fig2

Figure 2. Influence of hepatic steatosis on hepatocellular carcinoma visibility in a 71-year-old male with metabolic dysfunction steatotic liver disease. The nodule in segment VII of the liver is slightly visible and hyperattenuating compared to the background liver on unenhanced (A - arrow) CT image, while it is not visible (iso attenuating appearance) on contrast-enhanced CT images obtained during hepatic arterial (B) and portal venous phase (C). Note the intense signal drop of the background liver on MR out-of-phase T1 image (E) compared to T1 in-phase image (D) consistent with severe hepatic steatosis, which causes the relative hyperintensity of the nodule to the background liver on out-of-phase image due to fat sparing (E - arrow). The nodule is also visible as hyperintense on unenhanced T1 fat-suppressed image (F), while it is isointense and difficult to depict on gadolinium-enhanced fat-suppressed T1 images obtained during arterial (subtraction image - G), portal (H), and late venous phase (I). CT: Computed tomography; MR: magnetic resonance.