DICOM PS3.3 2019c - Information Object Definitions
C.8.15.3.7 CT Reconstruction Macro

Table C.8-123 specifies the Attributes of the CT Reconstruction Functional Group Macro.

Table C.8-123. CT Reconstruction Macro Attributes

Attribute Name

Tag

Type

Attribute Description

CT Reconstruction Sequence

(0018,9314)

1

Contains the Attributes holding information about the reconstruction techniques used.

Only a single Item shall be included in this Sequence.

>Reconstruction Algorithm

(0018,9315)

1C

Description of the algorithm used when reconstructing the image from the data acquired during the acquisition process.

Defined Terms:

FILTER_BACK_PROJ

ITERATIVE

Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

>Convolution Kernel

(0018,1210)

1C

A label describing the convolution kernel or algorithm used to reconstruct the data. A single value shall be present.

Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

>Convolution Kernel Group

(0018,9316)

1C

A label describing the group to which Convolution Kernel (0018,1210).

Defined Terms:

BRAIN

SOFT_TISSUE

LUNG

BONE

CONSTANT_ANGLE

Required if Convolution Kernel (0018,1210) is present. May be present otherwise.

>Reconstruction Diameter

(0018,1100)

1C

The diameter in mm of the region from which data were used in creating the reconstruction of the image. Data may exist outside this region and portions of the patient may exist outside this region. See Section C.8.15.3.6.1.

The diameter defines a circular region that is entirely contained within the encoded Pixel Data (7FE0,0010), unless the encoded image has been cropped after reconstruction.

Note

If not cropped or padded, for square images with square pixels, both values of Pixel Spacing (0028,0030) will be equal and equal to Reconstruction Diameter (0018,1100) / Rows (0028,0010) and Reconstruction Diameter (0018,1100) / Columns (0028,0011).

Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Reconstruction Field of View (0018,9317) is not present.

Otherwise may be present if Frame Type (0008,9007) Value 1 of this frame is DERIVED and Reconstruction Field of View (0018,9317) is not present.

>Reconstruction Field of View

(0018,9317)

1C

The field of view width followed by height as used for reconstruction in mm.

Note

If not cropped or padded, for both Pixel Spacing (0028,0030) and Reconstruction Pixel Spacing (0018,9322):

  • The first value (adjacent row spacing) will be equal to the second value of Reconstruction Field of View (0018,9317) / Rows (0028,0010).

  • The second value (adjacent column spacing) will be equal to the first value of Reconstruction Field of View (0018,9317) / Columns (0028,0011).

Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL and Reconstruction Diameter (0018,1100) is not present.

Otherwise may be present if Frame Type (0008,9007) Value 1 of this frame is DERIVED and Reconstruction Diameter (0018,1100) is not present.

>Reconstruction Pixel Spacing

(0018,9322)

1C

Physical distance in the patient between the center of each reconstructed pixel, specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing in mm. See Section 10.7.1.3 for further explanation of the value order.

Note

The values of Reconstruction Pixel Spacing (0018,9322) will equal the corresponding values of Pixel Spacing (0028,0030) unless the pixel data has been post-processed to change the pixel size after reconstruction and before storage.

Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

>Reconstruction Angle

(0018,9319)

1C

Angle (in degrees) over which the data from which the frame was reconstructed was collected, where 360 degrees signifies a complete revolution of the source around the gantry orbit. It is possible, in the case of over-scanning that the Reconstruction Angle is greater than 360 degrees.

Shall be 0 if Acquisition Type (0018,9302) is CONSTANT_ANGLE.

Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.

>Image Filter

(0018,9320)

1C

A label describing the filter applied to the reconstructed image after the original reconstruction has been completed.

Note

When Frame Type (0008,9007) Value 1 of this frame is DERIVED and Frame Type (0008,9007) Value 4 is FILTERED the type of filtration is described in Derivation Image Macro.

Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL.


DICOM PS3.3 2019c - Information Object Definitions