Objective: The objective of this study was to determine whether there are ultrasound characteristics that can be used to differentiate focal fatty sparing (FFS) from hepatocellular carcinoma and other liver malignancies in liver screening.
Methods: Data of patients with FFS found at ultrasound were reviewed, 136 patients with FFS were included, and 112 patients with hepatocellular carcinoma and 65 patients with liver metastatic tumor (173 tumors) were selected as control group. Ultrasound and color Doppler characteristics of FFS and liver malignancies were studied. Some characteristics drawn from this study were used as reference to validate the liver malignancies and FFS, and sensitivity, specificity, and positive and negative predictive values were calculated.
Results: Hyperechogenicity, isoechogenicity, heterogeneous echotexture, posterior acoustic shadowing, halo, hypervasculature presented exclusively in liver malignancies, posterior acoustic enhancement presented predominantly in liver malignancies, irregularly shaped morphology presented exclusively in FFS, arterial velocity, and maximal size of liver malignancies were significantly higher than those of FFS (P < 0.001). Halo presented in 109 of 285 liver malignancies (38.2%), but was absent in FFS (P < 0.001). The overall sensitivity, specificity, and positive and negative predictive values were 94.38%, 90.44%, and 95.39% and 88.49%, respectively.
Conclusions: Combination of hyperechogenicity, isoechogenicity, heterogeneous echotexture, posterior acoustic shadowing, posterior acoustic enhancement, halo appearance, and hypervascularity with high-speed artery has high sensitivity, specificity, and positive and negative predictive values for distinguishing liver malignancy and FFS.