8 Coding Schemes

Table 8-1 list the coding schemes (and their designators) defined for use in DICOM. Additionally, any coding scheme may be used that has an entry in the HL7 Registry of Coding Schemes, in which case the HL7 Symbolic Name shall be used as the value for the Coding Scheme Designator in DICOM, as long as it does not conflict with an entry in Table 8-1 and fits within the Value Representation of the DICOM Coding Scheme Designator (0008,0102) attribute.

Notes: 1. An earlier version of this table was formerly contained in Annex D of PS 3.3.

2. See PS3.3 “Coding Scheme Designator and Coding Scheme Version” for further description.

3. The Coding Scheme UIDs are provided for reference only; the normative specification of UIDs and their associated meaning is the responsibility of the coding scheme developer and/or HL7.

4. The HL7 registration of Coding Schemes is available at “http://www.hl7.org/oid/index.cfm”.

5. Use of some Coding Schemes may require a license.

Table 8-1 Coding Schemes

Coding Scheme Designator Coding Scheme UID Description
ACR 2.16.840.1.113883.6.76 ACR Index for Radiological Diagnosis Revised, 3rd Edition 1986
ASTM-sigpurpose 1.2.840.10065.1.12 ASTM E 2084 Signature Purpose codes (see Annex A1 of ASTM E 2084), ASTM Subcommittee E 31.20 Data and System Security for Health Information
BARI Bypass Angiography Revascularization Investigation, Alderman, EL and Stadius, M, Coronary Artery Disease 1992,3:1189-1207; endorsed by ACC/AHA Guidelines for Coronary Angiography, J Am Coll Cardiol 1999,33:1791
BI ACR Breast Imaging Reporting and Data System (BI-RADS®BI-RADS® ), Coding Scheme Version (0008,0103) is required; code values are section and paragraph identifiers within the publication where the code meaning is defined (e.g., “I.D.1”, where I = Breast Imaging Lexicon, D = Special Cases, 1 = Tubular Density, as the code value for “Tubular Density”). Note: In the HL7 registry, the abbreviation BI is assigned to a different coding scheme, specifically the Beth Israel problem list.
C4 2.16.840.1.113883.6.12 American Medical Association’s Current Procedure Terminology 4 (CPT-4)
C5 2.16.840.1.113883.6.82 American Medical Association’s Current Procedure Terminology 5 (CPT-5)
CD2 2.16.840.1.113883.6.13 American Dental Association’s (ADA) Current Dental Terminology 2 (CDT-2)
DCM 1.2.840.10008.2.16.4 DICOM Controlled Terminology; PS 3.16 Content Mapping Resource, Annex D (Note that HL7 also specifies an OID of 2.16.840.1.113883.6.31, but deprecates it in favor of 1.2.840.10008.2.16.4).
DCMUID 1.2.840.10008.2.6.1 DICOM UID Registry
FMA 2.16.840.1.113883.6.119 Digital Anatomist Foundational Model of Anatomy
HPC 2.16.840.1.113883.6.14 Healthcare Financing Administration (HCFA) Common Procedure Coding System (HCPCS)
I10 2.16.840.1.113883.6.3 International Classification of Diseases revision 10 (ICD-10)
I10P 2.16.840.1.113883.6.4 ICD-10 Procedure Coding System (ICD 10 PCS)
I9 2.16.840.1.113883.6.42 International Classification of Diseases revision 9 (ICD-9)
I9C 2.16.840.1.113883.6.2 International Classification of Diseases revision 9, with Clinical Modifications (ICD-9-CM)
ISO639_1 2.16.840.1.113883.6.99 Two-letter language codes (Note: HL7 uses “ISO639-1” for the symbolic name, with a hyphen rather than an underscore)
ISO639_2 2.16.840.1.113883.6.100 Three-letter language codes (Note: HL7 uses “ISO639-2” for the symbolic name, with a hyphen rather than an underscore)
ISO3166_1 2.16.1 ISO 3166-1 alpha-2 Country Codes (Note: HL7 uses “ISO3166-1” for the symbolic name, with a hyphen rather than an underscore)
ISO5218_1 Representation of Human Sexes (not used – see note)
ISO_OID ISO/IEC 8824-1– Information Technology – Abstract Syntaxt 1 (ASN.1): Specification of Basic Notation, and ISO/IEC 9834-1 – Information technology -- Open Systems Interconnection -- Procedures for the operation of OSI Registration Authorities: General procedures and top arcs of the ASN.1 Object Identifier tree
LN 2.16.840.1.113883.6.1 Logical Observation Identifier Names and Codes, Regenstrief Institute
MDC 2.16.840.1.113883.6.24 ISO/IEEE 11073 Medical Device Nomenclature, including all its subsections (-10101, -10102, etc.), encoded as decimal strings <partition>:<element>
MDNS Universal Medical Device (UMD) Nomenclature System
NBD 2.16.840.1.113883.15.2 NASPE/BPEG Defibrillator Code Bernstein AD, et al. “The NASPE/BPEG Defibrillator Code” PACE, 16:1776-1780, 1993
NBG 2.16.840.1.113883.15.3 NASPE/BPEG Generic Pacemaker Code (2000) Bernstein AD, et al. “The Revised NASPE/BPEG Generic Code for antibradycardia, adaptive-rate, and multisite pacing” PACE, 25:260-264, 2000
NCDR American College of Cardiology National Cardiovascular Data Registry™ Cath Lab Module Version 1.1, 1997; Version 2.0b, 1999
NPI HCFA National Provider Identifier
POS 2.16.840.1.113883.6.50 HCFA Place of Service (POS) Codes for Professional Claims
RADLEX 2.16.840.1.113883.6.256 RadLex
RFC3066 2.16.840.1.113883.6.121 RFC 3066, Tags for the Identification of Languages, Internet Engineering Task Force (Note: HL7 uses “IETF3066” for the symbolic name)
99SDM 2.16.840.1.113883.6.53 SNOMED DICOM Microglossary (Retired) (see Section 8.1)
SCPECG Standard Communications Protocol for Computer-Assisted Electrocardiography, Draft proposal for ISO Standard, AAMI, Revision 1.3
SNM3 2.16.840.1.113883.6.51 SNOMED International Version 3 (see Section 8.1)
SRT 2.16.840.1.113883.6.96 SNOMED-CT, using the “SNOMED-RT style” code values (see Section 8.1) (Note: HL7 uses “SNM” for the symbolic name)
UCUM 2.16.840.1.113883.6.8 Unified Code for Units of Measure
UMLS 2.16.840.1.113883.6.86 UMLS codes as CUIs making up the values in a coding system
UPC 2.16.840.1.113883.6.55 Universal Product Code - Universal Code Council

