GE Medical Systems LOGIQ 7, Справочное руководство, Страница: 123 / 244

Measurement Formulas
LOGIQ 7/LOGIQ 7 Pro Advanced Reference Manual 2
-
23
Direction 5116269-100 Rev. 2
Formulas–Vascular
Table 2-10: 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
a
PI Pulsatility Index two Doppler blood flow
peak velocities and
TAMAX
PI=(V
max
-V
diastole
)/TAMAX
a
RI Resistivity Index two Doppler blood flow
peak velocities
RI=(V
max
-V
diastole
)/ V
max
a
or
RI=(V
max
-V
min
)/V
max
a
HR Heart Rate (beats/minute) one 2 beat time interval
(measured manually or
automatically) HR[BPM]=120[sec]/
2 beat time[sec]
Vol. Flow Volume Flow dTamean*dDiam*dDiam*0.785
or
dTamax*dDiam*dDiam*0.785
a.V
diastole
= V
min
or V
end-diastole
(depends on preset selection)