We use ultrasound to assess the soft tissue structure of internal organs such as the liver, spleen, pancreas, bladder, and intestines. We may also use ultrasonic imaging while we are trying to collect a urine sample, bile from the gallbladder, a small sample from an internal organ or mass, or collect fluid from within the abdominal cavity. Light anesthesia is sometimes needed for this procedure, although we an quite often perform the desired procedure without it.