C.8.22 Enhanced PET Modules

This section describes the specific modules for the Enhanced PET Image IOD.

C.8.22.1 Enhanced PET Series Module

The Enhanced PET IODs use the General Series module described in section C.7.3.1, specialized by the Enhanced PET Series Module, to describe the DICOM Series Entity described in A.1.2.3, and to define what constitutes a Series for the context of PET device.

Table C.8.22-1 specifies the Attributes that identify and describe general information about the Enhanced PET Series.

Table C.8.22-1ENHANCED PET SERIES MODULE ATTRIBUTES

Attribute Name Tag Type Attribute Description
Modality (0008,0060) 1 Type of equipment that originally acquired the data used to create the images in this Series. Enumerated Values: PT See section C.7.3.1.1.1 for further explanation.
Referenced Performed Procedure Step Sequence (0008,1111) 1C Uniquely identifies the Performed Procedure Step SOP Instance to which the Series is related (e.g. a Modality or General-Purpose Performed Procedure Step SOP Instance). Only a single Item shall be included in this sequence. Required if the Modality Performed Procedure Step SOP Class or General Purpose Performed Procedure Step SOP Class is supported.
>Include ‘SOP Instance Reference Macro’ Table10-11
Related Series Sequence (0008,1250) 1C Identifying the series that was used for attenuation purposes. See C.7.3.1 Required if another series was used to perform attenuation correction. One or more Items shall be included in this sequence.
>Study Instance UID (0020,000D) 1 Instance UID of Study to which the related Series belongs
>Series Instance UID (0020,000E) 1 Instance UID of Related Series
>Purpose of Reference Code Sequence (0040,A170) 2 Describes the purpose for which the reference is made. Zero or more Items shall be included in this sequence. When absent, implies that the reason for the reference is unknown.
>>Include Code Sequence Macro Table 8.8-1 Defined CID 7210.

C.8.22.2 Enhanced PET Acquisition Module

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

Table C.8.22-2ENHANCED 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 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 AcquisitionStart Condition (0018,0073) equals RESP_TRIG.
Acquisition Termination Condition (0018,0071) 1C Description of how the data collection for the series was stopped. See 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 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
View Code Sequence (0054,0220) 1 Sequence that describes the projection of the anatomic region of interest. Only a single Item shall be included in this sequence.
>Include ‘Code Sequence Macro’ Table 8.8-1 Baseline CID 26.
>View Modifier Code Sequence (0054,0222) 2C View Modifier. Required if needed to fully specify the View. Zero or one item shall be included in this sequence.
>>Include ‘Code Sequence Macro’ Table 8.8-1 Baseline CID 23.
Slice Progression Direction (0054,0500) 1C Describes the anatomical direction that a set of slices, identified by the same Stack ID (0020,9056), are progressing, as the slices are considered in order by In Stack Position Number (0020,9057). Meaningful only for cardiac images. Enumerated are: APEX_TO_BASE BASE_TO_APEX ANT_TO_INF = Anterior to Inferior INF_TO_ANT = Inferior to Anterior SEPTUM_TO_ WALL = Septum to Lateral Wall WALL_TO_SEPTUM = Lateral Wall to Septum Required if View Code Sequence (0054,0220) equals (G-A186, SRT,”Short Axis”). May be present otherwise.

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. The Defined Terms and definitions are:

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 which has actually applied to the data collection. The Defined Terms and definitions are:

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.

C.8.22.3 Enhanced PET Image Module

Table C.8.22-3 specifies the attributes of the Enhanced PET Image Module.

