Focal fatty sparing of the liver (CEUS)

A circumscribed area of relatively lower echogenicity can be seen in the 4B segment, adjacent to the falciform ligament, in an otherwise hyperreflective liver. 

Based on the location and morphology, findings make focal sparing in hepatic steatosis the most likely cause, but as the abnormality was previously not known CEUS was recommended to confirm the benign etiology. 

Firstly the liver is scanned using standard B-mode again, the abnormality is measured and documented (image 1).

The CEUS mode is switched on (left half of the screen). Note that from this point onwards the greyscale view (right side) is an artificially generated "B-mode-like" image with much lower contrast resolution. Keeping smaller abnormalities in the field of view (FOV) might therefore likely to be more challenging (image 2, T 0:00).

The cine recording is started when the first contrast agent microbubbles arrive in the FOV (T 00:10) as rapid changes may occur during the important early arterial phase (note: only the early arterial phase is shown from the recording due to the high frame rate and file size).The lesion shows identical contrast enhancement kinetics to the adjacent liver.

The lesion has to be occasionally controlled during the sinusoidal and late phase (image recorded at T 03:46), and the whole liver should be scanned again to identify possible other lesions showing washout. The abnormality retains contrast identical to the surrounding liver.

By T: 04:50, both the lesion and the adjacent liver has lost almost all of the contrast, the exam can be terminated.