Annex C Ultrasound Application Profile(Normative)

C.1 Class and Profile Identification

This Annex defines Application Profiles for Ultrasound Media Storage applications. Each Application Profile has a unique identifier used for conformance claims. Due to the variety of clinical applications of storage media in Ultrasound, a family of application profiles are described in this section to best tailor an application choice to the specific needs of the user. The identifier used to describe each profile is broken down into three parts: a prefix, mid-section, and suffix. The prefix describes the overall Application Profile Class and is common for all ultrasound application profiles. The mid section describes the specific clinical application of the profile. The suffix is used to describe the actual media choice the profile will use.

The prefix for this class of application profiles is identified with the STD-US identifier.

Note: Conformance Statements may use the earlier prefix of APL which is equivalent to STD. This use is deprecated and may be retired in future versions of the standard.

The midsection is broken down into three subclasses which describes the clinical use of the data. These classes are: Image Display (ID identifier), Spatial Calibration (SC identifier), and Combined Calibration (CC identifier). All three subclasses can be applied to either single frames (SF) images or single and multi-frames (MF) images. The SC subclass enhances the ID class by adding the requirement for region specific spatial calibration data with each IOD. The CC subclass enhances the SC subclass by requiring region specific pixel component calibration.

The suffix, xxxx, is used to describe the actual media choice used for the conformance claim. Any of the above mentioned classes can be stored onto one of eight pieces of media described in the Table C.3-3.

The specific Application Profiles are shown in the following table.

Table C.1-1ULTRASOUND APPLICATION PROFILE IDENTIFIERS

Application Profile Single Frame Single & Multi-Frame
Image Display STD-US-ID-SF-xxxx STD-US-ID-MF-xxxx
Spatial Calibration STD-US-SC-SF-xxxx STD-US-SC-MF-xxxx
Combined Calibration STD-US-CC-SF-xxxx STD-US-CC-MF-xxxx

The ID Application Profile Classes are intended to be used for the transfer of ultrasound images for display purposes.

The SC Application Profile Classes are intended to be used for the transfer of ultrasound images with spatial calibration data for quantitative purposes (see section C.4).

The CC Application Profile Classes are intended to be used for the transfer of ultrasound images with spatial and pixel component calibration data for more advanced quantitative purposes (see section C.5).

C.2 Clinical Context

These classes of Application Profiles facilitate the interchange of ultrasound data on media. Typical interchanges would be between ultrasound systems, between an ultrasound system and a display workstation, between display workstations, or between an ultrasound system and a data archive. This context is shown in Figure C.2-1.

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Figure C.2-1 CLINICAL CONTEXT

The operational use of the media transfer is potentially both intra-institutional and inter-institutional.

C.2.1 Roles

C.2.1.1 FILE SET CREATOR

The role of File Set Creator shall be used by Application Entities which generate a File Set under the STD-US class of Application Profiles. Typical entities using this role would include ultrasound imaging equipment, workstations, and archive systems which generate a patient record for transfer. File Set Creators shall be able to generate the DICOMDIR directory file, single and/or multi frame Ultrasound Information Object files, and depending on the subclass, region specific calibration in the defined Transfer Syntaxes.

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.

C.2.1.2 FILE SET READER

The role of File Set Reader shall be used by Application Entities which receive a transferred File Set. Typical entities using this role would include ultrasound systems, display workstations, and archive systems which receive a patient record from a piece of media. File Set Readers shall be able to read the DICOMDIR directory file and all Information Objects defined for the specific Application Profiles, using the defined Transfer Syntaxes.

C.2.1.3 FILE SET UPDATER

The role of File Set Updater shall be used by Application Entities which receive a transferred File Set and updates it by the addition or deletion of objects to the media. Typical entities using this role would include ultrasound systems adding new patient records to the media and workstations which may add an information object containing a processed or modified image.

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.

The FSU role is not defined for the STD-US-xx-xx-DVD profiles (i.e. for DVD media that is not DVD-RAM).

C.3 General Class Profile

C.3.1 Abstract and Transfer Syntaxes

Application Profiles in this class, STD-US, shall support the appropriate Information Object Definitions (IOD) and Transfer Syntaxes for the Media Storage SOP Class in the following table. In the role of FS-Updater or FS-Creator the application can choose one of the three possible transfer Syntaxes to create an IOD. In the role of FS-Reader an application shall support all transfer Syntaxes defined for the STD-US application profile.

