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Chapter 4: Measurements and Calculations 59

Measurements

To make a correction, select Undo

on-screen, backtrack with the touchpad, or

press the

BACKSPACE key.

d Press the

SET key to complete the trace.

e Save the calculation.

For information on the automatic trace tool, see

“To trace automatically (Doppler)” on

page 46.

To calculate Isovolumic Relaxation Time

(IVRT)

1 On a frozen Doppler spectral trace, press the

CALCS key.

2 From the calculations menu, select MV and then

select IVRT.

A vertical caliper appears.

3 Using the touchpad, position the caliper at the

aortic valve closure.

4 Press the

SELECT key.

A second vertical caliper appears.

5 Using the touchpad, position the second caliper

at onset of mitral inflow.

6 Save the calculation. (See “To save a

calculation” on page 47.)

To calculate Delta Pressure: Delta Time

(dP:dT)

To perform the dP:dT measurements, the CW

Doppler scale must include velocities of 300 cm/s

or greater on the negative side of the baseline.

(See “Spectral trace controls” on page 29.)

1 On a frozen CW Doppler spectral trace, press

the

CALCS key.

2 From the calculations menu, select MV, and

then select dP:dT.

A horizontal dotted line with an active caliper

appears at 100 cm/s.

3 Position the first caliper along the waveform at

100 cm/s.

4 Press the

SELECT key.

A second horizontal dotted line with an active

caliper appears at 300 cm/s.

5 Position the second caliper along the waveform

at 300 cm/s.

6 Save the calculation. (See “To save a

calculation” on page 47.)

To calculate Aortic Valve Area (AVA)

The AVA calculation requires a measurement in 2D

and two measurements in Doppler. After the

measurements are saved, the result appears in the

patient report.

1 Measure from LVOT (2D):

a On a frozen 2D image, press the

CALCS key.

b From the calculations menu, select LVOT D.

c Position the calipers. (See “Working with

calipers” on page 43.)

d Save the calculation. (See “To save a

calculation” on page 47.)

2 Measure from LVOT, and then measure from AV

(Doppler):

•For Vmax, see “To measure peak

velocity” on page 57. From the

calculations menu, select AV, select sample

site, and then select Vmax.

• For VTI, see “To calculate Velocity Time

Integral (VTI)” on page 57. From the

calculations menu, select AV, select sample

site, and then select VTI.

To calculate Qp/Qs

The Qp/Qs calculation requires two measurements

in 2D and two measurements in Doppler. After the

measurements are saved, the result appears in the

patient report.

1 On a frozen 2D image, press the

CALCS key.

2 Do the following to measure from LVOT D and

again to measure from RVOT D:

1 2 ... 66 67 68 69 70 71 72 73 74 75 76 ... 197 198

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