Patient Position Attribute
| Tag | (0018,5100) |
|---|---|
| Type | Conditionally Required (1C) |
| Keyword | PatientPosition |
| Value Multiplicity | 1 |
| Value Representation | Code String (CS) |
| Example Values |
|
Patient position descriptor relative to the patient support device.
Required if Isocenter Position (300A,012C) is present. May be present otherwise.
See Section C.8.8.12.1.2 for Defined Terms and further explanation.
Note
The orientation of the patient relative to the patient support device is denoted in the same manner as in the RT Patient Setup Module. It defines the relation of the DICOM Patient-Based Coordinate System identified by the Frame of Reference Module of the RT Image to the IEC coordinate system and together with Isocenter Position (300A,012C) allows the RT Image to be placed into the Patient Frame of Reference. It also allows a system using an RT Image to verify that the patient is setup in a similar position relative to the patient support device.
Section C.8.8.12.1.2
C.8.8.12.1.2 Patient Position
Defined Terms for Patient Position shall be those specified in Section C.7.3.1.1.2, plus the following:
Defined Terms:
- SITTING
-
In the sitting position, the patient's face is towards the front of the chair
RT Patient Setup Module
C.8.8.12 RT Patient Setup Module
The RT Patient Setup Module contains information describing the positioning of the patient with respect to the treatment machine, along with any fixation devices used. It also describes the shielding devices applied to the patient. The Module contains a Sequence of patient setup descriptions, each of which may be referenced by one of more beams or brachy application setups.
Table C.8-48. RT Patient Setup Module Attributes
|
Attribute Name |
Tag |
Type |
Attribute Description |
|---|---|---|---|
|
Patient Setup Sequence |
(300A,0180) |
1 |
Sequence of patient setup data for current plan. One or more Items shall be included in this Sequence. |
|
>Patient Setup Number |
(300A,0182) |
1 |
Identification number of the Patient Setup. The value of Patient Setup Number (300A,0182) shall be unique within the RT Plan in which it is created. |
|
>Patient Setup Label |
(300A,0183) |
3 |
The user-defined label for the Patient Setup. |
|
>Patient Position |
(0018,5100) |
1C |
Patient position descriptor relative to the equipment. Required if Patient Additional Position (300A,0184) is not present. See Section C.8.8.12.1.2 for Defined Terms and further explanation. |
|
>Patient Additional Position |
(300A,0184) |
1C |
User-defined additional description of patient position. Required if Patient Position (0018,5100) is not present. |
|
>Referenced Setup Image Sequence |
(300A,0401) |
3 |
Sequence of setup verification images for this patient setup. One or more Items are permitted in this Sequence. |
|
>>Setup Image Comment |
(300A,0402) |
3 |
Comment on the Setup Image. |
|
>>Include Table 10-3 “Image SOP Instance Reference Macro Attributes” |
|||
|
>Fixation Device Sequence |
(300A,0190) |
3 |
Sequence of Fixation Devices used in Patient Setup. One or more Items are permitted in this Sequence. |
|
>>Fixation Device Type |
(300A,0192) |
1 |
Type of Fixation Device used during in Patient Setup. Defined Terms:
|
|
>>Fixation Device Label |
(300A,0194) |
2 |
User-defined label identifier for Fixation Device. |
|
>>Fixation Device Description |
(300A,0196) |
3 |
User-defined description of Fixation Device. |
|
>>Fixation Device Position |
(300A,0198) |
3 |
Position/Notch number of Fixation Device. |
|
>>Fixation Device Pitch Angle |
(300A,0199) |
3 |
The Fixation Device Pitch Angle, i.e., orientation of PITCHED FIXATION DEVICE coordinate system with respect to IEC PATIENT SUPPORT coordinate system (degrees). Pitching is the rotation around IEC PATIENT SUPPORT X-axis. |
|
>>Fixation Device Roll Angle |
(300A,019A) |
3 |
