1. An ultrasound imaging apparatus, comprising: a scanner configured to transmit ultrasound waves to a subject and receive reflected waves from the subject; an image generator configured to generate tomographic image data based on the reflected waves; a marker generator configured to generate a first marker and a second marker; and a display controller configured to cause a display to display a tomographic image based on the tomographic image data, and cause the display to display the first marker and the second marker so as to be superimposed on the tomographic image in a state that the second marker is included in a range of the first marker, wherein: the scanner is configured to execute scan with ultrasound waves on the range specified based on the first marker; and the image generator is configured to generate three-dimensional image data based on, of data acquired in the scan, data included in a range specified based on the second marker.