Ultrasound diagnosis apparatus and method of setting sound velocity

A ultrasound diagnosis apparatus, comprising:

• an image creating unit configured to create an ultrasound image from data created by adding a reflected wave signal of an ultrasound wave transmitted to an imaging target portion of a subject by using a reception delay time calculated from a predetermined sound velocity being set as a sound velocity in the imaging target portion, wherein the predetermined sound velocity is in a variable range in which the ultrasound diagnosis apparatus can variably set sound velocities;
• an image-creation controller configured to sequentially switch the predetermined sound velocity being set at a present moment to one of a plurality of predetermined sound velocities in the variable range in which the ultrasound diagnosis apparatus can variably set sound velocities, based on an instruction from an operator received via an input unit, and to control the image creating unit so as to create a corresponding plurality of ultrasound images each using a reception delay time corresponding to each of the predetermined sound velocities to be switched;
• and
• a display controller configured to control a display to display the ultrasound images created by the image-creation controller on the display,
• wherein the input unit is configured to receive information from the operator who refers to the plurality of ultrasound images displayed on the display, the information indicating a preferred predetermined sound velocity among the predetermined sound velocities that the operator desires to set as the sound velocity in the imaging target portion.