imaging-data-commons

The saved excerpt is a snapshot from when this skill was listed. The external source remains the complete and most current version.

---
name: imaging-data-commons
description: Queries and downloads public cancer imaging data from NCI Imaging Data Commons. Supports IDC collection discovery, DICOM access, radiology (CT, MR, PET) and pathology AI datasets, metadata SQL, visualization, licensing, and citations. Uses public metadata and download routes without authentication; optional BigQuery and Google Healthcare routes require Google credentials.
compatibility: Requires network access for hosted APIs, index fetching, citations, and downloads. Local Python workflows target idc-index 0.12.5; BigQuery and Google Healthcare require Google credentials.
license: This skill is provided under the MIT License. IDC data itself has individual licensing (mostly CC-BY, some CC-NC) that must be respected when using the data.
metadata:
  version: "1.8"
  last-reviewed: "2026-09-30"
  source-skill-version: "1.8.1"
  skill-author: Andrey Fedorov, @fedorov
  idc-index: "0.12.5"
  idc-data-version: "v24"
  repository: https://github.com/ImagingDataCommons/imaging-data-commons-skill
---

# Imaging Data Commons

## Overview

Query and download public cancer imaging data from the National Cancer Institute Imaging Data Commons (IDC). No authentication required for data access.

**Expected network access:** IDC metadata is reachable three ways — a bundled local DuckDB index (offline after installation; additional indices are fetched from GitHub and clinical tables from S3), or the hosted IDC service over MCP or REST (`api.imaging.datacommons.cancer.gov`, no authentication). File downloads use public GCS (`storage.googleapis.com`) and AWS S3 (`s3.amazonaws.com`) — no authentication required. DICOMweb access uses either the public IDC proxy (`proxy.imaging.datacommons.cancer.gov`, no auth) or the Google Cloud Healthcare API (`healthcare.googleapis.com`, requires GCP authentication). Optional BigQuery queries (`bigquery.googleapis.com`) also require GCP authentication. Citation resolution contacts DOI services. Public IDC routes require no credentials; optional Google clients use Application Default Credentials.

**Reviewed 2026-09-30:** idc-index 0.12.5, idc-index-data 24.2.2, IDC v24; hosted API 3.0.0b3. Recheck at use time.

**Choose the access path first.** There is no single default: the cheapest correct path depends
on the session and the task.

1. **Session already has the IDC MCP server?** Route discovery and metadata there — see *IDC
   MCP Server*.
2. **Otherwise, is `idc-index` installed and current?** Run `python scripts/check_version.py`. If it passes,
   use `idc-index` for everything.
3. **Not installed, and the task is read-only metadata** — counts, attribute values, collection
   lookups, SQL under 10 000 rows, licenses, citations, viewer URLs? **Use the REST API over
   `curl`; do not install anything.** Installing costs ~77 MB of packaged index data plus
   pandas, pyarrow, and duckdb, which a metadata question does not need. See *Data Access
   Options*.
4. **Not installed, and the task needs more than metadata** — downloading files, pandas or
   plotting, pydicom/SimpleITK, pathology tiling, results past 10 000 rows, or a version-pinned
   script the user re-runs? Install `idc-index`: `check_version.py` exits non-zero and prints
   the exact install command for the running interpreter. Prefer a virtual environment, then
   restart Python.

`idc-index` ([GitHub](https://github.com/imagingdatacommons/idc-index)) is still the most
capable Python path, with query and download helpers in one client. `check_version.py` never installs anything itself — it also flags a newer
`idc-index` or skill release when one exists.

**Setup for the `idc-index` path:** use the intended interpreter for `scripts/check_version.py`
and confirm its `meets pinned minimum` message before continuing. A launch failure is not a pass.

```python
from idc_index import IDCClient
client = IDCClient()

# Verify IDC data version (should be "v24")
print(f"IDC data version: {client.get_idc_version()}")