What Happens During a HIDA Scan
A HIDA scan helps your doctor to evaluate the flow of bile from the liver to the gallbladder and into the small intestine. The scan also measures the gallbladder's ejection fraction (this is the rate at which the gallbladder releases bile into the small intestine).
This test is usually not performed until after an ultrasound has been done on the gallbladder to check for gallstones. This is because the HIDA scan is a more expensive test and slightly more invasive. As far as invasiveness goes, the test is pretty tame. You'll have to endure an I.V. and a long, boring period of time lying on your back. You should expect to receive your results within 24 hours.
HIDA scan prep
You are instructed to refrain from eating or drinking for six hours prior to a HIDA scan. This ensures that the gallbladder is not already reacting to something in your system. My test was scheduled for 9am, so it was easy to fast overnight and head straight to the hospital.
That's about all you have to do to prepare. I wasn't even required to change out of my street clothes once I arrived for my test.
First step, the radioactive tracer
The HIDA scan gets its name from the radioactive tracer used in the test; it stands for Hepatobiliary Iminodiacetic Acid. This portion of the test can take anywhere from 30 minutes to an hour and a half, depending on the person's digestive system. The lab technician will ask you to lie on a table and will then administer an I.V. This is how the radioactive tracer dye will be injected into your bloodstream. He explained to me that I wouldn't be able to feel the tracer once it was in my body, and he was right. There were no side effects at all.
Once the HIDA scan dye was in, the technician moved the table under a machine which he positioned over my liver area. The machine took a series of photos (one photo took a full five minutes) over the next 20 minutes, and then I was asked to go and sit in a waiting area for 15 - 20 minutes. He took one more photo when I got back and then hooked a tube into my I.V.
CCK injection side effects - how bad was it for you?
HIDA scan side effects of CCK (Cholecystokinin)
The second part of my HIDA scan included a CCK injection. CCK is a medication that makes the gallbladder contract, expelling its contents. The ejection fraction of the gallbladder is determined by what happens to the radioactive tracer during and after the CCK is administered.
The lab tech explained to me that the medication would be administered through my I.V. over a period of 30 minutes, and that the machine would be taking pictures the entire time. Then, after the medication was stopped, the pictures would continue for an additional 15 minutes. After explaining that the tracer would have no side effects, I was a little wary when he didn't mention anything about side effects from the CCK part of the test, so I asked "And how bad will that suck?"
He chuckled a bit, realizing he wasn't going to get away with this tactic of omission, and explained that most people will experience a sense of fullness or a bloated feeling in the abdomen. I think the CCK side effects will vary greatly by person, depending on how bad their gallbladder attacks normally get.
My experience appears to be pretty standard -- a sudden feverish feeling, followed by mild intestinal cramping. The feverishness subsided rather quickly, but the abdominal discomfort stuck around. I spent the remainder of the test praying I wouldn't have to pass gas (phew, crisis averted!). I was a little bit lightheaded when I stood up at the end; whether this was from the medication or the lack of circulation from lying on that hard table, I can't be certain. The sensation passed by the time I had walked out to my car.
I noticed that my desire to eat and drink, which were very strong before the test, had become undesirable by the end of the test. And when I got home, it was necessary to "go"...and go...and go. For me, this is what my symptoms are usually like when my body is reacting negatively to something I ate; so your experience will probably be similar to what happens when you eat a trigger food.
HIDA scan recovery
After eating lunch, I realized I was very sleepy. I took a short cat nap before returning to work that afternoon, but I wished I had taken the entire day off. I was very tired the rest of the day. It could have been stress related, or it could have been part of my body's reaction to the medication. It's hard to say.
If you have to get a HIDA scan, I would suggest taking the whole day off. Even mildly invasive tests can be stressful on the body, so give yourself time to recover.
© 2013 Kristine McAdams