DICOM PS3.3 2019d - Information Object Definitions

C.8.2.2 Multi-energy CT Image Module

The table in this Section contains IOD Attributes that describe a Multi-energy CT image.

Table C.8.2.2-1. Multi-energy CT Image Module Attributes

Attribute Name

Tag

Type

Attribute Description

Multi-energy CT Acquisition Sequence

(0018,9362)

1

The attributes of a Multi-energy CT Image acquisition.

One Item shall be included in this Sequence.

>Multi-energy Acquisition Description

(0018,937B)

3

Human readable summary of the Multi-Energy technique applied during the acquisition.

>Include Table C.8.2.2-2 “Multi-energy CT X-Ray Source Macro Attributes”

>Include Table C.8.2.2-3 “Multi-energy CT X-Ray Detector Macro Attributes”

>Include Table C.8.2.2-4 “Multi-energy CT Path Macro Attributes”

>Include Table C.8-124 “CT Exposure Macro Attributes”

>Include Table C.8-125 “CT X-Ray Details Sequence Macro Attributes”

>Include Table C.8-119 “CT Acquisition Details Macro Attributes”

>Include Table C.8-122 “CT Geometry Macro Attributes”

Multi-energy CT Processing Sequence

(0018,9363)

3

How the acquired Multi-energy data was processed to generate this image.

Only a single Item is permitted in this Sequence.

>Include Table C.8.15.3.13-1 “Multi-energy CT Processing Attributes”

Multi-energy CT Characteristics Sequence

(0018,9364)

1C

Multi-energy characteristics of the generated image.

Required if Image Type (0008,0008) Value 4 is VMI. May be present otherwise.

Only a single Item shall be included in this Sequence.

>Include Table C.8.15.3.12-1 “Multi-energy CT Characteristics Macro Attributes”


C.8.2.2.1 Multi-energy CT X-Ray Source Macro

Attributes for the CT X-Ray Source(s).

Table C.8.2.2-2. Multi-energy CT X-Ray Source Macro Attributes

Attribute Name

Tag

Type

Attribute Description

Multi-energy CT X-Ray Source Sequence

(0018,9365)

1

X-Ray Source (see Section C.8.2.2.1.1) information.

One or more Items shall be included in this Sequence.

>X-Ray Source Index

(0018,9366)

1

Identification number of this item in the Multi-energy CT X-Ray Source Sequence.

The number shall be 1 for the first Item and increase by 1 for each subsequent Item.

>X-Ray Source ID

(0018,9367)

1

Identifier of the physical X-Ray source. This might be the serial number.

The X-Ray Source ID (0018,9367) will have the same value for different values of X-Ray Source Index (0018,9366) if a single source generates different nominal energies.

>Multi-energy Source Technique

(0018,9368)

1

Technique used to acquire Multi-energy data.

Defined Terms:

SWITCHING_SOURCE

a physical X-Ray source (tube) uses beam mode switching

CONSTANT_SOURCE

a physical X-Ray source (tube) uses a beam with constant characteristics

>Source Start DateTime

(0018,9369)

1

The date and time this X-Ray source (see Section C.8.2.2.1.1) was first used in this Multi-energy acquisition.

>Source End DateTime

(0018,936A)

1

The date and time this X-Ray source (see Section C.8.2.2.1.1) was last used in this Multi-energy acquisition.

>Switching Phase Number

(0018,936B)

1C

A number, unique within the sequence, to identify the switching phase.

Required if Multi-energy Source Technique (0018,9368) is "SWITCHING_SOURCE".

>Switching Phase Nominal Duration

(0018,936C)

3

Duration, in microseconds, that the energy is nominally in the target KV for this switching phase. I.e., the Switching Phase Nominal Duration does not include the Switching Phase Transition Duration (0018,936D).

The target KV is the value of KVP (0018,0060) for the item in the CT X-Ray Details Sequence (0018,9325) that identifies the Multi-energy CT Path Index (0018,937A) that corresponds to this X-Ray Source.

Note

Applicable if Multi-energy Source Technique (0018,9368) is "SWITCHING_SOURCE".

>Switching Phase Transition Duration

(0018,936D)

3

Duration, in microseconds, that the energy has left the target KV for this switching phase, but has not yet reached the target KV for the next phase.

The target KV is the value of KVP (0018,0060) for the item in the CT X-Ray Details Sequence (0018,9325) that identifies the Multi-energy CT Path Index (0018,937A) that corresponds to this X-Ray Source.

Note

Applicable if Multi-energy Source Technique (0018,9368) is "SWITCHING_SOURCE".

>Generator Power

(0018,1170)

3

Power in kW going into the X-Ray generator.


C.8.2.2.1.1 Multi-energy X-Ray Source Description

Each item in the Multi-energy CT X-Ray Source Sequence (0018,9365) might describe either a constant source, a constant source with energy selective filter or one output corresponding to a specific energy of a KV switching source. The attributes will refer to a source, meaning one item in the Multi-energy CT X-Ray Source Sequence (0018,9365). The attributes use the phrase "physical X-Ray Source" when it is necessary to refer to the actual device (tube) rather than the current item.

DICOM PS3.3 2019d - Information Object Definitions