An imaging apparatus for acquiring reflected light from a tubular tissue while moving a transmitting / receiving unit that continuously transmits and receives light in the axial direction in the tubular tissue, and generates an image based on the reflected light. A line data generation unit that generates line data used for generating a cross-sectional image of the tubular tissue based on the detection unit, a detection unit that detects a branch of the tubular tissue based on the line data, and a detection result by the detection unit A cross section in a direction intersecting the axial direction of the tubular tissue based on the setting unit for setting the construction angle of the longitudinal cross-sectional image in a direction substantially parallel to the axial direction of the tubular tissue, and the line data and the detection result by the detection unit A cross-sectional image generating unit that generates an image, and a vertical cross-sectional image generating unit that generates a vertical cross-sectional image based on the line data and the construction angle.光の送受信を連続的に行う送受信部を、管状組織において軸方向に移動させながら管状組織からの反射光を取得し、当該反射光に基づいて画像を生成する画像診断装置であって、反射光に基づいて管状組織の断面画像の生成に用いられるラインデータを生成するラインデータ生成部と、ラインデータに基づいて、管状組織の分枝を検出する検出部と、検出部による検出結果に基づいて、管状組織の軸方向と略平行な方向の縦断面画像の構築角度を設定する設定部と、ラインデータと検出部による検出結果とに基づいて、管状組織の軸方向と交差する方向の横断面画像を生成する横断面画像生成部と、ラインデータと構築角度とに基づいて、縦断面画像を生成する縦断面画像生成部とを備える。
