Table C.8-122 specifies the Attributes of the CT Geometry Macro.
Table C.8-122. CT Geometry Macro Attributes
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Contains the Attributes defining the CT geometry. If Multi-energy CT Acquisition (0018,9361) is NO or is absent, only a single Item shall be included in this Sequence. If Multi-energy CT Acquisition (0018,9361) is YES, one or more Items shall be included in this Sequence. |
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References the X-Ray Path Index (0018,937A) in the Multi-energy CT Path Sequence (0018,9379) for this exposure. |
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Distance in mm from source to detector center. See Section C.8.15.3.6.1. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL or Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise. |
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Distance in mm from source to data collection center. See Section C.8.15.3.6.1. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL or Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise. |
In Figure C.8-19 the relationship of the Geometric Attributes within the CT Geometry and CT Reconstruction Functional Groups is shown. In this example, the Pixel Data is shown encoding the entire reconstructed region with no outside padding or clipping, and the reconstructed region is illustrated as being square, i.e., the value of Reconstruction Diameter would be the same as both values of Reconstruction Field of View, whichever Attribute is present. Figure C.8-19, viewed from the front of the gantry (where the table enters the gantry), is informative only and is not meant to represent a standardization of an equipment-based Frame of Reference.
