Fig 3. Manual segmentation of a 12-mm large carotid ophthalmic artery aneurysm with the 3D rotational angiography (3D-RA) volumetric measurement software.

A, Volume-rendering display of a 3D-RA representation of the aneurysm obtained after rotational angiography of the right ICA. The gross contour of the aneurysm is first extracted with the cutting graphical tool of the software (yellow line).

B, Cutting of the aneurysm is refined to extract only the contour of the aneurysm (yellow line).

C, Finally, the volume is given by placing the segmented aneurysm inside the sphere giving a volume of 591 mm³, which corresponds to a 34% overestimation provided by the ellipsoid approximation.