones, and craniofacial involvement. This pictorial review provides a structured diagnostic approach to prompt consideration of CNO, facilitate differentiation from bacterial osteomyelitis and bone tumors in the differential diagnosis, and support early, targeted anti-inflammatory therapy.

Perinatal stroke (PS) is a heterogeneous group of cerebrovascular diseases occurring between 20 weeks of gestation and 28 days of post-natal life. PS may be due to arterial or venous compromise resulting in an ischemic or hemorrhagic injury to the brain. Arterial ischemic stroke (AIS) is the most common form of PS, with neonates (between 0-28 days) being at a particularly increased risk. Several risk factors have been implicated in the development of neonatal AIS (NAIS), including but not limited to complicated labor, infection, poor Apgar score, and metabolic derangements. Seizures are the most common presentation of NAIS. MRI is the investigation of choice in cases of suspected NAIS, enabling identification of the injury, detection of vascular changes, and associated downstream network injury. Even though treatment is primarily supportive, various MRI techniques have played a key role in understanding functional and microstructural changes following NAIS as well as predicting outcomes, thereby empowering clinicians and parents to make informed decisions about future care and rehabilitation.

Abusive spinal injuries, although often clinically silent, may require treatment and have medicolegal significance. Abused infants are prone to ligamentous injury of the craniocervical junction and upper cervical spine, which is often associated with brain hypoxic-ischemic injury. Although they are relatively common and highly specific for abuse, thoracolumbar spine injuries (e.g., thoracolumbar compression fractures and spinal extra-axial hemorrhages) are most often clinically occult. Additionally, they are often undetectable on skeletal survey and are frequently found in the absence of cervical spine injuries. Therefore, MRI screening of the whole spine is needed in selected cases of abusive trauma with potential for spinal injuries. This review discusses indications and summarizes recommendations for whole-spine imaging in cases of suspected child abuse. Imaging examples that emphasize the importance of whole-spine MRI in child abuse are provided. Vertebral fracture, spinal cord injury, spinal hemorrhage, and ligamentous and paraspinal soft tissue injury are discussed and illustrated.

Background: Previous studies exploring preoperative intrahepatic portal venous system to evaluate Rex shunt efficacy in pediatric cavernous transformation of the portal vein have yielded controversial results.

Objective: To develop a novel postoperative intrahepatic portal venous system classification to predict long-term outcomes of Rex shunt in children with cavernous transformation of the portal vein.

Materials and methods: From October 2014 to February 2024, children with cavernous transformation of the portal vein who underwent Rex shunt were retrospectively analyzed. One week after Rex shunt, intrahepatic portal venous system were classified into types A-C using ultrasound based on the patency of the connection between the Rex vein and the right portal vein. These types were further subdivided into subtypes based on the Rex vein inner diameter. We compared spleen length, spleen thickness, and esophageal variceal grading before and one year after Rex shunt across these types, as well as the incidence of vascular complications one year after Rex shunt.

Results: The study included 160 children: 129 type A (124 type A1, 5 type A2), 25 type B (17 type B1, 8 B2), 6 type C1, with subtypes distinguished by an Rex vein inner diameter ≤ 4 mm. Type A exhibited superior outcomes compared to types B and C, which had comparable results. Type A1 demonstrated the most significant benefits, with fewer complications and improved variceal grading, although splenic size reduction was similar to that of type B1. Type B1 outperformed type B2 in terms of complications, variceal grading, and splenic measurements, and surpassed type A2 in splenic length reduction and type C1 in variceal grading and splenic thickness reduction.

Conclusions: The novel one-week postoperative intrahepatic portal venous system is effective to predict one-year postoperative outcomes of Rex shunt.

Low-grade epilepsy-associated tumors (LEATs) are a distinct group of tumors commonly encountered in pediatric drug-resistant epilepsy that necessitate surgical intervention. Like tumors elsewhere in the central nervous system, molecular characterization is becoming an increasingly important consideration in pediatric neuro-oncology prognostication and management for LEATs. Thus, familiarity with relevant tumor mutations and radiogenomic features of LEATs is important for radiologists caring for affected patients. This article will review the genetic alterations and imaging characteristics of LEATs, formatted according to the three categories defined by the World Health Organization (WHO): glioneuronal and neuronal tumors (ganglioglioma, dysembryoplastic neuroepithelial tumor, papillary glioneuronal tumor, multinodular and vacuolating neuronal tumor); circumscribed astrocytic gliomas (pilocytic astrocytoma, pleomorphic xanthoastrocytoma); and pediatric-type diffuse low-grade gliomas (diffuse astrocytoma MYB or MYBL1-altered, angiocentric glioma, diffuse low-grade glioma MAPK pathway-altered, polymorphous low-grade neuroepithelial tumor of the young).