Thirdly, move the probe slightly over to the right to view the IVC in longitudinal section.
Viewing the IVC as it passes through the diaphragm can give an indication of the load on the right side of the heart.
If the diameter is >2.5 cm with minimal collapse (as shown in the image bottom right. Click the image to see a larger version), this is indicative of increased right atrial (RA) pressure (e.g. Cor Pulmonale, fluid overload). A diameter of <1.5 cm with complete collapse is indicative of being under filled .
This is not a mandatory requirement of the AAA scan but is useful in helping to estimate volume status.