mpUS pinpoints greater levels of injury than CT or MRI.
Liver injury due to COVID-19 infection can best be seen with multi-parametric ultrasound (mpUS) rather than MRI or CT.
In a study published July 9 in the Journal of Ultrasound in Medicine, investigators from Latvia determined that mpUS is more sensitive to any impact of COVID-19 on the liver parenchyma.
“Due to the main pathogenic mechanism of cell invasion of SARS-CoV-2, which is through binding to ACE2 receptors, the liver is among the first-line targets of cell injury in COVID-19 by its high expressions of ACE2,” said the team led by Davis Simanis Putrins from the Diagnostic Radiology Institute of Paula Stradins Clinical University Hospital. “Multi-parametric ultrasound evaluation of liver parenchyma in individuals after COVID-19 revealed increased liver stiffness and steatosis (attenuation) values indicative of liver injury compared to the clinically healthy control group.”
For their study, the team randomly enrolled 90 patients between October 2020 and December 2020 – 56 patients had COVID-19 between three-and-nine months prior to enrollment and 34 individuals were in a healthy control group. All patients underwent mpUS, and 76 also had a thoracic CT, an abdominal MRI, and blood test analysis performed on the same day.
Based on their evaluation, they determined that patients who had COVID-19 also experienced significantly altered liver elasticity, viscosity, and steatosis values. They also had higher fibrosis scores than did individuals in the control group.
In addition, the team found that increased liver stiffness in the research group also had a statistically significant positive correlation with increased levels of biomarkers of liver injury, such as plasma alanine aminotransferase and gamma-glutamyl transferase. They also saw a positive correlation with body mass index (BMI) which was also associated with more severe forms of COVID-19 infection.
In contrast, however, the team did not find any similar relationships between these biomarkers and the findings from CT or MRI scans.
Overall, they said, 60 percent of the research group were hospitalized and had a nine-times higher likelihood of steatosis compared to the control group with those suffering from the most severe disease having the highest steatosis grade. In addition, study participants who had increased liver echogenicity had an eight-times higher risk of experiencing a severe disease course – those patients with increased attenuation imaging values had a five-times greater risk.
Ultimately, the team said, their results indicate that mpUS could be the optimal imaging strategy for assessing COVID-19-related liver damage.
“This allows [us] to conclude that multi-parametric ultrasound might be more sensitive than CT or MRI in evaluating liver injury that is reflected both on the supra-cellular and cellular level prior [to] developed cirrhosis,” they concluded. “Research on all these factors is just at its beginning, but the presented study strongly suggests that mpUS would be highly suitable method for such future work, in particular, for the long-term follow-up of patients with prolonged course of the [COVID-19].”
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