DICOM PS3.3 2021e - Information Object Definitions
C. Wedges Definition Macro

This Macro defines the geometric configuration elements which cannot vary during delivery.

Table C. Wedges Definition Macro Attributes

Attribute Name



Attribute Description

Number of Wedges



Number of Wedges defined in the Wedge Definition Sequence (300A,0651).

Required if RT Radiation Physical and Geometric Content Detail Flag (300A,0638) equals FULL. May be present otherwise.

Wedge Definition Sequence



Treatment wedge definitions.

Required if Number of Wedges (300A,00D0) is present and has a non-zero value.

The number of Items included in this Sequence shall equal the value of Number of Wedges(300A,00D0).

>Include Table C. “RT Accessory Device Identification Macro Attributes”.

DCID 9546 “Radiotherapy Wedge Types”.

>Device Index



Index of this Item in this Sequence.

The value shall start at 1 and increase monotonically by 1.

>Referenced Defined Device Index



Device Index value that links the device defined by this Sequence Item to the corresponding device in an RT Radiation Instance. The device identification of the two devices may or may not be the same.

The value is the index of a device in the Wedges Definition Sequence (300A,0651) within the single SOP Instance referenced by Referenced RT Instance Sequence (300A,0631).

Required if the Instance referenced in Referenced RT Instance Sequence (300A,0631) contains the device that corresponds to the device defined by this Sequence Item.

See Section C.

>Radiation Beam Wedge Angle



Nominal wedge angle in degrees.

See Section C.

>Radiation Beam Effective Wedge Angle



Effective wedge angle in degrees.

See Section C.

>Beam Modifier Orientation Angle



Angle in degrees of the Beam Modifier Coordinate System with respect to the Base Beam Modifier Coordinate System. The angle is a Continuous Rotation Angle, see Section C.

The direction from thick edge to thin edge is along the positive y-axis of the Beam Modifier Definition Plane.

See Section C. and Section C.

C. Wedges Definition Macro Attribute Description
C. Radiation Beam Wedge Orientation and Radiation Beam Wedge Angle

For an Equipment Frame of Reference UID 1.2.840.10008. the wedge orientation has the value of 0 degree when the thin edge of the wedge is directed towards the positive direction of the y-axis of the Beam Modifier Coordinate system.

Beam Modifier Orientation Angle

Figure C. Beam Modifier Orientation Angle

Radiation Beam Wedge Angle

Figure C. Radiation Beam Wedge Angle

DICOM PS3.3 2021e - Information Object Definitions