An image processing method of accurately fully automatically detecting Tag Points (16) of a tagged image (10) of a sequence of MRI tagged images (for example, SPAMM protocol) comprises the steps of estimating (13) optimum value points of the intensity profile; labeling said points as Candidate Points (14) of a tag; automatically constructing (18) a Predicted Image (17) from determined Tags equations (19) of at least a preceding image of the sequence and from spatial and temporal parameters; detecting (15) Tag Points (16) among Candidate Points (14), using characteristics of the constructed Predicted Image (17); determining (20) Tag equations (21) from detected Tag Points (16), said Tag equations (21) intended to be used in the construction (18) of at least another Predicted Image for a next image of the sequence. The method further allows assigning a Tag Point to a specific Tag whatever the temporal resolution, this feature allowing the tracking of Tags from one image to the next of the sequence.