Chapter 26- Venous Testing Non-Imaging

Question 1

What are some reasons why we would have a false positive study ??

When we thought a test was positive but its actually negative.

Answer 1

extrensic compressions such as tumors
ascites, 
pregnancy
severe arterial disease
COPD
Cold room

Question 2

What are some reasons why we would have false negative study?

( when we thought it was negative but its really a positive study)

Answer 2

well collateralized venous thrombosis.

Question 3

When we see continuous flow with no respiratory variation or augmentation in the lower extremity, what should this indicate?

Answer 3

this qualitative information shows there is probably proximal obstruction.

Question 4

When we see spontaenous flow with respiratory phasicity, what should this indicate?

Answer 4

Normal flow

Question 5

What is the venous filling index?

Answer 5

shows the rate of venous filling, calculated using venous volume and venous filling time.

Question 6

What is the ejection fraction?

Answer 6

measures the calf muscle pump function. This should be around 60% …this is because the calf muscle SHOULD eject a lot of blood with one contraction

Question 7

What is the residual volume fraction?

Answer 7

The blood left following activiation of the calf pump ( should be low)

Question 8

IS AC Coupling used in arterial photo-plethysmography or venous?

Answer 8

used for arterial studies

Question 9

Is DC coupling used in arterial or venous photoplethysmography?

Answer 9

used for venous

Question 10

What is the normal venous refill (recovery) time when using photo-plethysmogrpahy

Answer 10

Normal is > 20 seconds

Abnormal is <20 seconds