An ultrasound diagnostic apparatus for measuring the IMT of the blood vessel wall of carotid artery, a transmission process for transmitting ultrasonic waves to the short axis cross-section at a plurality of positions different along the carotid artery, jugular of the ultrasonic probe has received receiving a signal based on the reflected ultrasonic wave from the artery and generates a reception processing unit for performing a reception process of generating a reception signal of the short-axis cross section at a plurality of positions, a plurality of two-dimensional images corresponding to each of a plurality of frames 2 a dimensional image generating unit, based on the short-axis cross-section of the carotid artery existing in each of the plurality of two-dimensional images, to measure at least one of the circumferential length or the sectional area of the vessel wall of the carotid artery, the circumference or cross-sectional area of at least one, more defining Bulb boundary detecting section for detecting the boundary position between the two-dimensional images acquired common carotid artery and the carotid bulb on the basis of the information indicating the location of the carotid artery and the measurement range for measuring the IMT on the basis of the boundary position and ROI determination unit for determining the ROI, it was an IMT measurement unit.頚動脈の血管壁のＩＭＴを計測する超音波診断装置であって、頚動脈に沿った異なる複数の位置における短軸断面に対して超音波を送信する送信処理と、超音波探触子が受信した頸動脈からの反射超音波に基づく信号を受信し、複数位置における短軸断面の受信信号を生成する受信処理とを行う送受信処理部と、複数フレームそれぞれに対応する複数の２次元画像を生成する２次元画像生成部と、複数の２次元画像それぞれに存する頚動脈の短軸断面に基づき、頚動脈の血管壁の周長又は断面積の少なくとも１つを測定し、周長又は断面積少なくとも１つと、複数の２次元画像を取得した頚動脈の位置を示す情報とに基づき総頚動脈と頚動脈球部との境界位置を検出するＢｕｌｂ境界検出部と、境界位置に基づきＩＭＴを計測するための計測範囲を規定するＲＯＩを決定するＲＯＩ決定部と、ＩＭＴ計測部とを備えた。
