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
PatientMModule - Patient
Clinical Trial SubjectUModule - Patient
General StudyMModule - Study
Patient StudyUModule - Study
Clinical Trial StudyUModule - Study
General SeriesMModule - Series
Clinical Trial SeriesUModule - Series
SynchronizationUModule - Frame of Reference
General EquipmentMModule - Equipment
General AcquisitionMModule - Acquisition
General ImageMModule - Image
General ReferenceUModule - Image
Image PixelMModule - Image
Contrast/BolusCModule - Image
CineCModule - Image
Multi-frameCModule - Image
Frame PointersUModule - Image
MaskCModule - Image
Display ShutterUModule - Image
DeviceUModule - Image
InterventionUModule - Image
SpecimenUModule - Image
X-Ray ImageMModule - Image
X-Ray AcquisitionMModule - Image
X-Ray CollimatorUModule - Image
X-Ray TableCModule - Image
XA PositionerMModule - Image
DX DetectorUModule - Image
Overlay PlaneUModule - Image
Multi-frame OverlayCModule - Image
Modality LUTCModule - Image
(0028,1052) Rescale Intercept1CDecimal String
(0028,1053) Rescale Slope1CDecimal String
(0028,1054) Rescale Type1CLong String
(0028,3000) Modality LUT Sequence1CSequence
(0028,3002) LUT Descriptor1US or SS
(0028,3003) LUT Explanation3Long String
(0028,3004) Modality LUT Type1Long String
(0028,3006) LUT Data1US or OW
VOI LUTUModule - Image
SOP CommonMModule - Image
Common Instance ReferenceUModule - Image
Frame ExtractionCModule - Image
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
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.

LUT Descriptor Attribute

Tag(0028,3002)
TypeRequired (1)
KeywordLUTDescriptor
Value Multiplicity3
Value RepresentationUS or SS

Specifies the format of the LUT Data in this Sequence.

See Section C.11.1.1 for further explanation.

Section C.11.1.1

C.11.1.1 Modality LUT Module Attribute Descriptions

C.11.1.1.1 LUT Descriptor

The three values of LUT Descriptor (0028,3002) describe the format of the LUT Data in the corresponding LUT Data (0028,3006) Attribute.

The first value is the number of entries in the lookup table. When the number of table entries is equal to 216 then this value shall be 0.

The second value is the first stored pixel value mapped. The Value Representation of the second value (US or SS) is specified by Pixel Representation (0028,0103). This stored pixel value is mapped to the first entry in the LUT. All stored pixel values less than the first value mapped are also mapped to the first entry in the LUT Data. A stored pixel value one greater than the first value mapped is mapped to the second 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 number of entries + first value mapped - 1 that is mapped to the last entry in the LUT Data. Stored pixel values greater than or equal to number of entries + first value mapped are also mapped to the last entry in the LUT Data.

The third value specifies the number of bits for each entry in the LUT Data. It shall take the value 8 or 16. The LUT Data shall be stored in a format equivalent to 8 bits allocated when the number of bits for each entry is 8, and 16 bits allocated when the number of bits for each entry is 16, where in both cases the high bit is equal to bits allocated - 1.

Note

Some implementations have encoded 8 bit entries with 16 bits allocated, padding the high bits; this can be detected by comparing the number of entries specified in the LUT Descriptor with the actual value length of the LUT Data entry. The value length in bytes should equal the number of entries if bits allocated is 8, and be twice as long if bits allocated is 16.

The third value also conveys the range of LUT entry values. It shall take the value 8 or 16, corresponding with the LUT entry value range of 256 or 65536.

Note

Since LUT Descriptor (0028,3002) is multi-valued, in an Explicit VR Transfer Syntax, only one value representation (US or SS) may be specified, even though the first and third values are always by definition interpreted as unsigned. The explicit VR actually used is dictated by the VR needed to represent the second value, which will be consistent with Pixel Representation (0028,0103).

The LUT Data contains the LUT entry values.

The output range of the Modality LUT Module depends on whether or not Rescale Slope (0028,1053) and Rescale Intercept (0028,1052) or the Modality LUT Sequence (0028,3000) are used.

In the case where Rescale Slope and Rescale Intercept are used, the output ranges from (minimum pixel value*Rescale Slope+Rescale Intercept) to (maximum pixel value*Rescale Slope+Rescale Intercept), where the minimum and maximum pixel values are determined by Bits Stored and Pixel Representation.

Note

This range may be signed even if Pixel Representation is unsigned.

In the case where the Modality LUT Sequence is used, the output range is from 0 to 2n-1 where n is the third value of LUT Descriptor. This range is always unsigned.

C.11.1.1.2 Modality LUT and Rescale Type

Specifies the units of the output of the Modality LUT or rescale operation.

Defined Terms:

OD

The number in the LUT represents thousands of optical density. That is, a value of 2140 represents an optical density of 2.140.

