Deep-learning-based hepatic fat assessment (DeHFt) on non-contrast chest CT and its association with disease severity in COVID-19 infections: A multi-site retrospective study.

BACKGROUND: Hepatic steatosis (HS) identified on CT may provide an integrated cardiometabolic and COVID-19 risk assessment. This study presents a deep-learning-based hepatic fat assessment (DeHFt) pipeline for (a) more standardised measurements and (b) investigating the association between HS (liver-to-spleen attenuation ratio <1 in CT) and COVID-19 infections severity, wherein severity is defined as requiring invasive mechanical ventilation, extracorporeal membrane oxygenation, death. METHODS: DeHFt comprises two steps. First, a deep-learning-based segmentation model (3D residual-UNet) is trained (N.ß=.ß80) to segment the liver and spleen. Second, CT attenuation is estimated using slice-based and volumetric-based methods. DeHFt-based mean liver and liver-to-spleen attenuation are compared with an expert's ROI-based measurements. We further obtained the liver-to-spleen attenuation ratio in a large multi-site cohort of patients with COVID-19 infections (D1, N.ß=.ß805; D2, N.ß=.ß1917; D3, N.ß=.ß169) using the DeHFt pipeline and investigated the association between HS and COVID-19 infections severity. FINDINGS: The DeHFt pipeline achieved a dice coefficient of 0.95, 95% CI [0.93...0.96] on the independent validation cohort (N.ß=.ß49). The automated slice-based and volumetric-based liver and liver-to-spleen attenuation estimations strongly correlated with expert's measurement. In the COVID-19 cohorts, severe infections had a higher proportion of patients with HS than non-severe infections (pooled OR.ß=.ß1.50, 95% CI [1.20...1.88], P.ß<.ß.001). INTERPRETATION: The DeHFt pipeline enabled accurate segmentation of liver and spleen on non-contrast CTs and automated estimation of liver and liver-to-spleen attenuation ratio. In three cohorts of patients with COVID-19 infections (N.ß=.ß2891), HS was associated with disease severity. Pending validation, DeHFt provides an automated CT-based metabolic risk assessment. FUNDING: For a full list of funding bodies, please see the Acknowledgements.

Fatty Liver Change in Korean Adults in a Systematic Social Distancing System Amid the COVID-19 Pandemic: A Multicenter Analysis.

In response to the COVID-19 pandemic, the Korean government implemented policies including the systematic social distancing (SSD) system which started on 28 June 2020. The present study investigated the development and aggravation of fatty liver measured using ultrasonography during the transition period (from pre-SSD to SSD) compared to the fatty liver changes during the pre-SSD period. Changes in fatty liver and liver enzymes were assessed in different groups stratified by alcohol consumption. Our retrospective cohort analysis included 5668 participants who underwent health checkups at 13 university hospitals during the SSD period and two or more checkups before the SSD period. Fatty liver developed and aggravated more in the transition period (13.6% development and 12.0% aggravation) than in the pre-SSD period (10.8% development and 10.1% aggravation) in the alcohol consumption group. This finding was more prominent in women than in men. Abnormal alanine transaminase levels were more often developed in the transition period than in the pre-SSD period, especially in men (11.1% vs. 8.6% in each period). In conclusion, the SSD system may contribute to fatty liver changes in individuals who regularly consume alcohol. Further research of the post-pandemic period is needed to assess long-term changes in fatty liver disease.

Correlation between COVID-19 severity, body mass index and radiological hepatic morphology / Correlación entre la gravedad de COVID-19, el índice de masa corporal y la morfología hepática radiológica

