DICOM PS3.3 2025b - Information Object Definitions
C.36.2.4.5 3D RT Cone-beam Imaging Geometry Macros

The 3D RT Cone-Beam Imaging Geometry Macros describe the parameters to be applied for a Cone-Beam acquisition in a Radiotherapy context.

Table C.36.2.4.5-1. 3D RT Cone-Beam Imaging Geometry Macro Attributes

Attribute Name

Tag

Type

Attribute Description

Scan Arc Type

(3002,012E)

3

Categorization of the amount of rotation of the scan.

Enumerated Values:

FULL_ARC

360 deg

HALF_ARC

180 deg

CUSTOM_ARC

user defined scan range

Scan Start Position Sequence

(3002,012B)

1

Start Position of the 3D RT Cone Beam Radiation Imaging Acquisition. The angle is a Continuous Rotation Angle; see Section C.36.1.1.5.

Only a single Item shall be included in this Sequence.

>Include Table C.36.2.4.3-1 “Parameterized RT Imaging Geometry Macro Attributes”

Scan Stop Position Sequence

(3002,012C)

1

Stop Position of the 3D RT Cone Beam Radiation Imaging Acquisition. The angle is a Continuous Rotation Angle; see Section C.36.1.1.5.

Only a single Item shall be included in this Sequence.

>Include Table C.36.2.4.3-1 “Parameterized RT Imaging Geometry Macro Attributes”

Detector Positioning Type

(3002,012F)

3

Fan type of acquisition.

Enumerated Values:

CENTERED

Full fan, detector is centered, resulting in a normal field of view.

SHIFTED

Half fan, detector is laterally shifted by half of the detector size to increase the field of view.

Parameters Specification Sequence

(0018,9913)

3

Acquisition parameters.

One or more Items are permitted in this Sequence.

>Include Table 10.25-1 “Attribute Value Constraint Macro Attributes”

Only Attributes defined in Table C.34.10-1 (i.e., in the Acquisition Protocol Element Sequence (0018,9920) in the Performed CT Acquisition Module) and Private Data Elements associated with this acquisition protocol element may be specified as Selector Attributes.

The semantics of Values of Constraint Violation Significance (0082,0036) in the Macro are assigned in Section C.34.9.3.

The same Attribute shall not appear in more than one Item in the Sequence with the same values for Selector Sequence Pointer (0072,0052) and Selector Sequence Pointer Items (0074,1057).


Table C.36.2.4.5-2. 3D RT Cone-Beam Imaging Geometry Optional Macro Attributes

Attribute Name

Tag

Type

Attribute Description

Scan Arc Type

(3002,012E)

3

Categorization of the amount of rotation of the scan.

Enumerated Values:

FULL_ARC

360 deg

HALF_ARC

180 deg

CUSTOM_ARC

user defined scan range

Scan Start Position Sequence

(3002,012B)

3

Start Position of the 3D RT Cone Beam Radiation Imaging Acquisition. The angle is a Continuous Rotation Angle; see Section C.36.1.1.5.

Only a single Item is permitted in this Sequence.

>Include Table C.36.2.4.3-1 “Parameterized RT Imaging Geometry Macro Attributes”

Scan Stop Position Sequence

(3002,012C)

3

Stop Position of the 3D RT Cone Beam Radiation Imaging Acquisition. The angle is a Continuous Rotation Angle; see Section C.36.1.1.5.

Only a single Item is permitted in this Sequence.

>Include Table C.36.2.4.3-1 “Parameterized RT Imaging Geometry Macro Attributes”

Detector Positioning Type

(3002,012F)

3

Fan type of acquisition.

Enumerated Values:

CENTERED

Full fan, detector is centered, resulting in a normal field of view.

SHIFTED

Half fan, detector is laterally shifted by half of the detector size to increase the field of view.


DICOM PS3.3 2025b - Information Object Definitions