Evaluation of fatty liver using semiquantitative classification and attenuation coefficient

Abstract

Objective: In this study, we aimed to investigate how the evaluation of fatty liver changed when the B-mode semiquantitative and attenuation methods were used in combination. Subjects and Methods: The study subjects were 1,169 subjects who underwent abdominal ultrasonography. Fatty liver was defined as mild or severe by the B-mode semiquantitative method or as an attenuation coefficient of 0.62 dB/cm/MHz or greater. Results and Discussion: Among the 1,169 subjects, the attenuation coefficients could be measured in 1,039 subjects. Of the 541 patients who were determined to have fatty liver either on the basis of the B-mode finding or by the attenuation method, 53.8% were determined by both methods, 28.8% on the basis of the B-mode finding alone, and 17.4% by the attenuation method alone. These results suggest that the attenuation method can detect fatty liver in some cases that could not be determined on the basis of the B-mode finding alone, whereas many cases of fatty liver were missed by the attenuation method alone. In 11.1% of 130 subjects in which the attenuation coefficient could not be measured, the more advanced the fatty liver, the higher the percentage of cases in which the attenuation coefficient could not be measured. This suggests that the attenuation method is effective in cases where the B-mode cannot be determined as a fatty liver. Conclusion: In this study, we showed that the combined use of the B-mode semiquantitative and attenuation methods effectively detects fatty liver that could not be determined on the basis of the B-mode finding alone.