Help with gallbladder ultrasound

[Diver249]

Hi. Had a recent trip to A&E where cholecystis diagnosed ( probable a calculous because no gallstones) but waiting for OP appointment to discuss further) . I had raised liver bloods, CTA and US of gall bladder. These reports have been posted in my GP records which I can view in the NHS app. I understand their content except this in the US report : “no free cholecystic fluid” . Can anyone explain this and its implications please. I know what cholecystic fluid is but don’t understand what is meant by “no free fluid”.