Intracranial aneurysms are localized dilations in blood vessels occurring in 1-6% of the population which can have devastating consequences in the event of rupture. Many aneurysms are asymptomatic, found incidentally, and fall below the surgical size threshold. For this reason, physicians choose to follow aneurysms with imaging rather than opting for surgical or endo-vascular intervention. Here we further our analysis of a previously presented image processing technique using contrast-enhanced MRA to follow intracranial aneurysms longitudinally. We investigate the measurement error of this post-processing technique in 100 intracranial aneurysms, and evaluate the differential effects of imaging at 1.5T and 3T.