Images and Case Report by Dr. Sanida Lukovic
Case:
75 yo F presenting with RUQ pain, nausea and vomiting for 5 days. In the ED, the patient was afebrile and hemodynamically stable. She was in moderate distress due to pain; her abdomen was soft, non-distended, TTP in the epigastrium and RUQ with voluntary guarding but no rebound. Labs were significant only for a mild leukocytosis (WBC 12,000/mm^3). On bedside ultrasound, the patient had a positive sonographic Murphy’s, pericholecystic fluid, thickened anterior gallbladder wall, and a small gallstone surrounded by sludge.
Image 1: Long axis view of gallbladder; pericholecystic fluid; sludge in lumen.
Image 2: Short axis view of gallbladder; wall thickened.
Patient proceeded to have a CT abdomen/pelvis with IV contrast, which also suggested acute cholecystitis. She was started on Zosyn, evaluated by the surgery consult team and admitted to their service for further management.
Teaching points:
- Gallstones usually create a thin echogenic rim with shadowing, but small stones may not shadow at all.
- Gallbladder sludge is the result of very small stones making the bile viscous. On ultrasound, it appears as hyperechoic material with a meniscus in the gallbladder lumen.
- Normal gallbladder wall is less than 4 mm. Always measure the narrowest part of the anterior wall in the short axis. But gallbladder wall thickness is a non-specific finding for cholecystitis, as it is also associated with ascites, heart failure, pancreatitis and liver disease. The same is true for pericholecystic fluid.
- So what do you look for? Gallstones and a sonographic Murphy’s sign! The presence of both has a positive predictive value of 92% for acute cholecystitis; their absence has a negative predictive value of 95% (1).
- Keep in mind that ultrasound is NOT the most sensitive (88%) or specific (80%) imaging modality for acute cholecystitis (1). However, given its widespread availability, lack of ionizing radiation, short study time, and ability to elicit tenderness with the probe, ultrasound is an excellent initial imaging modality in the work-up of RUQ pain.
- Bedside POCUS can be a useful tool to provide quick answers to the ED physician in order to help expedite surgical evaluation, admission, additional imaging, antibiotics.
- Cholescintigraphy (e.g. HIDA scan) is 97% sensitive and 90% specific for acute cholecystitis (1). But it takes hours to perform, limiting its utility in the ED.
Acknowledgements:
Thanks to Dr. Maninder Singh for helping capture the images and videos for this case. And for all the teaching!
References:
- Fox, Christian, and William P. Scruggs. “Biliary Ultrasound.” ACEP Sonoguide, www.acep.org/sonoguide/biliary.html.
- Tintinalli, Judith E., et al. Tintinallis Emergency Medicine a Comprehensive Study Guide. McGraw-Hill Education, 2016.