Dicom2OMOP

This project builds on a published work, "Development of Medical Imaging Data Standardization for Imaging-Based Observational Research: OMOP Common Data Model Extension". A copy of the full paper can also be found in the files folder. This project looks at creating a controlled vocabulary for the DICOM Pt 6 Data Dictionary, focusing on CS code strings in the OMOP vocabulary format and harmonizing common data elements (CDE).

• Create a library that takes a dicom tag
• • (eg Part 6 0010,0040 Patient Sex)
  • (Link to Part 16 CID 7455 Sex)
  • (Ingest FHIR JSON)
  • (Create "maps to" from Source to Standard vocabulary for OMOP gender)
• Identify current gaps in SNOMED and LOINC mapping from DICOM

References

• Part 5 of Dicom Standard identifying Code Structures.
• Part 6 Dicom Data Dictionary
• Part 16 Dicom Context Groups
• OHDSI Vocabulary Tables CDM 5.4
• DICOM Vocab Browser

Requirements

Developed and Tested for:

• WSL Ubuntu 22.04.3 LTS (Jammy Jellyfish)
• openjdk version "11.0.21" 2023-10-17
• Python 3.10.12

Instructions

0. Ensure the system is up to date and install dependencies

sudo apt update && sudo apt upgrade
sudo apt install bzip2 default-jdk default-jre xsltproc libxml2-utils python3-pip python3.10-venv

For macOS, use Homebrew package management system

brew update
brew upgrade # if needed

Verify java installation

java -version

openjdk version "11.0.21" 2023-10-17

The macOS has its legacy Java, and it is possible that your macOS is not using openjdk. You can install it and read the output for next steps (e.g., setting symlink and path)

brew install openjdk
brew info openjdk

Symlink

sudo ln -sfn /usr/local/opt/openjdk/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk.jdk

Set path

echo 'export PATH="/usr/local/opt/openjdk/bin:$PATH"' >> ~/.zshrc

1. Download the current source and rendering pipeline from dicom.nema.org using curl (wget or another method will also work)

curl https://dicom.nema.org/medical/dicom/current/DocBookDICOM2024a_sourceandrenderingpipeline_20240120075929.tar.bz2 --output sourceandrenderingpipeline.tar.bz2

2. Extract to a directory, remove archive, and navigate to the directory

mkdir sourceandrenderingpipeline 

tar -xvf sourceandrenderingpipeline.tar.bz2 -C sourceandrenderingpipeline

rm sourceandrenderingpipeline.tar.bz2

cd sourceandrenderingpipeline

3. Update absolute paths using the provided bash script

./updateabsolutepaths.sh

If you get an error message that gsed: command not found, then install gsed package first and run it again.

brew install gnu-sed

4. Generate the databases for the parts (example for part 16)

./generateolinkdb.sh 16

5. Generate FHIR valuesets

5.1 Navigate to the valuesets subdirectory and download Java package dependencies

cd valuesets
curl https://repo1.maven.org/maven2/javax/json/javax.json-api/1.0/javax.json-api-1.0.jar --output javax.json-api-1.0.jar
curl https://repo1.maven.org/maven2/org/glassfish/javax.json/1.0.4/javax.json-1.0.4.jar --output javax.json-1.0.4.jar

5.2 Create a backup of the bash script used to extract valuesets, then modify the reference to the Java packages in the bash file and run it

cp extractvaluesets.sh{,.old}
sed -i 's|${HOME}/work/pixelmed/imgbook/lib/additional/|./|g' extractvaluesets.sh
./extractvaluesets.sh

For macOS, -i syntax needs explicit argument specifying the extension for backup files.

cp extractvaluesets.sh{,.old}
sed -i.bak 's|${HOME}/work/pixelmed/imgbook/lib/additional/|./|g' extractvaluesets.sh
./extractvaluesets.sh

5.3 Count the extracted json files to validate they match

find ./valuesets/fhir/json/ -type f -name "*.json" | wc -l

1341

6. Setup the Python virtual environment

note: this should be done in the root DICOM2OMOP directory. We use cd ../.. here to navigate there from DICOM2OMOP/sourceandrenderingpipeline/valuesets

This may take a few minutes as packages are installed.

cd ../..
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

python DICOM_P16_harvest_json.py

References

• Part 5 of Dicom Standard identifying Code Structures.
• Part 6 Dicom Data Dictionary
• Part 16 Dicom Context Groups
• OHDSI Vocabulary Tables CDM 5.4
• DICOM Vocab Browser