HU

Hounsfield Units (CT)

US

Unspecified

MGML

mg/ml

Z_EFF

Effective Atomic Number (i.e., Effective-Z)

ED

Electron density in 1023 electrons/ml

EDW

Electron density normalized to water in units of N/Nw where N is number of electrons per unit volume, and Nw is number of electrons in the same unit of water at standard temperature and pressure.

HU_MOD

Modified Hounsfield Unit

PCT

Percentage (%)

Other values are permitted, but are not defined by the DICOM Standard.

C.11.1.1.2.1 Recommended Rescale Type Assignments For Multi-energy CT Image

Multi-energy CT Images can have multiple assignments of Rescale Types to Image Type Attributes. These are the recommended assignments for Rescale Type and Real World Value Mapping Attributes.

Table C.11.1.1.2.1-1. Recommended Rescale Type Assignments for Multi-energy CT Image

Multi-energy Image Family

Recmd. Rescale Type (0028,1054)

Image Type (0008,0008)

See Note 3.

Rescale Intercept (0028,1052)

Rescale Slope (0028,1053)

Real World Value First Value Mapped (0040,9216)

Real World Value Last Value Mapped (0040,9211)

Real World Value Intercept (0040,9224)

Real World Value Slope (0040,9225)

LUT Label (0040,9210) in Real World Value Mapping Macro

Measurement Units Code Sequence (0040,08EA) in Real World Value Mapping Macro

Objective Image Family

Virtual Monoenergetic Image

HU

VMI

-1024

1

0

4095

-1024

1

VMI

([hnsf'U], UCUM, "Hounsfield unit")

-8192

1

0

65535

-8192

1

Effective AN (Z) Image (see Note 1)

10^-2 Z_EFF

EFF_ATOMIC_NUM

0

1

0

4000

0

0.01

EFF_ATOMIC_NUM

(129320, DCM, "Effective Atomic Number")

Electron Density Image

10^-2ED

ELECTRON_DENSITY

0

1

0

4000

0

0.01

ELECTRON_DENSITY

(10*23/ml, UCUM, "Electron Density")

10^-3EDW

ELECTRON_DENSITY

0

1

0

4000

0

0.001

ELECTRON_DENSITY

({ratio}, UCUM, "ratio")

Material Quantification Family

Material-Specific Image

10^-2MGML

MAT_SPECIFIC

(0) - (-10)

1

0

4000

-3

0.01

MAT_SPECIFIC

(mg/cm3, UCUM, "mg/cm^3")

HU

MAT_SPECIFIC

-1024

1

0

4095

-1024

1

MAT_SPECIFIC

([hnsf'U], UCUM, "Hounsfield unit")

-8192

1

0

65535

-8192

1

Material-Removed Image (see Note 2)

HU

MAT_REMOVED

-1024

1

0

4095

-1024

1

MAT_REMOVED

([hnsf'U], UCUM, "Hounsfield unit")

-8192

1

0

65535

-8192

1

HU_MOD

MAT_REMOVED

-1024

1

0

4095

-1024

1

MAT_REMOVED

(129321, DCM, "Modified Hounsfield Unit")

-8192

1

0

65535

-8192

1

Fractional Map Image

10^-1 PCT

MAT_FRACTIONAL

0

1

0

1000

0

0.1

MAT_FRACTIONAL

(%, UCUM, "Percent")

Value-based Map Image

US

MAT_VALUE_BASED

0

1

0

100

0

1

MAT_VALUE_BASED

([arb'U], UCUM, "arbitrary unit")

Material Visualization Family

Material-Modified Image

HU_MOD

MAT_MODIFIED

-1024

1

0

4095

-1024

1

MAT_MODIFIED

(129321, DCM, "Modified Hounsfield Unit")

-8192

1

0

65535

-8192

1


Note

  1. This example assumes a scaling of 0.01 for the Effective Atomic Number which would be reasonable for images for which the effective atomic number was not greater than 40 for any pixels.

  2. The real-world value mapped pixels in the image may have been adjusted to represent the attenuation as if the pixel was filled with the remaining materials to preserve the relationship between the HU value of the pixel and the materials contained (shown as HU in the first row), or they may have not been adjusted (shown as HU_MOD).

  3. In the CT Image IOD, multi-energy types are encoded in the CT Image Module Image Type (0008,0008) Value 4. In the Enhanced CT Image IOD, multi-energy types are encoded in the Enhanced CT Image Module Image Type (0008,0008) Value 5 and/or the Frame Type (0008,9007) Value 5.

  4. For HU- and HU_MOD-based table rows, recommended numeric values are provided for both 12-bit and 16-bit representations (as determined by the value of Bits Stored (0028,0101)). 16-bit representations are increasingly preferable to handle images with a large dynamic range of pixel values, such as low-dose lung scans which can result in HU values below -1000, MTF images with sharp kernels which can result in HU values below -4000, and images containing metals and other dense materials which can result in HU values like 15000 (for Titanium) and higher. The alternative of clipping such data to fit within a 12-bit range can disrupt subsequent image processing and analysis.