asymptomatic; thin, imperceptible homogeneous wall; unilocular; nonenhancing; not causing biliary obstruction or communicating with biliary system; anechoic on US and/or low-density fluid (< 20 HU) on CT and/or fluid signal on MRI. No further imaging follow-up recommended.
Benign, complicated cyst:
asymptomatic; hemorrhagic/proteinaceous cyst +/- calcification +/- thin septations AND nonenhancing; not causing biliary obstruction or communicating with biliary system. No further imaging follow-up recommended.
Probably benign, complicated cyst:
asymptomatic; equivocally enhancing; thin, regular, possibly enhancing wall; few possibly enhancing septations; no mural nodularity. Consider follow-up US, CT or MRI liver in 6 to 12 months for 2 years, and/or Surgery referral.
Neoplastic, complicated cyst:
thick, irregular, enhancing wall; multiple enhancing septations; multilocular; mural nodularity. Surgery referral is recommended.
Infectious, complicated cyst:
clinical history and signs of infection; peripheral rim enhancement; surrounding edema or inflammation; “cluster of grapes” sign; “double target” sign; large unilocular or multilocular cysts +/- crescentic mural calcifications; multiseptated with daughter cysts. Clinical correlation is recommended.