Effects of short-term supervised exercise training on liver fat in adolescents with obesity: a randomized controlled trial.

OBJECTIVE: The objective of this study was to quantify the effects of a 4-week, supervised, high-intensity interval training (HIIT) on intrahepatic triglyceride content (IHTG, percentage), cardiorespiratory fitness (CRF), and cardiometabolic markers in adolescents with obesity. METHODS: A total of 40 adolescents (age 13-18 y, BMI 36.7 ± 5.8 kg/m2 ) at risk for metabolic dysfunction-associated steatotic liver disease (MASLD) based on obesity and elevated Fibroscan measured controlled attenuation parameter (CAP) scores were randomized to HIIT three times a week for 4 weeks (n = 34) or observation (control; n = 6). Liver magnetic resonance imaging proton-density fat-fraction (MRI-PDFF), CAP, oral glucose tolerance test, serum alanine aminotransferase, dual-energy x-ray absorptiometry, and CRF tests were performed before and after intervention. Within- and between-group differences were compared. RESULTS: A total of 13 (38%) and 4 (66%) children had MASLD by MRI-PDFF (IHTG ≥ 5%) in the HIIT and control groups, respectively. The implemented HIIT protocol had no impact on CRF or IHTG (baseline 5.26%, Δ = -0.31 percentage points, 95% CI: -0.77 to 0.15; p = 0.179), but it decreased the 2-h glucose concentration (baseline 116 mg/dL, Δ = -11 mg/dL; 95% CI: -17.6 to -5.5; p < 0.001). When limiting the analysis to participants with MASLD (n = 17), HIIT decreased IHTG (baseline 8.81%, Δ = -1.05 percentage points, 95% CI: -2.08 to -0.01; p = 0.048). Between-group comparisons were not different. CONCLUSIONS: The implemented exercise protocol did not reduce IHTG, but it led to modest improvement in markers of cardiometabolic health.

Circulating microRNAs Are Associated With Metabolic Markers in Adolescents With Hepatosteatosis.

Background: Altered hepatic microRNA (miRNA) expression may play a role in the development of insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD). Circulating miRNAs could mirror the liver metabolism. Objective: This study aimed to assess the relationship between serum miRNA profile in children with obesity, IR, and NAFLD. Methods: Adolescents with obesity (n = 31) were stratified based on insulin resistance and NAFLD status. One-hundred seventy-nine miRNAs were determined in the serum by quantitative RT-PCR. Differentially expressed miRNAs were compared between groups, and log-transformed levels correlated with metabolic markers and intrahepatic triglyceride. Results: Serum miR-21-5p, -22-3p, -150-5p, and -155-5p levels were higher in children with IR and NAFLD, and their expression levels correlated with hepatic fat and serum triglyceride. In patients with NAFLD, miR-155-5p correlated with ALT (r = 0.68, p<0.01) and AST (r = 0.64, p<0.01) and miR-21-5p and -22-3p levels correlated with plasma adiponectin (r = -0.71 and r = -0.75, respectively, p<0.05) and fibroblast growth factor-21 (r = -0.73 and r = -0.89, respectively, p<0.01). miR-27-3a level was higher in children without IR and NAFLD. Conclusions: Several miRNAs are differentially expressed in children with IR and NAFLD. Determining their mechanistic roles may provide newer diagnostic tools and therapeutic targets for pediatric NAFLD.

Osteomyelitis of the Rib in a Child With Indolent Symptoms.

We describe a case of osteomyelitis of the rib caused by methicillin-susceptible Staphylococcus aureus. The patient presented with a subtle, indolent course leading to a suspected 2-year delay in diagnosis. This case highlights that the diagnosis of rib osteomyelitis, which can readily mimic other diagnoses, such as costochondritis, intraabdominal infections, pneumonia, or malignancies warrants a high index of suspicion. Albeit rare, pediatricians should be aware of the possibility of rib osteomyelitis in healthy children to help ensure a prompt diagnosis and appropriate, timely management.

Fibroblast Growth Factor-21 to Adiponectin Ratio: A Potential Biomarker to Monitor Liver Fat in Children With Obesity.

