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.
The most common technique is an ultrasound exam. This quick, painless procedure uses high-frequency sound waves to create pictures of the gallbladder, bile duct, and their contents. CT scans are also sometimes done to look at the anatomy of your internal organs. A more complicated test may be used if the doctor suspects that a gallstone is lodged in a bile duct.