An ultrasound apparatus comprising: an ultrasound image data obtainer configured to obtain first B mode image data and first Doppler data about a target object to which a medicine is injected, and obtain second Doppler data about the target object after the first B mode image data and the first Doppler data are obtained and then a preset time elapses; a controller configured to detect a first area of the target object from which the first Doppler data is obtained and a second area from which the second Doppler data is obtained and determine a first diffusion boundary of the medicine, based on the first area and a second diffusion boundary of the medicine, based on the second area; and a display configured to mark the first diffusion boundary of the medicine and the second diffusion boundary of the medicine on a B mode image (400,700) that is generated by using the first B mode image data, and display, on the B mode image, comparison data obtained by comparing an estimated diffusion range of the medicine with an actual diffusion range of the medicine, wherein the controller is further configured to estimate the diffusion range of the medicine, based on at least one of information about a position to which the medicine is injected and an injection amount of the medicine, obtain the actual diffusion range of the medicine, based on the first area and the second area, compare the estimated diffusion range of the medicine with the actual diffusion range of the medicine, wherein the display is further configured to display the comparison data, such as an error rate, obtained by comparing the estimated diffusion range of the medicine with the the actual diffusion range of the medicine. an ultrasound image data obtainer configured to obtain first B mode image data and first Doppler data about a target object to which a medicine is injected, and obtain second Doppler data about the target object after the first B mode image data and the first Doppler data are obtained and then a preset time elapses; a controller configured to detect a first area of the target object from which the first Doppler data is obtained and a second area from which the second Doppler data is obtained and determine a first diffusion boundary of the medicine, based on the first area and a second diffusion boundary of the medicine, based on the second area; and a display configured to mark the first diffusion boundary of the medicine and the second diffusion boundary of the medicine on a B mode image (400,700) that is generated by using the first B mode image data, and display, on the B mode image, comparison data obtained by comparing an estimated diffusion range of the medicine with an actual diffusion range of the medicine, wherein the controller is further configured to estimate the diffusion range of the medicine, based on at least one of information about a position to which the medicine is injected and an injection amount of the medicine, obtain the actual diffusion range of the medicine, based on the first area and the second area, compare the estimated diffusion range of the medicine with the actual diffusion range of the medicine, wherein the display is further configured to display the comparison data, such as an error rate, obtained by comparing the estimated diffusion range of the medicine with the the actual diffusion range of the medicine.