Hepatobiliary Scan

A HIDA (hepatobiliary iminodiacetic acid) scan is a type of nuclear medicine study that creates images of the liver, gallbladder, bile ducts and small intestine. Like other nuclear medicine scans, HIDA uses a radioactive chemical or tracer to highlight organs. The terms “cholescintigraphy,” “hepatobiliary scintigraphy” and “hepatobiliary scan” can be used interchangeably.

HIDA is frequently used to evaluate the flow of bile from your liver to your small intestine. Your doctor may also use a HIDA scan as part of a test to measure the rate at which bile is released from your gallbladder (gallbladder ejection fraction) and screen for a condition known as sphincter of Oddi dysfunction (SOD), which occurs when the sphincter muscle does not open on time. SOD prevents the body’s bile and pancreatic juices from flowing properly and can create a backlog of digestive juices. The backup can cause severe abdominal pain. HIDA can aid in the detection and diagnosis of conditions such as bile duct obstruction or leakage, congenital abnormalities in the bile ducts, gallbladder inflammation (cholecystitis) and/or gallstones.

A radioactive tracer is injected into the arm and will make its way through the bloodstream to the liver, where bile-producing cells will absorb the radioactive material. The radioactivity travels with the bile from your liver, to your gallbladder, and through the bile ducts to the small intestine.

You’ll likely be asked to change into a gown before your scan begins. Your health care team will position you on a table, usually on your back, where you will need to remain still for the majority of the procedure. You will then be injected with a radioactive material, which will penetrate your liver, gallbladder and small bowel. A special gamma camera then passes over your abdomen, obtaining pictures as the tracer moves through your body. Each picture takes about a minute. The camera takes pictures continuously for about an hour until the tracer empties into the small intestine. Your doctor can watch the scan’s progress on a monitor . The HIDA scan is stopped when the radioactive tracer enters your small intestine. This typically takes about an hour.

The radiologist will then interpret the images and prepare a report for your referring physician. Most of the radioactive material will pass through your urine or stool, and any remainder will disappear over time.

In preparation for your procedure your doctor may ask you to fast for several hours or in some cases delay certain medications. Follow any written or verbal instructions provided by your health care team. You may be asked to bring any previous imaging study results (x-ray, MRI, CT, etc.) to your appointment. Inform your radiologist or technician if there is any chance you are or could be pregnant.