Gastric Volume Calculation

The Gastric Volume Calculation allows the user to assess the volume of the gastric content.

Manually calculating the gastric volume

1. From the scan screen select the Abdomen, Abdomen Deep, or the Pediatric Abdomen preset.
2. Select the Actions button  on the bottom right corner of the screen. 
3. Under the “Calculations” heading, select Gastric Volume.
4. When you have identified a view you would like to capture, select the freeze button to freeze the image.
5. Tap the Actions button on the bottom of the screen.
6. Select the measurement button to begin measuring. You will have the option of selecting Mean Antero-posterior Diameter (MAD), Mean Craniocaudal Diameter (MCD), and Age.
7. Adjust calipers as appropriate. As the calipers are adjusted, the measurement label will adjust to show the input.
8. Once satisfied with caliper placement, tap the confirm button to add the measurement to the report and capture an image.
9. Only one of each measurement may be added. To edit an input, delete it from the report or the screen and re-measure.
10. At the bottom of the screen, your measurements will be visible. When you take all three measurements, an estimated volume will appear at the bottom of the screen.
11. A measurement may be deleted before confirming or unfreezing by selecting the “x” next to the measurement label or the trash can icon in the report.
12. You will exit the Gastric Volume calculation package when you upload your study. To exit the calculation package before uploading a study, select the X on the bottom of your screen or select the Actions menu and exit by selecting the X underneath. You will be prompted to confirm exporting or deleting of captured measurements if you exit via the Actions menu or the bottom of your screen.
13. When the volume calculation package is exported, the output will be available in the notes field of the study. This can be retrieved and edited in the study reel prior to upload. After uploading the study, notes are available in the archive screen and in the desktop cloud.

Note: Once the gastric volume calculation package is exited, the inputs may not be edited.

Note: The gastric volume calculation uses the following two equations depending on the age:

1. >= 18 years: gastric volume (mL) = 27 + 14 * (MAD * MCD *  pi / 4) - 1.28 * Age (in years)
2. 4-18 years: gastric volume (mL) = -7.8 + 3.5 × (MAD × MCD × pi / 4) + 0.127 × Age (in months)