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.
A hepatobiliary (HIDA) scan is an imaging procedure used to diagnose problems of the liver, gallbladder and bile ducts. For a HIDA scan, also known as cholescintigraphy and hepatobiliary scintigraphy, a radioactive tracer is injected into a vein in your arm.
Gallstones are stone-like substances that are found in the gallbladder. There are two types of gallstones: pigment stones and cholesterol stones. In the majority of patients cholesterol stones are present. In many people the cause for gallstones appears to be interaction between hereditary causes and the diet.