Self-Gated Radial Free-Breathing Liver MR Elastography: Assessment of Technical Performance in Children at 3 T.

BACKGROUND: Conventional liver magnetic resonance elastography (MRE) requires breath-holding (BH) to avoid motion artifacts, which is challenging for children. While radial free-breathing (FB)-MRE is an alternative for quantifying liver stiffness (LS), previous methods had limitations of long scan times, acquiring two slices in 5 minutes, and not resolving motion during reconstruction. PURPOSE: To reduce FB-MRE scan time to 4 minutes for four slices and to investigate the impact of self-gated (SG) motion compensation on FB-MRE LS quantification in terms of agreement, intrasession repeatability, and technical quality compared to conventional BH-MRE. STUDY TYPE: Prospective. POPULATION: Twenty-six children without fibrosis (median age: 12.9 years, 15 females). FIELD STRENGTH/SEQUENCE: 3 T; Cartesian gradient-echo (GRE) BH-MRE, research application radial GRE FB-MRE. ASSESSMENT: Participants were scanned twice to measure repeatability, without moving the table or changing the participants' position. LS was measured in areas of the liver with numerical confidence ≥90%. Technical quality was examined using measurable liver area (%). STATISTICAL TESTS: Agreement of LS between BH-MRE and FB-MRE was evaluated using Bland-Altman analysis for SG acceptance rates of 40%, 60%, 80%, and 100%. LS repeatability was assessed using within-subject coefficient of variation (wCV). The differences in LS and measurable liver area were examined using Kruskal-Wallis and Wilcoxon signed-rank tests. P < 0.05 was considered significant. RESULTS: FB-MRE with 60% SG achieved the closest agreement with BH-MRE (mean difference 0.00 kPa). The LS ranged from 1.70 to 1.83 kPa with no significant differences between BH-MRE and FB-MRE with varying SG rates (P = 0.52). All tested methods produced repeatable LS with wCV from 4.4% to 6.5%. The median measurable liver area was smaller for FB-MRE (32%-45%) than that for BH-MRE (91%-93%) (P < 0.05). DATA CONCLUSION: FB-MRE with 60% SG can quantify LS with close agreement and comparable repeatability with respect to BH-MRE in children. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

Uncertainty-aware physics-driven deep learning network for free-breathing liver fat and R2 * quantification using self-gated stack-of-radial MRI.

PURPOSE: To develop a deep learning-based method for rapid liver proton-density fat fraction (PDFF) and R2 * quantification with built-in uncertainty estimation using self-gated free-breathing stack-of-radial MRI. METHODS: This work developed an uncertainty-aware physics-driven deep learning network (UP-Net) to (1) suppress radial streaking artifacts because of undersampling after self-gating, (2) calculate accurate quantitative maps, and (3) provide pixel-wise uncertainty maps. UP-Net incorporated a phase augmentation strategy, generative adversarial network architecture, and an MRI physics loss term based on a fat-water and R2 * signal model. UP-Net was trained and tested using free-breathing multi-echo stack-of-radial MRI data from 105 subjects. UP-Net uncertainty scores were calibrated in a validation dataset and used to predict quantification errors for liver PDFF and R2 * in a testing dataset. RESULTS: Compared with images reconstructed using compressed sensing (CS), UP-Net achieved structural similarity index >0.87 and normalized root mean squared error <0.18. Compared with reference quantitative maps generated using CS and graph-cut (GC) algorithms, UP-Net achieved low mean differences (MD) for liver PDFF (-0.36%) and R2 * (-0.37 s-1 ). Compared with breath-holding Cartesian MRI results, UP-Net achieved low MD for liver PDFF (0.53%) and R2 * (6.75 s-1 ). UP-Net uncertainty scores predicted absolute liver PDFF and R2 * errors with low MD of 0.27% and 0.12 s-1 compared to CS + GC results. The computational time for UP-Net was 79 ms/slice, whereas CS + GC required 3.2 min/slice. CONCLUSION: UP-Net rapidly calculates accurate liver PDFF and R2 * maps from self-gated free-breathing stack-of-radial MRI. The pixel-wise uncertainty maps from UP-Net predict quantification errors in the liver.

Gut Microbes and Circulating Cytokines in Preterm Infants with Growth Failure.

