PROBLEM TO BE SOLVED: To provide an ultrasonic system and sensor coordinate calibration method for calibrating a sensor by matching images between a three-dimensional CT image and a three-dimensional ultrasonic image.
SOLUTION: The ultrasonic system includes: an ultrasonic image forming part including an ultrasonic probe for forming a three-dimensional ultrasonic image of a subject; a sensor connected to the ultrasonic probe; a storage part for storing a three-dimensional CT image of the subject and position information on the positional relations between the three-dimensional ultrasonic image and the sensor; and a processor for matching the images between the three-dimensional CT image and the three-dimensional ultrasonic image, forming a first transformation function for transforming the position of the sensor to a corresponding position of the three-dimensional CT image, and calibrating the sensor by applying the position information to the first transformation function.