Accuracy of elastography versus biopsy in assessing severity of liver fibrosis in young Fontan patients.

OBJECTIVES: We performed a single-centre retrospective study comparing the accuracy of non-invasive elastography with liver biopsy in accurate assessment of Fontan-associated liver disease. METHODS: Fontan patients who underwent combined assessment with a percutaneous liver biopsy and non-invasive elastography between January 2015 and December 2023 at our Children's hospital were included. Liver biopsies were classified using the Congestive Hepatic Fibrosis Score as early Fontan-associated liver disease (scores 1, 2) and advanced Fontan-associated liver disease (score 3/bridging fibrosis and score 4/cirrhosis). Elastography values were categorised as advanced Fontan-associated liver disease for liver elasticity >2.1 m/s by ultrasound and liver stiffness >5 KPa on magnetic resonance elastography. RESULTS: We included 130 patients (116 children, 89%, mean age at biopsy: 14.6 years ± 3.6) who underwent liver biopsy at a mean duration of 11.1 years (±0.3) following Fontan surgery. Advanced Fontan-associated liver disease was noted in 41 (31.5%) patients with 13 (10%) showing frank cirrhosis. Pre-biopsy ultrasound showed advanced liver fibrosis in 18/125 (14%), with low sensitivity (23%), high specificity (90%), and low accuracy (68%, k = 0.1) in diagnosing advanced Fontan-associated liver disease. Similarly, pre-biopsy magnetic resonance elastography showed advanced fibrosis in 23/86 (27%) of patients, with low sensitivity (30%), fair specificity (75%), and low accuracy (63%, k = 0.1). Interestingly, advanced Fontan-associated liver disease was missed by ultrasound in 29% and by magnetic resonance elastography in 25% of patients. Advanced Fontan-associated liver disease was associated with lower platelet count (p = 0.02) and higher Gamma-glutamyl Transferase levels (p = 0.02). CONCLUSION: Advanced hepatic fibrosis is common among paediatric Fontan patients. Non-invasive elastography may overestimate and underestimate the degree of liver fibrosis, and therefore, liver biopsy may be required for confirming disease severity.

Organ fat in Latino youth at risk for type 2 diabetes.

PURPOSE: Obesity in youth increases the risk for type 2 diabetes (T2D) and elevated abdominal adipose tissue and organ fat may be particularly deleterious. The purpose of this study was to examine associations among measures of adiposity including total, visceral, and organ fat (hepatic and pancreatic) and whether these measures were independently associated with glycemia in Latino youth at risk for diabetes. METHODS: Latino adolescents (47 boys and 32 girls, 13.7 ± 1.4 years) with obesity (BMIz 2.3 ± 0.3) were assessed for total fat by DXA and visceral and organ fat by 3 T magnetic resonance imaging. Glycemic indicators included HbA1c, fasting glucose (FG), and 2-h glucose (2-HrG) following an oral glucose tolerance test. Pearson correlations and stepwise linear regression analyses controlling for age and sex were used to examine independent associations between adiposity and glycemia. RESULTS: Total fat was associated with visceral (r = 0.66, p = 0.001) and hepatic fat (r = 0.34, p < 0.01) while visceral fat was associated with hepatic (r = 0.42, p < 0.001) and pancreatic fat (r = 0.36, p < 0.001). In stepwise linear regression analysis, hepatic and pancreatic fat were significant predictors of FG, explaining 4.7% and 5.2% of the variance, respectively (total R2  = 0.14, p = 0.02). Hepatic fat was the only significant predictor of 2-HrG explaining 9.9% of the variance in the model (total R2  = 0.12, p = 0.03). No measure of adiposity was retained as a significant predictor of HbA1c. CONCLUSION: Hepatic and pancreatic fat were the only adiposity measures independently associated with glycemia but the small amount of variance explained underscores the need for additional T2D biomarkers in high risk youth.

Communicating incidental and reportable findings from research MRIs: considering factors beyond the findings in an underrepresented pediatric population.