BACKGROUND: Growth failure (GF) is a multifactorial problem in preterm infants. The intestinal microbiome and inflammation may contribute to GF. OBJECTIVES: This study's objective was to compare the gut microbiome and plasma cytokines in preterm infants with and without GF. METHODS: This was a prospective cohort study of infants with birth weights of <1750 g. Infants with a weight or length z-score change from birth to discharge or death that was less than or equal to -0.8 (GF group) were compared with infants without GF [control (CON) group]. The primary outcome was the gut microbiome (at weeks 1-4 of age), assessed by 16S rRNA gene sequencing using Deseq2. Secondary outcomes included inferred metagenomic function and plasma cytokines. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States determined metagenomic function, which was compared using ANOVA. Cytokines were measured by 2-multiplexed immunometric assays and compared using Wilcoxon tests and linear mixed models. RESULTS: GF (n = 14) and CON group (n = 13) had similar median (IQR) birth weight (1380 [780-1578] g vs. 1275 [1013-1580] g) and gestational age (29 [25-31] weeks vs. 30 [29-32] weeks). Compared with the CON group, the GF group had a greater abundance of Escherichia/Shigella in weeks 2 and 3, Staphylococcus in week 4, and Veillonella in weeks 3 and 4 (P-adjusted < 0.001 for all). Plasma cytokine concentrations did not differ significantly between the cohorts. When all time points are combined, fewer microbes were involved in TCA cycle activity in the GF group compared with the CON group (P = 0.023). CONCLUSIONS: In this study, when compared with CON infants, GF infants had a distinct microbial signature with increased Escherichia/Shigella and Firmicutes and fewer microbes associated with energy production at later weeks of hospitalization. These findings may suggest a mechanism for aberrant growth.

Using Free-Breathing MRI to Quantify Pancreatic Fat and Investigate Spatial Heterogeneity in Children.

BACKGROUND: MRI acquisition for pediatric pancreatic fat quantification is limited by breath-holds (BH). Full segmentation (FS) or small region of interest (ROI) analysis methods may not account for pancreatic fat spatial heterogeneity, which may limit accuracy. PURPOSE: To improve MRI acquisition and analysis for quantifying pancreatic proton-density fat fraction (pPDFF) in children by investigating free-breathing (FB)-MRI, characterizing pPDFF spatial heterogeneity, and relating pPDFF to clinical markers. STUDY TYPE: Prospective. POPULATION: A total of 34 children, including healthy (N = 16, 8 female) and overweight (N = 18, 5 female) subjects. FIELD STRENGTH AND SEQUENCES: 3 T; multiecho gradient-echo three-dimensional (3D) stack-of-stars FB-MRI, multiecho gradient-echo 3D Cartesian BH-MRI. ASSESSMENT: A radiologist measured FS- and ROI-based pPDFF on FB-MRI and BH-MRI PDFF maps, with anatomical images as references. Regional pPDFF in the pancreatic head, body, and tail were measured on FB-MRI. FS-pPDFF, ROI-pPDFF, and regional pPDFF were compared, and related to clinical markers, including hemoglobin A1c. STATISTICAL TESTS: T-test, Bland-Altman analysis, Lin's concordance correlation coefficient (CCC), one-way analysis of variance, and Spearman's rank correlation coefficient were used. P < 0.05 was considered significant. RESULTS: FS-pPDFF and ROI-pPDFF from FB-MRI and BH-MRI had mean difference = 0.4%; CCC was 0.95 for FS-pPDFF and 0.62 for ROI-pPDFF. FS-pPDFF was higher than ROI-pPDFF (10.4% ± 6.4% vs. 4.2% ± 2.8%). Tail-pPDFF (11.6% ± 8.1%) was higher than body-pPDFF (8.9% ± 6.3%) and head-pPDFF (8.7% ± 5.2%). Head-pPDFF and body-pPDFF positively correlated with hemoglobin A1c. DATA CONCLUSION: FB-MRI pPDFF is comparable to BH-MRI. Spatial heterogeneity affects pPDFF quantification. Regional measurements of pPDFF in the head and body were correlated with hemoglobin A1c, a marker of insulin sensitivity. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

A Pilot Single-Site Randomized Control Trial: Investigating the Use of Donor Milk in Late Preterm and Term Infants in the Neonatal Intensive Care Unit.

