DICOM PS3.3 2019c - Information Object Definitions

C.8.22.2 Enhanced PET Acquisition Module

Table C.8.22-2 specifies the Attributes that describe PET Acquisitions.

Table C.8.22-2. Enhanced PET Acquisition Module Attributes

Attribute Name

Tag

Type

Attribute Description

Acquisition Start Condition

(0018,0073)

1C

Description of how the data collection was started.

See Section C.8.22.2.1.1 for Defined Terms.

Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.

Start Density Threshold

(0018,9715)

1C

The count density that triggered the start of the acquisition, in counts/sec. Required if Acquisition Start Condition (0018,0073) equals DENS.

Start Relative Density Difference Threshold

(0018,9716)

1C

The relative count density that triggered the start of the acquisition, in counts/sec. Required if Acquisition Start Condition (0018,0073) equals RDD.

Start Cardiac Trigger Count Threshold

(0018,9717)

1C

The number of cardiac triggers that occurred before starting the acquisition. Required if Acquisition Start Condition (0018,0073) equals CARD_TRIG.

Start Respiratory Trigger Count Threshold

(0018,9718)

1C

The number of respiratory triggers that occurred before starting the acquisition. Required if Acquisition Start Condition (0018,0073) equals RESP_TRIG.

Acquisition Termination Condition

(0018,0071)

1C

Description of how the data collection for the Series was stopped.

See Section C.8.22.2.1.2 for Defined Terms.

Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.

Termination Counts Threshold

(0018,9719)

1C

The count value that triggered the termination of the acquisition.

Required if Acquisition Termination Condition (0018,0071) equals CNTS.

Termination Density Threshold

(0018,9720)

1C

The count density that triggered the termination of the acquisition, in counts/sec.

Required if Acquisition Termination Condition (0018,0071) equals DENS.

Termination Relative Density Threshold

(0018,9721)

1C

The count relative density that triggered the termination of the acquisition, in counts/sec.

Required if Acquisition Termination Condition (0018,0071) equals RDD.

Termination Time Threshold

(0018,9722)

1C

The time duration after which the acquisition was terminated, in sec.

Required if Acquisition Termination Condition (0018,0071) equals TIME

Termination Cardiac Trigger Count Threshold

(0018,9723)

1C

The number of cardiac triggers that triggered the termination of the acquisition.

Required if Acquisition Termination Condition (0018,0071) equals CARD_TRIG

Termination Respiratory Trigger Count Threshold

(0018,9724)

1C

The number of respiratory triggers that triggered the termination of the acquisition.

Required if Acquisition Termination Condition (0018,0071) equals RESP_TRIG

Type of Detector Motion

(0054,0202)

1C

Describes the type of detector motion during acquisition.

Defined Terms:

STATIONARY

No motion

STEP AND SHOOT

Interrupted motion, acquire only while detectors are stationary

CONTINUOUS

Gantry motion and acquisition are simultaneous and continuous

WOBBLE

wobble motion

CLAMSHELL

clamshell motion

Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.

Detector Geometry

(0018,9725)

1C

Physical arrangement of the detectors in the acquisition system.

The radiation entrance surface of a detector may be curved or flat. A curved surface is referred to as cylindrical.

Detectors may simultaneously subtend all possible transverse angles from the center of the field of view. Detectors that do not are referred to as partial.

Defined Terms:

CYLINDRICAL_RING

CYL_RING_PARTIAL

MULTIPLE_PLANAR

MUL_PLAN_PARTIAL

Required if Image Type (0008,0008) Value 1 is ORIGINAL and Type of Detector Motion (0054,0202) equals STATIONARY. May be present otherwise, if Image Type (0008,0008) Value 1 is DERIVED and Type of Detector Motion (0054,0202) equals STATIONARY.

Transverse Detector Separation

(0018,9726)

1C

Distance between opposing detectors, in mm.

Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.

Axial Detector Dimension

(0018,9727)

1C

Axial detector size in mm. Size of the detector along the table axis.

Required if Image Type (0008,0008) Value 1 is ORIGINAL May be present otherwise.

Collimator Type

(0018,1181)

1C

Collimator Type.

Defined Terms:

NONE

no collimator

RING

transverse septa

Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.

Coincidence Window Width

(0054,1210)

1C

The width of the coincidence-timing window, in nanoseconds. The maximum time difference between two single events in two opposing detectors that will be accepted as a coincidence event.

Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.

Energy Window Range Sequence

(0054,0013)

1C

Sequence of Items that describes the energy windows used for this Image.

One or more Items shall be included in this Sequence.

See Section C.8.22.2.1.3 for explanation.

Required if Image Type (0008,0008) Value 1 is ORIGINAL. May be present otherwise.

>Energy Window Lower Limit

(0054,0014)

1

The lower limit of the energy window, in KeV.

>Energy Window Upper Limit

(0054,0015)

1

The upper limit of the energy window, in KeV.

Table Motion

(0018,1134)

1

Enumerated Values:

STATIC

Table is stationary during data acquisition.

DYNAMIC

Table is moving during data acquisition.

Time of Flight Information Used

(0018,9755)

1

Specifies whether or not Time-of-Flight information was used in creation of the image.

Enumerated Values:

TRUE

FALSE

Include Table 10-24 “Mandatory View and Slice Progression Direction Macro Attributes”

Isocenter Position

(300A,012C)

3

Isocenter coordinates (x,y,z), in mm. Specifies the location of the machine isocenter in the Patient-Based Coordinate System associated with the Frame of Reference. It allows transformation from the Equipment-Based Coordinate System to the Patient-Based Coordinate System.

Scan Progression Direction

(0054,0501)

3

The anatomical order in which the slices were acquired.

Enumerated Values:

FEET_TO_HEAD

Slices closest to the patient's feet were acquired first.

HEAD_TO_FEET

Slices closest to the patient's head were acquired first.


C.8.22.2.1 Enhanced PET Acquisition Module Attribute Descriptions
C.8.22.2.1.1 Acquisition Start Condition

Acquisition Start Condition (0018,0073) is the method of starting acquisition data collection.

Defined Terms:

DENS

preset count density (counts/sec) was reached

RDD

preset relative count density difference (change in counts/sec) was reached

MANU

acquisition was started manually

AUTO

start automatically, when ready

CARD_TRIG

preset number of cardiac triggers was reached

RESP_TRIG

preset number of respiratory triggers was reached

C.8.22.2.1.2 Acquisition Termination Condition

Acquisition Termination Condition (0018,0071) is the method of acquisition termination that has actually applied to the data collection.

Defined Terms:

CNTS

preset counts was reached

DENS

preset count density (counts/sec) was reached

RDD

preset relative count density difference (change in counts/sec) was reached

MANU

acquisition was terminated manually

OVFL

data overflow occurred

TIME

preset time limit was reached

CARD_TRIG

preset number of cardiac triggers was reached

RESP_TRIG

preset number of respiratory triggers was reached

C.8.22.2.1.3 Energy Window Range Sequence

Multiple energy windows are allowed in order to allow coincidence events based on additional Energy Windows (e.g., Compton events scattered in the detector). All energy windows are assumed to contribute to all frames in this image.

DICOM PS3.3 2019c - Information Object Definitions