- What specific ultrasound finding is labeled “A”?
- Stone in neck. This is also known as the “SIN” sign. A stone lodged in the neck of the gallbladder is much more likely to cause cholecystitis than a stone elsewhere such as in the fundus. To see if a stone is truly lodged in the neck of the gallbladder, the patient should also be scanned in the left lateral decubitus or prone position to see if it rolls away.
- What is the structure labeled “B”?
- Duodenal bulb. Be careful not to mistake this structure for the gallbladder. Remember to look for landmarks such as the portal triad and main lobar fissure to confirm that the structure you are seeing is really the gallbladder. The duodenum will also exhibit peristalsis if you watch carefully.
- Let’s say the point of maximal tenderness was elicited when palpating with the probe while obtaining the above images, however the patient’s labs are completely normal including no leukocytosis or transaminitis. What diagnosis is most likely?
- Acute cholecystitis. There is unfortunately no single laboratory or imaging finding to sufficiently rule in or out cholecystitis. While abnormal labs can help make the diagnosis, normal labs do not exclude it. The combination of certain findings, however, can make the diagnosis much more likely. This question describes the technique for the Sonographic Murphy Sign. It was found that a combination of the presence of gallstones with a positive Sonographic Murphy has a positive predictive value of 92% for acute cholecystitis. The presence of a SIN sign alone was found to has a PPV of 93% for acute cholecystitis.
- What are the 5 sonographic signs associated with this diagnosis?
- Stone in neck (SIN sign) – Sp 97%
- Sonographic Murphy sign – Sn 86%, Sp 35%
- Pericholecystic fluid (secondary finding, low specificity by itself)
- Anterior gallbladder wall thickening (>4 mm is abnormal, secondary finding, low specificity by itself)
- Gallbladder hydrops (distended gallbladder measuring greater than 10 cm in length and 5 cm in width [increased width more specific])
56M p/w R knee pain and swelling x4 days after prolonged kneeling
- What structure corresponds to label A?
- Patellar tendon (patellar ligament) since it attaches from the patella to the tibial tuberosity. The quadriceps tendon would be a continuation of the quadriceps muscle and attaches to the superior aspect of the patella which we do not see in these images.
- Which bursa corresponds to label B and is it abnormal?
- Superficial infrapatellar bursa. Note the small anechoic collection here indicating bursitis. `
- Which bursa corresponds to label C and is it abnormal?
- Deep infrapatellar bursa. Note the larger anechoic collection here indicating effusion/bursitis.
- If an infectious etiology is not clinically suspected, what is the diagnosis and how is it treated?
- Infrapatellar bursitis (also known as Clergyman’s knee) with effusion. This is very similar to prepatellar bursitis (Housemaid’s or Carpenter’s knee) which would be inflammation of the bursa just superficial to the patella. It is important to first distinguish from septic bursitis/arthritis. If no infectious component, management is supportive typically with NSAIDs, rest, compression bandages, elevation, and warm compresses. Fluid aspiration is sometimes performed for symptomatic relief however is controversial due to increased risk of infectious complications.
55M w/ hx of L ureteral stent p/w abdominal pain and dysuria
- How would you grade the level of hydronephrosis in A?
- Moderate hydronephrosis.
- Explanation: Mild hydronephrosis is dilatation of the renal pelvis. In higher grade cases of mild hydronephrosis, the dilatation may begin to involve the calyces. Moderate hydronephrosis is when the calyces become so dilated that they obtain a rounded appearance called the “Bear Paw Sign”. Severe hydronephrosis is when there is cortical thinning and loss of borders between the ballooned renal pelvis and calyces.
- What other positive finding do you see in A?
- Nephrolithiasis. There is an intraparenchymal stone at the right-most calyx. Notice the shadow artifact.
- What positive finding do you see in B?
- There is a ureter stone. Again, notice the shadowing.
- What finding regarding the bladder do you notice in C?
- There is a large bladder stone. This was actually found to be obstructing the ureterovesical junction.
57F p/w epigastric pain with RUQ ttp on exam
- What is the name of this ultrasound finding?
- Wall Echo Shadow (WES) sign
2. What is the etiology of this finding?
- Large gallstone or numerous smaller gallstones filling the lumen of a contracted gallbladder
3. What are three things that should be on
your differential when you see this?
- Air-filled bowel loop, porcelain gallbladder, emphysematous cholecystitis
4. Is this finding a sign of cholecystitis?
- No. The five sonographic signs of cholecystitis are: stone impaction in neck, anterior wall thickening, pericholecystic fluid, gallbladder hydrops, and sonographic Murphy sign
WES sign is non-specific, so if acute cholecystitis is suspected,
CT or HIDA scan may be appropriate
26 y/o male presents with abdominal pain and emesis. RLQ POCUS performed as below.
What do you think?
- What is the diagnosis? Acute appendicitis without rupture
- What are the sonographic landmarks
for performing this exam? RLQ and point of maximal tenderness; must visualize iliac vessels and psoas muscle
- What are the sonographic “hard” signs
of a positive exam? Non-compressible, non-peristaltic, avascular blind-ended tubular structure traceable to cecum measuring >6 mm
- What are the sonographic “soft” signs? Appendicolith, RLQ free fluid, periappendiceal fat stranding (increased echogenicity), “Ring of Fire” (increased peripheral vascularity), enlarged mesenteric lymph nodes
Note that appendix may be compressible if it is ruptured!