Automatic subregional assessment of knee cartilage degradation

This repository provides code for the following manuscript: "Open source software for automatic subregional assessment of knee cartilage degradation using quantitative T2 relaxometry and deep learning"

Link to paper: https://journals.sagepub.com/doi/abs/10.1177/19476035211042406?journalCode=cara

This software provides the following automated functionality for multi-echo spin echo T2-weighted knee MRIs:

• Segmentation of femoral cartilage
• Projection of the femoral cartilage onto a 2D plane
• Division of the projected cartilage into 12 subregions along medial-lateral, superficial-deep, and anterior-central-posterior boundaries
• Calculation of the average T2 value in each subregion
• Calculation of the change in average T2 value over time for each subregion (if 2 imaging time points are available for a given person)
• Comparison of results across different readers/models

FullPipeline.ipynb walks through an example of how to use the full pipeline to analyze individual images, calculate changes in a patient over time, and compare results for segmentations from different readers.

Requires CUDA Version 9.0.176. Tested with CUDA 9.0 and cudnn 7.3.0 in Ubuntu 18.04.

Instructions for getting started

Follow these instructions for installing the appropriate version of CUDA and cudnn: https://github.com/akirademoss/cuda-9.0-installation-on-ubuntu-18.04

Download this repository onto your computer:

git clone https://github.com/kathoma/AutomaticKneeMRISegmentation.git

Enter into the directory you just downloaded:

cd AutomaticKneeMRISegmentation

From here there are two options: Run the analysis in a docker container, or set up an environment:

Option 1: Docker Container (easy way to have the model analyze your images)

Install docker or nvidia-docker

Put your MRIs into /input/ subdirectory. Each MRI should be a zipped directory. Each zipped directory should only contain the slices/echo-times of the image volume.

Build the docker:

sudo docker build -t kneeseg .

Run the docker:

sudo bash run.sh

When the analysis is done, the output will be in the /output/ subdirectory

Option 2: Set up an environment (if you want to do more of your own development)

Download software for creating a virtual environment, then create a new virtual environment called kneeseg and activate it:

pip install virtualenv
virtualenv -p /usr/bin/python3 kneeseg
source kneeseg/bin/activate

Install the necessary dependencies in your new virtual environment:

pip install -r requirements_python3.txt

Make a directory for the model weights:

mkdir model_weights
cd model_weights

Download the weights for the trained model:

wget https://storage.googleapis.com/automatic_knee_mri_segmentation/model_weights_quartileNormalization_echoAug.h5
cd ..

See DemoAnalysis.ipynb for an example of how to use the main features of the analysis pipeline.

Also see the steps in FullPipeline.ipynb for additional examples of how to (1) track longitudinal changes using two imaging timepoints from the same patient and (2) compare the agreement between segmentations of several readers.