Importance of imaging and recent developments in diagnosis of nonalcoholic fatty liver disease

Figure 1 Ultrasonographic images show the hepatosteatosis stages. A: Grade 1: mild fatty liver; B: Grade 2: moderate fatty liver; C: Grade 3: severe fatty liver.

Figure 2 Computed tomography evaluation of fatty liver using a liver-to-spleen attenuation difference with unenhanced computed tomography. A: Diffuse fatty infiltration of liver with attenuation much lower than the spleen on visual analysis; B: Multiple regions-of-interest (white circles, ROIs) show mean hepatic attenuation (25 HU) and splenic attenuation (51 HU) with -26 HU liver-to-spleen attenuation difference, pointing to moderate-to-severe hepatosteatosis.

Figure 3 Magnetic resonance imaging evaluation of fatty liver using chemical shift imaging. A: In-phase image; B: Out-of-phase image. When out-of-phase image is compared with in-phase images, it shows the signal intensity decrease.

Figure 4 Magnetic resonance spectroscopy image shows a lipid peak in a case of grade 3 hepatosteatosis.