Fitzpatrick The goal of this research is to develop, via perturbation methods, new expressions for error statistics associated with point-based rigid registration in medical imaging, with emphasis on target registration where the targets are typical "targets" of surgery. A specific motivation is that knowledge of these errors is crucial in the planning and guidance of surgery, especially brain surgery. The numerical methods to estimate these errors are extremely unwieldy and time consuming and if reliable closed form approximations were available they could substantially advance the utility of image guided surgery, among other applications of imaging. ***