Table C.8.22-3ENHANCED PET IMAGE MODULE ATTRIBUTES

Attribute Name Tag Type Attribute Description
Image Type (0008,0008) 1 Image characteristics. See sections C.8.22.3.1.1.
Include ‘Common CT/MR Image Description Macro’ Table C.8-131
Acquisition Number (0020,0012) 3 A number identifying the single continuous gathering of data over a period of time that resulted in this image, which may include multiple bed positions. Note: This number is not required to be unique across SOP Instances in a series. See also the description of the Referenced Raw Data Sequence (0008,9121).
Acquisition Datetime (0008,002A) 1C The date and time that the acquisition of data started. Notes: 1. The synchronization of this time with an external clock is specified in the synchronization Module in Acquisition Time synchronized (0018,1800) . 2. See C.7.6.16.2.2.1 for an overview of all acquisition related timing attributes. Required if Image Type (0008,0008) Value 1 of this frame is ORIGINAL, may be present otherwise.
Acquisition Duration (0018,9073) 1C The time in seconds needed to complete the acquisition of data. See C.7.6.16.2.2.1 for further explanation. Required if Image Type (0008,0008) Value 1 of this frame is ORIGINAL, may be present otherwise.
Counts Source (0054,1002) 1 The primary source of counts. Enumerated Values: EMISSION TRANSMISSION
Decay Corrected (0018,9758) 1 Decay (DECY) correction has been applied to image. Enumerated Values: YES NO
Attenuation Corrected (0018,9759) 1 Attenuation (ATTN) correction has been applied to image. Enumerated Values: YES NO
Scatter Corrected (0018,9760) 1 Scatter (SCAT) correction has been applied to image. Enumerated Values: YES NO
Dead Time Corrected (0018,9761) 1 Dead time (DTIM) correction has been applied to image. Enumerated Values: YES NO
Gantry Motion Corrected (0018,9762) 1 Gantry motion (MOTN) correction has been applied to image. Enumerated Values: YES NO
Patient Motion Corrected (0018,9763) 1 Patient motion (PMOT) correction has been applied to image. Enumerated Values: YES NO
Count Loss Normalization Corrected (0018,9764) 1 Count loss (CLN) normalization correction has been applied to image. Enumerated Values: YES NO
Randoms Corrected (0018,9765) 1 Randoms (RAN) correction has been applied to image. Enumerated Values: YES NO
Non-uniform Radial Sampling Corrected (0018,9766) 1 Non-uniform radial sampling (RADL) correction has been applied to image. Enumerated Values: YES NO
Sensitivity Calibrated (0018,9767) 1 Image is sensitivity calibrated using a dose calibrator (DCAL). Enumerated Values: YES NO
Detector Normalization Correction (0018,9768) 1 Detector normalization (NORM) correction has been applied to image. Enumerated Values: YES NO
Randoms Correction Method (0054,1100) 1C Type of randoms correction processing. Defined terms: DLYD = delayed event subtraction SING = singles estimation PDDL = Processed Delays, which is a correction based on a processed (filtered) version of the data acquired from the delayed coincidence channel. Required if Randoms Corrected (0018,9765) equals YES.
Attenuation Correction Source (0018,9738) 1C Contains the source of the attenuation map information used for attenuation correction. See C.8.22.3.1.2 Required if Attenuation Corrected (0018,9759) equals YES.
Attenuation Correction Temporal Relationship (0018,9770) 1C Contains the temporal relationship between the attenuation correction source image and the PET image data. See C.8.22.3.1.3 Required if Attenuation Corrected (0018,9759) equals YES.
Scatter Correction Method (0054,1105) 1C A textual description of the scatter correction processing. e.g. convolution-subtraction, dual energy window, model-based, use of attenuation data. Required if Scatter Corrected (0018,9760) equals YES.
Decay Correction DateTime (0018,9701) 1C The date and time to which all frames in this Image were decay corrected. Required if Decay Corrected (0018,9758) equals YES.
Referenced Raw Data Sequence (0008,9121) 3 A sequence that identifies the set of Raw Data SOP Class/Instance pairs of the Raw data that were used to derive this Image. One or more Items are permitted in this Sequence. Note: The items of in this sequence may identify raw data that has not been stored or encoded as a DICOM object. This allows recognition that images and spectra in different instances have been reconstructed from the same raw data. For such items the SOP Class UID would be “1.2.840.10008.5.1.4.1.1.66” (Raw Data SOP Class) and the SOP Instance UID would be any appropriate UID.
