A method for increasing accuracy of manual localization for skin markers in three-dimensional images

摘要

In cranial neurosurgery, a common approach to matching image space to physical space in the operating room is to attach markers to the skin of the patient. By localizing these markers in image space, and subsequently in physical space before the surgical procedure, a transformation between the two spaces may be determined. However, the accuracy of this transformation is to a large extent determined by the accuracy with which the markers may be identified in each space. In this paper, we investigate the effect of zoom and slice direction on the localization error of the markers in image space. We use a dataset of three-dimensional head images taken of patients wearing skin markers. We ask a set of qualified observers to localize the centroids of the markers as accurately as possible in each image, both with and without an enhancement designed to facilitate the localization process. This enhancement is an image reformatting step to ensure that the 2-D image slices lie in planes aligned with the principal axes of the marker being localized.