Note: Coding Scheme Designator ISO5218_1 was improperly specified in earlier editions of the standard. The codes attributed to that coding scheme have been added to the DICOM Controlled Terminology, and thus all references to coding scheme ISO5218_1 should be considered equivalent to coding scheme DCM.

8.1 SNOMED

SNOMED (the Systematized Nomenclature of Medicine) is the preferred coding system within DICOM for anatomy, clinical findings, procedures, pharmaceutical/biologic products (including contrast agents), and other clinical terms.

Note: SNOMED is a registered trademark of the International Health Terminology Standards Development Organisation.

SNOMED has had various versions, including SNOMED International (Version 3), which was issued in 1993 and revised through 1998, SNOMED Reference Terminology, the successor to SNOMED 3 that was published between 1999 and 2001, and SNOMED Clinical Terms, which has been the name since 2002. The coding scheme is fully backward-compatible across SNOMED 3, SNOMED-RT, and SNOMED CT. SNOMED CT introduced a solely numeric set of codes (ConceptID) in addition to the former alphanumeric codes (SnomedID), but all SNOMED terminology concepts have both a numeric and an alphanumeric code.

In previous editions of the DICOM Standard, the following Coding Scheme Designators were used for SNOMED codes in DICOM:

• "99SDM", denoting the provisional SNOMED DICOM Microglossary

• "SNM3", denoting SNOMED International (Version 3)

• “SRT”, originally denoting SNOMED-RT

All uses of SNOMED coded terms in DICOM are now indicated by the Coding Scheme Designator “SRT”, identifying them as SNOMED CT terms using the “SNOMED-RT style” alphanumeric code values, with some exceptions:

• The NM and PET Image IODs in some code sequences require the Coding Scheme Designator “99SDM” as an Enumerated Value (see PS3.3).

• The Mammography View Codes of CID 4014 and CID 4015 may use the Coding Scheme Designator “SNM3” for implementation adherence to regulatory approvals.

Consequently, when a Coding Scheme Designator of “99SDM” or “SNM3” is encountered, it shall be treated as equivalent to “SRT” for the purpose of interpreting the Code Value.

Note: “SRT” as a coding scheme designator is used only in the DICOM Standard. HL7v2 did not standardize a coding scheme designator for SNOMED-RT.

When interoperating with systems that use SNOMED CT codes obtained from a source other than the DICOM Standard, Application Entities may receive Code Sequences with a Coding Scheme Designator of “SNOMED-CT” and a numeric ConceptID code. It is the responsibility of such Application Entities to convert any such codes to the alphanumeric SnomedID with Coding Scheme Designator “SRT” for use in DICOM objects and services.

8.2 ISO_oID

ISO 8824 and ISO 9834-1 are the standards defined for the generation of object identifiers that are used as DICOM Unique Identifers (see PS 3.5), can also serve as a general mechanism for identifying organizations and objects defined by those organizations.

When the Coding Scheme Designator is ISO_OID, the Code Value shall be the numeric (dot delimited) form of a valid object identifier.

A repository of known existing object identifiers can be found at http://www.oid-info.com/index.htm. For example:

The re-use of object identifiers for existing concepts that do not have an alternative more appropriate coding scheme compatible with DICOM provides a mechanism to avoid defining new codes. For example, HL7 assigned object identifiers can be found at http://www.hl7.org/oid/index.cfm.

Though the intent of ISO_OID is to define organizational roots for the hierarchical assignment of object identifiers, and not specifically to identify organizations per se, the organizational root values can be construed as identifying the organization. For example, the DICOM Standards Organization itself can be identified by the value “1.2.840.10008”. See also CID 5002.