GE Medical Systems 500, User Manual, Page: 359 / 636

Vascular Summary Report
LOGIQ 500 Basic Users Manual
2276612–100 Rev. 0
11–9

Vascular Calculation Formulas
Calc
Mnemonic Calc Name Input Measurements Formula
RT ECA Right External Carotid Artery
Velocity one Doppler blood flow
peak velocity RT ECA=v1
[cm/s or m/s]
RT CCA Right Common Carotid Artery
Velocity one Doppler blood flow
peak velocity RT CCA=v1
[cm/s or m/s]
RT BIFURC Right Carotid Bifurcation Velocity one Doppler blood flow
peak velocity RT BIFURC=v1
[cm/s or m/s]
RT ICA Right Internal Carotid Artery
Velocity one Doppler blood flow
peak velocity RT ICA=v1
[cm/s or m/s]
RT ICA/CCA Right Internal Carotid Artery
Velocity/Common Carotid Artery
Velocity Ratio two Doppler blood flow
peak velocities RT ICA/CCA=V
ICA
/V
CCA
LT ECA, LT CCA,
LT BIFURC,
LT ICA,
LT ICA/CCA Same as above, for Left Carotid
Artery Same as above Same as above
A/B Ratio Velocities Ratio two Doppler blood flow
peak velocities A/B=V
1
/V
2
% Stenosis Stenosis Ratio two areas (by ellipse, trace,
circle or distance) % Stenosis=[1–(A
residual
/
A
lumen
)]x100
S/D Ratio Systolic Velocity/Diastolic
Velocities Ratio two Doppler blood flow
peak velocities S/D=V
systole
/V
diastole
*NOTE*
PI Pulsatility Index two Doppler blood flow
peak velocities and TAMAX PI=(V
max
–V
diastole
)/
TAMAX *NOTE*
RI Resistivity Index two Doppler blood flow
peak velocities RI=(V
max
–V
diastole
)/
V
max
*NOTE*
HR Heart Rate (beats/minute) one 2 beat time interval
(measured manually or
automatically) HR[BPM]=120[sec]/
2beat time[sec]
*NOTE*: V
diastole
= V
min
or V
end–diastole
(depends on preset selection)
Table 11–1. Vascular Calculation Formulas