Radiotracers for Molecular Imaging of Angiotensin-Converting Enzyme 2.

Angiotensin-converting enzymes (ACE) are well-known for their roles in both blood pressure regulation via the renin-angiotensin system as well as functions in fertility, immunity, hematopoiesis, and many others. The two main isoforms of ACE include ACE and ACE-2 (ACE2). Both isoforms have similar structures and mediate numerous effects on the cardiovascular system.

PET Imaging of Neurofibromatosis Type 1 with a Fluorine-18 Labeled Tryptophan Radiotracer.

Neurofibromatosis type 1 (NF1) is a neurocutaneous disorder. Plexiform neurofibromas (PNFs) are benign tumors commonly formed in patients with NF1. PNFs have a high incidence of developing into malignant peripheral nerve sheath tumors (MPNSTs) with a 5-year survival rate of only 30%.

Abusive Head Trauma Animal Models: Focus on Biomarkers.

Abusive head trauma (AHT) is a serious traumatic brain injury and the leading cause of death in children younger than 2 years. The development of experimental animal models to simulate clinical AHT cases is challenging. Several animal models have been designed to mimic the pathophysiological and behavioral changes in pediatric AHT, ranging from lissencephalic rodents to gyrencephalic piglets, lambs, and non-human primates.

Advanced Neuroimaging Approaches to Pediatric Brain Tumors.

Central nervous system tumors are the most common pediatric solid tumors; they are also the most lethal. Unlike adults, childhood brain tumors are mostly primary in origin and differ in type, location and molecular signature. Tumor characteristics (incidence, location, and type) vary with age.

Newly Diagnosed Children with Cancer Have Lower 25-Vitamin D Levels than Their Cancer-Free Peers: A Comparison across Age, Race, and Sex.

Children with cancer have a greater risk for vitamin D concerns because of compromised health before diagnosis, the disease itself, and treatments for the cancer. This IRB-approved retrospective, matched case−control study of children with and without cancer included three race categories: black, other, and Caucasian. This is the first study to directly compare serum 25-hydroxy vitamin D (25(OH)D) levels and status in newly diagnosed pediatric cancer patients with age-, sex-, and race-matched cancer-free children from the same geographic region of the US, all of whom are free from other conditions that negatively impact 25(OH)D levels.

Radiosynthesis of 1-(2-[18F]Fluoroethyl)-L-Tryptophan using a One-pot, Two-step Protocol.

The kynurenine pathway (KP) is a primary route for tryptophan metabolism. Evidence strongly suggests that metabolites of the KP play a vital role in tumor proliferation, epilepsy, neurodegenerative diseases, and psychiatric illnesses due to their immune-modulatory, neuro-modulatory, and neurotoxic effects. The most extensively used positron emission tomography (PET) agent for mapping tryptophan metabolism, α-[C]methyl-L-tryptophan ([C]AMT), has a short half-life of 20 min with laborious radiosynthesis procedures.

Tracheal narrowing in children and adults with mucopolysaccharidosis type IVA: evaluation with computed tomography angiography.

Background: Mucopolysaccharidosis type IVA (MPS IVA) is characterized by progressive skeletal dysplasia and respiratory issues with difficult airway management during anesthesia.

Objective: To characterize tracheal abnormalities in children and adults with MPS IVA including interplay of the trachea, vasculature, bones and thyroid at the thoracic inlet.

Materials And Methods: Computed tomography (CT) angiograms of the chest were analyzed for trachea shape, narrowing and deviation at the thoracic inlet, course of vasculature, bone alignment and thyroid location.

A Comparison of Lumbar Spine and Lateral Distal Femur Bone Density in Girls With Rett Syndrome.

Patients with Rett syndrome (RS) are at risk for low bone mineral density (BMD) and femoral fractures. In patients with RS, assessment with lateral distal femur (LDF) dual-energy X-ray absorptiometry (DXA) is recommended and clinically relevant. This study is the first to assess LDF BMD in girls with RS, and to compare LDF BMD results with lumbar spine BMD results in RS.

The Utility of DXA Assessment at the Forearm, Proximal Femur, and Lateral Distal Femur, and Vertebral Fracture Assessment in the Pediatric Population: 2019 ISCD Official Position.

Dual-energy X-ray absorptiometry (DXA) is widely used in the evaluation of bone fragility in children. Previous recommendations emphasized total body less head and lumbar spine DXA scans for clinical bone health assessment. However, these scan sites may not be possible or optimal for all groups of children with conditions that threaten bone health.

Adult Tourniquet for Use in School-Age Emergencies.

Background: Gunshot injuries are a leading cause of morbidity and mortality in the pediatric population. The Pediatric Trauma Society supports the use of tourniquets for exsanguinating hemorrhage in severe extremity trauma. The Combat Application Tourniquet (CAT) used with success in adults has not been prospectively tested in children.

Computerized Tomography Analysis of Young Children for Prevention of Aspiration Injuries.

Objective: The Small Parts Test Fixture (SPTF) (16 CFR 1501) was developed from cadavers of young children and foreign body (FB) data. Recent FB studies reveal that the SPTF misses outliers. Computerized tomography (CT) provides detailed dimensional data for young children.

Maturation of pelvic ossification centers on computed tomography in normal children.

Background: The pelvis is composed of three paired primary ossification centers: the pubis, the ischium and the ilium. During maturation, multiple secondary ossification centers can be seen in the synchondroses between these bones and in the pelvic apophyses. The fragmented appearance of these centers can be confused with pathology.