OBJECTIVE: We aimed to study donor milk (DM) supplementation when mother's own milk (MOM) was unavailable in term and late preterm infants (LPIs) admitted to the neonatal intensive care unit (NICU). We hypothesized that this study would be feasible, defined by the rate of consent, diet adherence, and study completion. We further hypothesized that compared with formula supplementation, DM supplementation, for no longer than 7 days from birth, would be associated with an increase in breastfeeding attempts and the percentage of MOM (MOM%) without adversely affecting growth. Breastfeeding attempts and MOM% were assessed over 48 hours at the end of the intervention, which was defined as NICU discharge or at the end of supplementation, whichever came sooner. STUDY DESIGN: This was a pilot study (n = 32). Infants with a gestational age > 34 weeks admitted to the NICU were included. Infants were randomized to one of two groups: human milk (MOM + DM) or formula (MOM + F). RESULTS: The consent rate was 52%. Adherence to the study diet was 97%, and completion was 100%. When the MOM + DM group was compared with the MOM + F group, there was no difference in breastfeeding attempts (median [interquartile range]: 3.5 [1.5-6] vs. 1.5 [0.5-4] times, p = 0.1) or MOM% (60 vs. 59%, p = 0.9). Weight and length at multiple time points were similar when the groups were compared. CONCLUSION: A study randomizing term and LPIs in the NICU to DM or formula when MOM was unavailable is feasible. It remains unclear if DM improves breastfeeding success in this population. KEY POINTS: · A study that randomizes term and late preterm infants in the NICU to DM or formula supplementation when mother's own milk is not available is feasible.. · It remains unclear if DM compared to formula supplementation improves direct breastfeeding.. · In general, growth was similar in infants who received DM or formula as a supplement..

Use of Intravenous Soybean and Fish Oil Emulsions in Pediatric Intestinal Failure-Associated Liver Disease: A Multicenter Integrated Analysis Report on Extrahepatic Adverse Events.

OBJECTIVE: To compare extrahepatic adverse events during fish oil lipid emulsion (FOLE) or soybean oil lipid emulsion (SOLE) treatment in children with intestinal failure-associated liver disease (IFALD). STUDY DESIGN: In this multicenter integrated analysis, bleeding, bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), infections, and signs of lipid emulsion intolerance were compared between FOLE recipients (1 g/kg/d) (n = 189) and historical controls who received SOLE (≤3 g/kg/d) (n = 73). RESULTS: When compared with SOLE recipients, FOLE recipients had a lower gestational age (30.5 vs 33.0 weeks; P = .0350) and higher baseline direct bilirubin (DB) (5.8 vs 3.0 mg/dL; P < .0001). FOLE recipients had a decreased incidence of bleeding (P < .0001), BPD (P < .001), ROP (P < .0156), bacterial and fungal infections (P < .0001), and lipid intolerance signs (P < .02 for all). Patients with bleeding vs patients without bleeding had higher baseline DB; the ORs for baseline DB (by mg/dL) and treatment (FOLE vs SOLE) were 1.20 (95% CI: 1.10, 1.31; P ≤ .0001) and 0.22 (95% CI: 0.11, 0.46; P ≤ .0001), respectively. In preterm infants, a higher BPD (P < .0001) and ROP incidence (P = .0071) was observed in SOLE recipients vs FOLE recipients. CONCLUSIONS: Children with IFALD who received FOLE had fewer extrahepatic adverse events, including a decreased incidence of bleeding, preterm comorbidities, and lipid intolerance signs compared with children with IFALD who received SOLE. TRIAL REGISTRATION CLINICALTRIALS.GOV: NCT00910104 and NCT00738101.

Free-breathing radial magnetic resonance elastography of the liver in children at 3 T: a pilot study.