SUMMARY: Obesity and fatty liver steatosis are already considered metabolic risk factors which may aggravate the severity of COVID-19. This study aims to investigate the correlation between COVID-19 severity, obesity, and liver steatosis and fibrosis. 230 consecutive patients with laboratory-confirmed COVID-19 aged between 15 and 84? years, admitted to a hospital devoted to COVID-19 patients, were enrolled in the study. COVID-19 severity was classified as severe versus non-severe based on admission to ICU. Obesity was assessed by Body Mass Index (BMI). CT-scan was used to check for the liver steatosis. Fibrosis-4 score was calculated. The study was conducted in March-May 2020. Obesity strongly and positively correlated with severe COVID-19 illness r: 0.760 (P<0.001). Hepatic steatosis had rather less of a correlation with COVID-19 severity r: 0.365 (P<0.001). Multivariable-adjusted association between hepatic steatosis or obesity, or both (as exposure) and COVID-19 severity (as the outcome) revealed increased risk of severe COVID-19 illness with obesity (Adjusted model I OR: 465.3, 95 % CI: 21.9-9873.3, P<0.001), with hepatic steatosis (Adjusted model I OR: 5.1, 95 % CI: 1.2-21.0, P<0.025), and with hepatic steatosis among obese patients (Adjusted model I OR: 132, 95 % CI: 10.3-1691.8, P<0.001). Obesity remained the most noticeable factor that strongly correlated with COVID-19 severity, more than liver steatosis. However, the risk to COVID-19 severity was greater in those with both factors: obesity and liver steatosis.

RESUMEN: La obesidad y la esteatosis del hígado graso ya se consideran factores de riesgo metabólico que pueden empeorar la gravedad de la COVID-19. Este estudio tiene como objetivo investigar la correlación entre la gravedad de COVID- 19, la obesidad y la esteatosis y fibrosis hepática. El estudio se realizó en 230 pacientes consecutivos entre 15 y 84 años con COVID-19 confirmado por laboratorio, ingresados en un hospital dedicado a pacientes con COVID-19. La gravedad de COVID-19 se clasificó como grave, versus no grave según el ingreso a la UCI. La obesidad se evaluó mediante el índice de masa corporal (IMC). Se utilizó una tomografía computarizada para verificar la esteatosis hepática. Se calculó la puntuación de Fibrosis-4. El estudio se realizó entre marzo-mayo de 2020. La obesidad se correlacionó fuerte y positivamente con la enfermedad grave de COVID-19 r: 0,760 (P <0,001). La esteatosis hepática tuvo una correlación bastante menor con la gravedad de COVID-19 r: 0.365 (P <0.001). La asociación ajustada multivariable entre la esteatosis hepática u obesidad, o ambas (como exposición) y la gravedad de COVID-19 (como resul- tado) reveló un mayor riesgo de enfermedad grave por COVID- 19 con obesidad (OR del modelo ajustado I: 465,3, IC del 95%: 21,9 -9873,3, P <0,001), con esteatosis hepática (OR del modelo I ajustado: 5,1, IC del 95 %: 1,2-21,0, P <0,025) y con esteatosis hepática entre los pacientes obesos (OR del modelo I ajustado: 132, IC del 95 % : 10,3-1691,8, P <0,001). La obesidad siguió siendo el factor más notable que se correlacionó significativamente con la gravedad de COVID-19, más que la esteatosis hepática. Sin embargo, el riesgo de gravedad de COVID-19 fue mayor en aquellos con ambos factores: la obesidad y esteatosis hepática.

Higher frequency of hepatic steatosis at CT among COVID-19-positive patients.

PURPOSE: Recent studies have demonstrated that obesity is significantly associated with increased disease severity, hospitalizations and mortality in COVID-19, with a potential role in the pathogenesis and prevalence in the new pandemic. The association with hepatic steatosis, however, a condition closely related to obesity within the spectrum of systemic metabolic dysfunctions, remains to be elucidated. We aimed to evaluate the frequency of hepatic steatosis as incidentally detected in chest CT examinations of COVID-19 positive patients in comparison to non-infected controls. METHODS: A retrospective study was performed with 316 patients (204 RT-PCR positive; 112 RT-PCR negative and chest CT negative). Steatosis was measured with placement of a single ROI in the right lobe of the liver (segments VI-VII) and defined as a liver attenuation value ≤ 40 HU. RESULTS: The frequency of hepatic steatosis was higher in the RT-PCR positive group in comparison to controls (31.9% vs. 7.1%, p < 0.001). Logistic linear regression analysis showed a 4.7 times odds of steatosis in the COVID-19 positive group as compared to controls after adjusting for age and sex (OR 4.698; 95% IC 2.12-10.41, p < 0.001). CONCLUSION: A significantly higher prevalence of steatosis was found among COVID-19 positive individuals. These findings are in accordance with other recent studies linking obesity and COVID-19 infection, as there is an intricate relationship between liver steatosis, metabolic syndrome and obesity. Further studies are required to confirm if such association remains after accounting for multiple variables, as well as possible relationships with disease severity and worst clinical outcomes.