Thalamic hydatid cyst: contrast-enhanced MR imaging findings.

The case is presented of a 4-yr-old boy with a thalamic hydatid cyst. On a MR imaging study, the pericyst, as well as the germinal layer of the lesion, apparently showed enhancement after administration of the contrast medium. A few previous MR imaging studies on cerebral hydatid cysts described such enhancement; however, its mechanism was unclear. In this communication we propose a mechanism on enhancement of the cystic walls.