Role of hepatic colour duplex ultrasound in assessment of non alcoholic fatty liver disease-nafld

Abstract

Abstract Background Gray-scale ultrasonography (US) is an initial, easy to use and widely available imaging modality for NAFLD, the presence of fat infiltration in the liver in the absence of excessive alcohol consumption and other causes of liver disease, is the most common cause of fatty liver, with a prevalence as high as 15-25% in many populations. Objective to determine the effect of obesity and NAFLD on the Doppler waveform pattern of the liver vascularity. Methods A case control study, conducted at Ain Shams University in the period between july and December 2018 . In both groups, liver span & subcutaneous fat was measured by ultrasonographic examination. Hepatic vein waveform pattern & portal vein mean flow velocity were assessed & hepatic artery resistance index was measured by duplex Doppler ultrasonography examination. Results Our study included 50 patients , 20 were control & 30 were cases.. The mean age of cases was 45.30 ± 10.15 SD & the mean age of control was 32.70 ± 10.95 SD rendering the mean age of cases & control of high statistical significance (p value=0.000). The Subcutaneous fat showed high significant statistical difference between cases & control groups with mean subcutaneous fat in control =0.75 ± 0.14 SD & mean subcutaneous fat in cases= 1.23 ± 0.42 SD with p –value = 0.000. The liver span showed high significant statistical difference between cases & control groups with mean in control =15.11 ± 0.85 SD & mean liver span in cases= 17.46 ± 1.67SD ( p value = 0.000). Hepatic vein wave pattern was normal in all 20 control (100%). In the 30 cases,the Hepatic vein wave pattern was triphasic in 12 patients (40%) & biphasic or monophasic In 18 patients (60%) with high statistical significance (p-value =0.000). There was negative correlation between the hepatic vein velocity & BMI with ( p value=0.0032). There was no statistically significant difference between cases & control as regards all Doppler indices including the Hepatic artery RI(resistive index), Hepatic artery PSV(peak systolic velocity), Portal vein velocity(maximum & minimum)& hepatic vein velocity (maximum velocity) where the p value was more than 0.05. Conclusion Patients with NAFLD have a high rate of abnormal hepatic vein Doppler waveform patterns ,which can be biphasic or monophasic rather than alterations in hepatic artery resistance index values by duplex Doppler ultrasonography. Also the fatty infiltration of hepatocytes can increase liver span & the subcutaneous fat.