Gallbladder Tests: Ultrasound, CT, HIDA Scan, ERCP

Blood Tests in Gallbladder Disease

When upper right abdominal pain suggests gallbladder disease or obstruction of the common bile duct, the following blood tests may be performed:

  • Bilirubin and liver enzyme alkaline phosphatase (AP) are often elevated in cases of gallstones in the gallbladder and common bile duct (1)
  • Aspartate aminotransferase (AST) and alanin aminotransferase (ALT) are often elevated in cases of gallstones in the common bile duct (1)
  • White blood cells are usually elevated in the inflamed gallbladder or common bile duct (mostly due to gallstones) (1)
  • Tumor marker CA 19-9 may be significantly elevated in gallbladder or common bile duct cancer, which are rare before 60 years of age (2)

NOTE. Gallstones in a non-inflamed gallbladder and early carcinoma of the gallbladder or bile duct may be present without any detectable changes in the blood.

Gallbladder Ultrasound

Ultrasonography is usually the first imaging investigation undertaken in suspected gallbladder disorder. Liver and pancreas are also usually investigated at the same time. Ultrasound can detect (1):

  • Gallstones in the gallbladder (but not reliably in bile ducts) as small as 2 mm
  • Thickened gallbladder wall in a gallbladder inflammation with gallstones (not reliable if no stones)
  • Cancer mass in the gallbladder can be detected in 50-75% of cases (3)

Combination of a normal ultrasound result and normal bilirubin and liver enzymes in the blood quite reliably excludes the possibility of stones in the common bile duct (1).

Ultrasound of the gallbladder can be safely done in pregnancy but can not be done in severe cases of skin disease or in non-cooperative patient. In obese patients, obtained images may not be sufficiently clear to confirm a diagnosis.  Ultrasound can not detect functional gallbladder or bile duct disorders, such as sphincter of Oddi dysfunction.

Negative result of gallbladder ultrasound (no abnormalities detected) does not 100% exclude any gallbladder disorder.

Preparation and Procedure

You will need to fast (not eat or drink anything) 6 hours before the procedure. You will lie flat on your back on the examination table and the doctor (gastroenterologist) will apply gel onto your upper abdomen. This allows for lubrication and prevents distortion of ultrasound waves when they penetrate the abdominal wall. The doctor will guide the probe over your belly skin and observe the image of the gallbladder, liver and pancreas on the monitor. The procedure usually lasts about 15 minutes, is usually not painful and sedation or anesthesia is not necessary. You will be able to discuss the results immediately after the procedure and you will get a written report within a few days.


There is no known harmful effect of ultrasound waves. Transmission of infection from patient to patient through the use of a common ultrasound probe is rare.

HIDA Scan (Cholescintigraphy)

HIDA scan of the gallbladder may be donewhen a gallbladder disorder is suspected but no gallstones are found by an ultrasonography.

Preparation and Procedure

You should have no barium tests two days prior to investigation and four hours of fasting is required before the procedure. You will lie on the table and a non-harmful radioactive dye HydroxyIminoDiaetic Acid (HIDA) will be injected into a vein in your arm. HIDA is excreted by liver into the bile and distribution of the bile among gallbladder, cystic and common bile duct can be traced and recorded by radio-detective camera. Then a hormone cholecystokinin (CCK), which causes gallbladder contraction, will be injected into your vein and another set of images will be made (this part of investigation is not always done). Percent of HIDA that is ejected out from the gallbladder is called ejection fraction (EF). EF above 50% is considered as normal, EF between 30-50% as boundary, and EF below 30% as abnormal (4). The test takes 1-2 hours.

HIDA scan may reveal:

  • Stones in the gallbladder (gallbladder is not completely filled with the dye)
  • Obstruction in the cystic duct (dye does not enter the gallbladder at all)
  • Obstruction of the common bile duct (dye is not excreted into the duodenum)
  • Bile leakage, if there is a perforation in the gallbladder or bile ducts (dye outside of biliary system)
  • Biliary dyskinesia (improper painful contraction of the gallbladder containing no gallstones) may be detected by CCK-HIDA scan (5)

False positive results (gallbladder or bile ducts do not fill with contrast, even if there is no gallstones or obstruction) may occur in liver disease (alcoholic cirrhosis) or in those fasting or receiving all nutrients through an intravenous infusion (1).

