In this example, the acquisition modality creates two instances of the Enhanced XA object: the instance “A” with mask frames and the instance “B” with contrast frames. A temporal filtering has been applied by the modality before the creation of the instances.
The workstation 1 performs a digital subtraction of the frames of the instance “B” by using the frames of the instance “A” as mask, then the resulting subtracted frames are stored in a new instance “C”.
Finally the workstation 2 processes the instance “C” by applying a zoom and edge enhancement, and the resulting processed frames are stored in a new instance “D”.
Figure FFF.2.4-2Example of various successive derivations
The following figure shows the values of the attributes of the instance “D” in the corresponding modules and macros related to derivation information. The Source Image Sequence (0008,2112) of the Derivation Image Sequence (0008,9124) does not contain the attribute Referenced Frame Number (0008,1160) because all the frames of the source images are used to generate the derived images.
|Image Type||(0008,0008)||=||DERIVED\ …|
|SOP Instance UID||(0020,000E)||=||UID "D"|
|Shared Functional Groups Sequence||(5200,9229)|
|>Derivation Image Sequence||(0008,9124)|
Figure FFF.2.4-3 Attributes of the example of various successive derivations