Материал: part03

Include Table 10-27 “RT Equipment Correlation Macro​

Attributes Description”​

C.8.2.1.1 CT Image Attribute Descriptions​

C.8.2.1.1.1 Image Type​

For CT Images, Image Type (0008,0008) is specified to be Type 1.​

Defined Terms for Value 3:​

AXIAL​ a CT Cross-sectional Image​

LOCALIZER​a CT Localizer Image​

Note​

Cross-sectional images include transverse, coronal, sagittal and oblique images.​

Image Type (0008,0008) Value 4 shall be present if Multi-energy CT Acquisition (0018,9361) has a value of YES.​

Defined Terms for Value 4 for Multi-energy CT Images:​

any of the removed material(s), the pixel values are unchanged.​

MAT_FRACTIONAL​ a Material-Fractional Image. Each real-world value mapped pixel represents the fraction of a voxel occupied​ by a material.​

EFF_ATOMIC_NUM​ an Effective Atomic Number Image. Each real-world value mapped pixel represents Effective Atomic Number​ of the materials in the voxel.​

ELECTRON_DENSITY​an Electron Density Image. Each real-world value mapped pixel represents the number of electrons per unit​ volume or the electron density relative to water.​

MAT_MODIFIED​ a Material-Modified Image. CT Image where real-world value mapped pixels have been modified to highlight​ a certain target material (either by partially suppressing the background or by enhancing the target material),​ or to partially suppress the target material.​

MAT_VALUE_BASED​aValue-BasedImage.CTImagewherereal-worldvaluemappedpixelsrepresentacertainvalueforaspecified​ material​

Note​

Multi-energy CT images are not necessarily DERIVED and may be ORIGINAL\PRIMARY.​

When an image is created by a generic transformation an implementation-specific Value 4 may be provided.​

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C.8.2.1.1.2 Samples Per Pixel​

Enumerated Values:​

1​

C.8.2.1.1.3 Photometric Interpretation​

Enumerated Values:​

MONOCHROME1​

MONOCHROME2​

See Section C.7.6.3.1.2 for definition of these terms.​

C.8.2.1.1.4 Bits Allocated​

Enumerated Values:​

16​

C.8.2.1.1.5 Bits Stored​

Enumerated Values:​

12​

13​

14​

15​

16​

C.8.2.1.1.6 High Bit​

For CT Images, High Bit (0028,0102) shall be one less than the value of Bits Stored (0028,0101).​

C.8.2.1.1.7 Calcium Scoring Mass Factor Patient and Device​

ThecalibrationfactorsfortheCalciumScoringMassFactorPatient(0018,9351)andCalciumScoringMassFactorDevice(0018,9352)​ Attributes are defined by the International Consortium for Multi-Detector CT Evaluation of Coronary Calcium, see McCollough, C.H.​ "A multi-institutional, multi-manufacturer, international standard for the quantification of coronary artery calcium using cardiac CT".​

C.8.2.2 Multi-energy CT Image Module​

The table in this Section contains IOD Attributes that describe a Multi-energy CT image.​

Table C.8.2.2-1. Multi-energy CT Image Module Attributes​

>Include Table C.8.2.2-2 “Multi-energy CT X-Ray Source Macro Attributes”​

>Include Table C.8.2.2-3 “Multi-energy CT X-Ray Detector Macro Attributes”​

>Include Table C.8.2.2-4 “Multi-energy CT Path Macro Attributes”​

>Include Table C.8-124 “CT Exposure Macro Attributes”​

>Include Table C.8-125 “CT X-Ray Details Sequence Macro Attributes”​

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Required if Image Type (0008,0008)​ Value 4 is VMI. May be present​ otherwise.​

Only a single Item shall be included in​ this Sequence.​

>Include Table C.8.15.3.12-1 “Multi-energy CT Characteristics Macro Attributes”​

C.8.2.2.1 Multi-energy CT X-Ray Source Macro​

Attributes for the CT X-Ray Source(s).​

Table C.8.2.2-2. Multi-energy CT X-Ray Source Macro Attributes​

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C.8.2.2.1.1 Multi-energy X-Ray Source Description​

Each item in the Multi-energy CT X-Ray Source Sequence (0018,9365) might describe either a constant source, a constant source​ with energy selective filter or one output corresponding to a specific energy of a KV switching source. The attributes will refer to a​ source, meaning one item in the Multi-energy CT X-Ray Source Sequence (0018,9365). The attributes use the phrase "physical X-​ Ray Source" when it is necessary to refer to the actual device (tube) rather than the current item.​

C.8.2.2.2 Multi-energy CT X-Ray Detector Macro​

Attributes for the CT X-Ray Detector(s).​

Table C.8.2.2-3. Multi-energy CT X-Ray Detector Macro Attributes​

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Note​

E.g., this can be calculated based on the beam spectrum or derived​ from the attenuation of phantom measurement.​

C.8.2.2.2.1 Multi-energy X-Ray Detector Description​

Each item in the Multi-energy CT X-Ray Detector Sequence (0018,936F) might describe either an integrating detector or one output​ corresponding to a specific spectrum of a physical detector like:​

•​One layer of a multi-layer detector.​

•​One energy bin of a photon counting detector.​

•​One energy threshold of a photon counting detector.​

The sequence attribute descriptions will refer to a detector, meaning one item in the Multi-energy CT X-Ray Detector Sequence​ (0018,936F).Theattributesusethephrase"physicaldetector"whenitisnecessarytorefertotheactualdeviceratherthanthecurrent​ item.​

C.8.2.2.3 Multi-energy CT Path Macro​

A Multi-energy CTPath is an X-Ray source paired with a corresponding X-Ray detector for a particular energy level.​

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