The Fixation Device Roll Angle, i.e., orientation of ROLLED FIXATION DEVICE coordinate system with respect to IEC PITCHED FIXATION DEVICE coordinate system (degrees). Rolling is the rotation around IEC PATIENT SUPPORT Y-axis. |
|
>>Accessory Code |
(300A,00F9) |
3 |
An identifier for the accessory intended to be read by a device such as a bar-code reader. |
|
>Shielding Device Sequence |
(300A,01A0) |
3 |
Sequence of Shielding Devices used in Patient Setup. One or more Items are permitted in this Sequence. |
|
>>Shielding Device Type |
(300A,01A2) |
1 |
Type of Shielding Device used in Patient Setup. Defined Terms:
|
|
>>Shielding Device Label |
(300A,01A4) |
2 |
User-defined label for Shielding Device. |
|
>>Shielding Device Description |
(300A,01A6) |
3 |
User-defined description of Shielding Device. |
|
>>Shielding Device Position |
(300A,01A8) |
3 |
Position/Notch number of Shielding Device. |
|
>>Accessory Code |
(300A,00F9) |
3 |
An identifier for the accessory intended to be read by a device such as a bar-code reader. |
|
>Setup Technique |
(300A,01B0) |
3 |
Setup Technique used in Patient Setup. Defined Terms:
|
|
>Setup Technique Description |
(300A,01B2) |
3 |
User-defined description of Setup Technique. |
|
>Setup Device Sequence |
(300A,01B4) |
3 |
Sequence of devices used for patient alignment in Patient Setup. One or more Items are permitted in this Sequence. |
|
>>Setup Device Type |
(300A,01B6) |
1 |
Type of Setup Device used for patient alignment. Defined Terms:
|
|
>>Setup Device Label |
(300A,01B8) |
2 |
User-defined label for Setup Device used for patient alignment. |
|
>>Setup Device Description |
(300A,01BA) |
3 |
User-defined description for Setup Device used for patient alignment. |
|
>>Setup Device Parameter |
(300A,01BC) |
2 |
Setup Parameter for Setup Device in appropriate [IEC 61217] coordinate system. Units shall be mm for distances and degrees for angles. |
|
>>Setup Reference Description |
(300A,01D0) |
3 |
User-defined description of Setup Reference used for patient alignment. |
|
>>Accessory Code |
(300A,00F9) |
3 |
An identifier for the accessory intended to be read by a device such as a bar-code reader. |
|
>Table Top Vertical Setup Displacement |
(300A,01D2) |
3 |
Vertical Displacement in IEC TABLE TOP coordinate system (in mm) relative to initial Setup Position, i.e., vertical offset between patient positioning performed using setup and treatment position. |
|
>Table Top Longitudinal Setup Displacement |
(300A,01D4) |
3 |
Longitudinal Displacement in IEC TABLE TOP coordinate system (in mm) relative to initial Setup Position, i.e., longitudinal offset between patient positioning performed using setup and treatment position. |
|
>Table Top Lateral Setup Displacement |
(300A,01D6) |
3 |
Lateral Displacement in IEC TABLE TOP coordinate system (in mm) relative to initial Setup Position, i.e., lateral offset between patient positioning performed using setup and treatment position. |
|
>Motion Synchronization Sequence |
(300A,0410) |
3 |
Sequence of Motion Synchronization. One or more Items are permitted in this Sequence. |
|
>>Respiratory Motion Compensation Technique |
(0018,9170) |
1 |
Technique applied to reduce respiratory motion artifacts. Defined Terms:
|
|
>>Respiratory Signal Source |
(0018,9171) |
1 |
Signal source from which respiratory motion is derived. Defined Terms:
|
|
>>Respiratory Motion Compensation Technique Description |
(0018,9185) |
3 |
Description of respiratory motion compensation technique. |
|
>>Respiratory Signal Source ID |
(0018,9186) |
3 |
Identifies the device providing the respiratory signal. |
C.8.8.12.1 RT Patient Setup Module Attribute Descriptions
C.8.8.12.1.1 Referenced Setup Image Sequence
Images with modality SC or VL serve as visible light photos for visual setup control. Images with modality RTIMAGE serve as reference images on plan level. RT Images present in this Sequence shall not be referenced in the Referenced Reference Image Sequence (300C,0042) of the RT Beams Module.
