An ultrasonic diagnostic device according to an embodiment is provided with an image acquisition unit (17a), a contour-position acquisition unit (17b), a volume-information calculation unit (17c), and a control unit (18). The image acquisition unit (17a) acquires a plurality of 2D ultrasonic image data groups generated by subjecting each of a prescribed plurality of cross sections to ultrasonic scanning at least during a prescribed interval of one heartbeat or more. The contour-position acquisition unit (17b) performs a tracking process including 2D pattern matching during the prescribed interval, and acquires chronological data of the contour position of the lumen and/or the external space at a prescribed site included in each of the plurality of 2D ultrasonic image data groups. The volume-information calculation unit (17c) calculates the volume information at the prescribed site on the basis of the chronological data for the plurality of contour positions that was acquired from each of the plurality of 2D ultrasonic image data groups. The control unit (18) controls so as to output the volume information.La présente invention concerne un dispositif de diagnostic ultrasonore qui, selon un mode de réalisation, est muni dune unité dacquisition dimage (17a), dune unité dacquisition de position de contour (17b), dune unité dacquisition dinformation sur le volume (17c) et dune unité de commande (18). Lunité dacquisition dimage (17a) acquiert une pluralité de groupes de données dimage ultrasonore 2D générées en soumettant chacune des sections transversales prescrites dune pluralité de sections transversales à un balayage ultrasonore au moins pendant un intervalle prescrit dun battement de cœur ou plus. Lunité dacquisition de position de contour (17b) exécute un processus de traçage comprenant lappariement de formes 2D pendant lintervalle prescrit, et acquiert des données chronologiques de la position de contour de la lumière et/ou de lespace externe en un site prescrit in
