GALLBLADDER & LIVER

RUQ US Pearls & Pitfalls

• Know your limitations: Ultrasound may help clarify findings elicited by a thorough history and physical exam.  When used correctly, it can greatly improve diagnostic accuracy, and help guide patient management, especially for time-critical diagnosis and treatment of unstable patients.  If you use ultrasound in your ED, your department should have a quality improvement program set up that is approved by both ED administration and radiology.
• The Sonographic Murphy’s Sign: To check for a sonographic Murphy’s sign, place the ultrasound probe at the maximal point of tenderness in the right upper quadrant. If the probe is placing direct pressure on the gallbladder fundus, you have a positive sonographic Murphy’s sign.
• The Gallbladder Wall: wall thickness can be up to 3mm. The most common conditions other than cholecystitis that may cause thickening of the gallbladder wall include hepatitis, hypoalbuminemia, tumor, hyperplastic cholecystosis, adenomyomatosis, and CHF.  Look for pericholecystic fluid as well.
• The Common Bile Duct: The normal common bile duct inner diameter should be under 4mm, but may be higher, up to 10mm, post-cholecystectomy. In addition the diameter may be higher in older patients, up to 1mm per decade of life.
• The Gallbladder Contents: Look for a dilated gallbladder, evidence of stone, and for sludge.  Stones should be mobile, unless they are impacted and should cast an acoustic shadow.
• Polyps vs. Stones: Mobility: Gallstones tend to be mobile if they are not impacted in the gallbladder neck, while polyps are non-mobile.  If you image a gallstone that is not impacted it should settle to a dependent position with gravity.  If you then reposition the patient, the gallstone will often settle into a new location.  Polyps, on the other hand, are by their nature attached to the gallbladder wall and do not settle with gravity.
• Polyps vs. Stones: Shadowing: Gallstones, unless they are very small, will cast an acoustic shadow.  This is a type of ultrasound artifact where a thin sector type area far-field from of sonically dense object, such as a gallstone will appear completely black.  See the comparison image.  Polyps however are not dense enough to cast a shadow.  Although they are echoic, some of the ultrasound waves still pass through and therefor, no shadow is cast.
• Pitfalls: Don’t miss a single obstructing gallstone hidden in the gallbladder neck.  Also, do not miss a AAA because you did not look. It is not that far away, and should be checked routinely in anyone over the age of 50 who is having an abdominal ultrasound for another reason.

*Want more educational images? Check out the ED Atlas on CD
****


Right Upper Quadrant Ultrasound



A single gallstone impacted in the gallbladder neck may be missed

Cholecystitis with pericholecystic fluid

*






Liver Abscess #2


Liver Abscess


*



Gallbladder Polyp – Long Axis

****

Do you want a pocket reference that has essential material on ED Ultrasound as well as other imaging, labs, EKG’s, procedures, risk management and more?

Then get Cornucopia: Emergency Medicine

****

WOULD YOU LIKE TO USE ONE OF OUR IMAGES?

As long as you paste the following statement with a weblink to this site, no problem: “Image reproduced with permission, ERPocketBooks.com”

****