Background: There is a pressing need for effective and non-invasive biomarkers to track intrahepatic triglyceride (IHTG) in children at-risk for non-alcoholic fatty liver disease (NAFLD), as standard-of-care reference tools, liver biopsy and magnetic resonance imaging (MRI), are impractical to monitor the course disease. Objective: We aimed to examine the association between serum fibroblast growth factor (FGF)-21 to adiponectin ratio (FAR) and IHTG as assessed by MRI in children with obesity. Methods: Serum FGF21 and adiponectin levels and IHTG were measured at two time points (baseline, 6 months) in obese children enrolled in a clinical weight loss program. The association between percent change in FAR and IHTG at final visit was examined using a multiple linear regression model. Results: At baseline, FAR was higher in the subjects with NAFLD (n = 23, 35.8 ± 41.9 pg/ng) than without NAFLD (n = 35, 19.8 ± 13.7 pg/ng; p = 0.042). Forty-eight subjects completed both visits and were divided into IHTG loss (≥1% reduction than baseline), no change (within ±1% change), and gain (≥1% increase than baseline) groups. At 6 months, the percent change in FAR was different among the three groups (p = 0.005). Multiple linear regression showed a positive relationship between percent change in FAR and the final liver fat percent in sex and pubertal stage-similar subjects with NAFLD at baseline (slope coefficient 6.18, 95% CI 1.90-10.47, P = 0.007), but not in those without NAFLD. Conclusions: Higher value in percent increase in FAR is positively associated with higher level of IHTG percent value at 6 months in children with baseline NAFLD. FAR could be a potential biomarker to monitor the changes in IHTG in children with NAFLD.

Making the diagnosis of midgut volvulus: Limited abdominal ultrasound has changed our clinical practice.

PURPOSE: To assess the diagnostic accuracy of limited abdominal ultrasound (US) examination for midgut volvulus (MGV) and to evaluate how clinical practice has changed in a free-standing children's hospital leading to the near obsolescence of upper GI (UGI) studies for the diagnosis of MGV. MATERIALS AND METHODS: All patients with suspected MGV who underwent abdominal US during 2016-2017 were identified using keyword search tools in the radiology information system. Retrospective, blinded image review was performed by a certificate of added qualification (CAQ), board certified pediatric radiologist. US images were evaluated for the presence of the superior mesenteric artery (SMA) cutoff sign and twisting of the bowel and mesentery around the SMA (whirlpool sign). The results were compared with the operative reports. RESULTS: 195 US studies were performed from 2016 to 2017. The most common presentations were vomiting (44%), abdominal pain (7%), and suspected malrotation (10%) 195 US studies were reviewed, of which 16 were nondiagnostic. The remaining 179 diagnostic studies showed MGV in 14 patients. Those 14 patients were surgically explored and confirmed to have midgut volvulus. 7 of the 16 nondiagnostic US studies were further evaluated with UGI examination with 1 patient demonstrating malrotation without volvulus, which was confirmed at surgery. 2 had CT exams which were normal. 4 were followed clinically. The remaining 3 patients went to surgery, all of which did not show MGV. There were 164 negative US, none of whom went to surgery. US was diagnostic in 92% of patients and when diagnostic the positive and negative predictive values of US were 100%. CONCLUSION: Limited abdominal US is a highly accurate examination for the diagnosis of midgut volvulus. UGI exposes patients to ionizing radiation and should be reserved for patients in whom US is nondiagnostic or inconclusive. TYPE OF STUDY: Retrospective review. LEVEL OF EVIDENCE: Level 3.

Optimizing image quality for pediatric torso computed tomography: the use of advanced iterative reconstruction and wide-detector scanning techniques.

OBJECTIVES: To compare radiation exposure and image quality in children undergoing torso helical acquisition computed tomography (CT) using filtered back projection (FBP) or adaptive iterative dose reduction (AIDR) 3D reconstruction algorithms. A secondary purpose is to compare radiation exposure and image quality in children undergoing torso CT acquired with helical or wide-detector techniques reconstructed with AIDR 3D. METHODS: The study was approved by the institutional review board. Phase 1 included 200 helical torso CT studies: 100 using FBP and 100 using AIDR 3D. The size-specific dose estimate (SSDE) was calculated for each study. Region of interest (ROI) noise measurements were recorded in the thorax, abdomen, and pelvis for each study. Unpaired t tests compared SSDE and image noise for each group. Phase 2 included 100 wide-detector CT torso studies using AIDR 3D. Size-specific dose estimate and ROI noise measurements were calculated. Unpaired t tests compared helical and wide-detector SSDE and ROI. Additional t tests looked for age- and weight-specific differences in the helical and wide-detector groups. RESULTS: Phase 1: AIDR 3D showed significant reduction in SSDE (P = 0.0001) and significant improvement in image quality. Phase 2: no significant difference in SSDE was observed. Children younger than 6 years had a significant reduction in SSDE with wide-detector technique (P = 0.0445) with no loss in image quality. CONCLUSIONS: Adaptive iterative dose reduction 3D produces significant reduction in radiation dose without degradation to image quality compared with FBP. Significant dose reduction without loss of image quality can also be obtained in younger, smaller children using wide-detector technique.

