C.8.7.8 X-Ray Acquisition Dose Module

This Module describes the attributes related to dose delivery from an X-Ray source during the acquisition of an X-Ray image.

Table C.8-33X-RAY ACQUISITION DOSE MODULE ATTRIBUTES

Attribute Name Tag Type Attribute Description
KVP (0018,0060) 3 Peak kilo voltage output of the X-Ray generator used.
X-Ray Tube Current (0018,1151) 3 X-Ray Tube Current in mA.
X-Ray Tube Current in µA (0018,8151) 3 X-Ray Tube Current in µA.
Exposure Time (0018,1150) 3 Duration of X-Ray exposure in msec.
Exposure Time in µS (0018,8150) 3 Duration of X-Ray exposure in µsec.
Exposure (0018,1152) 3 The exposure expressed in mAs, for example calculated from Exposure Time and X-Ray Tube Current.
Exposure in µAs (0018,1153) 3 The exposure expressed in µAs, for example calculated from Exposure Time and X-Ray Tube Current.
Distance Source to Detector (0018,1110) 3 Distance in mm from source to detector center. Note: This value is traditionally referred to as Source Image Receptor Distance (SID).
Distance Source to Patient (0018,1111) 3 Distance in mm from source to the table, support or bucky side that is closest to the Imaging Subject, as measured along the central ray of the X-Ray beam. Note: 1. This definition is less useful in terms of estimating geometric magnification than a measurement to a defined point within the Imaging Subject, but accounts for what is realistically measurable in an automated fashion in a clinical setting. 2. This measurement does not take into account any air gap between the Imaging Subject and the “front” of the table or bucky. 3. If the detector is not mounted in a table or bucky, then the actual position relative to the patient is implementation or operator defined. 4. This value is traditionally referred to as Source Object Distance (SOD).
Image and Fluoroscopy Area Dose Product (0018,115E) 3 X-Ray dose, measured in dGy*cm*cm, to which the patient was exposed for the acquisition of this image plus any non-digitally recorded fluoroscopy which may have been performed to prepare for the acquisition of this image. Notes: 1. The sum of the area dose product of all images of a Series or a Study may not result in the total area dose product to which the patient was exposed. 2. This may be an estimated value based on assumptions about the patient’s body size and habitus.
Body Part Thickness (0018,11A0) 3 The average thickness in mm of the body part examined when compressed, if compression has been applied during exposure.
Relative X-Ray Exposure (0018,1405) 3 Indication of the applied dose, in manufacturer specific units. Notes: 1. This value is intended to provide a single location where manufacturer specific information can be found for annotation on a display or film, that has meaning to a knowledgeable observer. 2. This may be a calculated or measured value. Examples are the detector entrance dose (KB), the CR sensitivity value (S), or the logarithmic median (lgM). 3. DICOM specifies standard Attributes in Table 10-23 ‘Exposure Index Macro’ which are recommended.
Entrance Dose (0040,0302) 3 Average entrance dose value measured in dGy at the surface of the patient during the acquisition of this image. Note: This may be an estimated value based on assumptions about the patient’s body size and habitus.
Entrance Dose in mGy (0040,8302) 3 Average entrance dose value measured in mGy at the surface of the patient during the acquisition of this image. Note: This may be an estimated value based on assumptions about the patient’s body size and habitus.
Exposed Area (0040,0303) 3 Typical dimension of the exposed area at the detector plane. If Rectangular: row dimension followed by column; if Round: diameter. Measured in cm. Notes: 1. The exposed area should be consistent with values specified in the X-Ray Collimator Module, if present. 2. This may be an estimated value based on assumptions about the patient’s body size and habitus. 3. This attribute is used in the Radiation Dose Module with units in mm (see Section C.4.16 Table C.4-16).
Distance Source to Entrance (0040,0306) 3 Distance in mm from the source to the surface of the patient closest to the source during the acquisition of this image. Note: This may be an estimated value based on assumptions about the patient’s body size and habitus.
Comments on Radiation Dose (0040,0310) 3 User-defined comments on any special conditions related to radiation dose encountered during the acquisition of this image.
X-Ray Output (0040,0312) 3 The X-Ray output at the patient entrance surface and kVp used to acquire the image, measured in mGy/mAs. Note: This value may be a calibrated value rather than measured during the exposure.
Half Value Layer (0040,0314) 3 The thickness of Aluminum in mm required to reduce the X-Ray Output (0040,0312) by a factor of two. Note: This value may be a calibrated value rather than measured during the exposure.
Organ Dose (0040,0316) 3 Average organ dose value measured in dGy during the acquisition of this image. Note: This may be an estimated value.
Organ Exposed (0040,0318) 3 Organ to which Organ Dose (0040,0316) applies. Defined Terms: BREAST GONADS BONE MARROW FETUS LENS Note: The anatomic regions described by these terms are those that are particularly radiosensitive and for which it is conventional to obtain organ specific dose parameters.
Anode Target Material (0018,1191) 3 The primary material in the anode of the X-Ray source. Defined Terms: TUNGSTEN MOLYBDENUM RHODIUM
Include ‘X-Ray Filtration Macro’ Table C.8.35a
Rectification Type (0018,1156) 3 Type of rectification used in the X-Ray generator. Defined Terms: SINGLE PHASE THREE PHASE CONST POTENTIAL
Include Table 10-23 ‘Exposure Index Macro’