C.8.5.6 US Image Module

Table C.8-18 specifies the Attributes that describe ultrasound images.

Table C.8-18US IMAGE MODULE ATTRIBUTES

Attribute Name Tag Type Attribute Description
Samples Per Pixel (0028,0002) 1 Number of samples (planes) in this image. See C.8.5.6.1.12 for specialization
Photometric Interpretation (0028,0004) 1 Specifies the intended interpretation of the pixel data. See C.8.5.6.1.2 for specialization.
Bits Allocated (0028,0100) 1 Number of bits allocated for each pixel sample. See C.8.5.6.1.13 for specialization.
Bits Stored (0028,0101) 1 Number of bits stored for each pixel sample. See C.8.5.6.1.14 for specialization.
High Bit (0028,0102) 1 Most significant bit for pixel sample data. See C.8.5.6.1.15 for specialization.
Planar Configuration (0028,0006) 1C Indicates whether the pixel data are sent color-by-plane or color-by-pixel. Required if Samples per Pixel (0028,0002) has a value greater than 1. See C.8.5.6.1.16 for specialization.
Pixel Representation (0028,0103) 1 Data representation of pixel samples. See C.8.5.6.1.3 for specialization.
Frame Increment Pointer (0028,0009) 1C Contains the Data Element Tag of the attribute which is used as the frame increment in Multi-frame pixel data (see C.7.6.6). Required if Number of Frames is sent. See C.8.5.6.1.4 for specialization.
Image Type (0008,0008) 2 Image identification characteristics. See C.8.5.6.1.1 for specialization.
Lossy Image Compression (0028,2110) 1C 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 Required if Lossy Compression has been performed on the Image.
Number of Stages (0008,2124) 2C Number of Stages in this protocol. Required if image was acquired in a Staged protocol.
Number of Views in Stage (0008,212A) 2C Number of views in this Stage. Required if image was acquired in a Staged protocol.
R Wave Time Vector (0018,6060) 3 The time offset(s) of the reported R Wave peaks, each relative to the time of the start of the acquisition of the first frame in msec. Multi-valued, with one value per reported R Wave.
Ultrasound Color Data Present (0028,0014) 3 This element indicates if any ultrasound color data is present in an image. Enumerated Values: 00 = Ultrasound color data not present in image 01 = Ultrasound color data is present in image. See C.8.5.6.1.10
Stage Name (0008,2120) 3 A Stage is a particular time slice of a protocol in which a set of images are collected. The names can be free form text. Recommended text for Stress Echo stage names are: PRE-EXERCISE, POST-EXERCISE, PEAK-EXERCISE, RECOVERY, BASELINE, LOW DOSE, PEAK DOSE
Stage Code Sequence (0040,000A) 3 Sequence of items describing the performed Ultrasound Protocol Stage(s). One or more Items are permitted in this Sequence.
>Include “Code Sequence Macro” Table 8.8-1. Baseline CID 12002.
Stage Number (0008,2122) 3 A number that identifies the Stage. Stage Number starts at one.
View Name (0008,2127) 3 A View is a particular combination of the position and orientation when a set of images are acquired. Images are acquired at the same View in different Stages for the purpose of comparison.
View Number (0008,2128) 3 A number that identifies the View. View Number starts at one.
Number of Event Timers (0008,2129) 3 The number of event timers used at the time of acquisition of a Multi-frame image.
Event Elapsed Time(s) (0008,2130) 3 An array of values associated with each event timer. Units in milliseconds.
Event Timer Name(s) (0008,2132) 3 Name that identifies the event timer.
Include 'General Anatomy Optional Macro' Table 10-7 For intravascular ultrasound, Defined CID 3010 and Defined CID 3015 are specified for the Anatomic Region Sequence and Defined CID 3019 is specified for the Anatomic Region Modifier Sequence. No other Context IDs are specified.
View Code Sequence (0054,0220) 3 Sequence that describes the view of the patient anatomy in this image. Only a single Item is permitted in this Sequence. See Section C.8.5.6.1.19.
