The linearized wave-equation MVA operator can be used for velocity analysis using both Born and Rytov approximations. The distinction arises from the method used to compute the image perturbations. Both approximations suffer from limitations that limit their practicality: the Born approximation is usable only for small anomalies, while the Rytov approximation requires phase unwrapping. Differential image perturbations can be used for arbitrarily large slowness anomalies and do not require phase unwrapping, but their accuracy decreases with increasing deviation from the background image. For simple cases, the differential image perturbation method is equivalent with phase-unwrapped Rytov.