DICOM PS3.3 2020e - Information Object Definitions
C.8.15.3.13 Multi-energy CT Processing Macro

This Macro defines the Attributes for Multi-energy CT processing.

Table C.8.15.3.13-1. Multi-energy CT Processing Macro Attributes

Attribute Name

Tag

Type

Attribute Description

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.

>Decomposition Method

(0018,937E)

1

Method used to decompose the acquired Multi-energy CT data into basis data.

Defined Terms:

PROJECTION_BASED

The acquired projection data was fully decomposed into basis projection data (i.e. sinograms).

IMAGE_BASED

The acquired projection data was fully reconstructed into images before being decomposed into basis image data.

HYBRID

The acquired projection data was reconstructed using knowledge in both projection and image space to produce basis image data. Decomposition and image reconstruction may be performed in a one-step approach.

Note

  1. Basis images and basis projection data are not necessarily instantiated as DICOM Instances.

  2. There may be additional processing steps (e.g. linear combination of basis data) creating the result image.

>Decomposition Description

(0018,937F)

3

Description of decomposition method

>Decomposition Algorithm Identification Sequence

(0018,9380)

3

Algorithm used for decomposition of the acquired data.

One or more Items are permitted in this Sequence.

>>Include Table 10-19 “Algorithm Identification Macro Attributes”

>Decomposition Material Sequence

(0018,9381)

3

Basis materials used in the decomposition process.

Two or more Items are permitted in this Sequence.

>>Material Code Sequence

(0018,937D)

1

Nominal material for Multi-energy CT processing.

Only a single Item shall be included in this Sequence.

>>>Include Table 8.8-1 “Code Sequence Macro Attributes”

BCID 300 “Multi-energy Relevant Materials”.

>>Material Attenuation Sequence

(0018,9382)

3

Attenuation curve of the material, defined as a set of points.

Two or more Items are permitted in this Sequence.

Note

Attenuation curves for non-standard materials can be generated by NIST http://physics.nist.gov/PhysRefData/Xcom/html/xcom1.html.

>>>Photon Energy

(0018,9383)

1

Photon energy in keV.

>>>X-Ray Mass Attenuation Coefficient

(0018,9384)

1

Attenuation of this material at the specific Photon Energy (0018,9383), normalized to material density.


DICOM PS3.3 2020e - Information Object Definitions