FFF.2.3.2.4 Examples

The user performs an X-Ray acquisition in three steps:

  1. First step of 5 frames for mask acquisition, without contrast agent injection;

  2. Second step of 20 frames to assess the arterial phase, with contrast agent injection, to be subtracted to the average of the 5 mask frames acquired in the first phase;

  3. Third step of 10 frames to assess the venous phase, without further contrast agent injection, to be subtracted to a new mask related to that phase and with a 20% of mask visibility.

In the three steps, the system automatically identifies the mask frame(s) to be associated with the contrast frames.

Below are the encoded values of the key attributes of this example:

Recommended Viewing Mode (0028,1090) = SUB
Mask Subtraction Sequence (0028,6100)
Item 1
>Mask Operation (0028,6101) = AVG_SUB
>Subtraction Item ID (0028,9416) = 1
>Applicable Frame Range (0028,6104) = 6\25
>Mask Frame Numbers (0028,6110) = 1\2\3\4\5
>Mask Selection Mode (0028,9454) = SYSTEM
Item 2
>Mask Operation (0028,6101) = AVG_SUB
>Subtraction Item ID (0028,9416) = 1
>Applicable Frame Range (0028,6104) = 27\35
>Mask Frame Numbers (0028,6110) = 26
>Mask Selection Mode (0028,9454) = SYSTEM
Frame Display Sequence (0008,9458)
Item 1
>Start Trim (0008,2142) = 1
>Stop Trim (0008,2143) = 5
>Skip Frame Range Flag (0008,9460) = DISPLAY
>Recommended Viewing Mode (0028,1090) = NAT
Item 2
>Start Trim (0008,2142) = 6
>Stop Trim (0008,2143) = 25
>Skip Frame Range Flag (0008,9460) = DISPLAY
>Recommended Viewing Mode (0028,1090) = SUB
>Mask Visibility Percentage (0028,9478) = 0
Item 3
>Start Trim (0008,2142) = 26
>Stop Trim (0008,2143) = 26
>Skip Frame Range Flag (0008,9460) = SKIP
>Recommended Viewing Mode (0028,1090) = NAT
Item 4
>Start Trim (0008,2142) = 27
>Stop Trim (0008,2143) = 35
>Skip Frame Range Flag (0008,9460) = DISPLAY
>Recommended Viewing Mode (0028,1090) = SUB
>Mask Visibility Percentage (0028,9478) = 20

Figure FFF.2.3-2Attributes of Mask Subtraction and display