In this example, the pixel shift -0.3\2.0 is applied to the frames 2 and 3 when they are subtracted to the mask frame 1 as defined in the Mask Subtraction Sequence.

The usage in a per-frame context is expected in a typical clinical scenario where the shift between the mask and the contrast frames is not constant across the frames of the Multi-frame Image to compensate for patient/organ movement.

The encoded values of the key Attributes of this example are shown in Figure FFF.2.3-4.

The usage in a per-frame context is also appropriate to specify more than one set of shifts in case of more than one region of interest suffered from patient/organ movement independently, like in case of the two legs imaged simultaneously.

In this example, two Subtraction Item IDs are defined in the Mask Subtraction Sequence.

The encoded values of the key Attributes of this example are shown in Figure FFF.2.3-5.