BACKGROUND: Magnetic resonance (MR) elastography of the liver measures hepatic stiffness, which correlates with the histopathological staging of liver fibrosis. Conventional Cartesian gradient-echo (GRE) MR elastography requires breath-holding, which is challenging for children. Non-Cartesian radial free-breathing MR elastography is a potential solution to this problem. OBJECTIVE: To investigate radial free-breathing MR elastography for measuring hepatic stiffness in children. MATERIALS AND METHODS: In this prospective pilot study, 14 healthy children and 9 children with liver disease were scanned at 3 T using 2-D Cartesian GRE breath-hold MR elastography (22 s/slice) and 2-D radial GRE free-breathing MR elastography (163 s/slice). Each sequence was acquired twice. Agreement in the stiffness measurements was evaluated using Lin's concordance correlation coefficient (CCC) and within-subject mean difference. The repeatability was assessed using the within-subject coefficient of variation and intraclass correlation coefficient (ICC). RESULTS: Fourteen healthy children and seven children with liver disease completed the study. Median (±interquartile range) normalized measurable liver areas were 62.6% (±26.4%) and 44.1% (±39.6%) for scan 1, and 60.3% (±21.8%) and 43.9% (±44.2%) for scan 2, for Cartesian and radial techniques, respectively. Hepatic stiffness from the Cartesian and radial techniques had close agreement with CCC of 0.89 and 0.94, and mean difference of 0.03 kPa and -0.01 kPa, for scans 1 and 2. Cartesian and radial techniques achieved similar repeatability with within-subject coefficient of variation=1.9% and 3.4%, and ICC=0.93 and 0.92, respectively. CONCLUSION: In this pilot study, radial free-breathing MR elastography was repeatable and in agreement with Cartesian breath-hold MR elastography in children.

Initial Laparotomy Versus Peritoneal Drainage in Extremely Low Birthweight Infants With Surgical Necrotizing Enterocolitis or Isolated Intestinal Perforation: A Multicenter Randomized Clinical Trial.

OBJECTIVE: The aim of this study was to determine which initial surgical treatment results in the lowest rate of death or neurodevelopmental impairment (NDI) in premature infants with necrotizing enterocolitis (NEC) or isolated intestinal perforation (IP). SUMMARY BACKGROUND DATA: The impact of initial laparotomy versus peritoneal drainage for NEC or IP on the rate of death or NDI in extremely low birth weight infants is unknown. METHODS: We conducted the largest feasible randomized trial in 20 US centers, comparing initial laparotomy versus peritoneal drainage. The primary outcome was a composite of death or NDI at 18 to 22 months corrected age, analyzed using prespecified frequentist and Bayesian approaches. RESULTS: Of 992 eligible infants, 310 were randomized and 96% had primary outcome assessed. Death or NDI occurred in 69% of infants in the laparotomy group versus 70% with drainage [adjusted relative risk (aRR) 1.0; 95% confidence interval (CI): 0.87-1.14]. A preplanned analysis identified an interaction between preoperative diagnosis and treatment group (P = 0.03). With a preoperative diagnosis of NEC, death or NDI occurred in 69% after laparotomy versus 85% with drainage (aRR 0.81; 95% CI: 0.64-1.04). The Bayesian posterior probability that laparotomy was beneficial (risk difference <0) for a preoperative diagnosis of NEC was 97%. For preoperative diagnosis of IP, death or NDI occurred in 69% after laparotomy versus 63% with drainage (aRR, 1.11; 95% CI: 0.95-1.31); Bayesian probability of benefit with laparotomy = 18%. CONCLUSIONS: There was no overall difference in death or NDI rates at 18 to 22 months corrected age between initial laparotomy versus drainage. However, the preoperative diagnosis of NEC or IP modified the impact of initial treatment.

Fish Oil Emulsion Reduces Liver Injury and Liver Transplantation in Children with Intestinal Failure-Associated Liver Disease: A Multicenter Integrated Study.

