IOTW 10/20/20

54M p/w left eye curtain-down vision loss preceded by 5 days of flashes and floaters

  1. What structure is indicated by label “A”?
    • Eyelid. To perform this study, copious gel is placed over the patient’s eye while their eyelid is closed. Thus the first structure seen nearest the footprint is the eyelid.
  2. What structure is indicated by label “B”?
    • Cornea.
  3. What structure is indicated by label “C”?
    • Iris and ciliary bodies.
  4. What is indicated by label “D”?
    • Pupil.
  5. What structure is indicated by label “E”?
    • Posterior capsule of the lens.
  6. What chamber is located between labels “B” and “C”?
    • Anterior chamber. The anterior segment is located between the cornea and lens. The anterior chamber of the anterior segment is located between the cornea and iris. The posterior chamber of the anterior segment is located between the iris and lens. These are both filled with aqueous humor.
  7. What chamber is indicated by label “F”?
    • Vitreous chamber. This is also known as the posterior segment.
  8. What structure is indicated by label “G”?
    • Optic nerve within optic nerve sheath.
  9. What is the diagnosis indicated by label “H”?
    • Retinal detachment (with some vitreous debris).
      • Your primary differential for a hyperechoic curvilinear structure running along the edge within the vitreous chamber is: posterior vitreous detachment, retinal detachment, or choroid detachment.
      • The vitreous layer is the innermost of these 3 layers. When detached, it is often fairly thin (best visualized with high gain settings), can be seen crossing the macula, and is mobile with oculokinetic movements.
      • The retina is located between the vitreous and choroid layers. When detached, it can be visualized inserting into the macula at the optic disk and is also mobile with oculokinetic movements.
      • The choroid is located between the retina and sclera. When detached, it appears as a thick echogenic pair of bands that remain fixed with oculokinetic movements.
  10. BONUS: What is being measured in the final image and what diagnosis does this exclude?
    • Presence of arterial flow over the central retinal artery. When a patient presents with symptoms concerning for amaurosis fugax, central retinal artery occlusion should be highly considered on your differential. Presence of adequate arterial flow over the central retinal artery excludes this diagnosis. .

IOTW 10/13/2020

36 y/o M p/w R scrotal pain

  1. What is the hyperechoic linear structure labeled “A”?
    • Mediastinum testis of the right testicle. It is a network of fibrous connective tissue formed by invagination of the tunica and not a pathologic finding.
  2. What is the hyperechoic structure labeled “B” in the images above?
    • Epididymal head. It is normally isoechoic or mildly hyperechoic compared to the testicle echotexture. It is located near the superior pole of the testicle. The epididymal body (not visualized) extends down the posterior aspect of the testicle leading to the epididymal tail (not visualized) near the inferior pole of the testicle which becomes the proximal ductus deferens.
  3. What is the layer labeled “C”?
    • Tunica albuginea. It is a fibrous covering of the testis and is best visualized in the presence of fluid.
  4. What is the layer labeled “D”?
    • Visceral layer of the tunica vaginalis. It is a serous membrane covering the testis.
  5. What is the layer labeled “E”?
    • Parietal layer of the tunica vaginalis. This layer is normally held tightly against the visceral layer however becomes separated in the presence of hydrocele.
  6. How would you describe the fluid collection indicated by “F”?
    • Complex hydrocele. Note the subtle layering of debris. Hydroceles form between the layers of the tunica vaginalis and may be congenital or acquired. They are normally anechoic and simple unless complicated by infection or hemorrhage.
  7. Does the presence of normal vascular flow rule out testicular torsion? In females, does the presence of normal vascular flow rule out ovarian torsion?
    • The presence of normal flow rules out testicular torsion in males at the time of the ultrasound examination. The presence of flow, however, DOES NOT rule out ovarian torsion in females. The sole blood supply to the testicle is the testicular artery, whereas the ovaries have dual blood supply from primarily the ovarian arteries with collateral flow from the uterine arteries. Be aware that in the case of intermittent testicular torsion and detorsion, testicular flow may be increased and appear hyperemic, making it difficult to distinguish from orchitis. Thus, a proper history and physical exam are extremely important.
  8. What is the most likely diagnosis in this case?
    • Right-sided epididymo-orchitis. Notice the more hyperechoic appearance and hypervascularity of the right epididymis and testicle when compared to the left. Management is targeted at treating sexually transmitted infections and/or enteric organisms depending on age and risk factors. Patients should follow-up with urology in 1 week if they do not meet admission criteria.

IOTW 10/6/2020

  1. 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.
  2. 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.
  3. 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.
  4. 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])

IOTW 9/28/2020

56M p/w R knee pain and swelling x4 days after prolonged kneeling

  1. 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.
  2. Which bursa corresponds to label B and is it abnormal?
    • Superficial infrapatellar bursa. Note the small anechoic collection here indicating bursitis. `
  3. Which bursa corresponds to label C and is it abnormal?
    • Deep infrapatellar bursa. Note the larger anechoic collection here indicating effusion/bursitis.
  4. 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.

IOTW 9/17/2020

55M w/ hx of L ureteral stent p/w abdominal pain and dysuria

  1. 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.
  2. What other positive finding do you see in A?
    • Nephrolithiasis. There is an intraparenchymal stone at the right-most calyx. Notice the shadow artifact.
  3. What positive finding do you see in B?
    • There is a ureter stone. Again, notice the shadowing.
  4. 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.