>Include ‘Code Sequence Macro’ Table 8.8-1 See Section C.8.5.6.1.19 for Context Group IDs.
>View Modifier Code Sequence (0054,0222) 3 Sequence that provides modifiers for the view of the patient anatomy. One or more Items are permitted in this Sequence. See Section C.8.5.6.1.19.
>>Include ‘Code Sequence Macro’ Table 8.8-1 See Section C.8.5.6.1.19 for Context Group IDs.
Acquisition DateTime (0008,002A) 1C The date and time that the acquisition of data that resulted in this image started. Required if Modality (0008,0060) = IVUS May be present otherwise. Note: The synchronization of this time with an external clock is specified in the Synchronization Module in Acquisition Time Synchronized (0018,1800).
Trigger Time (0018,1060) 3 Time interval measured in msec from the start of the R-wave to the beginning of data taking
Nominal Interval (0018,1062) 3 Average R-R interval used for these data, in msec
Beat Rejection Flag (0018,1080) 3 Beat length sorting has been applied. Enumerated Values: Y = yes N = no
Low R-R Value (0018,1081) 3 R-R interval low limit for beat rejection, in msec
High R-R Value (0018,1082) 3 R-R interval high limit for beat rejection, in msec
Heart Rate (0018,1088) 3 Beats per minute.
IVUS Acquisition (0018,3100) 1C Defined Terms: MOTOR_PULLBACK MANUAL_PULLBACK SELECTIVE GATED_PULLBACK See C.8.5.6.1.21 Required if Modality (0008,0060) = IVUS
IVUS Pullback Rate (0018,3101) 1C Required if IVUS Acquisition (0018,3100) value is MOTOR_PULLBACK. Specified in units of mm/sec. See C.8.5.6.1.22
IVUS Gated Rate (0018,3102) 1C Required if IVUS Acquisition (0018,3100) value is GATED_PULLBACK. Specified in units of mm/beat. See C.8.5.6.1.23
IVUS Pullback Start Frame Number (0018,3103) 1C Required if IVUS Acquisition (0018,3100) value is MOTOR_PULLBACK or GATED_PULLBACK. See C.8.5.6.1.24
IVUS Pullback Stop Frame Number (0018,3104) 1C Required if IVUS Acquisition (0018,3100) value is MOTOR_PULLBACK or GATED_PULLBACK. See C.8.5.6.1.25
Lesion Number (0018,3105) 3 Identifier(s) of the lesion(s) of interest imaged within the current SOP Instance. Each lesion shall have a unique numeric integer identifier within the study. See C.8.5.6.1.26.
Output Power (0018,5000) 3 Manufacturer defined character string description of ultrasound output level(s) used in generating a given image. Data may be expressed in dB, %, W/cm2, etc.
Transducer Data (0018,5010) 3 Manufacturer defined code or description of ultrasound transducer used.
Transducer Type (0018,6031) 3 Defined Terms: SECTOR_PHASED SECTOR_MECH SECTOR_ANNULAR LINEAR CURVED LINEAR SINGLE CRYSTAL SPLIT XTAL CWD IV_PHASED IV_ROT XTAL IV_ROT MIRROR ENDOCAV_PA ENDOCAV_MECH ENDOCAV_CLA ENDOCAV_AA ENDOCAV_LINEAR VECTOR_PHASED
Focus Depth (0018,5012) 3 The depth, from the transducer face, of the manufacturer defined beam focus used for the image, in cm.
Processing Function (0018,5020) 3 Manufacturer defined description of processing of echo information. Data may include code or description of gain (initial, overall, TGC, dynamic range, etc.), preprocessing, postprocessing, Doppler processing parameters, e.g. cutoff filters, etc., as used in generating a given image.
Mechanical Index (0018,5022) 3 See C.8.5.6.1.8 for Description.
Bone Thermal Index (0018,5024) 3 See C.8.5.6.1.8 for Description.
Cranial Thermal Index (0018,5026) 3 See C.8.5.6.1.8 for Description.
Soft Tissue Thermal Index (0018,5027) 3 See C.8.5.6.1.8 for Description.
Soft Tissue-focus Thermal Index (0018,5028) 3 See C.8.5.6.1.8 for Description.
Soft Tissue-surface Thermal Index (0018,5029) 3 See C.8.5.6.1.8 for Description.
Depth of Scan Field (0018,5050) 3 The depth, in mm, from the transducer face to the deepest point included in the displayed image- the field of view.
Overlay Subtype (60xx,0045) 3 Defined term which identifies the intended purpose of the ROI Overlay Type. See C.8.5.6.1.11 for specialization.

