Echo Views and Measurements

7

DAo

8

posterior MV leaflet

9

anterior MV leaflet

10

aortic valve, non coronary cusp

11

aortic valve, right coronary cusp

12

coronary sinus

15

LV, posterior wall

RV

RA

TV

posterior TV leaflet

Anterior TV leaflet

IVC

RV

Main pulmonary artery

PV

Right PV cusp

Anterior PV cusp

Right pulmonary artery

left pulmonary artery

LV

LV

posteriomedial papillary muscle

anteriolateral papillary muscle

RV

1

LV

2

Anterior MV leaflet

3

posterior MV leaflet

4

IVS

5

RV

1

LA

2

RA

3

RV

4

Pulmonary artery

5

TV

6

PV

7

Aortic valve, non coronary cusp

8

Aortic valve, right coronary cusp

9

Aortic valve, left coronary cusp

10

anterior TV leaflet

11

septal/medial TV leaflet

12

Right PV cusp

13

anterior PV cusp

14

IAS

7

anterior TV leaflet

8

septal/medial TV leaflet

9

anterior MV leaflet

10

posterior MV leaflet

14

RV free wall

15

inferior septal wall (LV)

16

anterior lateral wall (LV)

5

aorta

8

aortic valve

9

LVOT

4

inferior wall

5

anterior wall

1

RA

2

IVC

3

liver

4

hepatic vein

1

DAo

2

IVC

3

Ascending aorta

4

left common carotid artery

5

left subclavian artery

septal

inferior

lateral

anterior

parabolic flow

Has a bullet shaped profile, Velocity is highest in the center of the lumen and gradually decreases to its minimum at the vessel wall.

plug flow

Occurs when all of the layers and blood cells travel at the same velocity.

More common with intracardiac flow due to tapering of flow streams through the valves.

laminar flow

Movement of fluid along well defined parallel stream line (layers) with uniform flow velocities

Reynold’s number

Predicts the likelihood that turbulence will occur.

demodulation

The process of extracting the low Doppler frequency from the higher transducer frequency

Negative Doppler shift

Color flow is away from the tx and the spectrum is below the baseline (retrograde flow).

Positive Doppler shift

Color flow is toward the tx and the spectrum is above the baseline (antegrade flow).

antegrade flow

Another word for Positive Doppler shift

Spectral Doppler

allows us to measure the velocity (speed and direction) of blood flow (traveling toward or away from the tx); displayed in the form of a time/velocity graph.

On a Spectral Doppler graph, what does the horizontal plane represent?

Time

On a Spectral Doppler graph, what does the vertical plane represent?

Velocity

Peak velocity (PSV)

Maximum velocity

Velocity time integral (VTI)

mean velocity or mean pressure gradient

Planimetry

cross section of a specific intracardiac location and a specific time point in the cardiac cycle

Power Doppler

Measures the presence of moving blood cells by detecting a Doppler shift. Non-directional; all vessels are the same color. The strength (amplitude) of the reflected signal is processed - the amount of moving blood cells. Also called Color Angio.

Advantages of Power Doppler

1. no aliasing
2. unaffected by Doppler angle
3. Very sensitive to low flow.

Disadvantages of Power Doppler

1. susceptible to motion
2. lower frame rate than conventional color flow Doppler
3. You don't get direction

Bi-directional Doppler

distinguishes the direction of blood flow (phase quadrature processing)

Advantage of CW Doppler

No aliasing; able to accurately measure very high velocities.

Disadvantage of CW Doppler

Range ambiguity - inability to determine the exact location of the moving RBCs being Dopplered.

What is CW Doppler used for?

Stenotic valve gradients, and calculations of pressures - 4(v²)

Pedoff Probe

A blind, standalone Doppler probe (no 2D image, not steerable). Easily fits into rib spaces and suprasternal notch.

Aliasing

Blood cells moving at high velocities are displayed as moving in the wrong direction. Occurs when velocity of blood exceeds the Nyquinst limit equals 1/2 the pulse repetition frequency. Only occurs with PW, never with CW.

Nyquist limit formula

PRF/2

How to reduce aliasing

• increase the Doppler scale

• use a lower freq tx

• use a CW tx

• change to a shallower imaging depth (high PRF)

• drop the baseline

Color flow Doppler

Converts recorded flow frequency into different colors, allowing us to examine the direction and velocity of the blood flow through the chambers and valves. Allows for real time demonstration of flow patterns (velocities) superimposed on a gray scale image.