Annex E (Normative) - CT and MR Image Application Profiles

E.1 Profile Identification

This Annex defines Application Profiles for Computed Tomography and Magnetic Resonance Imaging interchange and storage on high capacity rewriteable magneto-optical disks (MOD) and CD-R and DVD-RAM and other DVD media uncompressed and with lossless compression.

Table E.1-1 - STD-CTMR Profiles

Application Profile Identifier Description
CT/MR Studies on 4.1GB MOD STD-CTMR-MOD41 Handles single frame 8, 12 or 16 bit grayscale and 8 bit palette color, uncompressed and lossless compressed images.
CT/MR Studies on CD-R STD-CTMR-CD Handles single frame 8, 12 or 16 bit grayscale and 8 bit palette color, uncompressed and lossless compressed images.
CT/MR Studies on DVD-RAM Media STD-CTMR-DVD-RAM Handles single frame 8, 12 or 16 bit grayscale and 8 bit palette color, uncompressed and lossless compressed images.
CT/MR Studies on DVD Media STD-CTMR-DVD Handles single frame 8, 12 or 16 bit grayscale and 8 bit palette color, uncompressed and lossless compressed images.

Note: Media Profiles STD-CTMR-MOD650, STD-CTMR-MOD12 and STD-CTMR-MOD23 were previously defined but have been retired. See PS 3.11 2004.

E.2 Clinical Context

These Application Profiles facilitate the interchange and storage of primary CT and MR images as well as related Secondary Capture Images with certain defined attributes, including grayscale and palette color images. CT, MR and SC images may co-exist within the same File-set.

Typical interchanges would be between acquisition devices, archives and workstations, within and between institutions.

E.2.1 Roles and Service Class Options

These Application Profiles uses the Media Storage Service Class defined in PS 3.4.

The Application Entity shall support one or more of the roles of File-set Creator, File-set Reader, and File-set Updater, defined in PS 3.10.

E.2.1.1 File Set Creator

The Application entity acting as a File-Set Creator generates a File Set under a STD-CTMR Application Profile. Typical entities using this role would include CT or MR equipment, and archive systems which generate a patient record for transfer to another institution. File Set Creators shall be able to generate the Basic Directory SOP Class in the DICOMDIR File with all types of Directory Records related to the SOP Classes stored in the File-set.

An FSC shall offer the ability to either finalize the disc at the completion of the most recent write session (no additional information can be subsequently added to the disc) or to allow multi-session (additional information may be subsequently added to the disc) or to allow packet-writing, if supported by the media and file system specified in the profile.

Note: A multiple volume (a logical volume that can cross multiple physical media) is not supported by this class of Application profile. If a set of Files, e.g., a Study, cannot be written entirely on one physical volume, the FSC will create multiple independent DICOM File-sets such that each File-set can reside on a single physical volume controlled by its individual DICOMDIR file. The user of the FSC can opt to use written labels on the physical volumes to indicate that there is more than one physical volume for this set of files (e.g., a study).

E.2.1.2 File Set Reader

The role of File Set Reader is used by Application Entities that receive a transferred File Set. Typical entities using this role would include display workstations, and archive systems that receive a patient record transferred from another institution. File Set Readers shall be able to read all the SOP Classes defined for the specific Application Profile for which a Conformance Statement is made, using all the defined Transfer Syntaxes.

E.2.1.3 File Set Updater

The role of File Set Updater is used by Application Entities that receive a transferred File Set and update it by the addition of information. Typical entities using this role would include analytic workstations, which, for instance, may add to the File-set an information object containing a processed image. Stations that update patient information objects would also use this role. File-set Updaters do not have to read the images. File-set Updaters shall be able to generate one or more of the SOP Instances defined for the specific Application Profile for which a conformance statement is made, and to read and update the DICOMDIR file.

An FSU shall offer the ability to either finalize the disc at the completion of the most recent write session (no additional information can be subsequently added to the disc) or to allow multi-session (additional information may be subsequently added to the disc) or to allow packet-writing if supported by the media and file system specified in the profile.

Note: If the volume has not been finalized, the File Set Updater will be able to update information assuming there is enough space on the volume to write a new DICOMDIR file, the information, and the fundamental volume control structures. Volume control structures are the structures that are inherent to the standards of the physical volume, see PS 3.12.

