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 pieces of solid material that form in the gallbladder. These stones develop because cholesterol and pigments in bile sometimes form hard particles. The two main types of gallstones are: 1  Cholesterol stones: Usually yellow-green in color, approximately 80% of gallstones are cholesterol stones. 2  Pigment stones: These stones are smaller and darker and are made up of bilirubin.