Lateral smearing increases with depth (as the beam widens). Transverse imaging with the probe tilted cranial or caudal will increase the apparent vertical diameter.
Both of these effects occur but will not change the assessment or management in the emergency or POCUS setting.

– The spectral Doppler here is only used qualitatively, to show arterial pulse wave (proving the vessel is an artery – but not which artery). The Doppler angle is too great to allow any measurement of flow rate in this picture. There is very little need for either colour Doppler or spectral Doppler in POCUS evaluation of the aorta for AAA.