Recent advances in noninvasive assessment of liver steatosis

Due to the steatosis epidemic, methods for noninvasive quantification of the liver fat content are of great interest. Magnetic resonance (MR)-based techniques, including proton MR spectroscopy and MR chemical shift imaging can quantify liver fat by measuring, directly or indirectly (the latter method), the proton density fat fraction, with excellent diagnostic accuracy. These techniques are currently the reference standard for noninvasive assessment of liver steatosis and are used in clinical trials for evaluation of changes in the liver fat content over time. Using ultrasonography (US), 3 different quantitative parameters can be obtained to estimate the liver fat content: attenuation coefficient, backscatter coefficient, and speed of sound. Controlled attenuation parameter (CAP), which estimates attenuation of the US beam, was the first available method for measuring fat content in the liver, and is performed with a nonimaging US system. Currently, several other algorithms are available on B -mode imaging US systems, and their accuracy is similar to or higher than that of CAP. This review summarizes the current knowledge about the application of these methods in patients with metabolic dysfunction-associated steatotic liver disease.