If your physician suspects gallbladder disease from your list of symptoms, he will first order a blood test to check for any abnormal levels of liver or pancreatic enzymes. The blood test will also show if there are signs of infection. If the results of the blood test come back positive, your physician might order the following tests. Ultrasonography uses sound waves as opposed to X-rays to display images of your organs. It is one of the best ways for your doctor to see if gallstones are present. Another tool in detecting gallstones is a CT scan. The CT scan uses computer generated X-rays in order to look at your organs.