Note: Referenced Overlay Sequence (0008,1130) and Referenced Curve Sequence (0008,1145) were previously included in this Module as optional Attributes but have been retired. See PS 3.3 2004.

C.8.5.6.1 US Image Attribute Descriptions

C.8.5.6.1.1 Image Type

For US Images, Image Type (0008,0008) is specified to be Type 2. The Defined Terms for Value 3 are:

ABDOMINAL BREAST CHEST
ENDOCAVITARY ENDORECTAL ENDOVAGINAL
EPICARDIAL FETAL HEART GYNECOLOGY
INTRACARDIAC INTRAOPERATIVE INTRAVASCULAR
MUSCULOSKELETAL NEONATAL HEAD OBSTETRICAL
OPHTHALMIC PEDIATRIC PELVIC
RETROPERITONEAL SCROTAL SMALL PARTS
TEE THYROID TRANSCRANIAL
TTE US BIOPSY VASCULAR

Value 4 is constructed as a modality bit map to allow for a description of multi-modality displays. In using this bit map, the sum of the values of the various modalities will unambiguously determine the constituent modalities.

0001 = 2D Imaging 0002 = M-Mode 0004 = CW Doppler
0008 = PW Doppler 0010 = Color Doppler 0020 = Color M-Mode
0040 = 3D Rendering 0100 = Color Power Mode 0200 = Tissue Characterization
0400 = Spatially-related frames

Notes: 1. All Values are hexadecimal encoded as a CS. See PS 3.5.

2. For example, Color Flow with CW spectral Doppler would have a value 4 = 0015. Note that no assumption should be made in Color Doppler or Color M-Mode regarding underlying B or M-Mode, respectively.

3. See Section A.59.1 for the relationship between a 3D volume set and the 3D Rendering, 3D MPR View, and Spatially-related frames image types. In the case of “3D Rendering”, Derivation Code Sequence (0008,9215) should be used to describe the specific type of 3D rendering (volume rendering, surface rendering, multiplanar reformatting, etc.).

C.8.5.6.1.2 Photometric Interpretation

For US Images, Photometric Interpretation (0028,0004) is specified to use the following Defined Terms:

MONOCHROME2 PALETTE COLOR RGB
ARGB (retired) YBR_FULL YBR_FULL_422
YBR_PARTIAL_422 YBR_RCT YBR_ICT
YBR_PARTIAL_420

Note: It is recommended that future implementations should not use ARGB photometric interpretation.

See PS 3.5 for restrictions imposed by compressed Transfer Syntaxes.

C.8.5.6.1.3 Pixel Representation

For US Images, Pixel Representation (0028,0103) is specified to use the following Enumerated Value:

0000H = unsigned integer

C.8.5.6.1.4 Frame Increment Pointer

For US Multi-frame images, the Attribute Frame Increment Pointer (0028,0009) of the Multi-frame Module (see Section C.7.6.6) is specified by the following Defined Terms:

00181063 = sequencing by Frame Time (0018,1063)

00181065 = sequencing by Frame Time Vector (0018,1065)

C.8.5.6.1.5 Retired

C.8.5.6.1.6 Retired

C.8.5.6.1.7 Retired

C.8.5.6.1.8 Mechanical Index, Bone Thermal Index, Cranial Thermal Index, Soft Tissue Thermal Index

The thermal and/or mechanical indices, when made available by a manufacturer, are defined according to the Standard for Real-Time Display of Thermal and Mechanical Acoustic Output Indices on Diagnostic Ultrasound Equipment , a voluntary performance standard jointly published by AIUM and NEMA.

