Written by: John Li, MD (NUEM ‘24) Edited by: Amanda Randolph (NUEM ‘21) Expert Commentary by: John Bailitz, MD & Mike Macias, MD
SonoPro Tips and Tricks
Welcome to the NUEM Sono Pro Tips and Tricks Series where Sono Experts team up to take you scanning from good to great for a problem or procedure!
For those new to the probe, we recommend first reviewing the basics in the incredible FOAMed Introduction to Bedside Ultrasound Book and 5 Minute Sono. Once you’ve got the basics beat, then read on to learn how to start scanning like a Pro!
Point of care right upper quadrant ultrasound has been shown to be a highly sensitive (82-91%), specific (66-95%), cost effective and efficient modality for emergency medicine physicians to quickly and effectively identify biliary pathology [1-5]. But despite its widespread utility, right upper quadrant ultrasound can often be a technically difficult study for the beginner sonographer, as there are multiple factors that can influence its ease of acquisition ranging from patient body habitus to bowel gas shadowing, and sonographer experience has been shown to influence its efficacy [1, 6-7].
Beyond the classic patient with right upper quadrant pain, what other scenarios do Sono-Pros use right upper quadrant ultrasound?
Epigastric abdominal pain being “diagnosed” and even over treated as GERD. Pick up the probe in the symptomatic patient taking their PPI, EGD negative, or already treated for H. pylori
Unexplained right shoulder or back pain.
Colicky pain in the right flank but no urinary findings of nephrolithiasis.
My gallstones are back! But my gallbladder is gone. Look for choledocholithiasis.
Chronically ill elderly or immunosuppressed patients with unexplained fever or sepsis.
SonoPro Tips - How to scan like a Pro
Always Start Smart: To Fail to Prepare is to Prepare to Fail whether in ED POCUS or ED Thoracotomy.
Start with the patient in either the left lateral decubitus position or supine with the bed at approximately 30 degrees.
Let the patient know “I’ll be asking you throughout this brief exam to take medium to deep breaths and hold for 5 sec, then automatically breathe out.”
Still not not getting great views?
Scan between the ribs to use the liver as an acoustic window and avoid bowel gas. Switch to a small footprint phased array probe if needed.
Not sure which intercostal space to use? Try about 7 centimeters to the right of the patient’s xiphoid process!
Ask the patient to position their arms above their head to open the intercostal space.
Ask the patients to bend their knees to relax the abdominal muscles.
In young, thin patients, the gallbladder may be more anterior and superior-- if you are scanning subcostally, try flattening out the probe even more!
Even a Small Pain in the Neck can be a Big Problem!
Don’t forget the neck. There is a reason the gallbladder was so nicely distended and easy to find. Be sure to scan carefully in two orthogonal planes to pick up subtle stones in the neck of the gallbladder!
If there is a lot of nearby bowel gas, tell your tech to look for these stones if your surgeons require a confirmatory comprehensive radiology ultrasound before operating.
In this GIF, you can see a long-axis view of the gallbladder. When you are initially looking at the body and the fundus of the gallbladder, there are no clear shadowing stones. However, as the sonographer fans to the neck of the gallbladder, they can visualize multiple stones, which are casting shadows posteriorly. Image courtesy of the POCUS Atlas.
SonoPro Tips - Pro Pick Ups!
Is that a stone or is that something else in the gallbladder? Roll the patient and see if the “stone” moves!
If the stone in the fundus or body moves, then it’s more likely a mobile stone.
If it doesn’t move, then consider a polyp or a malignancy. Polyps or malignancies generally are non-shadowing while stones are shadowing!
Impacted, “non-mobile” Neck Stone = Big Problem and likely to progress to acute cholecystitis.
What’s causing that shadow?
Stones shadow posteriorly.
Edges shadow on the sides. Edge artifact results when ultrasound beams scatter passing by a smooth-walled structure, creating an anechoic stripe that could be confused with true shadowing!
What if the entire gallbladder is casting a shadow?
Think about a gallbladder FULL of stones! This will cause only the most anterior stones to show up on ultrasound.
Here, on the right side of the screen you see a cross section of the gallbladder that has a large stone in it-- this is casting a shadow so you do not see the posterior wall of the gallbladder at all. This is called the wall echo sign-- where you will only see the most anterior surface of the stone. Image courtesy of the POCUS Atlas.
4. What are some of those pesky mimics of acute cholecystitis?
Think about hepatic pathologies! Acute hepatitis can cause a clinical Murphy’s sign. You can also have patients who present similarly when they have a congestive hepatopathy from their CHF. Even cirrhotic patients can present with a tender RUQ!
Here, you can see a dilated gallbladder with a thickened anterior wall and a small amount of pericholecystic fluid, all of which are consistent with acute cholecystitis. Image courtesy of the POCUS Atlas.
In this still image, you can see a thickened gallbladder wall (although be sure to measure the anterior wall, as the posterior wall can be thickened due to posterior acoustic enhancement!) and a small amount of pericholecystic fluid. Image courtesy of the POCUS Atlas.
Here, you can see a dilated gallbladder with an obstructing stone in the neck of the gallbladder. Image courtesy of the POCUS Atlas.
SonoPro Tips - What the Pro’s Do Next!
