PROBLEM TO BE SOLVED: To provide an image analysis device for extracting a parameter to be used for determining an abnormality in a tomographic image of an eyeball irrespective of visibility and resolution.SOLUTION: An image analysis device trims a two-dimensional MRI image of a head to a partial image including an eyeball to display the partial image on a display screen as a tomographic image 280, and displays a determining polygon 291 having an octagonal shape together on the tomographic image 280 (Figure (a)). Watching the tomographic image 280, an ophthalmology specialist moves the determining polygon 291 onto an eyeball area 281 (Figure (b)), and modifies the determining polygon 291 in shape such that eight vertices are located on a contour C of the eyeball area 281 (Figure (c)). On the basis of a determining polygon 292 after the modification, several parameters are extracted. Among the eight vertices, top and bottom end points on an eye axis A are located at an anterior point and a posterior point of the eyeball area 281, and right and left two vertices are located at both ends of a line segment V vertical to the eye axis. The remaining 4 vertices are located at intersection positions between the contour C and reference lines at a predetermined angle to the eye axis A, and used for extraction of information on a symmetric property and a shape of the posterior pole.【課題】鮮明度や解像度にかかわらず、眼球の断層画像から形態異常判定に用いるパラメータを抽出する。【解決手段】頭部の二次元MRI画像から眼球を含む部分をトリミングして、断層画像280としてディスプレイ画面上に表示し、その上に8角形の外形をもった判定用多角形291を併せて表示する(図(a) )。専門の眼科医が、当該画像を見ながら、判定用多角形291を眼球領域281の上に移動し(図(b) )、8頂点が眼球領域281の輪郭線C上にくるように形状の修正作業を行う(図(c) )。修正作業後の判定用多角形292に基づき、種々のパラメータを抽出する。8頂点のうち、眼軸Aの上下両端点は眼球領域281の前極点および後極点に配置され、左右2頂点は眼軸に直交する線分Vの両端に配置される。残りの4頂点は、眼軸Aに対して所定角度をなす参照線と輪郭Cとの交点位置に配置され、後極部の対称性や形状に関する情報抽出に利用される。【選択図】図27
