Acute Cholecystitis on Ultrasound (Inflamed Gallbladder)
Acute cholecystitis or an inflamed gallbladder is most commonly caused by stones which cause blockage of the outflow of the gallbladder. This often causes constant pain in the right upper abdomen, nausea, and fever. Unlike biliary colic or gallbladder pain, the pain of acute cholecystitis is longer and accompanied by other symptoms.
An ultrasound of the gallbladder will often be ordered when acute cholecystitis is suspected. A gallbladder ultrasound is the best test when an inflamed gallbladder is suspected, although other tests like CT may also show an inflamed gallbladder. An inflamed gallbladder is commonly caused by a stone blocking the outflow of the gallbladder. This will cause inflammation and potential infection of the gallbladder.
On ultrasound, we will often see a big distended gallbladder, thickened wall, fluid around the gallbladder and pain when applying pressure with the ultrasound probe. This is called a positive Murphy’s sign when there is pain after applying pressure to the gallbladder area. Sometimes an inflamed gallbladder can occur when there are no stones, especially in sick hospitalized patients.
Complications of acute cholecystitis are also seen on ultrasound. This can include gangrene of the gallbladder which happens when there is cut off blood supply and dead tissue in the wall. This can ultimately lead to gallbladder perforation or a tear in the wall.
An abscess or pocket of pus can be identified in some cases. Emphysematous cholecystitis can occur when there is infection of the gallbladder wall with gas forming organisms. Air will be seen in the gallbladder wall. This is a surgical emergency due high risk of death. In some cases, a fistula can occur where an abnormal communication between the inflamed gallbladder and adjacent organ or skin forms.
Cholecystitis is therefore a potentially dangerous and life threatening condition which must be treated promptly. Often surgery will be done for cases where complications are not seen. Other cases may be treated with a tube placed through the skin into the gallbladder to drain it. More imaging may be needed in some cases when the ultrasound is not clear or if complications are suspected that aren’t seen on the ultrasound.