Reference
DICOM Standard Parts
The DICOM standard is not a single document — it is 20 individual parts, each handling a different aspect of the standard. PS3.1 is the introduction. PS3.3 defines information objects. PS3.6 is the data dictionary. If you're new to DICOM, reading the whole set front to back is a multi-week project; knowing which parts to skip is a superpower.
The 20 parts
Each part is available as PDF and XML from dicomstandard.org/current. Our spec browser parses the XML directly — see licenses & sources for the full provenance chain.
| Part | Title | What it's for |
|---|---|---|
| PS3.1 | Introduction and Overview | High-level tour of the standard. Read once. |
| PS3.2 | Conformance | How conformance statements are structured. Required reading for integrators. |
| PS3.3 | Information Object Definitions | CIODs + modules + attribute usage. The spec browser's CIOD + Module pages come from here. |
| PS3.4 | Service Class Specifications | Defines Storage, Q/R, Worklist, MPPS, Storage Commitment, Print. Required for network integration. |
| PS3.5 | Data Structures and Encoding | VRs, transfer syntaxes, encoding rules. Required for any parsing work. |
| PS3.6 | Data Dictionary | Every standard attribute — tag, VR, VM, keyword, description. This is the spec browser's tag data. |
| PS3.7 | Message Exchange | DIMSE primitives (C-STORE, N-CREATE, etc.) — the message-level protocol. |
| PS3.8 | Network Communication Support | DUL PDUs, association negotiation, TCP/IP specifics. |
| PS3.10 | Media Storage and File Format | The Part-10 file format — 128-byte preamble, DICM, FMI, data set. |
| PS3.11 | Media Storage Application Profiles | CD, DVD, USB application profiles. Less relevant than it once was. |
| PS3.12 | Media Formats and Physical Media | Physical media specs — CDs, DVDs, BDs. |
| PS3.14 | Grayscale Standard Display Function | GSDF curve for calibrated grayscale monitors. Matters for radiology reading stations. |
| PS3.15 | Security and System Management Profiles | TLS profile, audit trail, Supplement 142 de-identification. Required reading for compliance. |
| PS3.16 | Content Mapping Resource | Coded terminology — SNOMED, LOINC, RadLex mappings used in SRs and reports. |
| PS3.17 | Explanatory Information | Informative — worked examples, rationale. Useful rather than required. |
| PS3.18 | Web Services | DICOMweb — WADO-RS, QIDO-RS, STOW-RS. Required for any HTTP-based DICOM. |
| PS3.19 | Application Hosting | Plugin API for DICOM applications. Rare in practice. |
| PS3.20 | Imaging Reports Using HL7 CDA | Bridge between DICOM and HL7 CDA report formats. |
Note: parts 3.9 and 3.13 were retired in 2006. The numbering is preserved for historical continuity.
The four parts you must read
If you're building an integration — not running a PACS, just pushing images between two vendors — read these four and accept that everything else is reference you'll look up as needed:
- PS3.2 — tells you how to write and read a conformance statement
- PS3.4 — tells you what services exist and what each does
- PS3.5 — tells you how the data gets encoded
- PS3.15 — tells you how to secure the resulting traffic
PS3.3 and PS3.6 are big (>2,000 pages combined) — use the browser for them. Our spec browser ingests both monthly.
Change Proposals (CPs) and Supplements
The standard evolves through two mechanisms:
- Supplements — significant new functionality. For example, Sup 11 introduced Enhanced CT Image Storage; Sup 142 defined the de-identification profiles; Sup 194 added Enhanced Color Presentation State.
- Change Proposals — bug fixes, clarifications, small additions. Each CP is reviewed by the working group and either accepted (folded into the next edition) or rejected.
Tracking active CPs is useful for anyone on the bleeding edge — they predict what's in the next edition 12-18 months out. The DICOM Working Group meeting notes (publicly posted) are the primary source.
Edition cadence
DICOM releases editions annually — 2024a, 2024b, 2025a, and so on. Letter suffixes indicate mid-year edition updates. Each edition consolidates accepted Supplements + CPs from the previous cycle. Our spec browser tracks NEMA 2025a as of 2026-04-22; refresh is automated on a monthly cron.
Browse current edition: spec browser · Generation provenance: licenses