Cross sectional imaging features of a hydrocele

What is a hydrocele, and what are its cross sectional imaging features?

A hydrocele is a collection of fluid within the scrotum adjacent to the testicle located between the visceral and parietal layers of the tunica vaginalis. It is the most common cause of scrotal enlargement.

On cross-sectional imaging, a hydrocele appears as fluid within the scrotum surrounding the testicle that is anechoic and has posterior acoustic enhancement on US, fluid attenuation (0 to 20 HU) on CT, and low T1-weighted and very high T2-weighted signal intensity on MRI.