The radiological appearances of the liver after surgical removal of hydatid cyst.

Simple excision of a hydatid cyst from the liver leaves a residual cavity. Depending upon the surgical management of the cavity this can appear cystic, hypoechoic or echogenic on subsequent ultrasound examination. Negative attenuation values on computed tomography are typical of omentoplasty. These appearances can mimic pathological lesions in the liver. Knowledge of the site and nature of previous surgery can prevent diagnostic confusion.