The FSU role is not defined for the STD-CTMR-DVD profile.

E.3 STD-CTMR ProfileS

E.3.1 SOP Classes and Transfer Syntaxes

These Application Profiles are based on the Media Storage Service Class (see PS 3.4).

SOP Classes and corresponding Transfer Syntaxes supported by these Application Profiles are specified in the Table E.3-1.

Table E.3-1STD-CTMR SOP Classes and Transfer Syntaxes

Information Object Definition Service Object Pair Class UID Transfer Syntax and UID FSC Require-ment FSR Require-ment FSU Require-ment (See Note 1)
Basic Directory 1.2.840.10008.1.3.10 Explicit VR Little Endian Uncompressed 1.2.840.10008.1.2.1 Mandatory Mandatory Mandatory
CT Image 1.2.840.10008.5.1.4.1.1.2 JPEG Lossless Process 14 (selection value 1) 1.2.840.10008.1.2.4.70 Optional Mandatory Optional
CT Image 1.2.840.10008.5.1.4.1.1.2 Explicit VR Little Endian Uncompressed 1.2.840.10008.1.2.1 Optional Mandatory Optional
MR Image 1.2.840.10008.5.1.4.1.1.4 JPEG Lossless Process 14 (selection value 1) 1.2.840.10008.1.2.4.70 Optional Mandatory Optional
MR Image 1.2.840.10008.5.1.4.1.1.4 Explicit VR Little Endian Uncompressed 1.2.840.10008.1.2.1 Optional Mandatory Optional
SC Image (grayscale) 1.2.840.10008.5.1.4.1.1.7 JPEG Lossless Process 14 (selection value 1) 1.2.840.10008.1.2.4.70 Optional Mandatory Optional
SC Image (grayscale) 1.2.840.10008.5.1.4.1.1.7 Explicit VR Little Endian Uncompressed 1.2.840.10008.1.2.1 Optional Mandatory Optional
SC Image (palette color) 1.2.840.10008.5.1.4.1.1.7 JPEG Lossless Process 14 (selection value 1) 1.2.840.10008.1.2.4.70 Optional Optional Optional
SC Image (palette color) 1.2.840.10008.5.1.4.1.1.7 Explicit VR Little Endian Uncompressed 1.2.840.10008.1.2.1 Optional Optional Optional

Notes: 1. The FSU requirement is not defined for STD-CTMR-DVD profile.

2. The Detached Patient management SOP Class was formerly defined in these profiles, but has been retired.

E.3.2 Physical Medium And Medium Format

The STD-CTMR-MOD41 application profile requires the 130 mm 4.1GB R/W MOD physical medium with the PCDOS Media Format, as defined in PS 3.12.

The STD-CTMR-CD application profile requires the 120 mm CD-R physical medium with the ISO 9660 Media Format, as defined in PS 3.12.

The STD-CTMR-DVD-RAM application profile requires the 120 mm DVD-RAM medium, as defined in PS 3.12.

The STD-CTMR-DVD application profile requires any of the 120 mm DVD media other than DVD-RAM, as defined in PS 3.12.

E.3.3 Directory Information in DICOMDIR

Conformant Application Entities shall include in the DICOMDIR File a Basic Directory IOD containing Directory Records at the Patient and subsidiary levels appropriate to the SOP Classes in the File-set. All DICOM files in the File-set incorporating SOP Instances defined for the specific Application Profile shall be referenced by Directory Records.

Note: DICOMDIRs with no directory information are not allowed by this Application Profile.

E.3.3.1 Additional Keys

File Set Creators and Updaters are required to generate the mandatory elements specified in PS 3.3, Annex F of the standard. Table E.3-2 specifies the additional associated keys. At each directory record level other additional data elements can be added, but it is not required that File Set Readers be able to use them as keys. Refer to the Basic Directory IOD in PS 3.3.

E.3.3.2 Localizer Related Attributes

Directory Records of type IMAGE shall include the mandatory attributes from the Frame of Reference and Image Plane modules, if present in the composite image object, as specified in PS3.3 and included in Table E.3-2, in order to allow the image to be referenced to a localizer image or other orthogonal image. The Rows (0028,0010) and Columns (0028,0011) attributes are required in order to facilitate annotation of such a localizer.