BACKGROUND: The application of advanced imaging in pediatric research trials introduces the challenge of how to effectively handle and communicate incidental and reportable findings. This challenge is amplified in underserved populations that experience disparities in access to healthcare as recommendations for follow-up care may be difficult to coordinate. Therefore, the purpose of the present report is to describe the process for identifying and communicating findings from a research MRI to low-income Latino children and families. METHODS: Latino adolescents (n = 86) aged 12-16 years old with obesity and prediabetes underwent a research MRI (3 Tesla Philips Ingenia®) as part of a randomized controlled diabetes prevention trial. The research MRIs were performed at baseline and 6 months to assess changes in whole-abdominal fat distribution and organ fat in response to the intervention. An institutional pathway was developed for identifying and reporting findings to participants and families. The pathway was developed through a collaborative process with hospital administration, research compliance, radiology, and the research team. All research images were reviewed by a board-certified pediatric radiologist who conveyed findings to the study pediatrician for determination of clinical actionability and reportability to children and families. Pediatric sub-specialists were consulted as necessary and a primary care practitioner (PCP) from a free community health clinic agreed to receive referrals for uninsured participants. RESULTS: A total of 139 images (86 pre- and 53 post-intervention) were reviewed with 31 findings identified and 23 deemed clinically actionable and reportable. The only reportable finding was severely elevated liver fat (> 10%, n = 14) with the most common and concerning incidental findings being horseshoe kidney (n = 1) and lung lesion (n = 1). The remainder (n = 7) were less serious. Of youth with a reportable or incidental finding, 18 had a PCP but only 7 scheduled a follow-up appointment. Seven participants without a PCP were referred to a safety-net clinic for follow-up. CONCLUSIONS: With the increased utilization of high-resolution imaging in pediatric research, additional standardization is needed on what, when, and how to return incidental and reportable findings to participants, particularly among historically underrepresented populations that may be underserved in the community. TRIAL REGISTRATION: Preventing Diabetes in Latino Youth, NCT02615353.

Bone marrow adipose tissue content in Latino adolescents with prediabetes and obesity.

OBJECTIVE: This study aimed to examine whether total, regional, and organ fat predicts bone marrow adipose tissue (BMAT) fat content and to explore whether BMAT fat content differs by sex among Latino youth. METHODS: Latino youth (n = 86; age 13.6 [1.4] years, 62% male) with obesity (BMI percentile = 98.5% [1.2%]) underwent a dual-energy x-ray absorptiometry scan to assess body composition and a magnetic resonance imaging scan to determine abdominal adiposity, liver fat, and vertebral BMAT fat content in the thoracic (average of T8-T12) and lumbar (average of L1-L5) spine. RESULTS: Male youth exhibited significantly greater thoracic (male youth = 30.8% [1.4%] vs. female youth = 24.5% [2.1%], p = 0.027) and lumbar (male youth = 36.3% [1.5%] vs. female youth = 30.2% [2.2%], p = 0.038) BMAT fat content compared with female youth. Visceral adipose tissue was a significant predictor of thoracic (ß = 0.434, t[86] = 3.016, p = 0.003) and lumbar (ß = 0.389, t[86] = 2.677, p = 0.009) BMAT fat content, explaining 8.9% and 6.9% of the variance, respectively. Liver fat was a significant predictor of both thoracic (ß = 0.487, t[86] = 4.334, p < 0.001) and lumbar (ß = 0.436, t[86] = 3.793, p < 0.001) BMAT fat content, explaining 17.6% and 13.8% of the variance, respectively. CONCLUSIONS: Male youth had significantly greater thoracic and lumbar BMAT fat content than female youth. Greater BMAT fat content is associated with greater liver fat and visceral adipose tissue among youth with obesity. Further investigation of the mechanistic underpinnings of BMAT may help to differentiate its metabolic and bone-related functions.

CT Findings of Pediatric Handlebar Injuries.

Direct bicycle handlebar injuries are a significant cause of chest and abdominal trauma and morbidity in the pediatric population. However, these injuries have been underemphasized. While blunt abdominal trauma has been described well, the literature is limited in reviewing trauma imaging specifically related to direct handlebar injuries in the pediatric population. Major chest injuries include lung contusions, pneumatoceles, and pneumothorax. In the abdomen, injuries to the pancreas, small bowel, mesentery, liver, and spleen are the more common abdominal injuries attributed to direct handlebar trauma. Traumatic abdominal wall hernias and groin injuries, which may be associated with vascular injuries, are other known injuries. The challenge is in both clinical and radiographic diagnosis. The physical findings are often underwhelming, and laboratory values in many studies are shown to be not very sensitive or specific. As a result, there is a risk of delay in imaging, diagnosis, and treatment of significant and sometimes life-threatening injuries. CT is considered the standard examination to delineate intra-abdominal trauma, with a reported sensitivity of 60%-88% and a specificity of 97%-99%. Moreover, CT helps in grading some types of injury and helps guide the surgical treatment course. It is important for radiologists who perform imaging in adults and children to be aware of the significance of direct handlebar injuries and their imaging findings. ©RSNA, 2020.