Patient Position Attribute
| Tag | (0018,5100) |
|---|---|
| Type | Conditionally Required, Empty if Unknown (2C) |
| Keyword | PatientPosition |
| Value Multiplicity | 1 |
| Value Representation | Code String (CS) |
| Example Values |
|
Patient position descriptor relative to the equipment. Required for images where Patient Orientation Code Sequence (0054,0410) is not present and whose SOP Class is one of the following: CT ("1.2.840.10008.5.1.4.1.1.2") or MR ("1.2.840.10008.5.1.4.1.1.4") or Enhanced CT ("1.2.840.10008.5.1.4.1.1.2.1") or Enhanced MR Image ("1.2.840.10008.5.1.4.1.1.4.1") or Enhanced Color MR Image ("1.2.840.10008.5.1.4.1.1.4.3") or MR Spectroscopy ("1.2.840.10008.5.1.4.1.1.4.2") Storage SOP Classes.
May be present for other SOP Classes if Patient Orientation Code Sequence (0054,0410) is not present.
See Section C.7.3.1.1.2 for Defined Terms and further explanation.
Section C.7.3.1.1.2
C.7.3.1.1.2 Patient Position
Patient Position (0018,5100) specifies the position of the patient relative to the imaging equipment space. This Attribute is intended for annotation purposes only. It does not provide an exact mathematical relationship of the patient to the imaging equipment.
When multiple subjects are present in the same image, and arranged with different positions, then the Patient Position (0018,5100) in the General Series Module is nominal, does not apply to each subject, but does define the relationship of the nominal Patient-Based Coordinate System to the machine.
Note
In conjunction with the Patient Position (0018,5100) in each Item of the Group of Patients Identification Sequence (0010,0027), Patient Position (0018,5100) in the General Series Module may be helpful to compute patient-relative spatial information for each subject from the Attributes of the Image Plane Module.
When facing the front of the imaging equipment, Head First is defined as the patient's head being positioned toward the front of the imaging equipment (i.e., head entering the front of the equipment). Feet First is defined as the patient's feet being positioned toward the front of the imaging equipment (i.e., feet entering the front of the equipment). Left First is defined as the patient's left side being positioned towards the front of the imaging equipment (i.e., patient's left side entering the front of the equipment). Right First is defined as the patient's right being positioned towards the front of the imaging equipment (i.e., patient's right side entering the front of the equipment). Prone is defined as the patient's face being positioned in a downward (gravity) direction. Supine is defined as the patient's face being in an upward direction. Decubitus Right is defined as the patient's right side being in a downward direction. Decubitus Left is defined as the patient's left side being in a downward direction.
Defined Terms:
- HFP
-
Head First-Prone
- HFS
-
Head First-Supine
- HFDR
-
Head First-Decubitus Right
- HFDL
-
Head First-Decubitus Left
- FFDR
-
Feet First-Decubitus Right
- FFDL
-
Feet First-Decubitus Left
- FFP
-
Feet First-Prone
- FFS
-
Feet First-Supine
- LFP
-
Left First-Prone
- LFS
-
Left First-Supine
- RFP
-
Right First-Prone
- RFS
-
Right First-Supine
- AFDR
-
Anterior First-Decubitus Right
- AFDL
-
Anterior First-Decubitus Left
- PFDR
-
Posterior First-Decubitus Right
- PFDL
-
Posterior First-Decubitus Left
Note
-
For quadrupeds, separate concepts for ventral and dorsal are not introduced, rather it is expected that anterior and posterior will be considered synonymous as they are when applied to the trunk.
-
There are no decubitus variants of left or right first, since for imaging equipment that is aligned horizontally with respect to gravity the patient cannot be both decubitus and have the left or right side towards the front of the imaging equipment.
-
There are no prone or supine variants of anterior or posterior first, since for imaging equipment that is aligned horizontally with respect to gravity the patient cannot be prone or supine and have the anterior or posterior side towards the front of the imaging equipment.
The Figure C.7.3.1.1.2-1 illustrates some of these Defined Terms for imaging equipment with a table, such as in X-Ray Angiography. The orientation of the patient related to gravity is always recumbent.
Figure C.7.3.1.1.2-1. Representation of the Eight Different Patient Positions on the X-Ray Table
Figure C.7.3.1.1.2-2. Example of Right First-Prone (RFP) Patient Position Relative to the Gantry and Table for a Small Animal