Objectives To compare complex quantitative magnetic resonance imaging (MRI) with MR spectroscopy (MRS) for quantification of hepatic steatosis (HS) and determine clinically significant MRI-based thresholds of HS in female youths. Methods This prospective, cross-sectional study was conducted in 132 healthy females (11–22 years, mean 13.3 ± 2). Proton density fat-fraction (PDFF) was measured using complex quantitative MRI and MRS. Body mass index (BMI), fasting labs [glucose, insulin, alanine aminotransferase (ALT), and other metabolic markers] were obtained. Outcomes were measured using regression analysis, Spearman-rank correlation, and receiver operator characteristics (ROC) analysis. HS was defined as MRI-PDFF >5.6 %. Results HS was detected by MRI-PDFF in 15 % of all subjects. Linear regression demonstrated excellent correlation and agreement [r2 = 0.96, slope = 0.97 (95 %CI: 0.94–1.00), intercept = 0.78 % (95 %CI: 0.58–0.98 %)] between MRI-PDFF and MRS-PDFF. MRI-PDFF had a sensitivity of 100 % (95 %CI: 0.79–1.00), specificity of 96.6 % (95 %CI: 0.91–0.99), and a kappa index of 87 % (95 %CI: 0.75-0.99) for identifying HS. In overweight subjects with HS, MRI-PDFF correlated with ALT (r = 0.84, p < 0.0001) and insulin (r = 0.833, p < 0.001), but not with BMI or WC. ROC analysis ascertained an optimal MRI-PDFF threshold of 3.5 % for predicting metabolic syndrome (sensitivity = 76 %, specificity = 83 %). Conclusion Complex quantitative MRI demonstrates strong correlation and agreement with MRS to quantify hepatic triglyceride content in adolescent girls and young women. A low PDFF threshold is predictive of metabolic syndrome in this population.

Purpose To validate adipose tissue magnetic resonance imaging (atMRI) for rapid, quantitative volumetry of visceral adipose tissue (VAT) and total adipose tissue (TAT). Materials and Methods Data was acquired on normal adults and clinically-overweight girls with IRB approval/parental consent using sagittal 6-echo 3D-SPGR (26-sec single-breath-hold) at 3T. Fat-fraction images were reconstructed with quantitative corrections, permitting measurement of a physiologically-based fat-fraction threshold in normals to identify adipose tissue, for automated measurement of TAT and semi-automated measurement of VAT. TAT accuracy was validated using oil phantoms and in vivo TAT/VAT measurements validated with manual segmentation. Group comparisons were performed between normals and overweight girls using TAT, VAT, VAT-TAT-ratio (VTR), body-mass-index (BMI), waist circumference, and waist-hip-ratio (WHR). Results Oil phantom measurements were highly accurate (< 3% error). The measured adipose fat-fraction threshold was 96% ± 2%. VAT and TAT correlated strongly to manual segmentation (normals r2 ≥ 0.96, overweight girls r2 ≥ 0.99). VAT segmentation required 30 ± 11 minutes/subject (14 ± 5 sec/slice) using atMRI, versus 216 ± 73 minutes/subject (99 ± 31 sec/slice) manually. Group discrimination was significant using WHR (p < 0.001) and VTR (p = 0.004). Conclusion The atMRI technique permits rapid, accurate measurements of TAT, VAT and VTR.

Title: Thyroid Storm with Concurrent COVID-19 Infection in a Pediatric Patient Background: A 16-year-old boy with recently diagnosed hyperthyroidism developed acute worsening of palpitations, tremor, diaphoresis, and shortness of breath in the setting of COVID-19 infection. There is increasing evidence of a relationship between COVID-19 and thyroid disease possibly due SARS-COV-2 use of ACE2 and the transmembrane protease serine 2 (TMPRSS2), which are highly expressed in the thyroid gland, to infect host cells.1 Clinical Case: Patient was diagnosed with hyperthyroidism after presenting to PCP with tremor, palpitations, and weight loss with a TSH &lt;0.02 mIU/L and FT4 6.86 ng/dL on day 0. No treatment was initiated and he was referred to outpatient endocrinology clinic. On day 2, he developed mild URI symptoms which improved by day 4. On day 5, he developed acute worsening of tremor, palpitations, and weakness and presented to the ED where he was febrile to 38.4 C, tachycardic to 161 BPM, and hypertensive to 139/91 mmHg. Initial laboratory evaluation was significant for TSH &lt;0.02 mIU/L, FT4 6.64 ng/dL and COVID-19 nucleic acid amplification test positivity. FT3 was &gt;20.0 pg/mL and TRAB was 20.68 IU/L consistent with Graves’ disease. He met diagnostic criteria for thyroid storm with a score of 45 points using the Burch and Wartofsky scoring system based on the presence of thermoregulatory dysfunction (10 points), cardiovascular dysfunction (25 points) and precipitant history (10 points). Patient was admitted to a pediatric ICU and started on methimazole 20 mg every 8 hours, potassium iodide 250 mg every 8 hours, propranolol 40 mg every 8 hours, and hydrocortisone 50 mg every 8 hours with resolution of fever, tachycardia, and hypertension. He was noted to have left ventricular hypertrophy with progressive, asymptomatic ST elevation/nonspecific repolarization changes on electrocardiogram (ECG). Echocardiogram was normal. B-natriuretic peptide and serial troponin were normal. On day 6, inflammatory markers and coagulation studies were reassuring against concurrent multisystem inflammatory syndrome in children. Potassium iodide was discontinued on day 6 and hydrocortisone was discontinued on day 8. Repolarization abnormalities persisted throughout his admission with appearance of prominent U waves and borderline QT prolongation, however no significant arrhythmias were noted. On day 9 FT4 was 1.99 ng/dL and FT3 was 4.8 pg/mL; he was discharged home in stable condition Conclusion: This is the first reported case of COVID-19 infection as presumed precipitant of thyroid storm in a pediatric patient with cardiac findings. [1] Scappaticcio, L., Pitoia, F., Esposito, K., Piccardo, A., & Trimboli, P. (2020). Impact of COVID-19 on the thyroid gland: an update. Reviews in endocrine & metabolic disorders, 1–13. Advance online publication. https://doi.org/10.1007/s11154-020-09615-z