Normal HIDA scan does not exclude disorders of bile duct function (biliary dyskinesia, sphincter of Oddi dysfunction).

The whole procedure takes about two hours. HIDA scan should not be done in pregnancy and in a known iodine allergy. Breast milk should be discarded for 48 hours after the test.


Side effects of HIDA scan are rare and include allergy to HIDA, pain during CCK injection, chills, nausea and rash.


ERCP (Endoscopic Retrograde Cholangio-Pancreatography) is a combination of endoscopic and X-ray investigation of the biliary tract; it can be performed when obstruction of cystic, common bile or pancreatic duct is suspected.

Preparation and Procedure

Preparation is like in gastroscopy (upper endoscopy). You should not eat or drink anything 6 hours prior the investigation. You’ll get sedative medication as an injection into the vein.

Procedure. Gastroscope – a flexible viewing tube – is administered through the mouth and proceeded toward the duodenum. A contrast substance is injected into biliary tract through its opening (papilla Vateri). An X-ray image is done to check eventual blockage of contrast distribution (due to gallstones, scars, inflammation, or cancer in biliary tree). Small stones can be removed or a stent (tube) inserted to keep affected duct open. A sample of the bile duct tissue can be cut (biopsy) for further investigation when cancer is suspected. The procedure lasts from 30 minutes to 2 hours. When gallstone is removed, patient stays in the hospital overnight.


Possible complications of ERCP include pancreatitis (quite often but usually mild), perforation of the esophagus, stomach, duodenum or bile duct, bleeding, infection and side effects of sedation (6). Some complications may be life threatening, so detailed discussion about the benefits and risks with your doctor is recommended.

ERCP showing stones in the bile duct (choledocholithiasis) (ERCP)

Picture 1. ERCP: gallstones within the common bile duct


MRCP (Magnetic Resonance Cholangio-Pancreatography) is an investigation of the cystic, common hepatic and pancreatic duct using MRI (magnetic resonance imaging). It is done for the same purposes like ERCP (see above) and can provide results of the same accuracy (7). The downside of MRCP is that unlike in ERCP, no treatment can be performed during the procedure.

Gallsones in the bile duct - choledocholithiasis

Picture 2. MRCP image showing two gallstones in the common bile duct
(source: Wikipedia)

Computer Tomography (CT)

CT of gallbladder is made to find:

  • Biliary sludge (condensed bile) or gallstones in the cystic or common bile duct
  • Cancer in the gallbladder or bile ducts, or to evaluate its spread
  • Complications, like rupture of the gallbladder or bile duct, or porcelain gallbladder
  • Air in the gallbladder (in gallbladder infection)

X-Ray of Abdomen

X-ray of the abdomen, usually done for other purposes, can show big calcified gallstones in the gallbladder. In gallbladder infection, the air in the gallbladder can be sometimes seen.


  1. Diagnosis of gallstones  (
  2. Gallbladder cancer  (
  3. Ultrasound and gallbladder cancer  (
  4. HIDA scan  (
  5. CCK-HIDA scan for diagnosis of biliary dyskinesia  (
  6. ERCP  (
  7. MRCP vs. ERCP  (
About Jan Modric (249 Articles)
Health writer
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  • ndube

    Hi! Dr.
    I have a problem of feeling bitter in my mounth especially in the mornings. i would feel like vomiting and if can happen to bring out, it will be a grren bitter liquid OOh!! it taste very bitte. Is this something to do with gall problems

  • Jan Modric

    To ndube.

    It’s likely the bitter liquid is bile, and your condition is called “biliary reflux”.

    Gallstones in the gallbladder or problems with a function of the bile duct could be a cause; ultrasound of the gallbladder is usually the first investigation.

  • hmoorehead

    I had a HIDA scan today and after first part was done the tech said that they couldnt see my gallbladder so they gave me morphine and another dose of the radioactive stuff. They made me wait 20 mins and then just took a picture of it (took about 5 mins for that) Before the tech gave me the morphine she said “its good and bad cause now you dont have to have the stuff that will make you sick” (the stuff that tricks the gall bladder into thinking it just had a lot of fat?)

