A few liver cysts have been found on my mri. does this mean i have a specific disease? will these multiply over time? is there a test to check for infection?

Hepatic cysts: The cause of most liver cysts is unknown. Liver cysts can be present at birth or can develop at a later time. They usually grow slowly and are not detected until adulthood. They generally don't "multiply" but can grow in size. And while yes infection can cause cystic formations (like those caused by a parasite, echinococcus that is found in sheep in different parts of the world) its pretty rare.