Computed Radiography ImageCIOD
CT ImageCIOD
MR ImageCIOD
Nuclear Medicine ImageCIOD
Ultrasound ImageCIOD
Ultrasound Multi-frame ImageCIOD
Secondary Capture ImageCIOD
Multi-frame Single Bit Secondary Capture ImageCIOD
Multi-frame Grayscale Byte Secondary Capture ImageCIOD
Multi-frame Grayscale Word Secondary Capture ImageCIOD
Multi-frame True Color Secondary Capture ImageCIOD
X-Ray Angiographic ImageCIOD
X-Ray Radiofluoroscopic ImageCIOD
RT ImageCIOD
RT DoseCIOD
RT Structure SetCIOD
RT PlanCIOD
Positron Emission Tomography ImageCIOD
Digital X-Ray ImageCIOD
Digital Mammography X-Ray ImageCIOD
Digital Intra-Oral X-Ray ImageCIOD
RT Beams Treatment RecordCIOD
RT Brachy Treatment RecordCIOD
RT Treatment Summary RecordCIOD
VL Endoscopic ImageCIOD
VL Microscopic ImageCIOD
VL Slide-Coordinates Microscopic ImageCIOD
VL Photographic ImageCIOD
Video Endoscopic ImageCIOD
Video Microscopic ImageCIOD
PatientMModule - Patient
Clinical Trial SubjectUModule - Patient
General StudyMModule - Study
Patient StudyUModule - Study
Clinical Trial StudyUModule - Study
General SeriesMModule - Series
Clinical Trial SeriesUModule - Series
General EquipmentMModule - Equipment
General AcquisitionMModule - Acquisition
General ImageMModule - Image
(0008,0008) Image Type3Code String
(0008,0023) Content Date2CDate
(0008,0033) Content Time2CTime
(0008,2218) Anatomic Region Sequence3Sequence
(0008,2228) Primary Anatomic Structure Sequence3Sequence
(0020,0013) Instance Number2Integer String
(0020,0020) Patient Orientation2CCode String
(0020,0062) Image Laterality3Code String
(0020,4000) Image Comments3Long Text
(0028,0300) Quality Control Image3Code String
(0028,0301) Burned In Annotation3Code String
(0028,0302) Recognizable Visual Features3Code String
(0028,2110) Lossy Image Compression3Code String
(0028,2112) Lossy Image Compression Ratio3Decimal String
(0028,2114) Lossy Image Compression Method3Code String
(0040,9096) Real World Value Mapping Sequence3Sequence
(0028,3003) LUT Explanation1Long String
(0040,08EA) Measurement Units Code Sequence1Sequence
(0008,0100) Code Value1CShort String
(0008,0102) Coding Scheme Designator1CShort String
(0008,0103) Coding Scheme Version1CShort String
(0008,0104) Code Meaning1Long String
(0008,0105) Mapping Resource1CCode String
(0008,0106) Context Group Version1CDate Time
(0008,0107) Context Group Local Version1CDate Time
(0008,010B) Context Group Extension Flag3Code String
(0008,010D) Context Group Extension Creator UID1CUnique Identifier
(0008,010F) Context Identifier3Code String
(0008,0117) Context UID3Unique Identifier
(0008,0118) Mapping Resource UID3Unique Identifier
(0008,0119) Long Code Value1CUnlimited Characters
(0008,0120) URN Code Value1CURL
(0008,0121) Equivalent Code Sequence3Sequence
(0008,0122) Mapping Resource Name3Long String
(0040,9210) LUT Label1Short String
(0040,9211) Real World Value Last Value Mapped1CUS or SS
(0040,9212) Real World Value LUT Data1CDouble
(0040,9213) Double Float Real World Value Last Value Mapped1CDouble
(0040,9214) Double Float Real World Value First Value Mapped1CDouble
(0040,9216) Real World Value First Value Mapped1CUS or SS
(0040,9220) Quantity Definition Sequence3Sequence
(0040,9224) Real World Value Intercept1CDouble
(0040,9225) Real World Value Slope1CDouble
(0088,0200) Icon Image Sequence3Sequence
(2050,0020) Presentation LUT Shape3Code String
General ReferenceUModule - Image
CineMModule - Image
Multi-frameMModule - Image
Image PixelMModule - Image
Acquisition ContextMModule - Image
DeviceUModule - Image
SpecimenCModule - Image
VL ImageMModule - Image
ICC ProfileUModule - Image
SOP CommonMModule - Image
Common Instance ReferenceUModule - Image
Frame ExtractionCModule - Image
Video Photographic ImageCIOD
VL Whole Slide Microscopy ImageCIOD
Real-Time Video Endoscopic ImageCIOD
Real-Time Video Photographic ImageCIOD
Dermoscopic Photography ImageCIOD
Grayscale Softcopy Presentation StateCIOD
Color Softcopy Presentation StateCIOD
Pseudo-Color Softcopy Presentation StateCIOD
Blending Softcopy Presentation StateCIOD
Basic Structured DisplayCIOD
