1 (If you don't know what these, are set them each to 0.5. 2  z is the value that specifies the level of confidence you want in your confidence interval when you analyze your data. 3  Typical levels of confidence for surveys are 95%, in which case z is set to 1.96. 4  E sets the accuracy of your sample proportions.
Tests and diagnosis discussion for Gallstones: Many gallstones, especially silent stones, are discovered by accident during tests for other problems. But when gallstones are suspected to be the cause of symptoms, the doctor is likely to do an ultrasound exam. Ultrasound uses sound waves to create images of organs.
Imaging is used to provide your doctor with valuable information about gallstones, such as location, size and effect on organ function. Some types of imaging that your doctor may order include: Abdominal ultrasound: Ultrasound produces pictures of the gallbladder and bile ducts. It shows signs of inflammation or indications that there is blockage of bile flow. Ultrasound is the most common test performed to evaluate gallbladder abnormalities.