Eye-position recording during brain MRI examination to identify and characterize steps of glioma diagnosis

MRI is an essential tool for brain glioma diagnosis thanks to its ability to produce images in any layout plan and to its numerous sequences adapted to both anatomic and functional imaging. In this paper, we investigate the use of an eyetracking system to explore relationships between visual scanning patterns and the glioma diagnostic process during brain MRI analysis. We divide the analyzed screen into Areas of Interest (AOIs), each AOI corresponding to one sequence. Analyzing temporal organization of fixation location intra AOI and inter AOI splits the diagnostic process into different steps. The analysis of saccadic amplitudes reveals clear delineation of three sequential steps. During the first step (characterized by large saccades), a radiologist performs a short review on all sequences and on the patient report. In the second step (characterized by short saccades), a radiologist sequentially and systematically scans all the slices of each sequence. The fixation duration in one AOI depends on the number of slices, on the lesion subtlety and on the lesion contrast in the sequence to be analyzed. In order to improve the detection, localization and characterization of the glioma, the radiologist compares sequences during the third step (characterized by large saccades). Eye-position recording enables one to identify each elementary task implemented during diagnostic process of glioma detection and characterization on brain MRI. Total dwell time associated with one MRI sequence (one AOI) and contrast in primary lesion area enable one to estimate the amount and subtleties of diagnosis criteria provided by the sequence. From this information, one could establish some rules to optimize brain MRI compression (depending on the sequence to be compressed).