The OB measurement tools toolbar contains the tools for calculating gestational age in ultrasound studies. Display the OB measurement tools toolbar by selecting OB Measurement Tools from the Toolbar item in the View menu. The OB measurement toolbar is visible but disabled if no ultrasound images exist in the viewer session.
The available OB measurement tools include the following:
Gestational sac diameter - Measurement of the mean gestational sac diameter.
Embryonic Crown-Rump Length (CRL) - Measurement from the top of the fetus’ head to its buttocks.
Bi-parietal Diameter (BPD) - Measurement of the transverse width between the two sides of the embryo head.
Head Circumference (HC) - Measurement of the perimeter of an ellipse of the head.
Abdominal Circumference (AC) - Measurement of the perimeter of an ellipse of the abdomen.
Femur Length (FL) - Measurement of the length of the baby’s femur.