OBJECTIVE: To compare the aspartate aminotransferase to platelet ratio index, liver transplantation, and mortality rates between children with intestinal failure-associated liver disease who received fish oil lipid emulsion (FOLE) or soybean oil intravenous lipid emulsion (SOLE). STUDY DESIGN: In this multicenter integrated analysis, FOLE recipients (1 g/kg/d) (n = 189) were compared with historical controls administered SOLE (≤3 g/kg/d) (n = 73). RESULTS: Compared with SOLE, FOLE recipients had a higher direct bilirubin level at baseline (5.8 mg/dL vs 3.0 mg/dL; P < .0001). Among FOLE recipients, 65% experienced cholestasis resolution vs 16% of SOLE recipients (P < .0001). The aspartate aminotransferase to platelet ratio index scores improved in FOLE recipients (1.235 vs 0.810 and 0.758, P < .02) but worsened in SOLE recipients (0.540 vs 2.564 and 2.098; P ≤ .0003) when baseline scores were compared with cholestasis resolution and end of study, respectively. Liver transplantation was reduced in FOLE vs SOLE (4% vs 12%; P = .0245). The probability of liver transplantation in relation to baseline direct or conjugated bilirubin (DB) was lower in FOLE vs SOLE recipients (1% vs 9% at DB of 2 mg/dL; 8% vs 35% at DB of 12.87 mg/dL; P = .0022 for both). Death rates were similar (FOLE vs SOLE: 10% vs 14% at DB of 2 mg/dL; 17% vs 23% at a DB of 12.87 mg/dL; P = .36 for both). CONCLUSIONS: FOLE recipients experienced a higher rate of cholestasis resolution, lower aspartate aminotransferase to platelet ratio index, and fewer liver transplants compared with SOLE. This study demonstrates that FOLE may be the preferred parenteral lipid emulsion in children with intestinal failure-associated liver disease when DB reaches 2 mg/dL. TRIAL REGISTRATION: Clinicaltrials.gov: NCT00910104 and NCT00738101.

Growth Failure Prevalence in Neonates with Gastroschisis : A Statewide Cohort Study.

OBJECTIVES: To perform a multicenter study to assess growth failure in hospitalized infants with gastroschisis. STUDY DESIGN: This study included neonates with gastroschisis within sites in the University of California Fetal Consortium. The study's primary outcome was growth failure at hospital discharge, defined as a weight or length z score decrease >0.8 from birth. Regression analysis was performed to assess changes in z scores over time. RESULTS: Among 125 infants with gastroschisis, the median gestational age was 37 weeks (IQR 35-37). Length of stay was 32 days (23-60); 55% developed weight or length growth failure at discharge (28% had weight growth failure, 42% had length growth failure, and 15% had both weight and length growth failure). Weight and length z scores at 14 days, 30 days, and discharge were less than birth (P < .01 for all). Weight and length z scores declined from birth to 30 days (-0.10 and -0.11 z score units/week, respectively, P < .001). Length growth failure at discharge was associated with weight and length z score changes over time (P < .05 for both). Lower gestational age was associated with weight growth failure (OR 0.70 for each gestational age week, 95% CI 0.55-0.89, P = .004). CONCLUSIONS: Growth failure, in particular linear growth failure, is common in infants with gastroschisis. These data suggest the need to improve nutritional management in these infants.

Growth from Birth to 30 months for Infants Born with Congenital Gastrointestinal Anomalies and Disorders.

OBJECTIVE: This study aimed to investigate growth among neonates with gastrointestinal disorders. STUDY DESIGN: Inclusion criteria included neonates with gastroschisis, omphalocele, intestinal atresia, tracheoesophageal fistula, Hirschsprung's disease, malabsorption disorders, congenital diaphragmatic hernia, and imperforate anus born between 2010 and 2018. Anthropometrics were collected for the first 30 months, and a subgroup analysis was performed for gastroschisis infants. RESULTS: In 61 subjects, 13% developed severe growth failure within the first month. One-, four-, and nine-month weight and length z-scores were less than birth weight in all infants (p < 0.05). In infants with gastroschisis, a similar pattern was observed for weight z-scores only (p < 0.05). From birth to 15 months, head circumference z-score increased over time in all infants (p = 0.001), while in gastroschisis infants, weight, length, and head circumference z-scores increased over time (p < 0.05). CONCLUSION: In a cohort of infants with gastrointestinal disorders, growth failure was followed by catch-up growth.

Intravenous Fish Oil Monotherapy as a Source of Calories and Fatty Acids Promotes Age-Appropriate Growth in Pediatric Patients with Intestinal Failure-Associated Liver Disease.

