US Multi-frame ImageCIOD
Secondary Capture ImageCIOD
Multi-frame Single Bit SC ImageCIOD
Multi-frame Grayscale Byte SC ImageCIOD
Multi-frame Grayscale Word SC ImageCIOD
Multi-frame True Color SC ImageCIOD
X-Ray Angiographic ImageCIOD
X-Ray Radiofluoroscopic ImageCIOD
RT Structure SetCIOD
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
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
Basic Voice Audio WaveformCIOD
Ambulatory ECGCIOD
Hemodynamic WaveformCIOD
Basic Cardiac Electrophysiology WaveformCIOD
Arterial Pulse WaveformCIOD
Respiratory WaveformCIOD
General Audio WaveformCIOD
Real-Time Audio WaveformCIOD
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 Structured ReportCIOD
Planned Imaging Agent Administration SRCIOD
Performed Imaging Agent Administration SRCIOD
Rendition Selection DocumentCIOD
Enhanced MR ImageCIOD
MR SpectroscopyCIOD
Enhanced MR Color ImageCIOD
PatientMModule - Patient
Clinical Trial SubjectUModule - Patient
General StudyMModule - Study
Patient StudyUModule - Study
Clinical Trial StudyUModule - Study
General SeriesMModule - Series
Clinical Trial SeriesUModule - Series
MR SeriesMModule - Series
Frame of ReferenceMModule - 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
(0018,9006) MR Imaging Modifier Sequence1Sequence
(0018,9042) MR Receive Coil Sequence1Sequence
(0018,9049) MR Transmit Coil Sequence1Sequence
(0018,9107) MR Spatial Saturation Sequence2Sequence
(0018,9112) MR Timing and Related Parameters Sequence1Sequence
(0018,9114) MR Echo Sequence1Sequence
(0018,9115) MR Modifier Sequence1Sequence
(0018,9117) MR Diffusion Sequence1Sequence
(0018,9118) Cardiac Synchronization Sequence1Sequence
(0018,9119) MR Averages Sequence1Sequence
(0018,9125) MR FOV/Geometry Sequence1Sequence
(0018,9152) MR Metabolite Map Sequence1Sequence
(0018,9197) MR Velocity Encoding Sequence1Sequence
(0018,9090) Velocity Encoding Direction1CDouble
(0018,9091) Velocity Encoding Minimum Value1CDouble
(0018,9217) Velocity Encoding Maximum Value1CDouble
(0018,9226) MR Image Frame Type Sequence1Sequence
(0018,9251) MR Arterial Spin Labeling Sequence1Sequence
(0018,9341) Contrast/Bolus Usage Sequence1Sequence
(0018,9621) Functional MR Sequence1Sequence
(0020,9071) Frame Anatomy Sequence1Sequence
(0020,9111) Frame Content Sequence1Sequence
(0020,9113) Plane Position Sequence1Sequence
(0020,9116) Plane Orientation Sequence1Sequence
(0020,9253) Respiratory Synchronization Sequence1Sequence
(0020,9310) Temporal Position Sequence1Sequence
(0028,9110) Pixel Measures Sequence1Sequence
(0028,9132) Frame VOI LUT Sequence1Sequence
(0028,9145) Pixel Value Transformation Sequence1Sequence
(0040,9096) Real World Value Mapping Sequence1Sequence
(5200,9230) Per-frame Functional Groups Sequence1CSequence
Multi-frame DimensionMModule - Image
Cardiac SynchronizationCModule - Image
Respiratory SynchronizationCModule - Image
Bulk Motion SynchronizationCModule - Image
Acquisition ContextMModule - Image
SpecimenCModule - Image
DeviceUModule - Image
Enhanced MR ImageMModule - Image
MR Pulse SequenceCModule - Image
ICC ProfileMModule - Image
SOP CommonMModule - Image
Common Instance ReferenceUModule - Image
Frame ExtractionCModule - Image
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
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
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
Basic DirectoryCIOD

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

Data synced with official DICOM standard on 12 May 2020. 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.

Velocity Encoding Direction Attribute

TypeConditionally Required (1C)
Value Multiplicity3
Value RepresentationDouble (FD)

The direction cosines of the velocity encoding vector with respect to the patient. See Section C. and Section C. for further explanation.

Required if Frame Type (0008,9007) Value 1 of this frame is ORIGINAL. May be present otherwise.


