Investigation of Features to Evaluate the Quality of Endoscopic Endonasal Stereoscopic Images of the Skull Base

Abstract

The study of neuroanatomy forms an integral part of the education and training for neurosurgeons and aspiring professionals in this field, in which the utilization of images and videos can fit in the pedagogy of this medical discipline. Furthermore, students who lack a solid understanding of three-dimensionality and proportion encounter challenges when interpreting two-dimensional images. Thus, stereoscopic images, a technique used by superimposing two images taken from the same region by moving the camera laterally, keeping the same horizontal plane and the same focal length, becomes valuable by presenting the viewer with the notion of depth and decreasing the learning time. However, when generating stereoscopic images, many of them do not present the expected result, could have their depth perception altered, and could cause discomfort to the observer when analyzed. In this study, a computational algorithm uses Pearson’s Correlation Coefficient, Angle between two vectors, and Oriented FAST and Rotated BRIEF (ORB) to analyze and compare the two stereo pair images. Thus, 6 parameters that best correlate the two images are described, classified in order using the Fisher Discrimant Ratio, and used to evaluate the quality of a set of 180 endoscopic endonasal stereo images of the skull base. The parameters are showcased in graphical results and discussed about its use to be employed as direct indicators for stereoscopic skull base images quality and expedite the analysis of stereoscopic brain images.