DICOM PS3.3 2023a - Information Object Definitions
C.36.2.4.4 RT Imaging Aperture Macro

The RT Imaging Aperture Macro defines the aperture of the imaging device to be applied during image acquisition.

Table C.36.2.4.4-1. RT Imaging Aperture Macro Attributes

Attribute Name

Tag

Type

Attribute Description

Imaging Aperture Specification Type

(3002,0115)

3

Type of specification of field aperture for imaging.

Enumerated Values:

OPEN

The aperture is specified to be fully opened.

BEAM

The aperture is specified to be the aperture in an RT Control point of the RT Radiation SOP Instance referenced in the Referenced Baseline Parameters RT Radiation Instance Sequence (3002,011E).

RELATIVE_TO_BEAM

The aperture is specified relative to the aperture in an RT Control point of the RT Radiation SOP Instance referenced in the Referenced Baseline Parameters RT Radiation Instance Sequence (3002,011E).

CUSTOM

The aperture is fully specified by the provided parameter values.

Imaging Source to Beam Modifier Definition Plane Distance

(3002,012D)

1C

Distance in mm from the Radiation Source to the origin of the Base Beam Modifier System.

Required ifImaging Aperture Specification Type (3002,0115) does not have a value of OPEN.

Referenced Radiation RT Control Point Index

(300A,073B)

1C

Index of the RT Control Point of the RT Radiation SOP Instance referenced in the Referenced Baseline Parameters RT Radiation Instance Sequence (3002,011E) which provides the basis for the aperture definition of the imaging source.

Required if Imaging Aperture Specification Type (3002,0115) has a value of BEAM or RELATIVE_TO_BEAM.

Imaging Aperture Sequence

(3002,0114)

1C

Parameters describing the aperture of the imaging source.

If Imaging Aperture Specification Type (3002,0115) has a value of CUSTOM, the provided parameter values fully specify the aperture.

If Imaging Aperture Specification Type (3002,0115) has a value of RELATIVE_TO_BEAM, the provided parameter values represent delta values with respect to the values in the referenced RT Control Point in the RT Radiation SOP Instance referenced in the Referenced Baseline Parameters RT Radiation Instance Sequence (3002,011E).

Required if Imaging Aperture Specification Type (3002,0115) has a value of CUSTOM or RELATIVE_TO_BEAM.

Only a single Item shall be included in this Sequence.

>Include Table C.36.2.2.21-1 “RT Beam Limiting Device Opening Sequence Macro Attributes”


DICOM PS3.3 2023a - Information Object Definitions