Diagnosis

Gallstones are diagnosed either when there are symptoms or signs that suggest gallstone, and the patient is being investigated for the diagnosis of gallstones or coincidentally while a non-gallstone-related
medical problem is being evaluated.

•Ultrasound.

Ultrasonography is the most important investigation for diagnosing gallstones.  An ultrasound confirms whether gallstones are present or not and can calculate their size.

Ultrasound scans are painless, do not involve X-rays or use of radioactive materials, have no known damaging effects on the body and can be repeated safely as many times as needed.

Ultrasound is an excellent procedure for diagnosing gallstones.  Abdominal ultrasound can identify many other abnormalities related to gallstones.

It can identify the thickened wall of the gall bladder when there is cholecystitis, enlarged gall bladders, ducts and even pancreatitis. The limitations of ultrasonography are that it can only identify gallstones larger than 4-5 millimeters in size, and it is poor at identifying gallstones in ducts.

• Oral Cholecystogram Or Chole scintigraphy. An oral cholecystogram (OCG) or cholescintigraphy involves receiving an injection of an iodine X-ray dye into a vein, or taking iodine-containing tablets for one or two nights in a row. X-rays are then taken of the gall bladder to see whether it contracts normally and stones are present.

OCG is an excellent procedure for diagnosing gallstones. OCG has been replaced by ultrasonography because ultrasonography is slightly better at diagnosing gallstones and can be done immediately and does not require exposure to X-rays. Sometimes OCG detects gallstones that are missed by ultrasonography. For this reason, if there is a strong suspicion that gallstones are present but ultrasonography does not show them, it is reasonable to consider doing an OCG.

• Computerised tomography (CT scan) and Magnetic resonance imaging (MRI) can also demonstrate gallstones. However, they are inferior to ultrasonography for the diagnosis of gallstones.

Diagnosing Stones in the Common Bile Duct

Diagnosing stones that have passed into the common bile duct can be more difficult. The tests, which are necessary in only a small percentage of people with gallstones are:

Endoscope

•ERCP (Endoscopic retrograde cholangiopancreatography) ERCP is a diagnostic procedure to examine the duodenum (the first portion of the small intestine), the bile ducts, the gall bladder and the pancreatic duct. The procedure is performed by using duodenoscope (a type of endoscope). It involves passing a thin, flexible endoscope through the stomach and duodenum to the small intestine and into the bile duct. A special dye is released which stains the gall bladder’s ducts. Any stones present in the ducts then can be seen on an X-ray.

Other specialised diagnostic procedures are PTC (Percutaneous transhepatic cholangiography)
and Magnetic resonance cholangio¬pancreatography (MRCP).