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Flashcards in EDE Deck (28)
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1
Q

How much fluid is normally in the pericardium?

A

50cc

2
Q

How much fluid is needed to see a pericardial effusion posteriorly in systole?

A

~100 cc

3
Q

How much fluid is needed to see a pericardial effusion posteriorly throughout the cardiac cycle?

A

100-300cc

4
Q

How much fluid is needed to see a pericardial effusion anteriorly and posteriorly?

A

> 300cc

5
Q

How much fluid can the pericardium accommodate (acutely) before there is hemodynamic compromise?

A

100-200 mL

If it accumulates slowly thats when you can see 300+ mL

6
Q

Name causes of false positives on Cardiac EDE?

A
  1. Epicardial fat
7
Q

How do you distinguish epicardial tissue from an effusion?

A

It appears anteriorly first and dissapears posteriorly where an effusion would collect posteriorly first.

8
Q

In Aorta scan how can you distinguish aorta from IVC?

A
  1. Wall thickness
  2. Compressibility
  3. Variation with resp (IVC will vary)
  4. Sniff test (IVC will change) or can bear down
9
Q

What is one scenerio where the sniff test will be falsely negative?

A

If there are high right sided pressures like having a tamponade

10
Q

How big does the aorta have to be to not have a AAA?

A

<3cm

11
Q

Why isnt EDE able to detect a AAA rupture?

A

It does not visualize the retroperitoneum so will not see any free fluid.

12
Q

In respect to AAA’s what is the 95% rule? (that I made up)

A

95% are fusiform (saccular are less common), 95% are infrarenal, 95% rupture over 5cm and 95% rupture into the retroperitoneum.

13
Q

What is Morisons pouch

A

The hepatorenal space

14
Q

Why is the RUQ the best view?

A
  • It is the 2nd lowest area in a supine pt (pelvis being the first) and the pelvis can only hold a small amount of fluid so any clinically significant bleed will track down into the RLQ via the right paracolic gutter.
  • Bleeding in the LUQ will track to the RUQ by the phrenicolic ligament and mesentery of the transverse colon (without passing through the pelvis)
15
Q

The hepatorenal view alone will detect ___% of clinically significant cases

A

80%

16
Q

How much fluid is needed for EDE to detect it in the abdomen?

A

Most studies state 500mL, some states 900mL

17
Q

What are causes of false positives on the LUQ scan? (5)

A
  1. Perinephric fat (often bilat and symmetrical and more echogenic)
  2. Ascities
  3. Peritoneal dialysis fluid (CAPD fluid)
  4. Ovarian cyst rupture
  5. Urine from rupture bladder
18
Q

What are 3 sources of false negatives on the Abdominal scan?

A
  1. Adhesions - can cause loculations of fluid to accumulate. If pt has abdomen scars dont trust EDE
  2. Delayed presentations (12-24 h after bleed, blood can clot and look more echogenic)
  3. LUQ variability
    - blood doesnt only accumulate in splenorenal interface but also medial and superiorly
19
Q

What are the pelvis scans visualizing?

A

In men the rectovesicular pouch and in women the rectouterine pouch (pouch of douglas)

20
Q

What are causes of false + in pelvis scan in women?

A

Normally can have physiological fluid

21
Q

Pelvic scan: why in men is fluid only see anteriorly?

A

The rectum is retroperitoneal in men so will only see ‘mickey mouse ears’ inferior + lateral to the bladder

22
Q

Pelvic scan: where is fluid seen in women?

A

Inferiorlateral to bladder and also under the uterus (which is the pouch of douglas).

The uterus is free floating so fluid can be seen anteriorly and posteriorly.

23
Q

___% of women with ectopic pregnancys are misdiagnosed at first contact

A

40%

24
Q

What is the rate of ectopic pregnancy?

What is the rate of heterotopic pregnancy?

A

ectopic - 1:80

heterotopic - 1:30,000

25
Q

In women undergoing fertility treatment what is the rate of heterotopic pregnancy?

A

up to 1%

26
Q

What must be seen to diagnose an intra-uterine pregnancy? (3)

A
  1. Decidual reaction
  2. Gestational sac (pocket of amniotic fluid)
  3. Yolk Sac (double ring sign - is echogenic layer within the gestational sac) - usu detected by 6-7 week transabdominally and 5 weeks transvaginally
  • Fetal pole (see crown and rump) and cardiac activity trump the above and confirms an IUP (usu seen >6 weeks)
27
Q

What are the 2 sources of error mentioned with regards to the obstetrical u/s

A
  1. Beware of psuedo-gestational sac - in ectopic this can form but will not have the yolk sac. So make sure the 3 things are seen
  2. Extra-uterine pregnancies
28
Q

Define:

1. Echogenic, echolucent, hyperechoic, hypoechoic

A

Echogenic: A material that produces echoes (i.e. U/S waves bounce off). The more
echogenic a substance is, the whiter the image it produces on the screen.

Echolucent: A material that does not produce echoes (i.e. allows U/S waves to pass
through). The more echolucent a substance is, the blacker the image it produces on the
screen.

Hyperechoic: More echogenic (therefore whiter/brighter) than surrounding tissue.

Hypoechoic: Less echogenic (therefore darker) than surrounding tissue.