64 yo female presents to the emergency department with periumbilical pain that was first noted yesterday after a meal. The pain subsequently moved to the RLQ. Patient has had intermittent vomiting since the pain started. Non bilious, non-bloody. Reports a few episodes similar to this one in the previous months, but states that this episode hurts much worse. The following evaluation began in the right lower quadrant:
Bedside ultrasound failed to show a dilated appendix, however, a large cystic structure was visualized. It was traced back up to the liver and found to be a severely dilated and diseased gallbladder with cholecystic fluid, sludge, thickened walls, and the presence of gallstones. The patient was taken to the operating room the next day. Intraoperatively, the gallbladder was found tethered to the RLQ abdominal wall.
Acute cholecystitis can be suspected clinically when a patient presents with RUQ pain that is worse with meals and associated with nausea, vomiting, fever or jaundice.1
While laboratory tests can be helpful, imaging is the preferred diagnostic modality, with gallbladder ultrasound being the method of choice.1
The sensitivity and specificity of ultrasound for the detection of cholecystitis has been reported to be as high as 90-97% and 95%, respectively.2
Acute cholecystitis can be diagnosed with the presence of gallstones and GB wall thickness >3mm, pericholecystic fluid and the presence of a sonographic Murphy’s sign. Keep in mind that the gallbladder wall can be thickened in the absence of cholecystitis.2
Either the phased array or the curvilinear probe should be placed in the subcostal region, right of midline. The probe should be placed in either the sagittal or transverse orientation, with the probe marker to the patient’s right.
If this standard view is not possible, the probe can be placed in the “X-7” position, which is approximately 7 cm to the right of the xiphoid.3 This technique may be preferred when patients have severe pain, as you do not have to press down on the abdomen, but eliminates your ability to assess for a sonographic Murphy’s sign.
A gallstone can be visualized as either a hyperechoic round structure with acoustic shadowing or a hyperechoic arc with shadowing. A stone will cause symptoms when it is impacted in the gallbladder, cystic duct or common bile duct. An common bile duct >7mm is consistent with choledocholithiasis.1
Blackstock U, Wu S, Lewiss R, Saul T, Bagley W. Focus On: Bedside Biliary Ultrasound. Accessed December 22, 2014. [article]
Dawson M, Mallin M, Introduction to bedside ultrasound volumes 1 + 2. [Inkling]
Fox JC, Scruggs WP. Biliary ultrasound. Accessed December 22, 2014. [article]