Abstract: On the basis of voxel data for a plurality of voxels constituting a set of ultrasound volume data, a voxel group identifying unit 50 identifies, in said ultrasound volume data, one or more voxel groups formed by a plurality of voxels in which voxel data satisfy a condition of being linked. On the basis of the voxel data for a plurality of voxels corresponding to each voxel group to be displayed, from among the one or more identified voxel groups, an image forming unit 80 forms an ultrasound image in which the voxel groups to be displayed are indicated clearly in a selective manner. It is thus possible for a three-dimensional image to be formed in such a way that one part of the image, such as floating matter in the amniotic fluid, does not interfere with another part of the image, such as a fetus.

Abstract: According to the present invention, when measurement of a distance (fetal head biparietal diameter) on an ultrasonic image is started, a first mobile marker for designating a start point and a standard range display graphic are displayed. The standard range display graphic is a graphic that is centered on the first mobile marker and comprises two circular graphics having radii that are configured to be a lower limit and upper limit of a fetal head biparietal diameter standard range. A user can designate the start point while recognizing, via the standard range display graphic, an end point candidate range. Subsequently, an end point can be designated while recognizing the end point candidate range via a stationary standard range display graphic.

Abstract: When measurement of a circumference (abdominal circumference of a fetus) on an ultrasonic image is started, a first mobile marker for designating a major axis start point of an ellipse to be measured is displayed. After the major axis start point is designated, a second mobile marker for designating a major axis end point of the ellipse to be measured and a standard range display graphic are displayed. The standard range display graphic comprises two ellipses in which the major axis start point and second mobile marker constitute a major axis or minor axis and the circumferences are configured to be a lower limit and upper limit of the abdominal circumference. A user can designate the major axis end point while recognizing the positional relationship between the standard range display graphic and the outline of an abdominal cross section. Furthermore, a minor axis end of the ellipse to be measured can be designated using the standard range graphic as a guide.