To provide an
improved method for achieving DSA images where the effect of residual motions in cardiac DSA during the
perfusion phase is reduced and in order to display subtracted images containing less motion artefacts, a method of performing
digital subtraction angiography DSA in an imaging apparatus comprises the steps of generating a first
image sequence of
mask images (10) of a subject to be examined, generating at least one first contrast image (22) at a first phase (16) whereby in the first contrast image part of the subject has a different contrast than in said first
image sequence, subtracting the
mask images (10) from the at least one first contrast image (22) generating a first DSA
image sequence (24), subtracting the DSA images of the first DSA image sequence (24) from the first contrast image (22) within the first phase (16) generating a sequence of extended
mask images (32); generating a second contrast image (34) with the imaging
system at a second phase (18), said second phase (18) being separated from the first phase (16) by a predetermined phase dividing
time limit (20), subtracting the images of the sequence of the extended mask images (32) from the second contrast image (34) generating a second DSA image sequence (38), displaying the second DSA image sequence (38) on a display (28).