Fadeout sign of liver

Excerpt

Abrupt reduction in the echoes in deeper portions of the liver on tissue harmonic compound sonography due to fatty infiltration is termed as the ‘fadeout sign’ [1, 2]. It is seen in the posterior portions of the liver, especially in segment 7 (Figs. 1, 2). Lee et al described the presence a dark band in the deep portion of the liver when compound sonography was converted to tissue harmonic compound sonography mode as the fadeout sign [1]. Compound sonography (which has better contrast and an improved signal-to-noise ratio) and tissue harmonic imaging (which has less noise and reverberation artifacts) are used together when investigating for liver focal lesions. Posterior shadowing occurring due to the effect of fatty infiltration on acoustic penetration becomes more conspicuous on tissue harmonic images leading to fadeout sign [2]. Sensitivity, specificity, and positive predictive value of the fadeout sign for the tissue harmonic ultrasound diagnosis of fatty liver were 78%, 94%, and 94.8%, respectively, with significant differences in fadeout areas according to severity of fatty infiltration [1].

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