Common Use Cases for IDC

Common Use Cases for IDC

Tested with: idc-index 0.11.9 (IDC data version v23)

This guide provides complete end-to-end workflow examples for common IDC use cases. Each use case demonstrates the full workflow from query to download with best practices.

When to Use This Guide

Load this guide when you need:

• Complete end-to-end workflow examples for training dataset creation
• Patterns for multi-step data selection and download workflows
• Examples of license-aware data handling for commercial use
• Visualization workflows for data preview before download

For core API patterns (query, download, visualize, citations), see the "Core Capabilities" section in the main SKILL.md.

Prerequisites

pip install --upgrade idc-index

Use Case 1: Find and Download Lung CT Scans for Deep Learning

Objective: Build training dataset of lung CT scans from NLST collection

Steps:

from idc_index import IDCClient

client = IDCClient()

# 1. Query for lung CT scans with specific criteria
query = """
SELECT
  PatientID,
  SeriesInstanceUID,
  SeriesDescription
FROM index
WHERE collection_id = 'nlst'
  AND Modality = 'CT'
  AND BodyPartExamined = 'CHEST'
  AND license_short_name = 'CC BY 4.0'
ORDER BY PatientID
LIMIT 100
"""

results = client.sql_query(query)
print(f"Found {len(results)} series from {results['PatientID'].nunique()} patients")

# 2. Download data organized by patient
client.download_from_selection(
    seriesInstanceUID=list(results['SeriesInstanceUID'].values),
    downloadDir="./training_data",
    dirTemplate="%collection_id/%PatientID/%SeriesInstanceUID"
)

# 3. Save manifest for reproducibility
results.to_csv('training_manifest.csv', index=False)

Use Case 2: Query Brain MRI by Manufacturer for Quality Study

Objective: Compare image quality across different MRI scanner manufacturers

Steps:

from idc_index import IDCClient
import pandas as pd

client = IDCClient()

# Query for brain MRI grouped by manufacturer
query = """
SELECT
  Manufacturer,
  ManufacturerModelName,
  COUNT(DISTINCT SeriesInstanceUID) as num_series,
  COUNT(DISTINCT PatientID) as num_patients
FROM index
WHERE Modality = 'MR'
  AND BodyPartExamined LIKE '%BRAIN%'
GROUP BY Manufacturer, ManufacturerModelName
HAVING num_series >= 10
ORDER BY num_series DESC
"""

manufacturers = client.sql_query(query)
print(manufacturers)

# Download sample from each manufacturer for comparison
for _, row in manufacturers.head(3).iterrows():
    mfr = row['Manufacturer']
    model = row['ManufacturerModelName']

    query = f"""
    SELECT SeriesInstanceUID
    FROM index
    WHERE Manufacturer = '{mfr}'
      AND ManufacturerModelName = '{model}'
      AND Modality = 'MR'
      AND BodyPartExamined LIKE '%BRAIN%'
    LIMIT 5
    """

    series = client.sql_query(query)
    client.download_from_selection(
        seriesInstanceUID=list(series['SeriesInstanceUID'].values),
        downloadDir=f"./quality_study/{mfr.replace(' ', '_')}"
    )

Use Case 3: Visualize Series Without Downloading

Objective: Preview imaging data before committing to download

from idc_index import IDCClient
import webbrowser

client = IDCClient()

series_list = client.sql_query("""
    SELECT SeriesInstanceUID, PatientID, SeriesDescription
    FROM index
    WHERE collection_id = 'acrin_nsclc_fdg_pet' AND Modality = 'PT'
    LIMIT 10
""")

# Preview each in browser
for _, row in series_list.iterrows():
    viewer_url = client.get_viewer_URL(seriesInstanceUID=row['SeriesInstanceUID'])
    print(f"Patient {row['PatientID']}: {row['SeriesDescription']}")
    print(f"  View at: {viewer_url}")
    # webbrowser.open(viewer_url)  # Uncomment to open automatically

For additional visualization options, see the IDC Portal getting started guide or SlicerIDCBrowser for 3D Slicer integration.

Use Case 4: License-Aware Batch Download for Commercial Use

Objective: Download only CC-BY licensed data suitable for commercial applications

Steps:

from idc_index import IDCClient

client = IDCClient()

# Query ONLY for CC BY licensed data (allows commercial use with attribution)
query = """
SELECT
  SeriesInstanceUID,
  collection_id,
  PatientID,
  Modality
FROM index
WHERE license_short_name LIKE 'CC BY%'
  AND license_short_name NOT LIKE '%NC%'
  AND Modality IN ('CT', 'MR')
  AND BodyPartExamined IN ('CHEST', 'BRAIN', 'ABDOMEN')
LIMIT 200
"""

cc_by_data = client.sql_query(query)

print(f"Found {len(cc_by_data)} CC BY licensed series")
print(f"Collections: {cc_by_data['collection_id'].unique()}")

# Download with license verification
client.download_from_selection(
    seriesInstanceUID=list(cc_by_data['SeriesInstanceUID'].values),
    downloadDir="./commercial_dataset",
    dirTemplate="%collection_id/%Modality/%PatientID/%SeriesInstanceUID"
)

# Save license information
cc_by_data.to_csv('commercial_dataset_manifest_CC-BY_ONLY.csv', index=False)

Resources

• Main SKILL.md for core API patterns (query, download, visualize)
• references/clinical_data_guide.md for clinical data integration workflows
• references/sql_patterns.md for additional SQL query patterns
• references/index_tables_guide.md for complex join patterns