Gallbladder Ultrasound

Typical Biliary colic

• post-prandial, fatty meal
  
• 2-6 hours duration
  
• late evening, early morning
• radiates to shoulder
• +/- N/V
• Risk factors: DM, Female, Fat, Forty, Fertile (Pregnancy), Family Hx
  
• DDx: PUD, gastritis, GERD, Pancreatitis
  

RUQ U/S
- Intercostal views, subcostal views to check murphy's
- longitudinal (marker to head), transverse views/short avis (marker to R) to check mickey mouse sign
- move patient, TRO impacted stone at the GB neck
- use doppler to see CBD better (no doppler flow)
- left lat decub maybe better
-if stone is noted, localize (neck/body/fundus) = if neck may cause biliary colic, impacted if it does not move upon patient on different position
- short axis plane best confirms gallstones

cholecystitis:
primary:
Gallstone with +ive Sonographic Murphy's = 92% PPV (Ralls, etc, Radiology 1985)

*secondary diagnostic signs
1. distended GB wall >10cm in length (?5cm in transverse diameter)
2. thick GB wall >3mm: short axis may see it better (some say it's >4mm)
(because of posterior acoustic enhancement brought by GB fluid, hard to measure, so anterior wall usually measured)
3. fluid/edema in GB wall
4. pericholecystic fluid (fluid just outside the wall): don't mistake it for +ive FAST
*improves PPV from 92 to 95%


- >8mm CBD inner to inner wall (normal 4mm, 5mm at 50 then 1mm/10 years)
- sonographic murphy's sign

if no stone:
acalculous cholecystitis or bile sludge (cholesterol crystals before becoming stones)

Acalculous cholecystitis: rare in ED
- ICU Patients with TPN, post surgical states, HIV = may need CT scan to dx

Signs:
- Exclamation point/dot sign: GB and portal vein (look at MLF/median lobar fissure of the liver between)
- Shotgun sign (double barrel, upper is dilated CBD), use doppler
- Antlers sign: dilated branching bile ducts = intrahepatic ductal dilatation from eg pancreatic mass
- WES: Wall Echo Shadow Sign (Contracted GB filled with stone)
1. Anterior GB wall
2. Echo (stone hyperechoic), can't see GB lumen usually post prandial
3. Shadow of the stone

FIndings:
- contracted GB if post prandial
- septated GB (divided by a membrane) = normal
- liver Ca (hyperechoic maybe multiple if mets or anechoic cystic structures)
- small stones don't shadow if <3mm

Pitfalls:
- Valves of Heister (no shadow) vs stone
- Hyperechoic stuffs at GB neck should thoroughly evaluated = ?stone
- gallstone vs loop of bowel (outside GB lumen, shadows differently more dirty light and dark looking vs gallstone = clear anechoic)
- gallstone ≠ biliary colic ≠ (definitely) cholecystitis
(smaller stones, situated at the neck more likely to cause pain)
- DDx of thick GB Wall:
1. cholecystitis
2. Hepatitis
3. Volume overload (CCF, renal failure, liver failure
4. low protein states (TPM)
- GB conditions
1. Polyps: small rounded hyperechoic structures clings to wall, defy gravity, no shadows (no hard cholesterols) will need follow up as it may lead to Ca
2. GB Mass: same but bigger, DDx Ca
3. Adenomyomatosis: gas pockets in GB wall

* SMS (sonographic murphy's sign)
= does giving analgesia limit assessment of SMS?
No. n=119. 25 given opioid before U/S. No difference on Sn and Sp between 2 groups
(Nelson BP et al. J Emergency Med. May 2005)