Table C.8-71 specifies the Attributes of the DX Detector Module, which describe a DX detector.
Table C.8-71. DX Detector Module Attributes
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Include Table C.8-71b “Digital X-Ray Detector Macro Attributes” |
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Time in mSec that the detector is active during acquisition of this image. |
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Offset time in mSec that the detector becomes active after the X-Ray beam is turned on during acquisition of this image. May be negative. |
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Shape of the Field of View, that is the image pixels stored in Pixel Data (7FE0,0010). |
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Dimensions in mm of the Field of View, that is the image pixels stored in Pixel Data (7FE0,0010). If Field of View Shape (0018,1147) is: |
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Offset of the TLHC of a rectangle circumscribing the Field of View, that is the image pixels stored in Pixel Data (7FE0,0010), before rotation or flipping, from the TLHC of the physical detector area measured in physical detector pixels as a row offset followed by a column offset. Required if Field of View Rotation (0018,7032) or Field of View Horizontal Flip (0018,7034) is present. See Section C.8.11.4.1.1 for further explanation. |
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Clockwise rotation in degrees of Field of View, that is the image pixels stored in Pixel Data (7FE0,0010), relative to the physical detector. Required if Field of View Horizontal Flip (0018,7034) is present. See Section C.8.11.4.1.1 for further explanation. |
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Whether or not a horizontal flip has been applied to the Field of View, that is the image pixels stored in Pixel Data (7FE0,0010), after rotation relative to the physical detector as described in Field of View Rotation (0018,7032). Required if Field of View Rotation (0018,7032) is present. See Section C.8.11.4.1.1 for further explanation. |
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Physical distance measured at the front plane of the detector housing between the center of each image pixel specified by a numeric pair - row spacing value(delimiter) column spacing value in mm. See Section 10.7.1.3 for further explanation of the value order. The value of this Attribute shall never be adjusted to account for correction for the effect of geometric magnification or calibration against an object of known size; Pixel Spacing (0028,0030) is specified for that purpose. |
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Include Table 10-10 “Basic Pixel Spacing Calibration Macro Attributes” |
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Identifier of the cassette that contains the photostimulable phosphor plate, for CR acquisitions. |
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Identifier of the photostimulable phosphor plate, for CR acquisitions. |
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Table C.8-71b contains common Attributes that describe digital X-Ray detector.
Table C.8-71b. Digital X-Ray Detector Macro Attributes
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Text description of operating mode of detector (implementation specific). |
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The ID or serial number of the detector used to acquire this image. |
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The date on which the detector used to acquire this image as identified in Detector ID (0018,700A) was last calibrated. |
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The time at which the detector used to acquire this image as identified in Detector ID (0018,700A) was last calibrated. |
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Total number of X-Ray exposures that have been made on the detector used to acquire this image as identified in Detector ID (0018,700A) since it was calibrated. |
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Total number of X-Ray exposures that have been made on the detector used to acquire this image as identified in Detector ID (0018,700A) since it was manufactured. |
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Time in Seconds since an exposure was last made on this detector prior to the acquisition of this image. |
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Number of active detectors used to generate a single pixel. Specified as number of row detectors per pixel then column. |
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Name of the manufacturer of the detector component of the acquisition system. |
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Model name of the detector component of the acquisition system. |
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Whether or not the detector is operating within normal tolerances during this image acquisition. |
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Detector sensitivity in manufacturer specific units. Note
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Physical dimensions of each detector element that comprises the detector matrix, in mm. |
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Physical distance between the center of each detector element, specified by a numeric pair - row spacing value(delimiter) column spacing value in mm. See Section 10.7.1.3 for further explanation of the value order. |
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Dimensions in mm of the active area. If Detector Active Shape (0018,7024) is: |
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Offset of the TLHC of a rectangle circumscribing the active detector area from the TLHC of a rectangle circumscribing the physical detector area, measured in physical detector pixels as a row offset followed by a column offset. See Section C.8.11.4.1.1 for further explanation. |
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The relationship between the Physical Detector Area, the Active Detector Area, the Field of View (what is stored in Pixel Data (7FE0,0010)), the Exposed Area (after X-Ray Collimation) and the Displayed Area is illustrated in the following diagrams.
Note
Some of these Attributes relate the image data to manufacturer specific characteristics of the detector that may be used for quality control purposes, e.g., correlation of image artifacts with a detector defect map, analysis of noise performance, etc.
The Displayed Area is defined in pixel coordinates relative to the stored image pixel values by the Attributes of the Display Shutter Module (see Section C.7.6.11). If this Module is not present or supported, then the Displayed Area is equal to the Field of View.
The Exposed Area is defined in pixel coordinates relative to the stored image pixel values by the Attributes of the X-Ray Collimator Module (see Section C.8.7.3).
For the Digital X-Ray IODs, the Field of View is usually rectangular in shape and usually has the same size as the stored Pixel Data (7FE0,0010). The shape and size of the Field of View and the spacing of the pixels are defined by the following Attributes:
In the case where the Field of View has the same size as the stored Pixel Data (7FE0,0010) the following relationships are verified:
If the Field of View Shape (0018,1147) Attribute equals RECTANGLE:
If the Field of View Shape (0018,1147) Attribute equals ROUND or HEXAGONAL:
The following Attributes define the relationship of the Field of View to the Physical Detector Area:
For the Digital X-Ray IODs, the Active Area, i.e., that part of the detector matrix that was activated for this exposure, is usually rectangular in shape. The shape and size of the Active Area and the size and spacing of the detectors are defined by the following Attributes:
Note
The following optional Attribute defines the relationship of the Active Area to the Physical Detector Area:
In the case where the Field of View has the same size as the stored Pixel Data (7FE0,0010), the relationship between detectors and stored image pixels is defined by Detector Binning (0018,701A), which specifies how many detectors, in each of the row and column directions, contribute to (are pooled or averaged to form) a single stored image pixel.
Note
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Detector Binning (0018,701A) may have values less than one if sub-sampling is used to derive an image with higher spatial resolution than the detector matrix.
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The detector binning results in the size of a stored image pixel being different from the contributing physical detector pixels. In this case it is important to notice that the Field Of View Origin (0018,7030) is defined with respect to the center of the detector element located at the TLHC of the Field of View.
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For images where the Field of View describes an area not equal to the size (rows and columns) of the stored Pixel Data (7FE0,0010), Detector Binning (0018,701A) does not fully specify the relationship between the contributing physical detector pixels and the stored image pixels.
