GE Medical Systems 500, User Manual, Page: 280 / 636

OB Measurements and Formulas
LOGIQ 500 Basic Users Manual
2276612–100 Rev. 0
9–18

Other OB Calculation Formulas (cont’d)
Calc
Mnemonic Calc Name
Input
Measurements Formula
Author
Reference
GS Gestational
Sac one distance Known LMP Case: Rempen
Sac
Unknown LMP Case:
CRL Crown Rump
Length one distance Known LMP Case:
Length
Unknown LMP Case:
BPD Biparietal
Diameter one distance Known LMP Case:
Diameter
Unknown LMP Case:
BPD Biparietal
Diameter one distance Known LMP Case: Hansmann:
Ultraschalldiag nostik in
Diameter
Unknown LMP Case:
Ultraschalldiag–nostik in
Begurtshilfe und
CRL Crown Rump
Length one distance Known LMP Case:
g
Gynakologie 1985
Length
Unknown LMP Case:
HC Head
Circumference Average of BIP
Average of FRO HC [mm = 2.325*
(BPD [mm] ^2 +
OFD [mm] ^2)^0.5
ThD Transverse
Thorax one distance Known LMP Case:
Thorax
Diameter
Unknown LMP Case:
FL Femur Length one distance Known LMP Case:
Unknown LMP Case:
AC Abdominal
Circumference one distance Known LMP Case:
Circumference
Unknown LMP Case:
EFW Estimated
Fetal Weight Average of BPD
Average of AC EFW[g] =
–3200.40479 +
157.07186 * AC[cm] +
15.90391 * BPD [cm] Merz, et al.,
Womens Hospital,
University of Mainz
BPD Biparietal
Diameter one distance Curve data is
available in the
Advanced Reference Tokyo Shinozuka Method,
1996
APTD x TTD
(AxT)
Antero
Posterior
Trunk
Diameter
Transverse
Trunk
Diameter
two distance
Advanced Reference
Manual
Table 9–6. OB Calculation Formulas—Other Selections (cont’d)