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World J Gastroenterol. Feb 7, 2023; 29(5): 834-850
Published online Feb 7, 2023. doi: 10.3748/wjg.v29.i5.834
Liver involvement in patients with COVID-19 infection: A comprehensive overview of diagnostic imaging features
Davide Ippolito, Cesare Maino, Federica Vernuccio, Roberto Cannella, Riccardo Inchingolo, Michele Dezio, Riccardo Faletti, Pietro Andrea Bonaffini, Marco Gatti, Sandro Sironi
Davide Ippolito, Pietro Andrea Bonaffini, Sandro Sironi, Milano Bicocca School of Medicine and Surgery, Milano 20126, Italy
Davide Ippolito, Cesare Maino, Fondazione IRCCS San Gerardo dei Tintori, Monza 20900, Italy
Federica Vernuccio, Institute of Radiology (DIMED), University Hospital of Padova, Padova 35128, Italy
Roberto Cannella, Section of Radiology-Department of Biomedicine, Neuroscience and Advanced Diagnostics (BiND), University of Palermo, Palermo 90127, Italy
Roberto Cannella, Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties (PROMISE), University of Palermo, Palermo 90127, Italy
Riccardo Inchingolo, Michele Dezio, Division of Interventional Radiology, Department of Radiology, Madonna delle Grazie Hospital, Matera 75100, Italy
Riccardo Faletti, Department of Surgical Sciences, University of Turin, Turin 10126, Italy
Pietro Andrea Bonaffini, Sandro Sironi, Department of Diagnostic Radiology, Papa Giovanni XXIII Hospital, Bergamo 24127, Italy
Marco Gatti, Department of Diagnostic Radiology, University of Turin, Turin 10126, Italy
Author contributions: Ippolito D designed the research; Maino C, Vernuccio F, Cannella R, Inchingolo R, Dezio M, Faletti R, Bonaffini PA, Gatti M and Sironi S performed the research; Maino C, Vernuccio F and Cannella R analyzed the data; Ippolito D, Maino C, Vernuccio F, Cannella R, Inchingolo R, Dezio M, Faletti R, Bonaffini PA and Gatti M wrote the paper.
Conflict-of-interest statement: Authors declare no conflict of interests for this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Davide Ippolito, MD, Associate Professor, Doctor, Milano Bicocca School of Medicine and Surgery, Piazza dell'Ateneo Nuovo, 1, Milano 20126, Italy. davide.atena@tiscali.it
Received: October 3, 2022
Peer-review started: October 3, 2022
First decision: November 26, 2022
Revised: December 6, 2022
Accepted: January 20, 2023
Article in press: January 20, 2023
Published online: February 7, 2023
Processing time: 125 Days and 16.3 Hours
Abstract

During the first wave of the pandemic, coronavirus disease 2019 (COVID-19) infection has been considered mainly as a pulmonary infection. However, different clinical and radiological manifestations were observed over time, including involvement of abdominal organs. Nowadays, the liver is considered one of the main affected abdominal organs. Hepatic involvement may be caused by either a direct damage by the virus or an indirect damage related to COVID-19 induced thrombosis or to the use of different drugs. After clinical assessment, radiology plays a key role in the evaluation of liver involvement. Ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) may be used to evaluate liver involvement. US is widely available and it is considered the first-line technique to assess liver involvement in COVID-19 infection, in particular liver steatosis and portal-vein thrombosis. CT and MRI are used as second- and third-line techniques, respectively, considering their higher sensitivity and specificity compared to US for assessment of both parenchyma and vascularization. This review aims to the spectrum of COVID-19 liver involvement and the most common imaging features of COVID-19 liver damage.

Keywords: Liver; Fatty liver; Hepatomegaly; Hepatic infarction; Liver diseases; Liver failure; Biliary tract diseases; COVID-19; SARS-CoV-2; Infection; X-Ray computed tomography; Magnetic resonance imaging; Ultrasonography; Adults; Pediatrics

Core Tip: Coronavirus disease 2019 (COVID-19) infection has an impact not only on lung involvement but also in other systems, in particular the gastrointestinal one, with a special focus on the liver. Hepatocytes express the receptor of angiotensin-converting enzyme which is the main door of the entrance of severe acute respiratory syndrome coronavirus 2. Consequently, different mechanisms can lead to different hepatic scenarios, such as hepatomegaly, steatosis, steatohepatitis, and drug-induced liver injury. As for lung involvement, the infection can lead to hepatic vascular involvement, especially portal vein thrombosis. Finally, it has been demonstrated a possible biliary involvement in COVID-19 patients.