PURPOSE: To obtain a brighter blood flow image and to shorten the time for photographing by impressing an inversion prepulse to a tomo9raphic section existing on the blood inflow side of the photographing region of the device for obtaining the blood flow image by collecting the echo signals from the photographing region of an examinee.

CONSTITUTION: The prepulse P1 of 180° is impressed to the prepulse impressing region B on the upstream side in the blood flow direction of the photographing region A before an excitation pulse is impressed to the photographing region A at the time of obtaining the blood flow image, for example, the blood flow image of the carotid artery. As a result, the magnetization of the blood flow flowing into the photographing region A is so impressed as to be shifted in the 180° direction (negative direction) so that only the blood flow part constitutes the negative signal at the time the excitation pulse P1 is impressed to this magnetization. Then, taking out of only the signal of the blood flow is possible and the bright blood flow image is obtd. if this signal profile is projected at the min. value. The image separating the artery and the vein is obtd. by one time of photographing and the time for photographing is shortened.