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Background: Multiparametric MRI provides assessment of functional and structural parameters in kidney allografts. It offers a non‐invasive alternative to the current reference standard of kidney biopsy. Purpose: To evaluate the diagnostic and prognostic utility of MRI parameters in the assessment of allograft function in the first 3‐months post‐transplantation. Study Type: Prospective. Subjects: 32 transplant recipients (54 ± 17 years, 20 females), divided into two groups according to estimated glomerular filtration rate (eGFR) at 3‐months post‐transplantation: inferior graft function (IGF; eGFR<45 mL/min/1.73 m2, n = 10) and superior graft function (SGF; eGFR ≥ 45 mL/min/1.73 m2, n = 22). Further categorization was based on the need for hemodialysis (C1) and decrease in s‐creatinine (C2) at 1‐week post‐transplantation: delayed‐graft‐function (DGF: n = 4 C1, n = 10 C2) and early graft‐function (EGF: n = 28 C1, n = 22 C2). Field Strength/Sequence: 3‐T, pseudo‐continuous arterial spin labeling, T1‐mapping, and diffusion‐weighted imaging. Assessment: Multiparametric MRI was evaluated at 1‐week in all patients and 3‐months after transplantation in 28 patients. Renal blood flow (RBF), diffusion coefficients (ADC, ΔADC, D, ∆D, D*, flowing fraction f), T1 and ∆T1 were calculated in cortex and medulla. The diagnostic and prognostic value of these parameters, obtained at 3‐months and 1‐week post‐transplantation, respectively, was evaluated in the cortex to discriminate between DGF and EGF, and between SGF and IGF. Statistical Tests: Logistic regression, receiver‐operating‐characteristics, area‐under‐the‐curve (AUC), confidence intervals (CIs), analysis‐of‐variance, t‐test, Wilcoxon‐Mann–Whitney test, Fisher's exact test, Pearson's correlation. P‐value<0.05 was considered significant. Results: DGF patients exhibited significantly lower cortical RBF and f and higher D*. The diagnostic value of MRI for detecting DGF was excellent (AUC = 100%). Significant differences between patients with IGF and SGF were found in RBF, ∆T1, and ∆D. Multiparametric MRI showed higher diagnostic (AUC = 95.32%; CI: 88%–100%) and prognostic (AUC = 97.47%, CI: 92%–100%) values for detecting IGF than eGFR (AUC = 89.50%, CI: 79%–100%). Data Conclusion: Multiparametric MRI may show high diagnostic and prognostic value in transplanted patients, yielding better results compared to eGFR measurements. Level of Evidence: 2 Technical Efficacy: Stage 1 [ABSTRACT FROM AUTHOR]

Objectives: Fat depots localization has a critical role in the metabolic health status of adults. Nevertheless, whether that is also the case in children remains under‐studied. Therefore, the aims of this study were: (i) to examine the differences between metabolically healthy (MHO) and unhealthy (MUO) overweight/obesity phenotypes on specific abdominal fat depots, and (ii) to further explore whether cardiorespiratory fitness plays a major role in the differences between metabolic phenotypes among children with overweight/obesity. Methods: A total of 114 children with overweight/obesity (10.6 ± 1.1 years, 62 girls) were included. Children were classified as MHO (n = 68) or MUO. visceral (VAT), abdominal subcutaneous (ASAT), intermuscular abdominal (IMAAT), psoas, hepatic, pancreatic, and lumbar bone marrow adipose tissues were measured by magnetic resonance imaging. Cardiorespiratory fitness was assessed using the 20 m shuttle run test. Results: MHO children had lower VAT and ASAT contents and psoas fat fraction compared to MUO children (difference = 12.4%–25.8%, all p < 0.035). MUO‐unfit had more VAT and ASAT content than those MUO‐fit and MHO‐fit (difference = 34.8%–45.3%, all p < 0.044). MUO‐unfit shows also greater IMAAT fat fraction than those MUO‐fit and MHO‐fit peers (difference = 16.4%–13.9% respectively, all p ≤ 0.001). In addition, MHO‐unfit presented higher IMAAT fat fraction than MHO‐fit (difference = 13.4%, p < 0.001). MUO‐unfit presented higher psoas fat fraction than MHO‐fit (difference = 29.1%, p = 0.008). Conclusions: VAT together with ASAT and psoas fat fraction, were lower in MHO than in MUO children. Further, we also observed that being fit, regardless of metabolic phenotype, has a protective role over the specific abdominal fat depots among children with overweight/obesity. [ABSTRACT FROM AUTHOR]

