US Gallbladder

US TIPS

• Always ask when the patient last ate (at least 4 hours of fasting is best)

• Have the patient supine or try left lateral decubitus for a better sonographic window

• Have the patient take varying levels of inspiration, especially if the GB is under the rib cage

• Use the ABD preset on the GE machine

• Start with 5 MHz curvilinear transducer

• Don't be shy! really press down with the transducer and use lots of gel

• One of the reasons the Sonographers get better images is that they press down harder than us

• If you can't find the common bile duct, use a cine and scan throughout the gb slowly.  To get a cine, hit the record image button without pausing. This will record the past few seconds of scanning

• When in doubt, don’t hesitate to recommend a HIDA

Saggital images of the GB

RUQ US PROTOCOL

• Sagittal and transverse images of the gallbladder

• NECK AND CBD

  • CBD < 6mm (+1 mm for each decade after 60)

  • Most common reason for an inadequate study on call is no CBD

    • Use color to differentiate vessels from ducts in the porta hepatis (both the CBD and hepatic artery have echogenic walls)

• GB Wall Thickening

  • If the patient's body habitus allows, use the 9 MHz linear to measure anterior wall thickness in transverse

  • Should be 1-3 mm thick

  • "Double wall" sign may be GB wall edema

• Pericholecystic fluid 

• Look for stones

  • Place the focal zone at the stone to demonstrate shadowing

  • WES sign (Wall Echo Shadow): stones completely fill GB-completely obscures post wall

• To differentiate adherent stones vs. polyps

  • Shake probe

  • Use color Doppler

  • Demonstrate shadowing

• 1% of cholecystitis is acalculous 

• Color doppler can demonstrate hyperemia in an inflamed gallbladder

• Assess for and document a sonographic Murphy's sign

  • Max tenderness during compression w/ transducer directly on GB

  • False negative sonographic Murphy's sign

    • Lack of patient responsiveness

    • Pain medication

    • Diabetes

    • Inability to press directly on GB 

    • Position deep to liver/protected by ribs

    • GB wall necrosis

Transverse images of GB

On this sagittal image, the hepatic artery (HA) is anterior to the common duct (CD)