Recommended Initial Imaging Modality for Suspected Fatty Liver Disease

Rationale for Ultrasonography as First-Line Imaging

Abdominal ultrasonography is the recommended primary screening modality for suspected fatty liver disease, offering robust diagnostic performance for moderate to severe steatosis, ability to evaluate the entire hepatobiliary system, wide availability, and cost-effectiveness, according to the Clinical and Molecular Hepatology guidelines 1, 2
Ultrasonography should be performed in patients with persistent liver enzyme elevations, type 2 diabetes mellitus, or metabolic syndrome or obesity, as recommended by the Clinical and Molecular Hepatology guidelines 1, 2

Ultrasonography has limited sensitivity when hepatic steatosis is less than 30% and cannot distinguish between non-alcoholic fatty liver and non-alcoholic steatohepatitis, as noted by the Clinical and Molecular Hepatology guidelines 1, 2
Examination difficulties in obese patients can limit the effectiveness of ultrasonography, according to the Clinical and Molecular Hepatology guidelines 1, 2

Magnetic Resonance Imaging (MRI) offers superior accuracy compared to ultrasonography, especially for mild steatosis, and is limited by cost and availability, as stated by the Clinical and Molecular Hepatology guidelines 1, 2
Transient Elastography with Controlled Attenuation Parameter (CAP) can quantify the degree of fat deposition in liver parenchyma and can be performed simultaneously with fibrosis assessment, according to the Clinical and Molecular Hepatology guidelines 1, 2

The American College of Radiology recommends performing abdominal ultrasonography in patients with risk factors as the initial screening, and considering additional tests such as transient elastography with CAP or MRI if ultrasonography is positive or inconclusive 1, 2

In pregnant patients, ultrasonography without Doppler is the imaging modality of choice due to lack of ionizing radiation, as recommended by the Hepatology guidelines 6
In children, ultrasonography remains the most practical initial screening tool, although evidence does not support its use for making a definitive diagnosis of fatty liver, according to the Clinical Gastroenterology and Hepatology guidelines 5
In patients with known chronic liver disease, ultrasonography with IV contrast, MRI with contrast, or multiphase CT are all appropriate for characterizing liver lesions, as stated by the Journal of the American College of Radiology guidelines 7, 8

Transient elastography with CAP offers a quantitative approach for monitoring changes in hepatic steatosis over time, according to the Clinical and Molecular Hepatology guidelines 1