>Include ‘Image SOP Instance Reference Macro’ Table 10-3
Referenced Waveform Sequence (0008,113A) 3 References to waveforms acquired in conjunction with this image. These Waveforms may or may not be temporally synchronized with this image. One or more Items are permitted in this sequence.
>Include ‘''Hierarchical SOP Instance Reference Macro’ Table C.17-3 Defined CID 7004.
Referenced Image Evidence Sequence (0008,9092) 1C Full set of Composite SOP Instances referring to image SOP Instances inside the frames of this Enhanced PET Image SOP Instance. See C.8.13.2.1.2 for further explanation. One or more Items shall be included in this sequence. Required if the Referenced Image Sequence (0008,1140) is present.
>Include ‘''Hierarchical SOP Instance Reference Macro’ Table C.17-3
Source Image Evidence Sequence (0008,9154) 1C Full set of Composite SOP Instances used as source image SOP Instances inside the frames of this Enhanced PET Image SOP Instance. See C.8.13.2.1.2 for further explanation. One or more Items shall be included in this sequence. Required if the Source Image Sequence (0008,2112) is present.
>Include ‘''Hierarchical SOP Instance Reference Macro’ Table C.17-3
Samples per Pixel (0028,0002) 1 Number of samples (planes) in this image. This value shall be 1.
Photometric Interpretation (0028,0004) 1 Specifies the intended interpretation of the pixel data. Enumerated Value: MONOCHROME2. See C.7.6.3.1.2 for definition of this term.
Bits Allocated (0028,0100) 1 Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. This value shall be 16.
Bits Stored (0028,0101) 1 Number of bits stored for each pixel sample. Each sample shall have the same number of bits stored. This value shall be 16.
High Bit (0028,0102) 1 Most significant bit for pixel sample data. Each sample shall have the same high bit. Shall be one less than the value in Bits Stored (0028,0101).
Content Qualification (0018,9004) 1 Content Qualification Indicator Enumerated Values: PRODUCT RESEARCH SERVICE See C.8.13.2.1.1 for further explanation.
Image Comments (0020,4000) 3 User-defined comments about the image
Burned in Annotation (0028,0301) 1 Indicates that the image does not contain burned in annotations. Enumerated Values: NO This means that images that contain this Module shall not contain burned in annotations.
Recognizable Visual Features (0028,0302) 3 Indicates whether or not the image contains sufficiently recognizable visual features to allow the image or a reconstruction from a set of images to identify the patient. Enumerated Values: YES NO If this Attribute is absent, then the image may or may not contain recognizable visual features.
Lossy Image Compression (0028,2110) 1 Specifies whether an Image has undergone lossy compression. Enumerated Values: 00 = Image has NOT been subjected to lossy compression. 01 = Image has been subjected to lossy compression. See C.7.6.1.1.5 for further explanation.
Lossy Image Compression Ratio (0028,2112) 1C Describes the approximate lossy compression ratio(s) that have been applied to this image. See C.7.6.1.1.5 for further explanation. May be multivalued if successive lossy compression steps have been applied. Note: For example, a compression ratio of 30:1 would be described in this Attribute with a single value of 30. Required if Lossy Image Compression (0028,2110) equals 01.
Lossy Image Compression Method (0028,2114) 1C A label for the lossy compression method(s) that have been applied to this image. See C.7.6.1.1.5 for further explanation. May be multi-valued if successive lossy compression steps have been applied; the value order shall correspond to the values of the Lossy Compression Ratio (0028,2112). Note: For historical reasons, the lossy compression method may also be described in Derivation Description (0008,2111). Required if Lossy Image Compression (0028,2110) equals 01.
Presentation LUT Shape (2050,0020) 1 Specifies an identity transformation for the Presentation LUT, such that the output of all grayscale transformations defined in the IOD containing this Module are defined to be P-Values. Enumerated Values: IDENTITY - output is in P-Values.
Icon Image Sequence (0088,0200) 3 This icon image is representative of the Image. Only a single iterm is permitted in this sequence.
>Include ‘Image Pixel Macro’ Table C.7-11b See C.7.6.1.1.6 for further explanation.

