Computed Radiography 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 Structure SetCIOD
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
Ambulatory ECGCIOD
Hemodynamic WaveformCIOD
Basic Cardiac Electrophysiology WaveformCIOD
Arterial Pulse WaveformCIOD
Respiratory WaveformCIOD
General Audio WaveformCIOD
Real-Time Audio WaveformCIOD
Routine Scalp ElectroencephalogramCIOD
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
Procedure LogCIOD
X-Ray Radiation Dose SRCIOD
Spectacle Prescription ReportCIOD
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 Beams Treatment RecordCIOD
Ophthalmic Tomography ImageCIOD
PatientMModule - Patient
Clinical Trial SubjectUModule - Patient
General StudyMModule - Study
Patient StudyUModule - Study
Clinical Trial StudyUModule - Study
General SeriesMModule - Series
Clinical Trial SeriesUModule - Series
Ophthalmic Tomography SeriesMModule - Series
Frame of ReferenceCModule - Frame of Reference
SynchronizationCModule - Frame of Reference
General EquipmentMModule - Equipment
Enhanced General EquipmentMModule - Equipment
Image PixelMModule - Image
Enhanced Contrast/BolusCModule - Image
Multi-frame Functional GroupsMModule - Image
(0008,0023) Content Date1Date
(0008,0033) Content Time1Time
(0020,0013) Instance Number1Integer String
(0020,0242) SOP Instance UID of Concatenation Source1CUnique Identifier
(0020,9161) Concatenation UID1CUnique Identifier
(0020,9162) In-concatenation Number1CUnsigned Short
(0020,9163) In-concatenation Total Number3Unsigned Short
(0020,9228) Concatenation Frame Offset Number1CUnsigned Long
(0022,0028) Stereo Pairs Present3Code String
(0028,0008) Number of Frames1Integer String
(0028,6010) Representative Frame Number3Unsigned Short
(5200,9229) Shared Functional Groups Sequence1Sequence
(0008,1140) Referenced Image Sequence2Sequence
(0008,9124) Derivation Image Sequence2Sequence
(0018,9118) Cardiac Synchronization Sequence1Sequence
(0018,9341) Contrast/Bolus Usage Sequence1Sequence
(0020,9071) Frame Anatomy Sequence1Sequence
(0020,9111) Frame Content Sequence1Sequence
(0020,9113) Plane Position Sequence1Sequence
(0020,9116) Plane Orientation Sequence1Sequence
(0022,0031) Ophthalmic Frame Location Sequence1Sequence
(0008,1150) Referenced SOP Class UID1Unique Identifier
(0008,1155) Referenced SOP Instance UID1Unique Identifier
(0008,1160) Referenced Frame Number1CInteger String
(0022,0032) Reference Coordinates1Single
(0022,0039) Ophthalmic Image Orientation1Code String
(0022,0041) Depth of Transverse Image2CSingle
(0040,A170) Purpose of Reference Code Sequence3Sequence
(0062,000B) Referenced Segment Number1CUnsigned Short
(0028,9110) Pixel Measures Sequence1Sequence
(5200,9230) Per-Frame Functional Groups Sequence1CSequence
(7FE0,0003) Encapsulated Pixel Data Value Total Length3UV
Multi-frame DimensionMModule - Image
Acquisition ContextMModule - Image
Cardiac SynchronizationCModule - Image
Ophthalmic Tomography ImageMModule - Image
Ophthalmic Tomography Acquisition ParametersMModule - Image
Ophthalmic Tomography ParametersMModule - Image
Ocular Region ImagedMModule - Image
SOP CommonMModule - Image
Common Instance ReferenceUModule - Image
Frame ExtractionCModule - Image
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
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 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.

Reference Coordinates Attribute

TypeRequired (1)
Value Multiplicity2-2n
Value RepresentationSingle (FL)

Image coordinates for the points on the referenced image that correspond to the points on this frame. See Section C.

Multiple pairs of values where the first value of each pair is the row and the second value of each pair is the column. Row is the vertical offset and column is the horizontal offset.