    I am so curious as to whats goin on my follow up is on Tues and to long to wait!!

    Is it bad when they have to give you the morphine? what does it mean? I have searched online all day and nothing!

  • katherine

    I have had pain under my right rib and problems with my digestion, espically digesting fats. This is followed with extensive gas and bloating as well as floating stools. I also wake in the middle of the night with pain in the middle and side of my chest. This is often accomanied with sweats. I have had MRCP and CT scan of the abdomen but these were all normal. I have also had a gastroscopy which has shown up some inflamation but no abnormality apart from this. My blood work has been normal apart from my white blood count being below the range for some time. I have also had a slightly raised ALP count. Are the scans that I have had the definitive tests for ruling out and identifying gallbladder disease? Or in view of my continuing symptoms hould I have an ERCP in the hope that this may show up the problem.

    Kind regards Katherine

  • Jan Modric


    before ERCP, you can have HIDA scan.

  • Bonnie Christen

    I just had a HIDA test done and after the first part of the test they said that they did not need to do the second part(where they see the function of the gallbladder)
    I have been trying to find out why they did not finish the entire test… Any information would be appreciated.

    • Jan Modric

      Bonnie Christen,

      what was the result of the first part of the test?

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  • ebscone

    To hmoorehead :

    The morphine helps to distinguish between chronic and acute cholecystitis. The morphine allows the gallbladder to “fill” with the radioactive isoptope that you received. The “stuff that will make you sick” is called CCK. It is a hormone that is produced natrually in the body. It causes the gallbladder to contract and squeeze out all of the bile in it. (This also happens when you eat a greasy meal such as a cheeseburger and fries.) These contractions can cause you to have abdominal pain and nausea.

    There are two parts to a HIDA scan. The first part tells the doctor whether or not the gallbladder is functioning. THe second part (with CCK) tells them just how well it is working if it is.

    To Bonnie Christen:

    The results of the first part often determines whether or not the second part is done. For instance, if you have gallstones, then the second part of the test typically isn’t done. The reason for this is because when CCK is given, it could cause the stones to travel causing an obstruction in the duct. Additionally, your doctor may not have ordered for the second part of the test to be done.

    FYI : HIDA scans can be performed on patients with a known iodine allergy since the radioactive isotope containes NO IODINE. It can also be performed during pregnancy if the benfits of the study greatly outweigh the risks. A dose with a reduced amount of radioactivity would be ordered for the patient. Obviously, imaging modalities that do not utilize ionizing radiation, such as ultrasound, would be used first. Patients that undergo this exam should also be aware that if they take narcotic pain relievers (i.e. morphine, demorrol) should not take them approximately 12 hours prior to their study. These medications can delay gallbladder filling and thus extending the test time. Normal test time is anywhere from 1.5 – 2 hours depending on facility and protocols.

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  • Carl

    For a Gallbladder ultrasound would I need to remove my pants?

    • Jan Modric


      no, if the gallbladder will be the only thing to check. Gallbladder lies just below the right rib cage.

  • ngibson0008

    i am a little worried i had an ultra sound done and they said they couldnt find my gall baladder the us was done to see if i had gallstones or not… now they want me to see a surgeon cause a few weeks ago i had a ct done on me and they incedently found gallstones so now they had the u/s done but couldnt find my gall bladder what does this mean should i be worried or not??

    • Jan Modric


      a CT is usually more accurate investigation than CT. A gallbladder with gallstones is usually removed if it causes symptoms, otherwise it’s not necessary. Your doctors should explain you the situation.

  • tosha

    I have been sick throwing up for 2weeks and iv had Ultrasound,Ct Scan,and a HIDA Scan and they all came back normal I’m still sick and in lots of pain under my right breast and I am swollen….. any tips on what I should do???

  • tori

    I had blood work done and it all cam back normal….am I safe to cancel the $600 Gal Bladder Ultra Sound?

    • Hi Tori. Blood tests may not conclusively identify a gallbladder condition, like gallstones for example. While an ultrasound can be quite pricy, it is nevertheless necessary if you have symptoms indicative of a gallbladder problem. Rather be safe than sorry and identify the exact condition as soon as possible. This may unfortunately involve tests that come up clear in the end but there is no way of knowing for sure without running the relevant test.