C.8.5.6.1.9 Image Transformation Matrix and Image Translation Vector

This section was defined in a previous version of the DICOM Standard. The Section is now retired. See PS 3.3 2003.

C.8.5.6.1.10 Ultrasound Color Data Present

Note: This data element can be used to indicate if an image contains any Ultrasound color data.

For example: Some Ultrasound images may have a Photometric Interpretation equal to RGB but the image will have no color information if R=G=B for all pixels.

For consistency within a particular implementation Monochrome Ultrasound images may be coded using a color photometric interpretation. In that case inclusion of this data element can significantly speed up processing. Since all components are known to be equal only one need be handled. The enhancements can be significant when compressed Transfer Syntaxes are used.

C.8.5.6.1.11 Overlay Subtype

For US Images, Overlay Subtype (60xx,0045) shall use the following Defined Terms:

ACTIVE 2D/BMODE IMAGE AREA = identification of the active area of a 2D/B-mode image.

C.8.5.6.1.12 Samples Per Pixel

For US Images, Samples Per Pixel (0028,0002) is specified to use the following values for specific Photometric Interpretations:

Table C.8-19US SAMPLES PER PIXEL

Photometric Interpretation Samples Per Pixel Value
MONOCHROME2 1
RGB 3
YBR_FULL 3
YBR_FULL_422 3
YBR_PARTIAL_422 3
YBR_RCT 3
YBR_ICT 3
YBR_PARTIAL_420 3
PALETTE COLOR 1

C.8.5.6.1.13 Bits Allocated

For US Images, Bits Allocated (0028,0100) is specified to use the following values for specific Photometric Interpretations:

Table C.8-20US BITS ALLOCATED

Photometric Interpretation Bits Allocated Value
MONOCHROME2 8
RGB 8
YBR_FULL 8
YBR_FULL_422 8
YBR_PARTIAL_422 8
YBR_RCT 8
YBR_ICT 8
YBR_PARTIAL_420 8
PALETTE COLOR 8 - 8 bit palette, or 16 - 16 bit palette

C.8.5.6.1.14 Bits Stored

For US Images, Bits Stored (0028,0101) is specified to use the following values for specific Photometric Interpretations:

Table C.8-21US BITS STORED

Photometric Interpretation Bits Stored Value
MONOCHROME2 8
RGB 8
YBR_FULL 8
YBR_FULL_422 8
YBR_PARTIAL_422 8
YBR_RCT 8
YBR_ICT 8
YBR_PARTIAL_420 8
PALETTE COLOR 8 - 8 bit palette, or 16 - 16 bit palette

C.8.5.6.1.15 High Bit

For US Images, High Bit (0028,0102) is specified to use the following values for specific Photometric Interpretations:

Table C.8-22US HIGH BIT

Photometric Interpretation High Bit Value
MONOCHROME2 7
RGB 7
YBR_FULL 7
YBR_FULL_422 7
YBR_PARTIAL_422 7
YBR_RCT 7
YBR_ICT 7
YBR_PARTIAL_420 7
PALETTE COLOR 7 - 8 bit palette, or 15 - 16 bit palette

C.8.5.6.1.16 Planar Configuration

For US Images, Planar Configuration (0028,0006) is specified to use the following values for specific Photometric Interpretations:

Table C.8-23US PLANAR CONFIGURATION

Photometric Interpretation Planar Configuration Value
RGB 0 - color-by-pixel, or 1 - color-by-plane
YBR_FULL 1
YBR_FULL_422 0
YBR_PARTIAL_422 0
YBR_RCT 0
YBR_ICT 0
YBR_PARTIAL_420 0

