Color Doppler examinations typically reveal no mass effect or vascular distortion, Some studies have examined the sensitivity and specificity of US for recognizing fat, as assessed on liver biopsy in patients suspected of having liver disease. Not surprisingly, the sensitivity of US imaging for the detection of fat increases with increasing degrees of steatosis. The mean sensitivity and specificity values vary from 60% to 90%, and from 80% to 95%, respectively. Unfortunately, US is not able to differentiate simple steatosis from non-alcoholic steatohepatitis, both of which may co-exist.
ultrasound images of Focal fatty liver on color Doppler US. On color Doppler evaluation, a vascular structure (arrowheads) courses, without distortion, between the hyperechoic nodules that represent focal fatty infiltration