OBJECTIVE: To compare growth in children with intestinal failure-associated liver disease (IFALD) who received a fish oil intravenous lipid emulsion (FOLE) to those who received a soybean oil intravenous lipid emulsion (SOLE). STUDY DESIGN: This multisite, retrospective study pair-matched FOLE (n = 82) to SOLE recipients (n = 41) using baseline serum direct bilirubin levels and postmenstrual age. Study subjects received open-label FOLE (1 g/kg/day) until IFALD resolved or parenteral nutrition was stopped. Historical control subjects received SOLE (up to 3 g/kg/day). Growth measures (changes in body weight, height/length, and head circumference), prealbumin, triglycerides, and glucose were compared between groups over time using the Wilcoxon rank-sum test. RESULTS: Although changes in all of the growth measures were similar for both groups (P > .05), FOLE recipients demonstrated an overall improved growth trajectory. After 28 weeks, FOLE recipients had a mean body weight within a z score range of -1 to 1 indicating age-appropriate growth. FOLE recipients consistently had higher prealbumin, lower triglyceride, and more normal glucose concentrations over time compared with SOLE recipients. CONCLUSIONS: Children with IFALD who received FOLE had similar growth and fewer metabolic abnormalities compared with those who received SOLE. TRIAL REGISTRATION: Clinicaltrials.gov: NCT00910104 and NCT00738101.

MicroRNA 122 Reflects Liver Injury in Children with Intestinal Failure-Associated Liver Disease Treated with Intravenous Fish Oil.

BACKGROUND: There is evidence that microRNA (MIR) 122 is a biomarker for various liver diseases in adults and children. To date, MIR122 has not been explored in children with intestinal failure-associated liver disease (IFALD, or hyperbilirubinemia associated with prolonged parenteral nutrition). OBJECTIVES: This study's purpose was to investigate changes in plasma miR-122, correlate miR-122 with serum liver function tests and enzymes, and investigate changes in whole blood transcripts including miR-122 targets in a group of children with IFALD who received pure intravenous fish oil (FO) as a treatment for cholestasis. METHODS: This was a prospective, observational study that enrolled children with IFALD who received intravenous FO (1 g/kg/d) and whose cholestasis resolved with FO. Plasma miR-122 was measured using reverse transcription-quantitative real-time PCR, and whole blood miR-122 targets were quantified using RNA sequencing. RESULTS: Fourteen subjects with median age 6 mo (IQR: 3-65 mo) were enrolled. RNA sequence data were available for 4 subjects. When compared with the start of FO, median miR-122 concentrations at 6 mo of FO therapy decreased [1.0 (IQR: 1.0-1.0) compared with 0.04 (IQR: 0.01-0.6), P = 0.009]. At the start of FO, miR-122 correlated with conjugated bilirubin (r = 0.56; P = 0.038). At ∼3 mo of FO, miR-122 correlated with conjugated bilirubin (r = 0.56; P = 0.045). Reactive oxygen species, heme metabolism, coagulation, adipogenesis, IL-6-Janus kinase-signal transducer and activator of transcription (JAK-STAT) 3, IL-2-STAT5, transforming growth factor-ß, TNF-α, inflammatory response, mammalian target of rapamycin gene families (normalized enrichment scores < -1.4), and miR-122 target genes were significantly downregulated with FO. CONCLUSIONS: In this small cohort of young children with IFALD, miR-122 decreased with FO therapy and correlated with conjugated bilirubin. Key pathways involving oxidation, inflammation, cellular differentiation, and nutrient regulation were downregulated. Data from this study provide information about IFALD and FO. This trial was registered at www.clinicaltrials.gov as NCT00969332.

Free-breathing Magnetic Resonance Imaging Assessment of Body Composition in Healthy and Overweight Children: An Observational Study.