Infographic courtesy of Justin Seltzer, MD
If you see nonshadowing masses in the gallbladder:
Measure it! If the polyp is >1cm, then there’s a ~50% chance that this could be malignant, so be sure to refer these patients for additional imaging and close follow up.
What if you’re hoping to be really thorough and get a beautiful image of the CBD, but despite your best efforts, you cannot find it?
Draw some LFTs! A number of our emergency medicine colleagues, including Becker et. al and Lahham et. al, have done studies on this and it has been shown to be very unlikely that the CBD will be pathologically dilated in the setting of normal LFTs. On the flip side, if the LFTs appear cholestatic in nature, that’s another indication for a right upper quadrant ultrasound! [9-10]
SonoPro Tips - Where to Learn More
Do you want to see more pathologic images that you may see when you are doing a right upper quadrant ultrasound? Be sure to check out The Pocus Atlas by our expert editor Dr. Macias! It’s a great resource that also shows some of the rarer etiologies of gallbladder pathology, such as emphysematous cholecystitis or choledocholithiasis.
If you’re interested in looking at some of the evidence behind the right upper quadrant ultrasound, be sure to check out the evidence atlas here as well!
Expert Commentary
Thank you to NWEM1 John Li for bringing this great idea for a NUEM Blog Series to life. And another thanks to NUEM Blog Founder Mike Macias for his help on both content and graphics!
This new series is intended to push your Sono skills from just good, to really great. We will not rehash the basics. There are already abundant great resources available that we are truly thankful for and utilize everyday. But instead, we will share SonoPro Tips to help you more quickly master challenging POCUS applications and procedures.
And there is no place better to start than Acute Cholecystitis. This is a great differentiator between the average and the expert clinician sonographer. As John outlines, start smart by expanding your indications and positioning your patient properly from the get go. Then breath, not you, the patient. Breath and hold again and again to bring the gallbladder and even difficult to discern pathology into clear view. Go beyond getting stones, and work to pick up, and explain other pathologies, as well as the bile ducts when needed.
Thanks again John and Mike! Looking forward to the next post in this new series...
John Bailitz, MD
Vice Chair for Academics, Department of Emergency Medicine
Professor of Emergency Medicine, Feinberg School of Medicine
Northwestern Memorial Hospital
Michael Macias, MD
Global Ultrasound Director, Emergent Medical Associates
Clinical Ultrasound Director, SoCal MEC Residency Programs
How To Cite This Post:
[Peer-Reviewed, Web Publication] Li, J. Randolph, A. (20201 Mar 22). SonoPro Tips and Tricks for Acute Cholecystitis. [NUEM Blog. Expert Commentary by Bailitz, J. Macias, M]. Retrieved from http://www.nuemblog.com/blog/sonopro-tips-and-tricks-for-acute-cholecystitis
Other Posts You May Enjoy
References
Jain A, Mehta N, Secko M, Schechter J, Papanagnou D, Pandya S, Sinert R. History, Physical Examination, Laboratory Testing, and Emergency Department Ultrasonography for the Diagnosis of Acute Cholecystitis. Acad Emerg Med. 2017 Mar;24(3):281-297. doi: 10.1111/acem.13132. PMID: 27862628.
Miller, Adam H., et al. “ED Ultrasound in Hepatobiliary Disease.” The Journal of Emergency Medicine, vol. 30, no. 1, 2006, pp. 69–74., doi:10.1016/j.jemermed.2005.03.017.
Shekarchi B, Hejripour Rafsanjani SZ, Shekar Riz Fomani N, Chahardoli M. Emergency Department Bedside Ultrasonography for Diagnosis of Acute Cholecystitis; a Diagnostic Accuracy Study. Emerg (Tehran). 2018;6(1):e11. Epub 2018 Jan 20. PMID: 29503836; PMCID: PMC5827043.
American College of Emergency Physicians: Emergency Ultrasound Imaging Criteria Compendium. Oct. 2014, www.acep.org/globalassets/new-pdfs/policy-statements/emergency-ultrasound-imaging-criteria-compendium.pdf.
Hilsden R, Leeper R, Koichopolos J, et al. Point-of-care biliary ultrasound in the emergency department (BUSED): implications for surgical referral and emergency department wait times. Trauma Surg Acute Care Open. 2018;3(1):e000164. Published 2018 Jul 30. doi:10.1136/tsaco-2018-000164
Ma, John, et al. Ma and Mateer's Emergency Ultrasound. McGraw-Hill Education, 2020.
Mallin, Mike, and Matthew Dawson. Introduction to Bedside Ultrasound: Volume 2. Emergency Ultrasound Solutions, 2013.
Macias, Michael. TPA, www.thepocusatlas.com/.
Becker BA, Chin E, Mervis E, Anderson CL, Oshita MH, Fox JC. Emergency biliary sonography: utility of common bile duct measurement in the diagnosis of cholecystitis and choledocholithiasis. J Emerg Med. 2014 Jan;46(1):54-60. doi: 10.1016/j.jemermed.2013.03.024. Epub 2013 Oct 11. PMID: 24126067.
Lahham S, Becker BA, Gari A, Bunch S, Alvarado M, Anderson CL, Viquez E, Spann SC, Fox JC. Utility of common bile duct measurement in ED point of care ultrasound: A prospective study. Am J Emerg Med. 2018 Jun;36(6):962-966. doi: 10.1016/j.ajem.2017.10.064. Epub 2017 Nov 20. PMID: 29162442.