• Obtain a chemistry panel, including electrolytes, liver enzymes, and bilirubin.
  

  • Choledocholithiasis can manifest only with elevation of serum alkaline phosphatase

    or bilirubin.

  • Nearly 50% of patients with symptomatic gallstone disease will have abnormal transaminases.

• A complete blood count is obtained routinely in patients suspected of cholelithiasis.
  

  • CBC might serve as a preoperative lab test normally obtained in patients undergoing major surgery, such as laparoscopic cholecystectomy.

  • An elevated white blood cell count alerts the clinician to the possibility of acute cholecystitis, a condition requiring more urgent treatment.

• Serum lipase and amylase levels are helpful in cases of diagnostic uncertainty or suspected concurrent pancreatitis.

• Coagulation parameters measured by prothrombin (PT) and partial thromboplastin time (PTT) might be abnormal in the severely jaundiced patient due to dysfunction in vitamin K absorption. These tests are routinely ordered preoperatively, especially in patients who are medically anticoagulated with warfarin .

Imaging Studies:
Upright and supine abdominal radiographs are useful.

• Approximately 15% of gallstones are radiopaque and can be seen on plain x-ray.

• A porcelain gallbladder (heavily calcified) should be removed surgically because of increased risk of gallbladder cancer.

• Other causes of abdominal pain diagnosed with the assistance of x-rays include perforated viscus, bowel obstruction, calcific pancreatitis, and renal stones.

Other Tests:
Ultrasound

• Ultrasound (US) is the most sensitive and specific test for the detection of gallstones.

• US provides information about the size of the common bile duct and hepatic duct and the status of liver parenchyma and the pancreas.

• Thickening of the gallbladder wall and presence of pericholecystic fluid are radiographic signs of acute cholecystitis.
  Computerized tomography scanning

• CT scanning often is used in workup of abdominal pain without specific localizing signs or symptoms.

• CT scanning is not a first-line study for detection of gallstones because of greater cost and invasive nature of the test.

• When present, gallstones usually are seen on CT scan.
  99mTc-image display and analysis scintigraphy scan

• 99mTc-image display and analysis (IDA) scintigraphy (HIDA) scan does not detect gallstones.

• HIDA scan identifies an obstructed gallbladder (eg, gallstone impacted in the neck of the gallbladder).

• HIDA scan is the most sensitive and specific test for acute cholecystitis.

• A poorly contracting gallbladder (biliary dyskinesia) might cause the patient’s symptoms, and HIDA scan makes the diagnosis.

• Acute acalculous cholecystitis is diagnosed most accurately with HIDA scan.