If the liver ultrasound is just looking at the condition of the liver, there is no need for fasting, but many times the gallbladder is also examined during the liver ultrasound, at which time fasting is required. If the liver ultrasound is to look at the condition of the liver, there is no need for fasting, but at the same time the examination of the gallbladder is also performed, at this time need to fasting, the purpose of doing so is to be able to better observe the condition and shape of the gallbladder wall. This is because the gallbladder will be fuller of bile and the view will be clearer only when you are fasting. Eating can cause the gallbladder to contract and bile to be discharged, and this is when the clarity of the ultrasound decreases. Specific cases need to consult the physician to clarify the precautions to avoid affecting the accuracy of the test results.