Ogo

Like the Ogopogo of the Okanagan, osteoporosis is elusive. Help build a fracture free future.

Docs	Tests

Overview

This repository contains command-line applications developed for performing bone health analysis from computed tomography images.

It includes tools for segmentation, calibration, image manipulation, segmentation validation and quantitative analysis. It is expected that the data format is NIfTI, so DICOM files should be converted using a trusted tool (we recommend https://github.com/dgobbi/vtk-dicom). It is also helpful to integrate this with the free finite element analysis FAIM tool, developed in the Bone Imaging Laboratory (https://bonelab.github.io/n88/faim.html).

A key function of Ogo is quantitative calibration of CT data, including internal calibration, which was presented at the ASBMR in 2018 and published in 2020:

• Michalski AS, Besler BA, Michalak GJ, Boyd SK, 2018 Feasibility of QCT internal density calibration for site-specific osteoporosis assessment. In American Society of Bone and Mineral Research Annual Meeting. Montreal, Canada. September 28 - October 1, 2018.
• Michalski AS, Besler BA, Michalak GJ, Boyd SK, 2020 CT-based internal density calibration for opportunistic skeletal assessment using abdominal CT scans. Med Eng Phys 78, 55-63. doi = 10.1016/j.medengphy.2020.01.009 url = https://www.ncbi.nlm.nih.gov/pubmed/32059948.

For further information about the Bone Imaging Laboratory see https://bonelab.ucalgary.ca. Please contact us for further questions, comments or interest in contributing to this project.

Install

# I would recommend you create a virtual environment
#  using conda
    conda create -n ogo -c numerics88 -c simpleitk -c conda-forge n88tools simpleitk pbr nibabel nose six python=3

    # Activate your conda environment, make sure you have conda installed on your system.
# Best way to install conda is through anaconda
conda activate ogo

# Install in an 'editable' format
pip install -e .

# You can also run the full install
python setup.py install

Utilities

ogo.util

ogo.util.echo_arguments

• utility function to use with a command-line application, or a function, to automatically print the arguments to the terminal

ogo.util.Helper

• numerous helper functions for tasks in the command line functions (many of these are legacy and not used anymore)

ogo.util.write_csv

• utility function for writing data stored in a dictionary to a csv file

ogo.util.graphcuts

• place holder for installing software for ogoGraphCuts. Read OGO_GRAPHCUTS_INSTALL.txt

ogo.dat

ogo.dat.OgoMasterLabels

• a dictionary of labels used by many of the command line interface functions. Any new labels must be defined here. Use ogoPrintLabels to output the dictionary.

ogo.dat.MassAttenuationTables

• the NIST table of mass attenuation versus energy levels used for internal calibration.

ogo.dat.RT_FEMUR_SIDEWAYS_FALL_REF

• the reference polygon data for alignment prior to finite element analysis.

ogo.dat.LT_FEMUR_SIDEWAYS_FALL_REF

• the reference polygon data for alignment prior to finite element analysis.

ogo.dat.L4_BODY_SPINE_COMPRESSION_REF

• the reference polygon data for alignment prior to finite element analysis.

ogo.calib

The calibration functionality is templated as described below and is best accessed using CLI ogoImageCalibration

ogo.calib.calibration

• top class for all types of calibration

ogo.calib.standard_calibration

• inherits from calibration and implements basic commands

ogo.calib.internal_calibration

• function for performing internal calibration; inherits from standard_calibration and calibration

ogo.calib.mindways_calibration

• function for performing phantom calibration; inherits from standard_calibration and calibration

Command Line Apps

Here is a list of all of the command-line apps that get installed along with the ogo package. For detailed usage instructions, type the command followed by -h into the terminal with the ogo environment activated.

Command	Description
ogoAnalyzeBMD	measure bone mineral density for each label provided from a calibrated CT scan
ogoCreateDatasetJSON	generates JSON for defining raw CT, labelled CT, and unlabelled CT for machine learning (nnUNet)
ogoGenerateFEM	prepares a label (femur, spine) for finite element analysis using FAIM (https://bonelab.github.io/n88/)
ogoGraphCuts	wrapper for using GraphCuts and requires user to install compiled software (see ogo.util)
ogoImageCalibration	perform internal calibration of phantom calibration
ogoImageCrop	utility to crop an image
ogoImageExam	utility to examine the header, histogram and dimensions of a NIfTI image
ogoImageIntensityWindowingFilter	applies a linear scale to the intensity levels of a NIfTI image
ogoImageThreshold	utility threshold a NIfTI image
ogoIntensityProjection	create a 2D projection of 3D computed tomography data
ogoIsotropicResampling	resample a 3D computed tomography datasets to new dimensions
ogoMergeLabels	combine labels from multiple images into a single image; useful for working with TotalSegmentator
ogoMorphologicalOperation	performs dilate, erode, opening, closing on labels
ogoPrintLabels	output the labels used for bones and other tissues
ogoProcrustes	determine whether two datasets have similar bone anatomy as per Procrustes
ogoReadPickle	read pickle files used in machine learning (deprecated)
ogoRepairNIfTI	fix instances of corrupted NIfTI files
ogoReplaceLabels	replace labels in an image with a new label or erase a label
ogoValidate	can validate accuracy of labels from machine learning and has basic repair functions
ogoValidateSummary	provides a summary of validation results from ogoValidate
ogoValidateSelectBest	a utility to identify best validation from multiple results output from ogoValidate
ogoVisualize	interactive visualization tool or offscreen rendering in 2D or 3D
ogodcm2nii	convert DICOM files to NIfTI images (deprecated)

Developer Notes

Style Guide Enforcement

flake8 is used for style guide enforcement. You will not be able to merge without passing the style guide.

cd ogo
flake8

Running Tests

nose is used for running tests. You will not be able to merge without your tests passing. And please, do write tests.

cd Ogo  # From root directory, not ogo
nosetests

Building Docs Locally

Use sphinx-build. This should rather fast.

cd Ogo  # From root directory, not ogo
sphinx-build docs/ docs/_build/html/