Monitoring renal allograft function after transplantation is key for the early detection of allograft impairment, which in turn can contribute to preventing the loss of the allograft. Multiparametric renal MRI (mpMRI) is a promising noninvasive technique to assess and characterize renal physiopathology; however, few studies have employed mpMRI in renal allografts with stable function (maintained function over a long time period). The purposes of the current study were to evaluate the reproducibility of mpMRI in transplant patients and to characterize normal values of the measured parameters, and to estimate the labeling efficiency of Pseudo-Continuous Arterial Spin Labeling (PCASL) in the infrarenal aorta using numerical simulations considering experimental measurements of aortic blood flow profiles. The subjects were 20 transplant patients with stable kidney function, maintained over 1 year. The MRI protocol consisted of PCASL, intravoxel incoherent motion, and T1 inversion recovery. Phase contrast was used to measure aortic blood flow. Renal blood flow (RBF), diffusion coefficient (D), pseudo-diffusion coefficient (D*), flowing fraction (f), and T1 maps were calculated and mean values were measured in the cortex and medulla. The labeling efficiency of PCASL was estimated from simulation of Bloch equations. Reproducibility was assessed with the within-subject coefficient of variation, intraclass correlation coefficient, and Bland-Altman analysis. Correlations were evaluated using the Pearson correlation coefficient. The significance level was p less than 0.05. Cortical reproducibility was very good for T1, D, and RBF, moderate for f, and low for D*, while medullary reproducibility was good for T1 and D. Significant correlations in the cortex between RBF and f (r=0.66), RBF and eGFR (r=0.64), and D* and eGFR (r=-0.57) were found. Normal values of the measured parameters employing the mpMRI protocol in kidney transplant patients with stable function were characterized and the results showed good reproducibility of the techniques. [ABSTRACT FROM AUTHOR]

Summary: Background: The early detection and management of children with metabolic associated fatty liver disease (MAFLD) is challenging. Objective: To develop a non‐invasive and accurate prediction protocol for the identification of MAFLD among children with overweight/obesity candidates to confirmatory diagnosis. Methods: A total of 115 children aged 8–12 years with overweight/obesity, recruited at a primary care, were enrolled in this cross‐sectional study. The external validation was performed using a cohort of children with overweight/obesity (N = 46) aged 8.5–14.0 years. MAFLD (≥5.5% hepatic fat) was diagnosed by magnetic resonance imaging (MRI). Fasting blood biochemical parameters were measured, and 25 candidates' single nucleotide polymorphisms (SNPs) were determined. Variables potentially associated with the presence of MAFLD were included in a multivariate logistic regression. Results: Children with MAFLD (36%) showed higher plasma triglycerides (TG), insulin, homeostasis model assessment of insulin resistance (HOMA‐IR), alanine aminotransferase (ALT), aspartate transaminase (AST), glutamyl‐transferase (GGT) and ferritin (p < 0.05). The distribution of the risk‐alleles of PPARGrs13081389, PPARGrs1801282, HFErs1800562 and PNLPLA3rs4823173 was significantly different between children with and without MAFLD (p < 0.05). Three biochemical‐ and/or SNPs‐based predictive models were developed, showing strong discriminatory capacity (AUC‐ROC: 0.708–0.888) but limited diagnostic performance (sensitivity 67%–82% and specificity 63%–69%). A prediction protocol with elevated sensitivity (72%) and specificity (84%) based on two consecutive steps was developed. The external validation showed similar results: sensitivity of 70% and specificity of 85%. Conclusions: The HEPAKID prediction protocol is an accurate, easy to implant, minimally invasive and low economic cost tool useful for the early identification and management of paediatric MAFLD in primary care. [ABSTRACT FROM AUTHOR]

Objectives: To examine the relationship between physical fitness and physical activity (PA) with specific abdominal fat depots and their potential implications for cardiometabolic risk and insulin resistance (IR) in children with overweight/obesity. Materials and Methods: A total of 116 children with overweight/obesity (10.7 ± 1.1 year, 54% girls) participated in the study. Abdominal visceral (VAT), subcutaneous (ASAT), and intermuscular abdominal adipose tissue (IMAAT) were assessed by magnetic resonance imaging. The cardiometabolic risk (MetS) score and the insulin resistance homeostasis model assessment (HOMA‐IR) were calculated. Health‐related physical fitness components (treadmill test, and 20 m shuttle run, handgrip, standing broad jump and 4 × 10 m tests) were evaluated, and PA was measured (accelerometry). Children were categorized as fit or unfit for each specific fitness test, and as active or inactive. Results: Higher VAT, ASAT, and IMAAT were associated with higher MetS score and HOMA‐IR (all p < 0.02). A better performance in all fitness tests and total and vigorous PA were strongly associated with lower VAT (all p < 0.04), ASAT (all p < 0.005), and IMAAT (all p < 0.005). Fit or active children had lower VAT, ASAT, and IMAAT (all p < 0.03) than their unfit or inactive counterparts. Conclusion: These results reinforce the importance of having adequate fitness and PA levels to reduce abdominal fat accumulation in children. Given that VAT, ASAT, and IMAAT are associated with higher risk of developing cardiovascular diseases and type 2 diabetes, the improvement of physical fitness by the promotion of PA should be goals of lifestyle interventions for improving health in children with overweight/obesity. [ABSTRACT FROM AUTHOR]