Table IV.
Private tags in the header of DICOM-CT-PD format.
| Tag | Attribute Name | Description |
|---|---|---|
| (7029,1010) | NumberofDetectorRows | The number of detector rows. |
| (7029,1011) | NumberofDetectorColumns | The number of detector columns. |
| (7029,1002) | DetectorElementTransverseSpacing | The width of each detector column, measured at the detector (mm). |
| (7029,1006) | DetectorElementAxialSpacing | The width of each detector row, measured at the detector (mm). |
| (7029,100B) | DetectorShape | The shape of the detector, such as “CYLINDRICAL,” “SPHERICAL,” or “FLAT.” |
| (7031,1001) | DetectorFocalCenterAngularPosition | ϕ0, the azimuthal angles of the detector’s focal center (rad). |
| (7031,1002) | DetectorFocalCenterAxialPosition | z0, the z location of the detector’s focal center (mm). |
| (7031,1003) | DetectorFocalCenterRadialDistance | ρ0, the in-plane distances between the detector’s focal center and the isocenter (mm). |
| (7031,1031) | ConstantRadialDistance | d0, the distance between the detector’s focal center and the detector element specified in Tag(7031,1033) (mm) |
| (7031,1033) | DetectorCentralElement | (Column X,Row Y), the index of the detector element aligning with the isocenter and the detector’s focal center. |
| (7033,100B) | SourceAngularPositionShift | Δϕ, the ϕ offset from the focal spot to the detector’s focal center (rad). |
| (7033,100C) | SourceAxialPositionShift | Δz, the z offset from the focal spot to the detector’s focal center (mm). |
| (7033,100D) | SourceRadialDistanceShift | Δρ, the ρ offset from the focal spot to the detector’s focal center (mm). |
| (7033,100E) | FlyingFocalSpotMode | The mode of flying focal spot (FFS). “FFSNONE” means no flying focal spot; “FFSZ” means flying focal spot along axial direction; “FFSXY” means in-plane flying focal spot; and “FFSXYZ” means flying focal spot in-plane and along axial direction. |
| (7033,1013) | NumberofSourceAngularSteps | The number of projections per complete rotation. |
| (7033,1061) | NumberofSpectra | The number of sources/tube voltages/detector layers/energy thresholds/energy bins used in the data acquisition. |
| (7033,1063) | SpectrumIndex | The index of the source/tube voltage/detector layer/energy threshold/energy bins. |
| (7033,1065) | PhotonStatistics | An array describing the spatial distribution of photons along the direction of the detector columns, from Column 1 to Column M (neglecting the variation across detector rows). Each element of the array corresponds to a detector column. |
| (7033,1067) | Timestamp | The timestamp in absolute time (ms). |
| (7037,1009) | TypeofProjectionData | “AXIAL” or “HELICAL” |
| (7037,100A) | TypeofProjectionGeometry | “FANBEAM” for third generation CT geometry. |
| (7039,1003) | BeamHardeningCorrectionFlag | A flag used to define whether the projection data have been corrected for beam hardening effects. “YES” or “NO.” |
| (7039,1004) | GainCorrectionFlag | A flag used to define whether the projection data have been calibrated for detector response with respect to the dynamic range available. “YES” or “NO.” |
| (7039,1005) | DarkFieldCorrectionFlag | A flag used to define whether the background signals prior to the x-ray exposure has been subtracted from the projection data. “YES” or “NO.” |
| (7039,1006) | FlatFieldCorrectionFlag | A flag used to define whether the gradient of flood field introduced by the heel effect and the bowtie filter has been compensated in the projection data. “YES” or “NO.” |
| (7039,1007) | BadPixelCorrectionFlag | A flag used to define whether abnormal pixels have been removed from the projection data by interpolation. “YES” or “NO.” |
| (7039,1008) | ScatterCorrectionFlag | A flag used to define whether the projection data has been corrected for scattered radiation. “YES” or “NO.” |
| (7039,1009) | LogFlag | A flag used to define whether the projection data has been logarithmically transformed. “YES” or “NO.” |
| (7041,1001) | WaterAttenuationCoefficient | A calibration factor μ’ for the conversion of measured linear attenuation coefficients μ to CT numbers (mm−1): CT numbers = 1000 * (μ− μ’) / μ’ |