C.8.5.6.1.19 View Code Sequence

The view of the patient anatomy may be described using coded terminology in the View Code Sequence (0054,0220). The view is typically specified by transducer position relative to the patient anatomy and/or transducer orientation,

The view may be described by a single Code Sequence Item, or by combination of post-coordinated Code Sequence Items. The principal coded item is specified in View Code Sequence, and modifier terms in the View Modifier Code Sequence (0054,0222). The Baseline Context IDs for post-coordinated encoding of view are:

Any of these Context Groups may be used in either the View Code Sequence or the View Modifier Code Sequence.

For cardiac imaging, a Baseline Context ID with pre-coordinated view codes is specified:

Note: Transducer Position Sequence (0008,2240) and Transducer Orientation Sequence (0008,2244), defined in this module in an earlier edition of the Standard (see PS3.3-2004), are retired.

C.8.5.6.1.20 (Retired)

C.8.5.6.1.21 IVUS Acquisition

This attribute denotes which of the following defined terms describes the method used to acquire the IVUS Images.

MOTOR_PULLBACK: The IVUS imaging catheter is positioned in the blood vessel under examination distal to the anatomical structures to be examined. Then the catheter is attached to a motorized mechanism capable of withdrawing the catheter through the vessel at a constant velocity specified by the attribute IVUS Pullback Rate (0018,3101) from the defined IVUS Pullback Start Frame Number (0018,3103) (see C.8.5.6.1.24) to the IVUS Pullback Stop Frame Number (0018,3104) (see C.8.5.6.1.25).

MANUAL_PULLBACK: The IVUS imaging catheter is positioned in the blood vessel under examination distal to the anatomical structures to be examined. Then the catheter is manually withdrawn through the vessel region of interest.

SELECTIVE: The IVUS imaging catheter is positioned in the blood vessel under examination near the anatomical structures to be examined. Then the catheter is manually withdrawn or advanced through the vessel region of interest.

GATED_PULLBACK: The IVUS imaging catheter is positioned in the blood vessel under examination distal to the anatomical structures to be examined. Then the catheter is attached to a motorized mechanism capable of withdrawing the catheter through the vessel at a rate specified by the attribute IVUS Gated Rate (0018,3102), once per heart cycle, from the defined IVUS Pullback Start Frame Number (0018,3103) (see C.8.5.6.1.24) to the IVUS Pullback Stop Frame Number (0018,3104) (see C.8.5.6.1.25).

C.8.5.6.1.22 IVUS Pullback Rate

The attribute IVUS Pullback Rate (0018,3101) is required when IVUS Acquisition (0018,3100) is MOTOR_PULLBACK and it specifies the velocity of withdrawal of the IVUS imaging catheter in millimeters per second.

C.8.5.6.1.23 IVUS Gated Rate

The attribute IVUS Gated Rate (0018,3102) is required when IVUS Acquisition (0018,3100) is GATED_PULLBACK and it specifies the velocity of withdrawal of the IVUS imaging catheter in millimeters per beat.

C.8.5.6.1.24 IVUS Pullback Start Frame Number

The IVUS Pullback Start Frame Number (0018,3103) specifies the frame number of a IVUS multi-frame acquisition upon which motorized or gated pullback begins.

C.8.5.6.1.25 IVUS Pullback Stop Frame Number

The IVUS Pullback Stop Frame Number (0018,3104) specifies the frame number of a IVUS multi-frame acquisition upon which motorized or gated pullback ends.

C.8.5.6.1.26 Lesion Number

Attribute Lesion Number identifies the lesion(s) of interest imaged within the current SOP Instance. Each lesion shall have a unique numeric integer identifier within the study. If during a study the same lesion is imaged more than once, the same Lesion Number should be used for both SOP Instances.

Notes: 1.Lesion Number is not a DICOM UID.

2.An IVUS pullback may contain multiple values in Lesion Number.