Duplex/color Flow Imaging (UE)

Question 1

Duplex/color flow imaging can be used for many reasons such as localizing a stenosis/occlusion, determining the presence of an aneurysm, and two more reasons….

Answer 1

• Post-op study: hemodialysis access or arterial bypass graft
• detect AVF’s

Question 2

When scanning a hemodialysis access graft, it may be difficult to adequately evaluate outflow vein due to ?

Answer 2

Increased collateral development

Question 3

In duplex/color flow imaging of the UE, what is the “pledge position”

Answer 3

Patient positioning of the arm at a 45 degree angle from the body and externally rotated

Question 4

Duplex scanning is a combination of these two things

Answer 4

Real-time B-mode imaging (brightness/gray scale evaluation) AND Doppler spectral analysis

Question 5

The SAMPLE SIZE for acquiring pulsed Doppler is ___mm, and can increase if needed

Answer 5

1-1.5mm

Question 6

T/F

It is UNCOMMON for arteries in the UE to become stenotic

Answer 6

TRUE

Question 7

Referring to hemodialysis access scans, what is a THRILL

Answer 7

A thrill is a vibration that a dialysis access can produce (or stenotic area)

Question 8

Put the following technique for evaluating a dialysis access graft in order from first to last step:

• observe for aneurysm, puncture sites, peri-graft fluid
• continue through body of graft looking for tears, fluid leaks, aneurysms
• evaluate outflow vein
• evaluate arterial anastomosis
• evaluate inflow artery
• observe for flow changes and/or turbulence
• evaluate venous anastomosis

Answer 8

1. evaluate inflow artery
2. evaluate arterial anastomosis
3. continue through body of graft looking for tears, fluid leaks, aneurysms
4. observe for aneurysm, puncture sites, peri-graft fluid
5. observe for flow changes and/or turbulence
6. evaluate venous anastomosis
7. evaluate outflow vein

Question 9

Name the 3 steps for a dialysis access FISTULA (e.g. Brescia-Cimino)

Answer 9

1. Inflow artery
2. Anastomosis
3. Outflow vein

Question 10

What is the typical diameter for a fistula

Answer 10

4 or 5 mm

Question 11

With dialysis access, what is the Brescia-Cimino

Answer 11

It is the involvement of the cephalic vein and the brachial artery

Question 12

Name two types of dialysis accesses used

Answer 12

Brescia-Cimino

Straight, looped synthetic graft

Question 13

T/F

Currently, no criteria for classifying stenosis disease

Answer 13

TRUE

Question 14

When interpreting an occlusion, we can look for this proverbial finding that is found proximal to an occlusion

Answer 14

A “thump”

Question 15

A dilation of the vessel from degeneration and/or weakening of the wall is a/n…

Answer 15

Aneurysm

Question 16

An ulnar artery aneurysm can form in response to using the palm as a hammer, this is called

Answer 16

Hypothenar hammer syndrome

Question 17

A subclavian aneurysm is often associated with _____ to the digits

Answer 17

Embolization to the digits

Question 18

Hemodialysis accesses can have variable PSV and EDV depending on the type of access, however, normally both are _____

Answer 18

Both are normally ELEVATED (e.g. PSV > 150cm/sec)

*increased pressure gradient difference

Question 19

A low PSV obtained in an access graft could indicate what

Answer 19

Arterial inflow problems

• rounded waveform prox. To the problem

Question 20

Why are follow up studies important for hemodialysis access interpretation

Answer 20

B/C there is no standardized velocity criteria currently, therefore, comparison of prior studies is helpful for interpretation

Question 21

If volume flow is calculated in an exam, what is it labeled

Answer 21

Measured in mL/min

Question 22

Due to initial hyperplasia or elevated arterial pressure, what is the site that is MOST COMMON for a stenosis with a hemodialysis access
(2)

Answer 22

The venous anastomosis
And
Outflow vein

Question 23

One hemodynamic complication is the large blood volumes in the venous circulation that can increase venous return resulting in?

Answer 23

Congestive heart failure

more with a neck access

Question 24

A hemodynamic complication when the distal arterial blood flow is reversed into the venous circulation and can cause hand pain on exertion, pallor and coolness of the skin distal to the shunt (arterial flow never gets to fingers)

Answer 24

Steal syndrome

*to compare, check index finger on opposite hand

Question 25

To assess for possible “steal” we can use PPG to evaluate flow in atleast 2 digits (one at a time), then applying manual pressure to dialysis access and RETAKE digit PPG tracings and/or pressures… How would this show if there is steal or no steal

Answer 25

If flow IMPROVES = there is a steal

If flow STAYS THE SAME = most likely not a steal