Ultrasound attenuation coefficient of the liver and spleen in adults: A preliminary observation.

OBJECTIVES

The aim of the study was to assess ultrasound attenuation coefficient (AC) in adult liver and spleen.

METHODS

After obtaining IRB approval and written informed consent, liver AC and spleen AC were measured, and AC liver to spleen ratio (AC L/S = AC /AC ) was calculated in 36 adult volunteers (16 men and 20 women, mean age 50y). Based on magnetic resonance imaging derived proton density fat fraction (MRI-PDFF), the participants were divided into normal liver (MRI-PDFF <5%) and steatotic liver (MRI-PDFF ≥5%) groups. Difference in AC between the liver and spleen in each group and differences in liver AC and AC L/S between the two groups were analyzed using two-tailed t-test. Diagnostic performance of liver AC and AC L/S for determining hepatic steatosis was tested by area under receiver operating characteristic curve (AUROC).

RESULTS

There were 12 normal livers and 24 steatotic livers in the study. The difference in AC between liver and spleen was significant in steatotic liver group (p < 0.001) whereas it was not in normal liver group (p > 0.05). Differences in liver AC and AC L/S between the two groups were significant (p < 0.001) whereas difference in spleen AC was not (p > 0.05). AUROC of liver AC and AC L/S for determining ≥ mild hepatic steatosis was 0.90 and 0.97, respectively.

CONCLUSION

Liver AC increased, and spleen AC did not change following the development of hepatic steatosis. The feasibility of AC L/S in determining hepatic steatosis needs further investigation.