Tests for Diagnosing Gallstones

Young woman having ultrasound on stomach
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Are you worried you might have gallstones? Has your doctor suggested you could have a disorder of the gallbladder such as gallstones, or another biliary tract disorder? Gallstones are a condition caused by the hardening of bile in the gallbladder. Imbalances in the substances that make up bile –– either too much cholesterol or bilirubin or not enough bile salts –– cause the bile to harden, forming gallstones.

The gallstones then block the common bile duct, which can lead to a gallbladder attack –– causing symptoms such as nausea and vomiting. Gallstones can range in size, from something as small as a grain of sand to as large as a golf ball. 

If your doctor thinks you might have gallstones, they have likely prescribed further testing to confirm their suspicions. Here’s a quick look at tests and procedures commonly used to diagnose and evaluate gallbladder and biliary tract disorders.

Tests for Gallstones 

1. Ultrasound. The ultrasound uses sound waves to visualize the bile ducts, liver, and pancreas. When gallstones are present, they are seen in either the gallbladder or bile ducts. Little risk is associated with the ultrasound test. The ultrasound may not see gallstones in obese patients, or in patients who have recently eaten.

2. Endoscopic Ultrasound. An endoscopic ultrasound utilizes a scope that has an ultrasound on the end of the instrument.

The special ultrasound scope is passed down into the intestines where internal visualization of the bile ducts, gallbladder, and pancreas ducts can occur. Special training is required to use the endoscopic ultrasound which is sometimes used to locate bile duct stones that may be missed by regular ultrasound.

Other uses for the endoscopic ultrasound include the diagnosis of pancreatic cancer and cancer of the bile ducts.

3. Computerized Tomography (CT) Scan. While the CT Scan may identify gallstones, it is usually not as effective as the ultrasound. A CT Scan can also diagnose cancer in the liver and pancreas. This test is the preferred method of assessing the severity of pancreatitis.

4. Endoscopic Retrograde Cholangiopancreatography (ERCP). ERCP is another type of endoscope that allows access to the bile ducts and pancreas ducts. The ERCP enables the performance of treatments that include removing gallstones from the bile ducts or the pancreas ducts. The measurement of the sphincter of Oddi muscle is often performed, utilizing another specialized test called Oddi manometry, during ERCP.

5. Magnetic Resonance Cholangiopancreatography (MRCP). MRCP utilizes the MRI or Magnetic Resonance Imaging equipment in a noninvasive test that uses special computer software that creates images of the bile ducts and pancreas ducts in a way that is similar to ERCP without the necessity of the internal scope. When MRCP reveals abnormal results further evaluation or treatment is necessary with ERCP or surgery.

Your treatment will likely depend on the results of your imaging tests. If your gallstones were detected via imaging, but without presenting symptoms, your doctor might advise you to wait and see if symptoms develop. Gallstones without symptoms, also known as silent gallstones, usually do not require surgical treatment. 

Source: American College of Gastroenterology