Pontine tegmental cap dysplasia with a 2q13 microdeletion involving the NPHP1 gene: insights into malformations of the mid-hindbrain.

The case of a young man with multiple brain and somatic anomalies that presented diagnostic difficulties, is discussed in this report. A majority of his features were suggestive of Joubert syndrome--although it was felt that he did not fully meet diagnostic criteria. The subsequent evaluations included a magnetic resonance image of the brain, that was found to be consistent with pontine tegmental cap dysplasia. Chromosomal microarray studies showed a 2q13 deletion. A gene associated with Joubert syndrome, NPHP1, is within this region. This case highlights several important aspects of the diagnosis and nosology of malformations of the mid-hind brain.

Development and implementation of a systems-based practice project requirement for radiology residents.

RATIONALE AND OBJECTIVES: Radiology residents must now participate in a learning activity that involves identification and analysis of system errors and implementation of potential solutions. Evidence of participation must be documented in the resident's learning portfolio. MATERIALS AND METHODS: An activity based on adult learning principles was designed for residents to increase their knowledge of health care systems and problems; gain experience in writing a proposal, conducting an investigation, and reporting results; organize and present information in a supportive environment; and document participation in their portfolio. Postgraduate year 2 residents identify a systems problem. A written proposal is required and must include a "plan" that includes a hypothesis, a methods section that explains what they will "do" as an intervention, a "study" that involves collection and analysis of relevant data, and a systems change or "act." Proposals approved by the program director are presented to the radiology department. Residents complete projects, evaluate their effectiveness, and present their results by spring of postgraduate year 3. RESULTS: Goals, objectives, and guidelines were written. Assessment tools were identified. From 2006 to 2008, nine projects were proposed and conducted by 12 residents. Local and national systems issues were selected, and interventions involved residents, faculty, and medical students. A timeline was imposed to promote sustained effort. CONCLUSION: Opportunities of daily work can be used to teach and learn systems-based practice concepts. Residents can use the scientific method to test effects of change on health care systems. Relevant and practical projects enable residents to learn while improving their clinical and learning environments.

Gadolinium-enhanced magnetic resonance angiography in neonates and infants suspected of caval or aortic thrombosis.

BACKGROUND: Gadolinium-enhanced magnetic resonance angiography (MRA)is a well-established technique in older children and adults. No studies have focused on its use in neonates and small infants. OBJECTIVE: Our objective was to study the use of gadolinium-enhanced MRA in neonates and infants suspected of caval or aortic thrombosis. MATERIALS AND METHODS: Gadolinium-enhanced MR angiography was performed on seven neonates and small infants for the evaluation of caval or aortic thrombosis. Gadolinium-DTPA at a dose of 0.3 mmol/kg (minimum dose 1 ml) was injected using a power injector (0.2 ml/s). Contrast-enhanced MRA was performed using a 3-D, fast, radiofrequency spoiled gradient-echo sequence (TR/TE: 4.8/1.1, flip angle 45 degrees , matrix 256 x 128, slice thickness 2.6 mm interpolated to 1.3 mm, FOV variable, NEX=1.0). RESULTS: Diagnostic-quality angiograms were obtained in all seven neonates. Superior vena cava thrombosis was identified in two neonates, and abdominal aortic thrombosis was present in one neonate. CONCLUSION: It is practical to perform gadolinium-enhanced MRA in neonates weighing as little as 600 g for the detection of caval or aortic thrombosis.

Imaging of articular disorders in children.

This article reviews aspects of arthritis imaging that are specific to children. The pediatric skeleton is unique and responds in characteristic ways to articular inflammation. Epiphyseal and physeal cartilage are affected by joint diseases, and disturbances of growth and maturation are sometimes the cardinal manifestations of arthritis. The target joints of pediatric articular diseases differ considerably from those of diseases in adults. Imaging techniques should be tailored to the children being studied.