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This template documents irradiation event-level summary data.
Table TID 10042. Irradiation Event Summary Data
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This shall correspond to the start of the first irradiation in the Irradiation Event. |
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This shall correspond to the end of the last irradiation in the Irradiation Event. |
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Identification the X-Ray source. This designation shall not change for a given source throughout the entire RDSR. Irradiation event values that apply to multiple sources, e.g., CTDI on a dual-source CT scanner, could be described by an instance of this template where the Identification of X-Ray Source indicates multiple sources, e.g., "1 and 2." Irradiation event valuesthat are not traditionally described across multiple sources, e.g., Dose (RP) on a biplane system, should not accumulate these values across both sources. |
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Cone-beam CT is expected to use (113613, DCM, "Rotational Acquisition"). |
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Reference to Image instances created during this event, if any. The UID reference(s) provided here shall be the values at the time the images were initially created. (Note that image UIDs may be changed as the images are managed over a long term). |
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Dose applied by this irradiation event, relative to defined reference point. This value may be provided at the Irradiation Event level, but is redundant if the Output Measurement Position is at the same position as the Reference Point defined in TID 10041. |
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If an acquisition is a repeat because an earlier acquisition was unsatisfactory, this may be recorded along with a coded reason and the earlier acquisition's irradiation event UID. This is intended to help with subsequent analysis by providing a priori information about why the study might be flagged as an outlier with higher dose exposure values than usual for the type of study. |
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If an acquisition is a rejected because it was unsatisfactory, this may be recorded along with a coded reason. This is intended to help with subsequent analysis by providing a priori information about why the study might be flagged as an outlier with higher dose exposure values than usual for the type of study. |
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If a precise count of pulses is not available, an estimated number shall be provided, and the Row 24 Concept Modifier shall indicate "Estimated". |
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Description of the method used during acquisition of the CT irradiation event. |
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DICOM Attributes exist for both Exposure Time in Seconds and Exposure Time in ms. This row uses milliseconds (ms). |
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"Mean CTDIvol" refers to the average value of the CTDIvol applied within this acquisition. CTDIvol is the volume CTDIw, where CTDIw is the weighted computed tomography dose index 100 as defined in [IEC 60601-2-44]. For Sequenced and Spiral scanning, CTDIvol = CTDIw / Pitch Factor. For Stationary and Free scanning, CTDIvol = CTDIw ✕ Cumulative Exposure Time/ Exposure Time Per Rotation. According to [IEC 60601-2-44] Ed 3 for Constant Angle Acquisition may be calculated as CTDIvol = (CTDIw / Current Time Product (mAs)) ✕ X-Ray Tube Current (mA) x (Nominal Total Collimation Width (mm) / Table Speed (mm/s)). NoteThe ratio CTDIw / Current Time Product is evaluated independently of the Constant Angle Acquisition but with the same settings of tube voltage and Total Collimation Width as those of the Constant Angle Acquisition. See also CTDIvol (0018,9345) and Spiral Pitch Factor (0018,9311) in the “Enhanced CT Image IODs” in PS3.3 . |
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The type of phantom used for CTDI measurement according to [IEC 60601-2-44] (e.g., Head 16 cm diameter PMMA, Body 32 cm diameter PMMA). |
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The CTDI freeair Calculation Factor is the CTDI freeair per mAs, expressed in units of mGy/mAs. The CTDI freeair Calculation Factor may be used in one method calculating Dose. For example, for this acquisition, Effective Dose = Mean X-Ray Tube Current ✕ Cumulative Exposure Time ✕ CTDI freeair Calculation Factor ✕ (Effective Dose/ CTDI freeair). |
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MeanCTDI freeair is the mean CTDI for this acquisition, evaluated free-in-air according to [IEC 60601-2-44]. MeanCTDI freeair = Mean X-Ray Tube Current ✕ Cumulative Exposure Time ✕ CTDI freeair Calculation Factor. The CTDI freeair may be used in one method of calculating Effective Dose. |
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For Spiral scanning, DLP = CTDI vol ✕ Scanning Length. For Sequenced scanning, DLP = CTDI vol ✕ Nominal Total Collimation Width ✕Cumulative Exposure Time / Exposure Time per Rotation. For Stationary and Free scanning, DLP = CTDI vol ✕ Nominal Total Collimation Width (according to [IEC 60601-2-44]). |
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More than one Size Specific Dose Estimate may be included, for example if different computation methods are used. |
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The methods of [AAPM Report 204] are listed in CID 10023 “Size Specific Dose Estimation Method for CT”; other methods may be used. The phantom size used for the calculation is available from the phantom type defined in Row 29. |
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The condition specifies inclusion of the Measured Lateral Dimension if it was used in the calculation. |
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The condition specifies inclusion of the Measured AP Dimension if it was used in the calculation. |
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The Derived Effective Diameter is conditionally included, whether it was derived from measurements or estimated from age, but may not be used for other (non-AAPM Report 204) methods. |
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A single value for Water Equivalent Diameter is encoded in Row 38 if the method uses a single value. It is required if the method uses a representative slice, but may also be present if the method used a Localizer or Raw Data at a single location rather than the entire scan range. |
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The modifier is intended to specify the family of methods and not the specific technique (e.g., for AAPM 220 (113987, DCM, "AAPM 220") is used, not (113981, DCM, "Water Equivalent Diameter Representative Value"), etc.). |
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If the method uses multiple slices across the scan range, the reconstructed image Series or (list of) Instances used is referenced; the values for Water Equivalent Diameter may or may not be recorded in the CT Image Module or the CT Exposure Macro of those images. More than one Series may be referenced if the reconstructed images for this acquisition used for Water Equivalent Diameter estimation span multiple series. If the Water Equivalent Diameter was computed from raw views rather than reconstructed images, then the Raw Data is referenced, if it was encoded in DICOM (it is not required to be). |
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This location is patient (not table or gantry) relative, to allow it to be defined in the Patient Coordinate System and hence related to the Image Position (Patient) in the reconstructed images. It is required if the method uses a representative slice, but may also be present if the method used a Localizer or Raw Data at a single location rather than the entire scan range. |
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Record of details associated with using the NEMA Dose Check Standard [NEMA XR 25-2019]. |
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The type of exposure modulation. May use the value of Exposure Modulation Type (0018,9323) from the CT Exposure Macro or from the CT Image Module. |
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People responsible for the administration of the radiation reported in the irradiation event. May include values that would appear in Performing Physicians' Name (0008,1050), Performing Physician Identification Sequence (0008,1052), Operators' Name (0008,1070) and/or Operator Identification Sequence (0008,1072). |
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The device that produced the irradiation in this irradiation event. This is not required to be present if the information is the same as that already recorded in TID 1004 “Device Observer Identifying Attributes” encoded via the inclusion of TID 1002 “Observer Context” in TID 10040 Row 5. |
| DICOM PS3.16 2024c - Content Mapping Resource |
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