Note: The Frame of Reference module is specified in PS 3.3 as mandatory for the CT and MR composite information objects, but not for Secondary Capture objects.

E.3.3.3 Icon Images

Directory Records of type SERIES or IMAGE may include Icon Images. The icon pixel data shall be as specified in PS 3.3 Icon Image Key Definition, and restricted such that Photometric Interpretation (0028,0004) shall be MONOCHROME2 or PALETTE COLOR, Bits Allocated (0028,0100) and Bits Stored (0028,0101) shall be equal to 8, and Rows (0028,0010) and Columns (0028,0011) shall be equal to 64.

E.3.4 Other Parameters

This section defines other parameters in the STD-CTMR profiles which need to be specified in order to ensure interoperable information interchange.

Table E.3-2STD-CTMR Additional DICOMDIR Keys

Key Attribute Tag Record Type Type Notes
Referenced Image Sequence (0008,1140) IMAGE 1C Required if present in image object.
>Referenced SOP Class UID (0008,1150) IMAGE 1C Required if Referenced Image Sequence (0008,1140) is present.
>Referenced SOP Instance UID (0008,1155) IMAGE 1C Required if Referenced Image Sequence (0008,1140) is present.
Image Position (Patient) (0020,0032) IMAGE 1C Required if present in image object.
Image Orientation (Patient) (0020,0037) IMAGE 1C Required if present in image object.
Frame of Reference UID (0020,0052) IMAGE 1C Required if present in image object.
Rows (0028,0010) IMAGE 1
Columns (0028,0011) IMAGE 1
Pixel Spacing (0028,0030) IMAGE 1C Required if present in image object.

Notes: 1. The Basic Directory Information Object definition in PS 3.3 defines the following attributes as Type 1 or 2: for PATIENT directory records: (0010,0010) Patient’s Name; for STUDY directory records: (0008,0050) Accession Number, (0008,0020) Study Date, (0008,1030) Study Description; for SERIES directory records: (0008,0060) Modality. Hence these are not redefined here.

2. The Basic Directory Information Object definition in PS 3.3 allows for the optional inclusion of Icon Images at the IMAGE or SERIES level. These remain optional for this profile, and the choice of whether or not to include Icon Images for every image or series, or in a more selective manner, is left up to the implementor. E.3.3.3 describes restrictions that apply to Icon Images that are included in this profile.

E.3.4.1 Image Attribute Values

The attributes listed in Table E.3-3 used within CT Image files, those listed in Table E.3-4 used within MR Image files, those listed in Table E.3-5 used within grayscale SC Image files, and those listed in Table E.3-6 used within color SC Image files, shall take the values specified, which are more specific than, but must be consistent with, those specified in the definition of the CT, MR and SC Image Information Object Definitions in PS 3.3.

Table E.3-3 STD-CTMRRequired Image Attribute Values for CT Images

Attribute Tag Value
Modality (0008,0060) CT
Photometric Interpretation (0028,0004) MONOCHROME2

Table E.3-4 STD-CTMRRequired Image Attribute Values for MR Images

Attribute Tag Value
Modality (0008,0060) MR
Photometric Interpretation (0028,0004) MONOCHROME2
Bits Stored (0028,0101) 8,12 to 16
High Bit (0028,0102) (0028,0101) Bits Stored - 1

Note: The definition of the MR Composite Image Object in PS 3.3 does not restrict (0028,0101) Bits Stored or (0028,0102) High Bit.

Table E.3-5 STD-CTMRRequired Image Attribute Values for Grayscale SC Images

Attribute Tag Value
Samples Per Pixel (0028,0002) 1
Photometric Interpretation (0028,0004) MONOCHROME2
Bits Allocated (0028,0100) 8 or 16
Bits Stored (0028,0101) (0028,0100) Bits Allocated
High Bit (0028,0102) (0028,0101) Bits Stored - 1

Table E.3-6 STD-CTMRRequired Image Attribute Values for Color SC Images

Attribute Tag Value
Samples Per Pixel (0028,0002) 1
Photometric Interpretation (0028,0004) PALETTE COLOR
Bits Allocated (0028,0100) 8
Bits Stored (0028,0101) 8
High Bit (0028,0102) 7

E.3.4.1.1 Attribute Value Precedence

Retired.