In a method for automatically selecting a region of interest covering a heated area, in the context of high intensity focused ultrasonic technology during acquisition of magnetic resonance data, phase data of a scanned area are acquired, and a heated area is identified in the scanned area according to the phase data acquired. An image is reconstructed and displayed, and in the displayed image a region of interest covering the heated area is automatically demarcated according to a predetermined size of said region of interest that covers and is larger than the heated area. The method causes the heated area to be automatically and completely included in the region of interest and eliminates the instability of a manual selection of the region of interest.