Part of the MR Velocity Encoding Functional Group Macro with usage: C

Required if Phase Contrast (0018,9014) equals YES and Image Type (0008,0008) Value 1 is ORIGINAL or MIXED. May be present otherwise.

Section C.

C. Image Position and Image Orientation

Image Position (0020,0032) specifies the x, y, and z coordinates of the upper left hand corner of the image; it is the center of the first voxel transmitted. Image Orientation (0020,0037) specifies the direction cosines of the first row and the first column with respect to the patient. These Attributes shall be provide as a pair. Row value for the x, y, and z axes respectively followed by the Column value for the x, y, and z axes respectively.

The direction of the axes is defined fully by the patient's orientation.

If Anatomical Orientation Type (0010,2210) is absent or has a value of BIPED, the x-axis is increasing to the left hand side of the patient. The y-axis is increasing to the posterior side of the patient. The z-axis is increasing toward the head of the patient.

If Anatomical Orientation Type (0010,2210) has a value of QUADRUPED, the

  • x-axis is increasing to the left (as opposed to right) side of the patient

  • the y-axis is increasing towards

    • the dorsal (as opposed to ventral) side of the patient for the neck, trunk and tail,

    • the dorsal (as opposed to ventral) side of the patient for the head,

    • the dorsal (as opposed to plantar or palmar) side of the distal limbs,

    • the cranial (as opposed caudal) side of the proximal limbs, and

  • the z-axis is increasing towards

    • the cranial (as opposed to caudal) end of the patient for the neck, trunk and tail,

    • the rostral (as opposed to caudal) end of the patient for the head, and

    • the proximal (as opposed to distal) end of the limbs


  1. The axes for quadrupeds are those defined and illustrated in Smallwood et al for proper anatomic directional terms as they apply to various parts of the body.

  2. It should be anticipated that when quadrupeds are imaged on human equipment, and particularly when they are position in a manner different from the traditional human prone and supine head or feet first longitudinal position, then the equipment may well not indicate the correct orientation, though it will remain an orthogonal Cartesian right-handed system that could be corrected subsequently.

The Patient-Based Coordinate System is a right handed system, i.e., the vector cross product of a unit vector along the positive x-axis and a unit vector along the positive y-axis is equal to a unit vector along the positive z-axis.


If a patient is positioned parallel to the ground, in dorsal recumbency (i.e., for humans, face-up on the table), with the caudo-cranial (i.e., for humans, feet-to-head) direction the same as the front-to-back direction of the imaging equipment, the direction of the axes of this Patient-Based Coordinate System and the Equipment-Based Coordinate System in previous versions of this Standard will coincide.

The Image Plane Attributes, in conjunction with the Pixel Spacing Attribute, describe the position and orientation of the image slices relative to the Patient-Based Coordinate System. In each image frame Image Position (Patient) (0020,0032) specifies the origin of the image with respect to the Patient-Based Coordinate System. RCS and Image Orientation (Patient) (0020,0037) values specify the orientation of the image frame rows and columns. The mapping of pixel location (i,j) to the RCS is calculated as follows:

Equation C. 


  • Pxyz The coordinates of the voxel (i,j) in the frame's image plane in units of mm.

  • Sxyz The three values of Image Position (Patient) (0020,0032). It is the location in mm from the origin of the RCS.

  • Xxyz The values from the row (X) direction cosine of Image Orientation (Patient) (0020,0037).

  • Yxyz The values from the column (Y) direction cosine of Image Orientation (Patient) (0020,0037).

  • i Column index to the image plane. The first column is index zero.

  • Δi Column pixel resolution of Pixel Spacing (0028,0030) in units of mm.

  • j Row index to the image plane. The first row index is zero.

  • Δj Row pixel resolution of Pixel Spacing (0028,0030) in units of mm.

Additional constraints apply:

  1. The row and column direction cosine vectors shall be orthogonal, i.e., their dot product shall be zero.

  2. The row and column direction cosine vectors shall be normal, i.e., the dot product of each direction cosine vector with itself shall be unity.

Section C.

C. Velocity Encoding Direction

The direction of the flow in a flow image is defined by the direction of the relevant flow vector in the MR Velocity Encoding Sequence (0018,9197).

The actual flow value (as specified in the Real World Value Mapping Sequence (0040,9096)) has a positive sign when the flow direction coincides with the Velocity Encoding Direction (0018,9090) vector.