Features on CT indicative of simple cysts are the following:
1. sharply defined, thin, distinct wall
2. spherical or slightly ovoid shape
3. homogenous content with a density close to water
4. non-enhancing with intravenous contrast.
The kidneys are the most common organ in the body to develop cysts. Simple cysts are benign and most often found as an incidental finding on ultrasound or CT. They may be singular, multiple, unilateral or bilateral.
Features on ultrasound indicative of simple cysts are the following:
1. sharply defined, thin, distinct wall
2. spherical or slightly ovoid shape
3. absence of internal echoes.
4. transmission of sound waves through the cyst with consequent acoustic enhancement behind the cyst