C.8.22.3.1 Enhanced PET Image Description Attribute Description

C.8.22.3.1.1 Image Type and Frame Type

The Image Type Attribute (0008,0008) and Frame Type (0008,9007) identifies important image characteristics in a multiple valued data element. In addition to the requirements specified in C.8.16.1 Image Type and Frame Type, the following additional requirements and Defined Terms are specified:

C.8.22.3.1.1.1 Pixel Data Characteristics

Value 1 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in C.8.16.1.1. No additional requirements or Defined Terms.

C.8.22.3.1.1.2 Patient Examination Characteristics

Value 2 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in C.8.16.1.2. No additional requirements or Defined Terms.

C.8.22.3.1.1.3 Image Flavor

Value 3 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in C.8.16.1.3. No additional requirements or Defined Terms.

C.8.22.3.1.1.4 Derived Pixel Contrast

Value 4 of Image Type (0008,0008) and Frame Type (0008,9007) is discussed in C.8.16.1.4. No additional requirements or Defined Terms.

C.8.22.3.1.2 Attenuation Correction Source

The attribute Attenuation Correction Source (0018,9738) contains the source of the attenuation map information used for attenuation correction.

Defined Terms:

CT

MR

POSITRON SOURCE

SINGLE PHOTON

CALCULATED Emission data is used to calculate the correction map.

C.8.22.3.1.3 Attenuation Correction Temporal Relationship

The attribute Attenuation Correction Temporal Relationship (0018,9770)specifies the temporal relationship between the attenuation correction source image and the PET image data.

Defined Terms:

CONCURRENT The attenuation correction source image is acquired at approximately the same time and with the patient in the same body position as the PET image. For example, as acquired on a hybrid scanner.

SEPARATE The attenuation correction source image is acquired at a different time, on a different system, or the patient has been moved significantly enough to cause soft tissue movement. For example, an attenuation correction source image acquired on a separate CT scanner, so that the patient must move from one bed to another.

SIMULTANEOUS The attenuation correction source image is acquired at the same time and with the patient in the same body position as the PET image.

C.8.22.4 Enhanced PET Isotope Module

Table C.8.22-9 contains IOD Attributes that describe a PET Isotope.

Table C.8.22-9ENHANCED PET ISOTOPE MODULE ATTRIBUTES

Attribute Name Tag Type Attribute Description
Radiopharmaceutical Information Sequence (0054,0016) 1 Sequence of Items that describe isotope information. One or more items shall be included in this sequence.
>Radiopharmaceutical Agent Number (0018,9729) 1 Identifying number, unique within this SOP Instance, of the agent administered. Used to reference this particular agent from the Radiopharmaceutical Functional Group Macro. The number shall be 1 for the first item and increase by 1 for each subsequent Item.
>Radionuclide Code Sequence (0054,0300) 1 Sequence that identifies the radionuclide. Only a single Item shall be included in this sequence.
>>Include ‘Code Sequence Macro’ Table 8.8-1 Baseline CID 4020
>Administration Route Code Sequence (0054,0302) 1 Sequence that identifies the administration route of the radiopharmaceutical. Only a single Item shall be included in this sequence.
>>Include ‘Code Sequence Macro’ Table 8.8-1 Baseline CID 11
>Radiopharmaceutical Volume (0018,1071) 3 Volume of administered radiopharmaceutical in cubic cm.
>Radiopharmaceutical Start Datetime (0018,1078) 1 Time of start of administration. The actual time of radiopharmaceutical administration to the patient for imaging purposes.
>Radiopharmaceutical Stop Datetime (0018,1079) 3 Time of end of administration. The actual ending time of radiopharmaceutical administration to the patient for imaging purposes.
>Radionuclide Total Dose (0018,1074) 2 The radiopharmaceutical dose administered to the patient measured in MegaBecquerels (MBq) at the Radiopharmaceutical Start Datetime (0018,1078).
>Radionuclide Half Life (0018,1075) 1 The radionuclide half life, in seconds, that was used in the correction of this image.
>Radionuclide Positron Fraction (0018,1076) 1 The radionuclide positron fraction (fraction of decays that are by positron emission) that was used in the correction of this image.
>Radiopharmaceutical Specific Activity (0018,1077) 3 The activity per unit mass of the radiopharmaceutical, in Bq/micromole, at the Radiopharmaceutical Start Datetime (0018,1078).
>Radiopharmaceutical Code Sequence (0054,0304) 1 Sequence that identifies the radiopharmaceutical. Only a single Item shall be included in this sequence.
>>Include ‘Code Sequence Macro’ Table 8.8-1 Baseline CID 4021

C.8.22.5 Enhanced PET Image Functional Group Macros

The following sections contain Functional Group macros specific to the Enhanced PET Image IOD.

Note: The attribute descriptions in the Functional Group Macros are written as if they were applicable to a single frame (i.e., the macro is part of the Per-frame Functional Groups Sequence). If an attribute is applicable to all frames (i.e. the macro is part of the Shared Functional Groups Sequence) the phrase “this frame” in the attribute description shall be interpreted to mean “ for all frames”.