Bone mineral density in mucopolysaccharidosis IVB.

To date, the only published reports of bone mineral density (BMD) in MPS IV involve patients with MPS IVA; no reports exist describing BMD for MPS IVB. In this prospective study of BMD in three patients with MPS IVB, BMD was acquired by dual-energy X-ray absorptiometry (DXA) at whole body (WB), lumbar spine (LS), and lateral distal femur (LDF). Functional abilities, ambulatory status, medical history, and height z-score were evaluated.

Bone mineral density in MPS IV A (Morquio syndrome type A).

Mucopolysaccharidosis IV A (MPS IV A), Morquio A, is caused by deficiency in lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS), which is responsible for the catabolism of the glycosaminoglycans (GAGs) keratan sulfate (KS) and chondroitin 6-sulfate (C6S). Accumulation of GAGs results in disrupted cartilage formation and skeletal dysplasia. In this prospective cross-sectional study, bone mineral density (BMD) of the whole body (WB), lumbar spine (LS), and lateral distal femur (LDF) was acquired by dual-energy X-ray absorptiometry (DXA) on patients with MPS IV A.

Longitudinal assessment of bone growth and development in a facility-based population of young adults with cerebral palsy.

Aim: Osteoporosis is a significant clinical problem in persons with moderate to severe cerebral palsy (CP), causing fractures with minimal trauma. Over the past decade, most studies examining osteoporosis and CP have been cross-sectional in nature, focused exclusively on children and adolescents and only involving one evaluation of bone mineral density (BMD). The purpose of this study was to assess BMD in a group including adults with CP, and changes in each individual's BMD over a 5- to 6-year period.

Pamidronate Treatment to Prevent Reoccurring Fractures in Children With Cerebral Palsy.

Background: Some children with cerebral palsy (CP) have frequent fractures due to low bone mineral density and receive treatment with pamidronate, an intravenous bisphosphonate. Our review evaluates the outcome of pamidronate treatment in these children.

Methods: A retrospective chart review was performed, and 32 patients (14 girls and 18 boys) with CP Gross Motor Function Classification System level III (2 patients), IV (3 patients), and V (27 patients) treated with 5 courses of pamidronate for low mineral density were identified.

Magnetic resonance evaluation of the knee in children and adolescents with achondroplasia.

Background: Achondroplasia is the most common form of skeletal dysplasia. Although the radiographic features are well described, MRI features of the knee in achondroplasia have not been reported.

Objective: To describe common MRI characteristics of the knee joint in symptomatic children and adolescents with achondroplasia.

Assessment of bone health in children with disabilities.

Evaluating the bone health of children with disabilities is challenging and requires consideration of many factors in clinical decision-making. Feeding problems and growth deficits, immobility/inability to bear weight, effect of medications, and the nature of his or her disease can all directly affect a child's overall picture of bone health. Familiarity with the tools available to assess bone health is important for practitioners.

Adaptation of the lateral distal femur DXA scan technique to adults with disabilities.

The technique that best addresses the challenges of assessing bone mineral density in children with neuromuscular impairments is a dual-energy X-ray absorptiometry (DXA) scan of the lateral distal femur. The purpose of this study was to adapt this technique to adults with neuromuscular impairments and to assess the reproducibility of these measurements. Thirty-one adults with cerebral palsy had both distal femurs scanned twice, with the subject removed and then repositioned between each scan (62 distal femurs, 124 scans).

Dual-energy X-ray absorptiometry interpretation and reporting in children and adolescents: the revised 2013 ISCD Pediatric Official Positions.

The International Society for Clinical Densitometry Official Revised Positions on reporting of densitometry results in children represent current expert recommendations to assist health care providers determine which skeletal sites should be measured, which, if any, adjustments should be made, reference databases to be used, and the elements to include in a dual-energy X-ray absorptiometry report. The recommended scanning sites remain the total body less head and the posterior-anterior spine. Other sites such as the proximal femur, lateral distal femur, lateral vertebral assessment, and forearm are discussed but are only recommended for specific pediatric populations.

Lower extremity bone mineral density in children with congenital spinal dysfunction.

Aim: To assess lower extremity bone mineral density (BMD) of children with congenital spinal dysfunction and examine factors that may influence BMD in this population.

Method: Forty-four children (25 females, 19 males) aged 6 to 18 years (mean 11 y 11 mo, SD 3 y 6 mo) with congenital spinal dysfunction (35 with myelomeningocele, seven with lipomas, one with sacral agenesis, one with caudal regression) were enrolled in the study. A health survey including ambulatory status, history of bladder augmentation, and history of fracture was administered.

Protocol for MRI of the hips after spica cast placement.

Background: In reduction of hip displacement in developmental dysplasia, concentric placement of the femoral head within the acetabulum is key. Magnetic resonance imaging (MRI) is an effective modality to assess the adequacy of the reduction, but sedation may be required due to the length of the examination. MRI is also more expensive than other imaging modalities.

Pre- and postoperative imaging of adolescents undergoing laparoscopic adjustable gastric banding surgery.

Background: As childhood obesity rates rise, laparoscopic adjustable gastric banding (LAGB) is being investigated as a bariatric surgical option in adolescents.

Objective: To examine pre- and postoperative imaging in adolescents undergoing LAGB, describe the most common abnormal preoperative imaging findings, and illustrate the typical appearance and variants on postoperative upper-gastrointestinal (UGI) examinations.

Materials And Methods: A retrospective chart review was performed of all adolescents from 2008 to 2010 undergoing LAGB at a single tertiary-care pediatric hospital.