OB calculations

• GA: Gestational Age.
• Fetal age: Conceptional age.
• EFW: Estimated fetal weight.
• AUA: Arithmetic ultrasound age.
• DOC: Date of conception.
• LMP: Last menstrual period.
• EDD: Estimated due date.

In Early OB

• CRL: Crown-rump length
• GS: Gestational sac.

In Mid-late OB

• AC: Abdominal circumference.
• HC: Head circumference.
• FL: Femur length.
• BPD: Biparietal diameter.

References

• Early OB calculations: Hadlock 1992. Fetal Crown-Rump Length: Reevaluation of Relation to Menstrual Age with High-Resolution Real-Time US.
• Mid-late OB calculations: Hadlock 1984 Hadlock F.P, Deter R.L, Harrist R.B. and Park S.K, Estimating fetal age: computer-assisted analysis of multiple fetal growth parameters, Radiology, 152, pp 497-501, 1984
• EFW equations: EFW by AC, BPD FL, and HC: Hadlock 1985 Hadlock F.P, Harrist R.B, Sharman R.S, Deter R.L, Park S.K, Estimation of fetal weight with the use of head, body, and femur measurements–a prospective study, Am.J.Obstet.Gynecol., 151, pp 333-337, 1985

PW mode measurement

The glossary of "Auto Measure"

• HR (bpm)：Heart rate
• PSV (cm/s)：Peak systolic velocity
• EDV (cm/s)：End diastolic velocity
• PI：Pulsatility index (of Gosling)
   PI = (PSV–EDV)/MV
   MV (cm/s)：Mean velocity
• RI：Resistance index (of Pourcelot)
   RI = (PSV–EDV)/PSV
• VTI (cm)：Velocity-time integral
• TAV Max (cm/s)：The maximum of time-averaged velocity
• S/B：The average RI of a cycle
• SD：Systolic/Diastolic Ratio
   SD = PSV/EDV
• ACCL (cm/s²)：The acceleration index
   ACCL = (PSV – EDV)/ACCT
• ACCT (s)：The time from the lowest (EDV) to the highest (PSV)
• VFM (ml/min)：Volume flow per minute
• VFC (ml)：Volume flow per cycle
• VFM Max (ml/min)：The maximum of volume flow per minute
• Diam (mm) ：Diameter
• *VFM, VFM Max, Diam values will be shown when you are in the frozen state.

The glossary of measure tool "PW V, T, HR"

• T (s)：Time
• HR (bpm)：Heart rate
• Range (cm/s)：The range of flow velocity

The glossary of measure tool "RI, S/D"

• PSV (cm/s)：Peak systolic velocity
• EDV (cm/s)：End diastolic velocity
• S/D：Systolic/Diastolic Ratio
   SD = PSV/EDV
• RI：Resistance index (of Poucelot)
   RI = (PSV–EDV)/PSV

The glossary of measure tool "PI"

• PSV (cm/s)：Peak systolic velocity
• D (cm/s)：End diastolic velocity
• Area (cm²)：Blood vessel cross-sectional area
• Diam (mm)：Diameter
• PI：Pulsatility index (of Gosling)
   PI = (PSV–EDV)/MV
   MV (cm/s)：Mean velocity
• VFM Max (ml/min)：The maximum of volume flow per minute
• TAV Max (cm/s)：The maximum of time-averaged velocity

The glossary of measure tool "VTI"

• VTI (cm)：Velocity-time integral

Cardiac measurement in B mode

• BSA: Body Surface Area
   = (Height * Weight / 3600)^½
• SV (ml): Stroke volume
   = EDV – ESV
• SI (ml/m²): Stroke volume index
   = SV / BSA
• CO (l/min): Cardiac output
   = SV * HR / 1000
• CI (l/m/m²): Cardiac Index
   = CO / BSA
• EF (%): Ejection fraction
   = SV / EDV * 100%