dicom-map 0.2.0

Memory-mapped O(log n) DICOM tag dictionary (private + public tags)

DICOM-Atlas

An open registry of public and private DICOM tags compiled from vendor conformance statements plus the PS3.6 standard, with additional entries contributed by pydicom and GDCM. Queryable from Rust, C, or Python in O(log n) with no runtime dependencies.

Current shipped size: 19,688 tags (14,559 private + 5,129 public) in a 3.9 MB tags.dmap file.

Private tag breakdown

Source	Tags	PDFs scraped
Siemens Healthineers (PDF scrape)	1,951	439
GE HealthCare (PDF scrape)	1,762	257
Philips Healthcare (PDF scrape)	791	807
Canon Medical (PDF scrape)	410	284
Acuson (PDF scrape)	214	53
PDF-scraped subtotal	5,128	1,840
pydicom / GDCM (community-compiled)	9,472	—
Total private	14,559
Public (PS3.6 standard)	5,129	—
Grand total	19,688

Quick start — use the dictionary

CLI

cargo build --release --bin dicom-lookup
./target/release/dicom-lookup 0008 0005
./target/release/dicom-lookup 0021 xx08 "Siemens: Thorax/Multix FD Lab Settings"
./target/release/dicom-lookup --json 0021 xx01 GEMS_XR3DCAL_01

Python

pip install maturin
cd dicom-map-py && maturin develop --release

import dicom_map
d = dicom_map.open("tags.dmap")
t = d.lookup(0x0021, 0x0008, "Siemens: Thorax/Multix FD Lab Settings")
# {'vr': 'US', 'name': 'Auto Window Flag', 'block_offset': True,
#  'sources': ['siemens_xr_c2-064.pdf#p41', ...], ...}

pydicom adapter

If you already use pydicom, register DICOM-Atlas's private dictionary into pydicom so private tags resolve automatically with no other code changes:

import dicom_map
import pydicom

dicom_map.patch_pydicom("tags.dmap")  # one-time at startup

ds = pydicom.dcmread("scan.dcm")
elem = ds[0x0021, 0x1008]
print(elem.name, elem.VR)             # resolved via dicom-map

By default patch_pydicom runs in mode="fill" — it only adds entries pydicom doesn't already have, so existing pydicom data is never clobbered. Pass mode="override" to make DICOM-Atlas take precedence on conflicts, or call dicom_map.unpatch_pydicom() to revert.

Rust

[dependencies]
dicom-map = { path = "dicom-map" }
# or with embedded mode (bakes tags.dmap into your binary):
# dicom-map = { path = "dicom-map", features = ["embedded"] }

let d = dicom_map::DmapDict::open("tags.dmap")?;
let t = d.lookup(0x0008, 0x0005, None).unwrap();
println!("{} {}", t.keyword(), t.vr());

C / C++

cargo build --release -p dicom-map-ffi
gcc my_app.c -I dicom-map-ffi/include -L target/release -ldicom_map_ffi

See dicom-map-ffi/include/dicom_map.h.

Quick start — rebuild from source

See DEVELOPMENT.md for the full repository layout, rebuild instructions, re-scrape pipeline, and test suite guide.

Data provenance and limitations

Private DICOM tags are inherently undocumented by design — the standard deliberately leaves the (gggg, xxxx, creator) space to vendors, who are under no obligation to publish or stabilise their tag definitions. Even official conformance statements vary across product versions, may contradict each other, and sometimes document tags that were quietly dropped or repurposed in later firmware. This registry is a best-effort compilation for non-critical use cases — it can help you understand what you're looking at in a DICOM file, but it should not be the basis for clinical decisions, automated de-identification, or any application where a wrong VR or stale name would cause harm.

Notice: The private tag data in this repository is extracted by automated parsing of vendor-published conformance statement PDFs. It is not an authoritative standard and comes with no warranty of completeness or accuracy.

Sources:

• Public tags: DICOM Standard Part 6 (PS3.6) via the Innolitics JSON export.
• Private tags: 1,840 conformance statement PDFs from GE HealthCare, Siemens Healthineers, Philips Healthcare, Canon Medical, and Acuson (Siemens ultrasound). GE, Siemens, and Philips PDFs are archived at archive.org/details/dicom-conformance-ge, archive.org/details/dicom-conformance-siemens, and archive.org/details/dicom-conformance-philips. Canon PDFs are fetched directly from global.medical.canon and archived at archive.org/details/dicom-conformance-canon. Acuson PDFs are fetched directly from the Siemens Healthineers product page. Original vendor source URLs are in data/sources.json.

Each private tag record carries a sources field listing the specific PDF file(s) (with page number anchors) that the definition was scraped from. This is exposed at runtime via the lookup API — TagView::sources() in Rust and the "sources" key in the Python dict — so you can always trace a tag back to the document it came from.

Known limitations:

• Only PDFs in which the vendor explicitly tabulates private tag dictionaries are harvested (~21% of the corpus). Many conformance statements describe service classes but do not enumerate private tags — these are not gaps in our extraction, they simply contain nothing to extract.
• Some widely-used private tags (e.g. (0019,100a) NumberOfImagesInMosaic for Siemens MRI mosaics) were established by community reverse-engineering and do not appear in official conformance PDFs. They are absent from this registry.
• Where the same (group, element, creator) appears in multiple PDFs with conflicting VR types, the majority vote wins; the vr_inferred flag marks the small number of cases where no majority existed.
• Cross-referenced against pydicom's private dictionary for validation; some VR values were backfilled or corrected where pydicom had higher-confidence data.
• Multi-vendor products (e.g. the Siemens/GE joint AdvantageSim RT planning system) can cause the same tag to appear in conformance PDFs from more than one vendor. The vendors field reflects all vendors whose documents reference a tag, not necessarily the vendor that originally defined it.

Status and roadmap

See ROADMAP.md for current state and planned work, and DEVELOPMENT.md for the binary format spec and contributor guide.

License

What	License
Source code (compiler/, dicom-map/, dicom-map-py/, dicom-map-ffi/, scraper/)	Apache-2.0
Original compiled data (entries in tags.csv / tags.dmap whose sources field references a PDF)	CC0 1.0 (public domain)
pydicom / GDCM-derived entries (sources = ["pydicom"])	MIT (pydicom) + BSD-3-Clause (GDCM) — see THIRD_PARTY_LICENSES.md

Full texts: LICENSE (Apache-2.0), LICENSE-DATA (CC0 1.0), THIRD_PARTY_LICENSES.md.