A hepatobiliary iminodiacetic acid (HIDA) scan with cholecystokinin (CCK) is a medical imaging study that traces the flow of bile from the liver, through the gallbladder, and into the small intestine. A doctor may recommend this test as part of the diagnostic process for a patient with a suspected biliary tract disorder. The HIDA scan with CCK is minimally invasive but does carry some risks, as it involves the use of a radioactive tracer material and requires the patient to fast prior to testing.
Before a HIDA scan with CCK, the patient will need to fast for four to six hours. Patients should discuss any medications they take with their doctors to determine if they temporarily need to stop taking drugs or need to taper back the dosage. In other cases, patients may need to take some extra medications to improve the quality of the test, and could receive these in the days prior or on the day of the test. Patients may find it helpful to schedule the test in the morning so the fasting will not present a hardship.
When a patient arrives at an imaging center for a HIDA scan with CCK, a technician can administer an intravenous injection of radioactive tracer and start the imaging study. The tracer attaches to bile and allows the technician to see how it moves through the body. A separate administration of CCK will cause the gallbladder to contract, allowing the technician to measure how much bile it secretes with each contraction. All this information can be pulled together in a set of detailed test results for the doctor.
One potential risk of a HIDA scan with CCK is a reaction to the tracer material. While most tracers are nonreactive, some patients do experience allergies and may notice symptoms like rashes and burning. People with a history of allergies may want to discuss them with the technician to determine if there are any ingredients in the tracer that might be a cause for concern. Some patients also find the fasting difficult and may experience stomach cramping or other discomfort. Small sips of water or sucking on ice chips can help with this.
Tracer dyes like those used in a HIDA scan with CCK should disappear from the body within a few days. Patients who need numerous imaging studies in a year may want to discuss the risks with a doctor to determine if there are any causes for concern. Repeat exposures to small doses of radiation can be an issue, and the doctor may want to change the testing schedule or determine if it is possible to wait on a test to allow the patient's body more time to recover from previous exposures.