C.8.22.5.1 PET Frame Type Macro

Table C.8.22-10 specifies the attributes of the PET Frame Type Functional Group macro.

Table C.8.22-10PET FRAME TYPE MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
PET Frame Type Sequence (0018,9751) 1 A sequence that describes general characteristics of this frame. Only a single Item shall be included in this sequence.
>Frame Type (0008,9007) 1 Type of Frame. A multi-valued attribute analogous to the Image Type (0008,0008). Enumerated Values and Defined Terms are the same as those for the four values of the Image Type (0008,0008) attribute, except that the value MIXED is not allowed. See C.8.16.1 and C.8.22.3.1.
>Include ‘Common CT/MR Image Description Macro' Table C.8-131

C.8.22.5.2 PET Frame Acquisition Macro

Table C.8.22-11 specifies the attributes of the PET Frame Acquisition Functional Group macro.

Table C.8.22-11PET FRAME ACQUISITION MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
PET Frame Acquisition Sequence (0018,9732) 1 Contains the attributes defining the PET acquisition mode. Only a single Item shall be included in this sequence.
>Table Height (0018,1130) 1 The distance in mm from the top of the patient table to the data collection center . The distance is positive when the table is below the data collection center.
>Gantry/Detector Tilt (0018,1120) 1 Nominal angle of tilt in degrees of the scanning gantry. Not intended for mathematical computations. Zero degrees means the gantry is not tilted, negative degrees are when the top of the gantry is tilted away from where the table enters the gantry.
>Gantry/Detector Slew (0018,1121) 1 Nominal angle of slew in degrees of the gantry. Not intended for mathematical computations. Zero degrees means the gantry is no slewed. Positive slew is moving the gantry on the patient’s left toward the patient’s superior, when the patient is supine.
>Data Collection Diameter (0018,0090) 1 The diameter in mm of the region over which data were collected. See C.8.22.5.4.1.

C.8.22.5.3 PET Detector Motion Details Macro

Table C.8.22-12 specifies the attributes of the PET Detector Motion Details Functional Group macro.

Table C.8.22-12PET DETECTOR MOTION DETAILS MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
PET Detector Motion Details Sequence (0018,9733) 1 Contains the attributes defining the details of the motion of the Detector. Only a single Item shall be included in this sequence.
>Rotation Direction (0018,1140) 1 Direction of rotation of the detector about the gantry, as viewed while facing the gantry where the table enters the gantry. Enumerated Values: CW = clockwise CC = counter clockwise
>Revolution Time (0018,9305) 1 The time in seconds of a complete revolution of the detector around the gantry orbit.

C.8.22.5.4 PET Position Macro

Table C.8.22-14 specifies the attributes of the PET Position Functional Group macro.

Table C.8.22-14PET POSITION MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
PET Position Sequence (0018,9735) 1 Contains the attributes defining the PET geometry. Only a single Item shall be included in this sequence.
>Table Position (0018,9327) 1C Relative longitudinal position of acquisition location of this frame in mm from an implementation specific reference point. Shall be relative to the same reference point for all frames in this SOP Instance, but may be different from the reference point in other SOP Instances. Positions as the table moves into the gantry viewed from the front are more negative. Notes: 1. For contiguous slices reconstructed from multiple detectors one would expect different values for adjacent slices. 2. Lateral positioning or tilting or swiveling are not described. Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Data Collection Center (Patient) (0018,9313) 1C The x, y, and z coordinates (in the patient coordinate system) in mm of the center of the region in which data were collected. See C.8.22.5.4.1. Required if Frame Type (0008,9007) Value 1 equals ORIGINAL. May be present otherwise.
>Reconstruction Target Center (Patient) (0018,9318) 1C The x, y, and z coordinates (in the patient coordinate system) of the reconstruction center target point as used for reconstruction in mm. See C.8.22.5.4.1. Note: If the reconstructed image is not magnified or panned the value corresponds with the Data Collection Center (0018,9313) attribute. Required if Frame Type (0008,9007) Value 1 equals ORIGINAL. May be present otherwise.

C.8.22.5.4.1 Relationships Between PET Geometric Attributes (Informative)

In Figure C.8.22-1 the relationship of the Geometric Attributes within the PET Geometry and PET Reconstruction functional groups is shown. The figure, viewed from the front of the gantry (where the table enters the gantry), is informative only and is not meant to represent a standardization of an equipment-based frame of reference.