XA/XRF Grayscale Softcopy Presentation StateCIOD
Advanced Blending Presentation StateCIOD
Variable Modality LUT Softcopy Presentation StateCIOD
Basic Voice Audio WaveformCIOD
12-Lead ECGCIOD
General ECGCIOD
Ambulatory ECGCIOD
Hemodynamic WaveformCIOD
Basic Cardiac Electrophysiology WaveformCIOD
Arterial Pulse WaveformCIOD
Respiratory WaveformCIOD
General Audio WaveformCIOD
Real-Time Audio WaveformCIOD
Routine Scalp ElectroencephalogramCIOD
ElectromyogramCIOD
ElectrooculogramCIOD
Sleep ElectroencephalogramCIOD
Multi-channel Respiratory WaveformCIOD
Body Position WaveformCIOD
General 32-bit ECGCIOD
Basic Text SRCIOD
Enhanced SRCIOD
Comprehensive SRCIOD
Key Object Selection DocumentCIOD
Mammography CAD SRCIOD
Chest CAD SRCIOD
Procedure LogCIOD
X-Ray Radiation Dose SRCIOD
Spectacle Prescription ReportCIOD
Colon CAD SRCIOD
Macular Grid Thickness and Volume ReportCIOD
Implantation Plan SR DocumentCIOD
Comprehensive 3D SRCIOD
Radiopharmaceutical Radiation Dose SRCIOD
Extensible SRCIOD
Acquisition Context SRCIOD
Simplified Adult Echo SRCIOD
Patient Radiation Dose SRCIOD
Planned Imaging Agent Administration SRCIOD
Performed Imaging Agent Administration SRCIOD
Rendition Selection DocumentCIOD
Enhanced X-Ray Radiation Dose SRCIOD
Enhanced MR ImageCIOD
MR SpectroscopyCIOD
Enhanced MR Color ImageCIOD
Raw DataCIOD
Enhanced CT ImageCIOD
Spatial RegistrationCIOD
Deformable Spatial RegistrationCIOD
Spatial FiducialsCIOD
Ophthalmic Photography 8 Bit ImageCIOD
Ophthalmic Photography 16 Bit ImageCIOD
Stereometric RelationshipCIOD
Hanging ProtocolCIOD
Encapsulated PDFCIOD
Encapsulated CDACIOD
Real World Value MappingCIOD
Enhanced XA ImageCIOD
Enhanced XRF ImageCIOD
RT Ion PlanCIOD
RT Ion Beams Treatment RecordCIOD
SegmentationCIOD
Ophthalmic Tomography ImageCIOD
X-Ray 3D Angiographic ImageCIOD
X-Ray 3D Craniofacial ImageCIOD
Breast Tomosynthesis ImageCIOD
Enhanced PET ImageCIOD
Surface SegmentationCIOD
Color PaletteCIOD
Enhanced US VolumeCIOD
Lensometry MeasurementsCIOD
Autorefraction MeasurementsCIOD
Keratometry MeasurementsCIOD
Subjective Refraction MeasurementsCIOD
Visual Acuity MeasurementsCIOD
Ophthalmic Axial MeasurementsCIOD
Intraocular Lens CalculationsCIOD
Generic Implant TemplateCIOD
Implant Assembly TemplateCIOD
Implant Template GroupCIOD
RT Beams Delivery InstructionCIOD
Ophthalmic Visual Field Static Perimetry MeasurementsCIOD
Intravascular Optical Coherence Tomography ImageCIOD
Ophthalmic Thickness MapCIOD
Surface Scan MeshCIOD
Surface Scan Point CloudCIOD
Legacy Converted Enhanced CT ImageCIOD
Legacy Converted Enhanced MR ImageCIOD
Legacy Converted Enhanced PET ImageCIOD
Corneal Topography MapCIOD
Breast Projection X-Ray ImageCIOD
Parametric MapCIOD
Wide Field Ophthalmic Photography Stereographic Projection ImageCIOD
Wide Field Ophthalmic Photography 3D Coordinates ImageCIOD
Tractography ResultsCIOD
RT Brachy Application Setup Delivery InstructionCIOD
Planar MPR Volumetric Presentation StateCIOD
Volume Rendering Volumetric Presentation StateCIOD
Content Assessment ResultsCIOD
CT Performed Procedure ProtocolCIOD
CT Defined Procedure ProtocolCIOD
Protocol ApprovalCIOD
XA Performed Procedure ProtocolCIOD
XA Defined Procedure ProtocolCIOD
Ophthalmic Optical Coherence Tomography En Face ImageCIOD
Ophthalmic Optical Coherence Tomography B-scan Volume AnalysisCIOD
Encapsulated STLCIOD
Encapsulated OBJCIOD
Encapsulated MTLCIOD
RT Physician IntentCIOD
RT Segment AnnotationCIOD
RT Radiation SetCIOD
C-Arm Photon-Electron RadiationCIOD
Tomotherapeutic RadiationCIOD
Robotic-Arm RadiationCIOD
RT Radiation Record SetCIOD
RT Radiation Salvage RecordCIOD
C-Arm Photon-Electron Radiation RecordCIOD
Tomotherapeutic Radiation RecordCIOD
Robotic-Arm Radiation RecordCIOD
RT Radiation Set Delivery InstructionCIOD
RT Treatment PreparationCIOD
Enhanced RT ImageCIOD
Enhanced Continuous RT ImageCIOD
RT Patient Position Acquisition InstructionCIOD
Microscopy Bulk Simple AnnotationsCIOD
InventoryCIOD
Photoacoustic ImageCIOD
Confocal Microscopy ImageCIOD
Confocal Microscopy Tiled Pyramidal ImageCIOD
Basic DirectoryCIOD