OBJECTIVE: Conventional, breath-holding magnetic resonance imaging (MRI) assesses body composition by measuring fat volumes and proton density fat fraction (PDFF). However, breath-holding MRI is not always feasible in children. This study's objective was to use free-breathing MRI to quantify visceral and subcutaneous fat volumes and PDFFs and correlate these measurements with hepatic PDFF. METHODS: This was an observational, hypothesis-forming study that enrolled 2 groups of children (ages 6-17 years), healthy children and overweight children with presumed nonalcoholic fatty liver disease. Free-breathing MRI was used to measure visceral and subcutaneous fat volumes and PDFFs, and hepatic PDFF. Imaging biomarkers were compared between groups, and correlations coefficients (r) and coefficients of determination (R) were calculated. RESULTS: When compared with the control group (n = 10), the overweight group (n = 9) had greater mean visceral (1843 vs 329 cm, P < 0.001) and subcutaneous fat volumes (7663 vs 893 cm, P < 0.001), as well as greater visceral (80% vs 45%, p < 0.001) and subcutaneous fat PDFFs (89% vs 75%, P = 0.003). Visceral fat volume (r = 0.79, P < 0.001) and PDFF (r = 0.92, P < 0.001) correlated with hepatic PDFF. In overweight subjects, for each unit increase in visceral fat PDFF, hepatic PDFF increased by 2.64%; visceral fat PDFF explained 54% of hepatic PDFF variation (R = 0.54, P = 0.02). CONCLUSIONS: In this study, we used free-breathing MRI to measure body composition in children. Future studies are needed to investigate the possible value of subcutaneous and visceral fat PDFFs, and validate free-breathing MRI body composition biomarkers.

Free-breathing 3-D quantification of infant body composition and hepatic fat using a stack-of-radial magnetic resonance imaging technique.

BACKGROUND: Body composition and hepatic fat correlate with future risk for metabolic syndrome. In children, many conventional techniques for quantifying body composition and hepatic fat have limitations. MRI is a noninvasive research tool to study body composition and hepatic fat in infants; however, conventional Cartesian MRI is sensitive to motion, particularly in the abdomen because of respiration. Therefore we developed a free-breathing MRI technique to quantify body composition and hepatic fat in infants. OBJECTIVE: In infants, we aimed to (1) compare the image quality between free-breathing 3-D stack-of-radial MRI (free-breathing radial) and 3-D Cartesian MRI in the liver and (2) determine the feasibility of using free-breathing radial MRI to quantify body composition and hepatic proton-density fat fraction (PDFF). MATERIALS AND METHODS: Ten infants ages 2-7 months were scanned with free-breathing radial (two abdominal; one head and chest) and Cartesian (one abdominal) MRI sequences. The median preparation and scan times were reported. To assess feasibility for hepatic PDFF quantification, a radiologist masked to the MRI technique scored abdominal scans for motion artifacts in the liver using a 3-point scale (1, or non-diagnostic, to 3, or no artifacts). Median visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and brown adipose tissue (BAT) volume and PDFF, and hepatic PDFF were measured using free-breathing radial MRI. We assessed repeatability of free-breathing radial hepatic PDFF (coefficient of repeatability) between back-to-back scans. We determined differences in the distribution of image-quality scores using McNemar-Bowker tests. P<0.05 was considered significant. RESULTS: Nine infants completed the entire study (90% completion). For ten infants, the median preparation time was 32 min and scan time was 24 min. Free-breathing radial MRI demonstrated significantly higher image-quality scores compared to Cartesian MRI in the liver (radial scan 1 median = 2 and radial scan 2 median = 3 vs. Cartesian median = 1; P=0.01). Median measurements using free-breathing radial were VAT=52.0 cm3, VAT-PDFF=42.2%, SAT=267.7 cm3, SAT-PDFF=87.1%, BAT=1.4 cm3, BAT-PDFF=26.1% and hepatic PDFF=3.4% (coefficient of repeatability <2.0%). CONCLUSION: In this study, free-breathing radial MRI in infants achieved significantly improved liver image quality compared to Cartesian MRI. It is feasible to use free-breathing radial MRI to quantify body composition and hepatic fat in infants.

Free-breathing quantification of hepatic fat in healthy children and children with nonalcoholic fatty liver disease using a multi-echo 3-D stack-of-radial MRI technique.

