Silent gallstones are often found on an abdominal ultrasound that is done for other reasons (Zakko 2018). In symptomatic cases, history-taking and a physical exam are essential to making an accurate diagnosis. Lab tests and imaging are used to confirm the presence of suspected gallstones and help determine whether they are the cause of the presenting symptoms (Zakko 2018; Chen 2012; Wang 2009).
Patients with acute cholecystitis may have fever, jaundice, and strong pain when the upper-right abdomen is pressed while the patient takes a deep breath, which is known as Murphy's sign. These and other signs and symptoms, such as a rapid heart rate and low blood pressure, indicate the possibility of other gallstone-related complications (Shaffer 2018; Tanaja 2018; Indar 2002).
Several other conditions are important to keep in mind as potential causes of upper-abdominal pain that may resemble symptoms caused by gallstones. These include peptic ulcer disease, non-gallstone-related acute cholecystitis, and non-gallstone-related pancreatitis (Shaffer 2018). Other conditions that can mimic biliary pain include heart attack, aneurysm of the abdominal aorta, gastritis, and hepatitis (Portincasa 2006).
Certain blood tests may help with diagnosis, including (Shaffer 2018; Resnick 2016):
- Complete Blood Count (CBC): The number of white blood cells is often elevated in patients with gallstone complications.
- Alanine Transaminase (ALT) and Alkaline Phosphatase (ALP): Elevated blood levels of these enzymes can be a sign of biliary obstruction. Typically, ALT levels rise quickly and ALP levels rise later.
- Bilirubin: Blood bilirubin level is usually elevated if a bile duct is obstructed.
- Amylase and Lipase: Elevated levels of these pancreatic enzymes suggest pancreatitis.
The best initial test for diagnosing gallstones is an abdominal ultrasound (Shaffer 2018; Tanaja 2018). It is highly accurate for detecting stones, can detect sludge as well as stones as small as 2 mm, and identify the presence of acute cholecystitis (Jones, Ghassemzadeh 2018). The ultrasound exam may also detect a dilation of the common bile duct, raising the suspicion of a bile duct stone, obstruction, or tumor (Tanaja 2018; Fogel 2016).
Gallstones with a substantial calcium content may be visible on an X-ray. Computed tomography (CT) and magnetic resonance imaging (MRI) can also detect gallstones, but are less likely than ultrasound to find acute cholecystitis (Jones, Ghassemzadeh 2018). A CT scan may help identify complications such as an abscess or perforation (Shaffer 2018).
A cholescintigraphy scan, also known as a hepatobiliary iminodiacetic acid or HIDA scan, is performed by injecting a radioactive tracer into the blood to evaluate the state of the gallbladder. This scan is used to confirm an unclear diagnosis of acute cholecystitis (Tanaja 2018). A HIDA scan can also be useful for diagnosing chronic cholecystitis and gallbladder motility disorders not related to gallstones (Jones, Ferguson 2018; Goussous 2014).
If ultrasound findings suggest there are gallstones in the common bile duct, an imaging test called magnetic resonance cholangiopancreatography (MRCP) may be used for confirmation (Jones, Ghassemzadeh 2018). An endoscopic ultrasound scan may provide similarly useful information, and is generally used in patients for whom MRCP is not an option, such as those with claustrophobia, as well as certain implanted devices like heart pacemakers or metal joint implants (Shaffer 2018; Pan 2016).
Endoscopic retrograde cholangiopancreatography (ERCP) is another useful diagnostic method. ERCP is an invasive test that involves the use of an injected dye. It can function as both a diagnostic and a therapeutic procedure and is sometimes used in emergency situations involving the bile ducts, since stones can be visualized and removed using this procedure (Shaffer 2018; Tanaja 2018; Lee 2018).
Gallbladder Dyskinesia and Sphincter of Oddi Dysfunction
Gallbladder motility disorder (dyskinesia) and sphincter of Oddi dysfunction are conditions that cause biliary symptoms similar to those caused by gallstones, yet are characterized by the absence of gallstones (Goussous 2014). The sphincter of Oddi is a muscular ring that sits at the junction of the biliary and pancreatic ducts and controls the flow of bile and pancreatic enzymes into the small intestine (Toouli 2002; George 2007). Dysfunction of the sphincter of Oddi can be related to problems with its biliary section, pancreatic section, or both (Seetharam 2008). Patients with gallbladder dyskinesia or dysfunction of the biliary section of the sphincter of Oddi have biliary pain resembling cholecystits (George 2007; Wybourn 2013), while patients with dysfunction of the pancreatic section of the sphincter of Oddi have pain that resembles acute pancreatitis (Behar 2006).
A diagnosis of gallbladder dyskinesia or sphincter of Oddi dysfunction is generally made after other causes of biliary or pancreatic symptoms are ruled out, although further tests may be needed for confirmation (Francis 2011; Behar 2006; Vassiliou 2008). The causes are not well understood, but changes in gallbladder motility are generally thought to be related to a combination of neuromuscular factors (Vassiliou 2008; Cafasso 2014; Behar 2006). Cholecystectomy provides partial or total relief of symptoms in over 85% of patients with gallbladder dyskinesia, as opposed to the nearly 100% success rate reported in patients with gallstone disease (Goussous 2014). Sphincterotomy, a surgery that involves cutting the sphincter, may be an option in severe cases of sphincter of Oddi dysfunction (Toouli 2002; Behar 2006).