Post‐COVID‐19 Liver Injury: Comprehensive Imaging With Multiparametric Ultrasound

Abstract

Objectives This study aimed to define patterns of liver injury after severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection using multiparametric ultrasound (mpUS) in a variable patient population with differing severities of COVID‐19. Methods Ninety patients were enrolled into the study: 56 had SARS‐CoV‐2 3–9 months prior to enrolment; 34 served as a clinically healthy control group. All patients underwent an mpUS evaluation of the liver (elastography, dispersion and attenuation imaging). Seventy‐six patients had abdominal magnetic resonance (MR) and noncontrast enhanced thoracic computed tomography (CT) scans performed at the same day. All patients were screened for biochemical markers of liver injury. Results Liver elasticity, viscosity, and steatosis values were significantly altered in patients after COVID‐19, with particularly higher fibrosis scores compared to the control group ( P < .001). Increased biochemical markers of liver injury correlated with changes in mpUS ( P < .05), but not with findings on CT or MR findings. Seventeen of 34 hospitalized patients had a moderate or severe course of the disease course with more pronounced changes in mpUS. Increased body mass index was found to influence liver injury and correlated with more severe forms of COVID‐19 ( P < .001). Conclusions COVID‐19 can cause liver injury observable using mpUS. More severe forms of COVID‐19 and patient obesity are related to increased values of liver damage observed. In comparison to MRI and CT, mpUS appears to be more sensitive to involvement of liver parenchyma. Further research is warranted to establish this promising method for evaluating post‐COVID‐19 liver involvement in the aftermath of the pandemic.

Abdominal Imaging Associates Body Composition with COVID-19 Severity

“…No other significant longitudinal changes were observed in any of our twelve IDPs following COVID-19 infection, despite previous case-control studies reporting differences detectable by MRI attributed to COVID-19 in multiple organs including the liver, kidneys, pancreas, spleen, and muscle [9,10,19,20,24]. Similarly, there are numerous case reports of individual patients which describe changes in organs throughout the body, although these are mostly linked to severe disease, where it is not always clear whether the reported changes relate to viral infection per se, hypoxia/mechanical ventilation or drug treatments.…”

“…A significant proportion of patients hospitalized with COVID-19 have developed moderate or severe kidney damage, resulting in dialysis [14][15][16], with reported imaging findings including renal infarcts, increased cortical echogenicity (a marker of renal disease), increased T1 (reported to indicate declining kidney function), reduced renal perfusion and increased perinephric fat stranding [9,10,17,18]. Reported changes in the liver include inflammation, fibrosis, elasticity, with conflicting reports regarding changes in liver fat and the biliary system including cholangiopathy, and presence of gallbladder 'sludge' [10,[19][20][21][22]. Despite biochemical changes suggesting pancreatic involvement, imaging observations have been few, with reports of a 'bulky' pancreas and peripancreatic fat stranding and inflammation [10,23].…”

COVID-19: Has the Liver Been Spared?

“…These changes have been also documented in a recent study with Multiparametric US (mpUS), where the sonographic evaluation of liver parenchyma in individuals after COVID-19 revealed significantly more frequent liver steatosis compared to the clinically healthy control group but also increased stiffness (fibrosis) and viscosity (inflammation) values, both indicative of liver injury. However, despite these mpUS features being correlated with an increase in biochemical markers of liver injury, they were not associated with correspondent CT or MR findings [ 100 ]. On the other hand, several studies have reported a considerably greater frequency of hepatic steatosis by Computed Tomography (CT) scans in confirmed COVID-19 cases compared to controls, defined as a hepatic attenuation of at least 10 Hounsfield Units (HU) compared to the density of the spleen or absolute liver attenuation of less than 40 HU [ 101 , 102 ].…”

SARS-CoV-2-mediated liver injury: pathophysiology and mechanisms of disease

“…Hypoxia can lead to cell necrosis and persistent reactive oxygen species generation promoting the release of pro-inflammatory factors, and thus further liver injury [ 97 – 99 ]. Radzina et al [ 100 ], using multiparametric ultrasound (mpUS) to evaluate liver parenchyma in COVID-19 patients, found increased liver stiffness suggestive of liver injury. This increase was demonstrated by higher shear wave (SWE) values.…”

“…This increase was demonstrated by higher shear wave (SWE) values. This finding was also associated with an increase in other multiparametric ultrasound (US) indicators of hepatic injury, such as viscosity (inflammation) and steatosis [ 100 ]. Moreover, another study on COVID-19 patients revealed that homogeneous or heterogeneous hepatic hypodensity as the most common upper abdominal computed tomography (CT) finding, in addition to the presence of pericholecystic fat stranding [ 101 ].…”