Santiago Martinez-Correa

Contrast-enhanced ultrasound and elastography are two ultrasound technologies that are becoming increasingly popular in the evaluation of different abdominal pathologies in children. The use of these technologies has expanded the diagnostic scope of ultrasound into areas that were traditionally covered by advanced imaging modalities such as computed tomography, magnetic resonance imaging, and fluoroscopy. In this review, we summarize the use of contrast-enhanced ultrasound and elastography in the evaluation of hepatic, renal, pancreatic, splenic, urinary tract, and scrotal pathologies in children. We describe the technical aspects, applications, and limitations, intending to make readers more acquainted with the technologies.

SUMMARY: Neurosonography is an invaluable diagnostic tool for assessing the neonatal brain and typically includes grayscale and conventional Doppler imaging. Microvascular imaging (MVI) is an emerging imaging technique that offers promising potential in evaluating neonatal intracranial pathology. MVI allows for sensitive and detailed assessment of neurovascular anatomy that can be challenging to visualize with other imaging modalities. This enhanced visualization not only improves the reliability in identifying neurovascular landmarks but also allows more accurate identification and assessment of adjacent parenchymal and extra-axial structures. Our review aims to offer an atlas of neurovascular structures as visualized with MVI, intended as a reference for future research in this field. Here, we focus specifically on the appearance of the intracranial arterial circulation as seen on MVI. Graphical Abstract

Cerebral ultrasound is the preferred modality for evaluating the infant brain, offering real-time bedside assessment without exposure to ionizing radiation. Microvascular imaging ultrasound (MVI), an advanced Doppler technique, enables the visualization of microvascular slow-flow structures without the need for contrast agents. This innovative approach has the potential to provide valuable insights into the developing brain9s vasculature and hemodynamics. The utility of MVI has been investigated in various neurological conditions affecting neonates and infants, demonstrating its promise as a complementary tool to existing imaging modalities. By providing detailed, real-time images of the brain9s microvasculature, MVI can aid in the early detection, monitoring, and understanding of cerebral pathologies. In this review, we aim to present a comprehensive atlas of cerebral venous structures as visualized with MVI, serving as a reference for future research in this field and promoting the adoption of this technique in clinical practice for improved diagnosis and management of neurological conditions in the infant population. ABBREVIATIONS: MVI = Microvascular Imaging.

BACKGROUND AND PURPOSE: Subpial hemorrhage is an underrecognized type of hemorrhagic stroke primarily affecting neonates. Blood accumulation in the impermeable pia mater compresses the adjacent cortex, leading to injury. The consequences of this stroke type remain poorly understood. The study aims to evaluate the association between imaging findings and neurological outcomes at follow-up in neonates with subpial hemorrhage. MATERIALS AND METHODS: We retrospectively included neonates with suspected subpial hemorrhage who underwent brain MRI between January 2012 and February 2024. Two pediatric neuroradiologists evaluated MRIs for subpial hemorrhage location, size, and pattern using a previously described system that classified subpial hemorrhage only (Pattern A), subpial hemorrhage with cortical injury (Pattern B), and subpial hemorrhage with cortical injury and intraparenchymal hemorrhage (Pattern C). They also assessed for medullary vein engorgement/thrombosis. We extracted demographic data, perinatal events, hospital outcomes, and Alberta Infant Motor Scale (AIMS) scores, when available. Descriptive analysis was used for demographic, clinical, and imaging findings. Fisher9s exact test evaluated associations between clinical outcomes and imaging findings. RESULTS: Twenty-nine patients (median gestational age 38 weeks, IQR: 37-39) were included, with 82% having birthweights >2500g. Subpial hemorrhages were most commonly on the right side (66%) and in the temporal lobe (62%). Most hemorrhages measured 1-4 cm (59%). Pattern C (15/29, 52%) was associated with delayed motor development as assessed by AIMS (9/15, 60%) (p=.042), while Pattern B (10/29, 35%) was associated with near-normal motor development (6/15, 40%) (p=.044). There was no statistically significant association between concurrent superficial and deep medullary vein engorgement/thrombosis and the presence of any neurological deficit (p=.055). CONCLUSIONS: The association between subpial hemorrhage patterns and neurological outcomes, particularly motor development, may have important prognostic and management implications. In our cohort, a pattern C of subpial hemorrhage was significantly associated with delayed motor development. Concurrent involvement of superficial and deep medullary vessels may indicate a higher risk of poor neurological outcomes. These findings highlight the importance of early intervention and monitoring in neonates presenting with subpial hemorrhage. ABBREVIATIONS: AIMS= Alberta Infant Motor Scale; IQR= Interquartile Ranges; NICU= Neonatal Intensive Care Unit; SD= Standard Deviations.

Childhood interstitial lung disease (chILD) encompasses a diverse group of genetic, infectious, and inflammatory conditions affecting infants and children. The recognition and understanding of these entities have highlighted the necessity for more accurate classification. This group of rare heterogeneous diseases comprises more than 200 different conditions and has a combined estimated prevalence of less than one patient per 100 000 children. Hence, a systematic diagnostic approach is crucial. This article describes a diagnostic approach for pediatric diffuse lung diseases in infancy, including an analysis of clinical presentations and imaging and histologic features to effectively distinguish among various chILD entities. Although they often have overlapping and nonspecific radiologic features, some chILD entities may exhibit typical imaging findings, resulting in a CT diagnosis or aiding in narrowing the differential diagnosis, thus guiding the clinician to the appropriate genetic tests, potentially limiting unnecessary biopsies. This approach aims to enhance the understanding and diagnosis of chILD in infants, thereby facilitating improved patient care.

Contrast-enhanced ultrasound, microvascular imaging, elastography, and fat quantification have varying degrees of utility, with some applications in the pediatric setting mirroring that in adults and having unique uses when applied to children in others. This review will present novel ultrasound technologies and the clinical context in which they are applied to the pediatric abdomen. New ultrasound technologies have a broad range of applications in clinical practice and represent a powerful diagnostic tool with the potential to replace other imaging modalities, such as magnetic resonance imaging and computed tomography, in specific cases.

In recent years, advances in ultrasound therapeutics have been implemented into treatment algorithms for the adult population; however, the use of therapeutic ultrasound in the pediatric population still needs to be further elucidated. In order to better characterize the utilization and practicality of sonothrombolysis in the juvenile population, the authors conducted a literature review of current pediatric research in therapeutic ultrasound. The PubMed database was used to search for all clinical and preclinical studies detailing the use and applications of sonothrombolysis, with a focus on the pediatric population. As illustrated by various review articles, case studies, and original research, sonothrombolysis demonstrates efficacy and safety in clot dissolution in vitro and in animal studies, particularly when combined with microbubbles, with potential applications in conditions such as deep venous thrombosis, peripheral vascular disease, ischemic stroke, myocardial infarction, and pulmonary embolism. Although there is limited literature on the use of therapeutic ultrasound in children, mainly due to the lower prevalence of thrombotic events, sonothrombolysis shows potential as a noninvasive thrombolytic treatment. However, more pediatric sonothrombolysis research needs to be conducted to quantify the safety and ethical considerations specific to this vulnerable population.