BACKGROUND: In adults, noninvasive chemical shift encoded Cartesian magnetic resonance imaging (MRI) and single-voxel magnetic resonance (MR) spectroscopy (SVS) accurately quantify hepatic steatosis but require breath-holding. In children, especially young and sick children, breath-holding is often limited or not feasible. Sedation can facilitate breath-holding but is highly undesirable. For these reasons, there is a need to develop free-breathing MRI technology that accurately quantifies steatosis in all children. OBJECTIVE: This study aimed to compare non-sedated free-breathing multi-echo 3-D stack-of-radial (radial) MRI versus standard breath-holding MRI and SVS techniques in a group of children for fat quantification with respect to image quality, accuracy and repeatability. MATERIALS AND METHODS: Healthy children (n=10, median age [±interquartile range]: 10.9 [±3.3] years) and overweight children with nonalcoholic fatty liver disease (NAFLD) (n=9, median age: 15.2 [±3.2] years) were imaged at 3 Tesla using free-breathing radial MRI, breath-holding Cartesian MRI and breath-holding SVS. Acquisitions were performed twice to assess repeatability (within-subject mean difference, MDwithin). Images and hepatic proton-density fat fraction (PDFF) maps were scored for image quality. Free-breathing and breath-holding PDFF were compared using linear regression (correlation coefficient, r and concordance correlation coefficient, ρc) and Bland-Altman analysis (mean difference). P<0.05 was considered significant. RESULTS: In patients with NAFLD, free-breathing radial MRI demonstrated significantly less motion artifacts compared to breath-holding Cartesian (P<0.05). Free-breathing radial PDFF demonstrated a linear relationship (P<0.001) versus breath-holding SVS PDFF and breath-holding Cartesian PDFF with r=0.996 and ρc=0.994, and r=0.997 and ρc=0.995, respectively. The mean difference in PDFF between free-breathing radial MRI, breath-holding Cartesian MRI and breath-holding SVS was <0.7%. Repeated free-breathing radial MRI had MDwithin=0.25% for PDFF. CONCLUSION: In this pediatric study, non-sedated free-breathing radial MRI provided accurate and repeatable hepatic PDFF measurements and improved image quality, compared to standard breath-holding MR techniques.

Association between consensus-based nutrition pathway and growth faltering in infants with gastroschisis: A retrospective cohort study.

BACKGROUND: The University of California Fetal Consortium published that 55% of infants with gastroschisis develop growth faltering by hospital discharge. To address this problem, we developed a nutrition pathway emphasizing (1) early provision of parenteral macronutrients, (2) use of human milk, and (3) growth faltering treatment. This study's goals were to assess adherence to and efficacy of this pathway in infants with gastroschisis across six California hospitals. METHODS: In 2015, the consortium standardized the care for infants with gastroschisis. To decrease growth faltering rates, between 2019 and 2020, nutrition guidelines were proposed, discussed, revised, and initiated. This study's primary outcome was weight or linear growth faltering (z score decline ≥0.8 in weight or length) at hospital discharge. Adherence measures were assessed. RESULTS: One hundred twenty-six infants with gastroschisis were born prepathway; 52 were born postpathway. Median gestational age was similar between cohorts. Adherence to components of the pathway ranged from 58% to 95%. The proportion of infants with weight or linear growth faltering at discharge was lower after pathway initiation (59.4% vs 36.2%, P = 0.0068). Adjusting for gestational age and fetal growth restriction, the pathway was associated with decreased weight or linear growth faltering (odds ratio [OR] 0.35 [0.16-0.75], P = 0.0060) and decreased linear growth faltering (OR 0.24 [0.096-0.56], P = 0.0062) at discharge. Hypertriglyceridemia, cholestasis, and days to full feeds were similar to published cohorts. CONCLUSION: Fewer infants with gastroschisis experienced weight or length growth faltering at hospital discharge following the implementation of a multicenter nutrition pathway.

Dilemmas in the delivery of intravenous lipid emulsions and approach to hypertriglyceridemia in very preterm and low birth weight infants.

Intravenous lipid emulsions (ILEs) are an essential component of parenteral nutrition for very preterm and very low birth weight infants (VLBWs). This article offers a perspective on advancements and controversies on ILE use in this population. ILEs prescribed after birth at a dose of 1.5-2 g/kg/day and advanced to 3 g/kg/day enhance growth. Growth appears to be similar for infants who receive an ILE composed of 100% soybean oil or a multi-oil ILE with 15% fish oil. 100% fish oil is the preferred ILE for the management of parenteral nutrition associated cholestasis and intestinal failure associated liver disease. Research is warranted to help determine how we can optimize ILEs to improve neurodevelopment and prematurity complications. Last, we lack a universal definition of hypertriglyceridemia (HTG) and consensus on triglyceride surveillance and HTG management. Investigation is required to determine the health impact of specific triglyceride ranges in very preterm infants and VLBWs.