In a patient with hepatic steatosis and elevated alanine transaminase (ALT), should repeat imaging utilize a FibroScan (transient elastography) or another type of ultrasound?

From the Guidelines

For patients with hepatic steatosis and elevated ALT requiring repeat imaging, FibroScan (transient elastography) is the preferred follow-up imaging modality. This recommendation is based on the most recent and highest quality study available, which suggests that FibroScan is a reliable and non-invasive method for assessing liver stiffness and steatosis quantification 1. The study recommends using a simplified rounded value of 8.0 kPa as the low cutoff to exclude clinically significant fibrosis, and a value of >12.0 kPa as the upper cutoff to indicate likely clinically significant fibrosis.

Some key points to consider when using FibroScan include:

• The typical protocol involves fasting for at least 3 hours before the examination, with results available immediately
• Alternative ultrasound-based options include shear wave elastography or magnetic resonance elastography if FibroScan is unavailable
• These non-invasive tests help monitor disease progression and response to interventions while avoiding repeated liver biopsies
• FibroScan is particularly valuable because it provides numerical measurements that can be tracked over time, allowing for objective assessment of improvement or worsening

It's also worth noting that other studies have validated the use of FibroScan for assessing liver fibrosis, including a study published in 2024 which recommends using FibroScan to rule out patients with compensated advanced chronic liver disease (cACLD) 1. However, the 2021 study published in Gastroenterology provides the most recent and comprehensive guidance on the use of FibroScan for patients with hepatic steatosis and elevated ALT 1.

In terms of other imaging modalities, a 2017 study published in the Journal of the American College of Radiology discusses the use of US elastography, including shear-wave elastography and strain elastography, for assessing liver fibrosis 1. However, this study is less recent and less directly relevant to the specific question of repeat imaging for patients with hepatic steatosis and elevated ALT.

Overall, the evidence suggests that FibroScan is a reliable and effective method for assessing liver stiffness and steatosis quantification in patients with hepatic steatosis and elevated ALT, and is the preferred follow-up imaging modality for these patients.

From the Research

Imaging Options for Hepatic Steatosis

When considering imaging options for hepatic steatosis with elevated ALT levels, several factors come into play. The choice between a FibroScan or other types of ultrasound (US) depends on the specific needs of the patient and the capabilities of the imaging modalities.

Non-Invasive Imaging Modalities

• Ultrasound (US) is a commonly used imaging modality for detecting hepatic steatosis, as it is non-invasive and widely available 2.
• Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) can also detect fat infiltration in the liver, but may have limitations in terms of quantification 2.
• Recent MRI techniques have shown promise in detecting and quantifying liver fat, making them a potential option for patients with hepatic steatosis 2.
• US elastography, including one-dimensional transient elastography and point shear wave elastography, can be used to assess liver fibrosis, which is often associated with hepatic steatosis 3.

FibroScan vs. Other US Modalities

• FibroScan is a type of US elastography that uses transient elastography to measure liver stiffness, which can indicate the presence of fibrosis 3.
• Other US modalities, such as point shear wave elastography or acoustic radiation force impulse imaging, may also be used to assess liver fibrosis and steatosis 3.
• The choice between FibroScan and other US modalities may depend on the specific clinical context and the availability of equipment and expertise.

Clinical Considerations

• Hepatic steatosis can be associated with elevated ALT levels, particularly in patients with low HBV DNA loads 4.
• Patients with hepatic steatosis may also have other underlying conditions, such as obesity, dyslipidemia, and hyperuricemia, which can impact the choice of imaging modality 4.
• The severity of inflammation and fibrosis can also impact the choice of imaging modality, with more advanced disease requiring more sensitive and specific imaging techniques 3, 4.