Specified with sub-pixel resolution such that the origin at the Top Left Hand Corner (TLHC) of the TLHC pixel is 0.0\0.0, the Bottom Right Hand Corner (BRHC) of the TLHC pixel is 1.0\1.0, and the BRHC of the BRHC pixel is Rows\Columns (see Figure C.10.5-1, except that row and column order is reversed). The values must be within the range 0\0 to Rows\Columns.


Part of the Ophthalmic Frame Location Functional Group Macro with usage: U

Section C.

C. Reference Coordinates

A frame can be described in terms of its "position" on another image. In the case of ophthalmic tomography (OPT) images with longitudinal orientation, the OPT image corresponds to a vertical slice along a trajectory on the referenced image. Each column of the OPT frame is nominally perpendicular to the image. Therefore, each column of the OPT frame can also correspond to a particular pixel on an associated image. It is normal in OPT analysis to indicate the location of the OPT slice by showing the corresponding pixel locations on the image. For Transverse frames, the position is indicated by two corners of a rectangle.


The simple geometric relationship Modules are not practical to use for describing the relationship between OPT and retinal photography images. The retinal surface is highly curved, and the optical path is influenced by the lens and other eye structures. It is impractical to measure all of the geometric and optical properties of the eye to the degree needed to establish the relationship by geometric computation. It is easy to capture a retinal image and the slice path on that image as part of the OPT acquisition.

The OPT columns for a retinal slice are not strictly perpendicular to the retina and there are minor systematic distortions as a result. This DICOM Functional Group does not attempt to capture the data needed to measure or correct for these effects, except for the presence of the Maximum Along-scan Distortion Attribute (0022,0038).

The relationship between the columns in the image frame and the reference image are illustrated in Figure C.8.17.10-1.

Frames can be captured using a linear scan with uniform column spacing. This permits the column position to be described by giving the endpoints of the line segment that was scanned. Figure C.8.17.10-1 shows such a scan labeled as "OCT Frame 1". When describing this frame using the Linear Column Locations Functional Group Macro, the Sequence Attributes would contain:

  1. The Attributes of the Image SOP Instance Reference Macro would point to a frame of the reference image.

  2. Reference Coordinates (0022,0032) would contain values that give the row and column coordinates for the image pixel on the referenced image that corresponds to the first column of the OPT Frame 1 and the row and column coordinates that corresponds to the last column of the OPT Frame 1.

Frames can also be taken along curved paths, or with non-uniform spacing. These frames cannot be described by just the two endpoints. These frames are described by specifying the referenced image pixel coordinates for each column in the frame. The frame labeled "OCT Frame 2" illustrates this kind of relationship. The Non-linear Column Locations Functional Group Macro description for this frame would contain:

  1. The Attributes of the Image SOP Instance Reference Macro would point to a frame of the reference image.

  2. Reference Coordinates (0022,0032) would contain 2N integer values. Their contents would be:

    1-2 (e,f)

    … other values

    2L-1, 2L (g,h)

    … other values

    2N-1, 2N (x,y)

A three dimensional OPT raster scan image would be described by a series of Linear Column Location Sequences, one for each frame.


One expected use of column location is the automatic generation of annotation graphics display. The slice location can be indicated and dynamically controlled on the reference image while examining the observed slices. This replaces the relatively inflexible practice of creating a modified retinal image with burned in annotation to indicate the slice locations.

Figure C.8.17.10-1. Relationship of Longitudinal (Nominally Perpendicular) OCT Frames to Reference Frame

In the case of ophthalmic tomography (OPT) images with a transverse orientation, the OPT image corresponds to a sub-rectangle of the reference image. See Figure C.8.17.10-2. The OPT frame is nominally parallel to the reference image. Therefore, each corner of the OPT frame can also correspond to a particular pixel on an associated image. It is assumed that the edges of OPT frame are exactly parallel to the edges of the reference image.

Figure C.8.17.10-2. Relationship of Transverse (Nominally Parallel) OCT Frame to Reference Frame

Figure C.10.5-1

Figure C.10.5-1. Sub-pixel Addressing Units in PIXEL Space