Built with by Innolitics, a team of medical imaging software developers.

Data synced with official DICOM standard on 18 April 2024. The DICOM Standard is under continuous maintenance, and the current official version is available at http://www.dicomstandard.org/current/. DICOM Parts 3, 4, and 6, © NEMA. Please note that the most recent PDF version of the standard is the official reference, and should checked when making technical decisions.

Measurement Units Code Sequence Attribute

Tag(0040,08EA)
TypeRequired (1)
KeywordMeasurementUnitsCodeSequence
Value Multiplicity1
Value RepresentationSequence (SQ)

Units of measurement.

Only a single Item shall be included in this Sequence.

See Section C.7.6.16.2.11.1 for further explanation.

Section C.7.6.16.2.11.1

C.7.6.16.2.11.1 Real World Value Representation
C.7.6.16.2.11.1.1 Real World Value Mapping Sequence

The Items in the Real World Value Mapping Sequence (0040,9096) may be used to translate stored values into Real World Values when there is such a relationship. The Real World Value Mapping Sequence (0040,9096) is independent of the Modality LUT (or Pixel Value Transformation Macro), as illustrated in Figure C.7.6.16-6.

Each Item specifies the range of stored values as well as the associated mapping function. Each Item can specify either a linear mapping, using Real World Value Slope (0040,9225) and Real World Value Intercept (0040,9224), or a non-linear mapping using Real World Value LUT Data (0040,9212). More than one Real World Value Mapping Item is allowed.

The range of stored pixel values specified by different Real Value World Mapping Sequence (0040,9096) Items can overlap (as illustrated in the example in Figure C.7.6.16-7).

Figure C.7.6.16-6. The Real World Value LUT and the Image Viewing Pipeline


Note

For example, MR images may contain data that is not only the result of the physical/chemical properties of the scanned anatomy, but may also contain information that is representing Real World Values, such as, temperature [in degrees C], flow [in l/min], speed [in m/sec], relative activity [in %], relative contrast enhancement [in %], diffusion [in sec/mm2], etc.

