Prototyping of interactive quantitative analysis software of eyeball shapes by MRI using a template figure

In the previous report, we have proposed a novel disease classification method based on eyeball shape parameters related to high myopia disease prognosis, by measuring 3-dimensional eyeball features without invasion using MRI. In order to apply the proposed method, we had to create volume-rendered images of each eyeball after 3D-MRI T2-weighted scanning of a head. In other words, we could not apply the previous method for 2D-MRI or T1-weighted scanned images of heads. In this paper, we propose a semi-automatic interactive analysis method using a template figure. An operator (normally ophthalmologist) stretches and moves a defined template figure in order to fit it around outline of an eyeball area in 2D-MRI slice image on a computer screen. Then four kinds of parameters as axial length, posterior roundness, horizontal or vertical symmetry, which had been defined in the previously proposed method, are calculated automatically. We have compared analysis results by this newly proposing method with those by the previously proposed using several types of 3D-MRI T2-weighted scanned images of heads for 5 high myopia cases. As a result, differences of all analyzed parameters have been less than 5% as far as 2-D resolution of the source 2D-MRI had been the same as that of 3D-MRI volume images.