Table C.3-1ULTRASOUND ABSTRACT AND TRANSFER SYNTAXES

Information Object Definition SOP Class UID Transfer Syntax Transfer Syntax UID
DICOM Media Storage Directory 1.2.840.10008.1.3.10 Explicit VR Little Endian Uncompressed 1.2.840.10008.1.2.1 (see PS 3.10 section 8.6)
Ultrasound Image Storage 1.2.840.10008.5.1.4.1.1.6.1 Explicit VR Little Endian Uncompressed 1.2.840.10008.1.2.1
Ultrasound Image Storage 1.2.840.10008.5.1.4.1.1.6.1 RLE Lossless Image Compression 1.2.840.10008.1.2.5
Ultrasound Image Storage 1.2.840.10008.5.1.4.1.1.6.1 JPEG Lossy, Baseline Sequential with Huffman Coding (Process 1) 1.2.840.10008.1.2.4.50
Ultrasound Multi-frame Image Storage 1.2.840.10008.5.1.4.1.1.3.1 Explicit VR Little Endian Uncompressed 1.2.840.10008.1.2.1
Ultrasound Multi-frame Image Storage 1.2.840.10008.5.1.4.1.1.3.1 RLE Lossless Image Compression 1.2.840.10008.1.2.5
Ultrasound Multi-frame Image Storage 1.2.840.10008.5.1.4.1.1.3.1 JPEG Lossy, Baseline Sequential with Huffman Coding (Process 1) 1.2.840.10008.1.2.4.50

C.3.1.1 Ultrasound Single and Multi-frame Pixel Formats Supported

The STD-US application profile requires that all ultrasound image objects only be stored using the values described in PS 3.3 US Image Module and the specializations used for the Ultrasound Single and Multi-Frame IODs.

In the role of FS-Updater or FS-Creator the application can choose any of the supported Photometric Interpretations described in PS 3.3 US Image Module to create an IOD. In the role of FS-Reader, an application shall support all Photometric Interpretations described in PS 3.3 US Image Module.

Table C.3-2 describes restrictions on the use of various Transfer Syntaxes with the supported Photometric Interpretations for both single and multi-frame images.

Table C.3-2DEFINED PHOTOMETRIC INTERPRETATION AND TRANSFER SYNTAX PAIRS

Photometric Interpretation Value Transfer Syntax Transfer Syntax UID
MONOCHROME2 Uncompressed RLE Lossless Image Compression 1.2.840.10008.1.2.1 1.2.840.10008.1.2.5
RGB Uncompressed RLE Lossless Image Compression 1.2.840.10008.1.2.1 1.2.840.10008.1.2.5
PALETTE COLOR Uncompressed RLE Lossless Image Compression 1.2.840.10008.1.2.1 1.2.840.10008.1.2.5
YBR_FULL RLE Lossless Image Compression 1.2.840.10008.1.2.5
YBR_FULL_422 Uncompressed JPEG Lossy 1.2.840.10008.1.2.1 1.2.840.10008.1.2.4.50
YBR_PARTIAL_422 Uncompressed JPEG Lossy 1.2.840.10008.1.2.1 1.2.840.10008.1.2.4.50

C.3.2 Physical Media And Media Formats

An ultrasound application profile class may be supported by any one of the media described in Table C.3-3.

Table C.3-3MEDIA CLASSES

Media Media Classes Media Format PS 3.12
2.3GB 90mm MOD MOD23-90 DOS, unpartitioned (removable media) Annex Q
CD-R CDR ISO/IEC 9660 Annex F
DVD-RAM DVD-RAM UDF1.5 Annex J
120 mm DVD DVD UDF or ISO 9660 Annex P

Note: Media Classes FLOP, MOD128, MOD230, MOD540, MOD640, MOD650, MOD12 AND MOD23 were previously defined but have been retired. See PS 3.11 2004.

C.3.3 DICOMDIR

The Directory shall include Directory Records of PATIENT, STUDY, SERIES, IMAGE corresponding to the information object files in the File Set. All DICOM files in the File Set incorporating SOP Instances (Information Objects) defined for the specific Application Profile shall be referenced by Directory Records. At the image level each file contains a single ultrasound image object or a single ultrasound multi-frame image object as defined in PS 3.3 of the standard.

NOTE: For all media selected in this Application Profile Class, STD-US, the following applies as defined in PS 3.12.

All implementations should include the DICOM Media Storage Directory in the DICOMDIR file. There should only be one DICOMDIR file on a single media. The DICOMDIR file should be found in the root directory of the media. For the case of double-sided MOD media, there shall be a DICOMDIR on each side of the media.

On a single media the patient ID key at the patient level shall be unique for each patient directory record.

C.3.3.1 Additional Keys

File Set Creators and Updaters are only required to generate mandatory elements specified in PS 3.10. At each directory record level any additional data elements can be added as keys, but is not required by File Set Readers to be able to use them as keys.

C.3.3.2 File Component lDs

Note: File Component IDs should be created using a random number filename to minimize File Component ID collisions as described in PS 3.12. The FS-Updater should check the existence of a Component ID prior to creating that ID. Should an ID collision occur, the FS-Updater should try another ID.

C.4 Spatial Calibration (SC) Class Requirements

All implementations conforming to the Application Profile Class SC shall include the US Region Calibration Module with the exception of pixel component organization data element (0018,6044) and other data elements which are conditional on that data element.

C.5 Combined Calibration (CC) Class Requirements

All implementations conforming to the Application Profile Class CC shall include the US Region Calibration Module including the pixel component organization data element (0018,6044) and other data elements which are conditional on that data element.