Objectives To develop a risk assessment model for early detection of hepatic steatosis using common anthropometric and metabolic markers. Study design Cross-sectional study of 134 girls, age 11–22 years (mean 13.3±2), Ethnicity: 27% Hispanic, 73% Non-Hispanic; Race: 64% Caucasian, 31% African-American, 5% Asian, from a middle school and clinics (Madison, WI). Fasting glucose, fasting insulin, alanine aminotransferase (ALT), body mass index (BMI), waist circumference (WC) and other metabolic markers were assessed. Hepatic fat was quantified using magnetic resonance proton density fat fraction (MR-PDFF). Hepatic steatosis was defined as MR-PDFF >5.5%. Outcome measures were sensitivity, specificity, and positive predictive value (PPV) of BMI, WC, ALT, fasting insulin and ethnicity as predictors of hepatic steatosis, individually and combined, in a risk assessment model. Classification and regression tree methodology constructed a decision tree for predicting hepatic steatosis. Results MR-PDFF revealed hepatic steatosis in 16% of subjects (27% overweight, 3% non-overweight). Hispanic ethnicity conferred an odds ratio of 4.26 (CI 1.65–11.04, p=0.003) for hepatic steatosis. BMI and ALT did not independently predict hepatic steatosis. A BMI > 85% combined with ALT > 65 U/L had 9% sensitivity, 100% specificity and 100% PPV. Lowering ALT to 24 U/L increased sensitivity to 68%, but reduced PPV to 47%. A risk assessment model incorporating fasting insulin, total cholesterol, WC, and ethnicity increased sensitivity to 64%, specificity to 99% and PPV to 93%. Conclusions A risk assessment model can increase specificity, sensitivity, and PPV for identifying risk of hepatic steatosis and guide efficient use of biopsy or imaging for early detection and intervention.

Purpose To evaluate free-breathing chemical shift-encoded (CSE) magnetic resonance imaging (MRI) for quantification of hepatic proton density fat-fraction (PDFF). A secondary purpose was to evaluate hepatic R2* values measured using free-breathing quantitative CSE-MRI. Materials and Methods Fifty patients (mean age, 56 years) were prospectively recruited and underwent the following four acquisitions to measure PDFF and R2*; 1) conventional breath-hold CSE-MRI (BH-CSE); 2) respiratory-gated CSEMRI using respiratory bellows (BL-CSE); 3) respiratory-gated CSE-MRI using navigator echoes (NV-CSE); and 4) single voxel MR spectroscopy (MRS) as the reference standard for PDFF. Image quality was evaluated by two radiologists. MRI-PDFF measured from the three CSE-MRI methods were compared with MRS-PDFF using linear regression. The PDFF and R2* values were compared using two one-sided t-test to evaluate statistical equivalence. Results There was no significant difference in the image quality scores among the three CSE-MRI methods for either PDFF (P = 1.000) or R2* maps (P = 0.359–1.000). Correlation coefficients (95% confidence interval [CI]) for the PDFF comparisons were 0.98 (0.96–0.99) for BH-, 0.99 (0.97–0.99) for BL-, and 0.99 (0.98–0.99) for NV-CSE. The statistical equivalence test revealed that the mean difference in PDFF and R2* between any two of the three CSE-MRI methods was less than ±1 percentage point (pp) and ±5 s−1, respectively (P < 0.046). Conclusion Respiratory-gated CSE-MRI with respiratory bellows or navigator echo are feasible methods to quantify liver PDFF and R2* and are as valid as the standard breath-hold technique.