Friday, May 25, 2007

Answer: VizD Challenge Week of 5/21/2007

*NY Emergency Medicine Exclusive*

Congratulations to Jay - he is the first person to submit the correct answer to this week's VizD. Jay is the winner of $5

To view Jay's answer, click here.

View the VizD Question of the week.

This week, Dr Steve Menlove, Director of Emergency Ultrasound at Bellevue Hospital in New York City will discuss the answer to this weeks VizD

NYEM: What are the main features of this ultrasound?

SM: The most important finding is gas in the anterior wall of the GB. Sonographically, gas bubbles are hyperechoic, cast “dirty shadows” (as opposed to the “clean shadows” cast by stones) and create ring-down artifact – all of which are seen in this image. There appears to be some pericholecystic fluid on this image, but it’s not very clear. Less importantly, the GB is distended (greater than 4cm in transverse diameter).

NYEM: What clinical entity is this ultrasound typically associated with?

SM: Emphysematous cholecystitis.

NYEM: Can this be mistaken for other clinical conditions?

SM: There is nothing else that really looks like this image, but for the sake of discussion I’ll mention a few things: Air bubbles in the duodenum (recall that the “C-loop” of the duodenum abuts the GB) can be mistaken either for gallstones or for air in the GB wall. A porcelain GB has a calcified wall, which shadows (although the shadows should be cleaner and would not create ring-down like gas does.) There is a common normal variant called adenomyomatosis in which the wall is thick and contains cholesterol crystals which are bright reflectors and cast short (about 1cm) comet-tails. A GB which is chock-full of stones and has little surrounding bile creates the ultrasound sign called “Wall-Echo-Shadow” – a hyperechoic line (GB wall), then another hyperechoic line (the top layer of stones) then a shadow from the stones. The back wall of the GB would not be visible in this case.

NYEM: How is this condition treated?

SM: Emergency Cholecystectomy. IV antibiotics should be given as early as possible in the ED.

NYEM: How often have you seen this finding on ultrasound?

SM: Less than once a year.

NYEM: What is your favorite ultrasound textbook?

SM: I recommend A Practical Guide to Emergency Ultrasound by Karen S. Cosby and John L. Kendall to my residents. Emergency Ultrasound by Ma and Mateer is also excellent (a close second). There are many great US books which are not oriented to EP’s (my current favorite is Case Review: General and Vascular Ultrasound by William D. Middleton).

NYEM: If you were going to practice medicine in a remote village and could bring an ultrasound machine with only one probe, which probe would you bring?

SM: I guess a typical abdominal probe (curvilinear 3-5mHz).

NYEM: How did you become interested in ultrasound?

SM: I spent a month doing an ultrasound elective at an obstetrical hospital during my residency (back in 1992) and took to it. How great is it to be able to see into the body?

NYEM: What is the most challenging body part to ultrasound?

SM: Every body part can be tricky at times – especially so when patients are obese, gassy, or have had prior surgery. The neck of the gallbladder is often overlooked. Abnormal adnexae (e.g. TOA’s) take experience. The tail of the pancreas is often obscured by gas. Evaluating heart valves and regional wall motion abnormalities are beyond the scope of ED ultrasound imho. The danger inherent in all ED ultrasound is acting on faulty information. It is important to be cautious…

NYEM: Ultrasound use in EM is mainly used to examine the abdominal organs, heart, and pelvis; what is the next popular area you see us using it for?

SM: Ultrasound enthusiasts are coming up with new uses all the time (e.g. the eye and the lung have received attention recently). I think “rule out DVT” is a very useful indication (and not too difficult to learn.) Ultrasound for guiding procedures is also very useful.

NYEM: Thanks for your time

SM: My pleasure

VizD is a weekly contest of an interesting or pathognomonic image from emergency medicine. Its goal is to integrate learning into a fun and relaxed environment. All images are original and are posted with the consent of the patient. For more information please refer to the following link.


JC Jones MA RN said...

Never heard of that one before. Thanks for the information. What are the 3 causative organisms? Great stuff...w

Adam said...

Thanks jc jones ma rn...
E. coli

JC Jones MA RN said...

Thanks, Adam.