[pic]

Figure C.8.22-1: Geometry of PET Acquisition System

C.8.22.5.5 PET Frame Correction Factors Macro

Table C.8.22-15 specifies the attributes of the PET Frame Correction Factors Functional Group macro.

Table C.8.22-15PET FRAME CORRECTION FACTORS MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
PET Frame Correction Factors Sequence (0018,9736) 1 Contains the attributes that describe the correction factors applied to this frame. Only a single Item shall be included in this sequence.
>Primary (Prompts) Counts Accumulated (0054,1310) 1C The sum of events that occur in the primary event channel. The counts include Trues +Scatter+ Randoms if Corrected Image (0028,0051) includes RAN; otherwise the counts are Trues +Scatter. Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Slice Sensitivity Factor (0054,1320) 1C The slice-to-slice sensitivity correction factor that was used to correct this frame. The value shall be one if no slice sensitivity correction was applied. Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.
>Decay Factor (0054,1321) 1C The decay factor that was used to scale this frame. Required if Decay Corrected (0018,9758) equals YES.
>Scatter Fraction Factor (0054,1323) 1C An estimate of the fraction of acquired counts that were due to scatter and that were corrected in this frame. The value shall be zero if no scatter correction was applied. Required if Frame Type (0008,9007 Value 1 is ORIGINAL. May be present otherwise.
>Dead Time Factor (0054,1324) 1C The average dead time correction factor that was applied to this frame. The value shall be one if no dead time correction was applied. Required if Frame Type (0008,9007) Value 1 is ORIGINAL. May be present otherwise.

C.8.22.5.6 PET Reconstruction Macro

Table C.8.22-17 specifies the attributes of the PET Reconstruction Functional Group Macro, which describe the method used to reconstruct this image.

Table C.8.22-17PET RECONSTRUCTION MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
PET Reconstruction Sequence (0018,9749) 1 Contains the attributes describing the reconstruction process for this frame. Only a single Item shall be included in this sequence.
>Reconstruction Type (0018,9756) 1C Description of the type of algorithm used when reconstructing the image from the data acquired during the acquisition process. Defined Terms: 2D 3D 3D_REBINNED Required if Frame Type (0008,9007) Value 1 equals ORIGINAL. May be present otherwise.
>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 REPROJECTION RAMLA MLEM Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.
>Iterative Reconstruction Method (0018,9769) 1 Iterative Reconstruction Method used. Enumerated Values: YES NO
>Number of Iterations (0018,9739) 1C Number of iterations. Required if Frame Type (0008,9007) Value 1 equals ORIGINAL and Iterative Reconstruction Method (0018,9769) equals YES. May be present otherwise.
>Number of Subsets (0018,9740) 1C Number of subsets. Required if Frame Type (0008,9007)) Value 1 equals ORIGINAL and Iterative Reconstruction Method (0018,9769) equals YES. 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 C.8.22.5.4.1. Required if Frame Type (0008,9007) Value 1 equals ORIGINAL and Reconstruction Field of View (0018,9317) is not present. Otherwise may be present if Frame Type (0008,9007) Value 1 equals DERIVED and Reconstruction Field of View (0018,9317) is not present.
>Reconstruction Field of View (0018,9317) 1C The field of view width (x-dimension) followed by height (y-dimension) as used for reconstruction in mm. Required if Image Type (0008,9007) Value 1 equals ORIGINAL and Reconstruction Diameter (0018,1100) is not present. Otherwise may be present if Frame Type (0008,9007) Value 1 equals DERIVED and Reconstruction Diameter (0018,1100) is not present.

C.8.22.5.7 PET Table Dynamics Macro

Table C.8.22-18 specifies the attributes of the PET Table Dynamics Functional Group Macro, which describes the table motion during acquisition of the data.

Table C.8.22-18PET TABLE DYNAMICS MACRO ATTRIBUTES

Attribute Name Tag Type Attribute Description
PET Table Dynamics Sequence (0018,9734) 1 Contains the attributes describing the movement of the PET Table. Only a single Item shall be included in this sequence.
>Table Speed (0018,9309) 1 The distance in mm that the Table moves in one second during the gathering of data that resulted in this frame.