In some cases the conversion from Stored Values to Real World Values can be linear (through "slope" and "intercept") or non-linear (through look-up tables).

Both transformation methods can be applied to one range of stored values. Overlapped ranges might be used for different representations such as log versus linear scales or for different representations in units such as cm/sec versus mm/sec. Alternative methods can be identified by the labels assigned to the transformations.

C.7.6.16.2.11.1.2 Real World Value Mapping Sequence Attributes

The Real World Value First Value Mapped (0040,9216) and Real World Value Last Value Mapped (0040,9211) Attributes describe the range of stored pixel values that are mapped by the Sequence Item. Stored pixel values less than the first value mapped, or greater than the last value mapped have no real value attached.

When the Real World Value Intercept (0040,9224) and Real World Value Slope (0040,9225) Attributes are supplied, the stored value (SV) is converted to a Real World Value (RV) using the equation:

RV = (Real World Value Slope) * SV + Real World Value Intercept

When the Real World Value LUT Data (0040,9212) Attribute is supplied, Real World Values are obtained via a lookup operation. The stored pixel value of the first value mapped is mapped to the first entry in the LUT Data. Subsequent stored pixel values are mapped to the subsequent entries in the LUT Data up to a stored pixel value equal to the last value mapped.

The number of entries in the LUT data is given by:

Number of entries = Real World Value Last Value Mapped- Real World Value First Value Mapped + 1

Note

If the stored pixel values that are encoded as floating point rather than integer values, only the equation and not the lookup operation is defined.

The Value Representation of Real World Value First Value Mapped (0040,9216) and Real World Value Last Value Mapped (0040,9211) (US or SS) is determined by the value of Pixel Representation (0028,0103) in the case of integer pixel data, or is SS in the case of floating point pixel data if these Attributes are present.

Note

In practice, integer values may well be sufficient to define an input range that exceeds the actual stored floating point pixel value range. The reason to permit floating point alternatives to an integer range is that sometimes the stored floating point values may be very large and exceed what can be specified as an integer value.

The physical units for the Real World Values obtained from the Sequence Item are given by the Measurement Units Code Sequence (0040,08EA).

The quantity that the Real World Values represent may be described by the Quantity Definition Sequence (0040,9220), which consists of a list of name-value pairs, in which the coded concept name specifies what aspect of the physical quantity is being described.

Note

  1. For example, Relative Regional Blood Flow may be described by units and quantity as follows:

    Additional information about how the relative blood flow was derived, e.g., the reference region used, can also be encoded as name-value pairs in the Quantity Definition Sequence (0040,9220). See the example in Annex EEEE “Encoding Diffusion Model Parameters for Parametric Maps and ROI Measurements (Informative)” in PS3.17.

  2. For example, the Apparent Diffusion Coefficient (ADC) may be described by units and quantity as follows:

    Additional information about how the ADC was derived, e.g., the model used, method of fitting and acquisition b-values used, can also be encoded as name-value pairs in the Quantity Definition Sequence (0040,9220). Other diffusion models and quantities are also defined. See the example in Annex EEEE “Encoding Diffusion Model Parameters for Parametric Maps and ROI Measurements (Informative)” in PS3.17.

The Quantity Definition Sequence (0040,9220) describes only the stored pixel values that are mapped using the Real World Values Mapping, and does not describe derived values from multiple pixels to which the Real World Values Mapping applies.

Note

I.e., the mapping is a "point" operation, and as a consequence various modifiers that might be applied to a group of pixels, such as in an ROI, should not be used. E.g., an ROI encoded in a Structured Report using TID 1419 "ROI Measurements" might be the mean or maximum value (e.g., SUVbw mean or SUVbw max), and be encoded with (121401, DCM, "Derivation") = (373098007, SCT, "Mean") or (56851009, SCT, "Maximum"), respectively. These would not be appropriate to use within Quantity Definition Sequence (0040,9220), unless the individual pixel values were themselves derived in such a manner, e.g., when multiple images are averaged together. Thus the Content Items used in an SR to describe an ROI might be a superset of the name-value pairs used in Quantity Definition Sequence (0040,9220).

Figure C.7.6.16-7. Example of Mapping Stored Values to Real World Values