C.8.8.12.1.2 Patient Position
Defined Terms for Patient Position shall be those specified in Section C.7.3.1.1.2, plus the following:
Defined Terms:
- SITTING
-
In the sitting position, the patient's face is towards the front of the chair
Frame of Reference Module
C.7.4.1 Frame of Reference Module
Table C.7-6 specifies the Attributes of the Frame of Reference Module, which are necessary to uniquely identify a Frame of Reference that ensures the spatial relationship of Images within a Series. It also allows Images across multiple Series to share the same Frame of Reference. This Frame of Reference (or coordinate system) shall be constant for all Images related to a specific Frame of Reference.
When a Frame of Reference is identified, it is not important how the imaging target (patient, specimen, or phantom) is positioned relative to the imaging equipment or where the origin of the Frame of Reference is located. It is important that the position of the imaging target and the origin are constant in relationship to a specific Frame of Reference.
Note
Since the criteria used to group images into a Series is application specific, it is possible for imaging applications to define multiple Series within a Study that share the same imaging space. Previous versions of the DICOM Standard specified that all images within the Series must be spatially related. However, insufficient information was available to determine if multiple Series within a Study were spatially related.
Table C.7-6. Frame of Reference Module Attributes
|
Attribute Name |
Tag |
Type |
Attribute Description |
|---|---|---|---|
|
Frame of Reference UID |
(0020,0052) |
1 |
Uniquely identifies the Frame of Reference for a Series. See Section C.7.4.1.1.1 for further explanation. |
|
Position Reference Indicator |
(0020,1040) |
2 |
Part of the imaging target used as a reference. See Section C.7.4.1.1.2 for further explanation. |
C.7.4.1.1 Frame of Reference Module Attribute Descriptions
C.7.4.1.1.1 Frame of Reference UID
The Frame of Reference UID (0020,0052) shall be used to uniquely identify a Frame of Reference for a Series. Each Series shall have a single Frame of Reference UID. However, multiple Series within a Study may share a Frame of Reference UID. All images in a Series that share the same Frame of Reference UID shall be spatially related to each other.
Note
-
Previous versions of this Standard defined a Data Element "Location", which has been retired. Frame of Reference UID provides a completely unambiguous identification of the image location reference used to indicate position.
-
A common Frame of Reference UID may be used to spatially relate localizer images with a set of transverse images. However, in some cases (e.g., multiple localizer images being related to a single set of transverse images) a common Frame of Reference UID may not be sufficient. The Referenced Image Sequence (0008,1140) provides an unambiguous method for relating localizer images.
C.7.4.1.1.2 Position Reference Indicator
The Position Reference Indicator (0020,1040) specifies the part of the imaging target that was used as a reference point associated with a specific Frame of Reference UID. The Position Reference Indicator may or may not coincide with the origin of the fixed Frame of Reference related to the Frame of Reference UID.
For a Patient-related Frame of Reference, this is an anatomical reference point such as the iliac crest, orbital-medial, sternal notch, symphysis pubis, xiphoid, lower costal margin, or external auditory meatus, or a fiducial marker placed on the patient. The Patient-Based Coordinate System is described in Section C.7.6.2.1.1.
For a slide-related Frame of Reference, this is the slide corner as specified in Section C.8.12.2.1 and shall be identified in this Attribute with the value "SLIDE_CORNER". The slide-based coordinate system is described in Section C.8.12.2.1.
For an Ophthalmic Coordinate System, the Frame of Reference is based upon the corneal vertex. The corneal vertex is determined by the measuring instrument and shall be identified in this Attribute with the value CORNEAL_VERTEX_R (for the right eye) or CORNEAL_VERTEX_L (for the left eye). The Ophthalmic Coordinate System is described in Section C.8.30.3.1.4.
The Position Reference Indicator shall be used only for annotation purposes and is not intended to be used as a mathematical spatial reference.
Note
The Position Reference Indicator may be encoded as zero length when it has no meaning, for example, when the Frame of Reference Module is required to relate mammographic images of the breast acquired without releasing breast compression, but where there is no meaningful anatomical reference point as such.