Diffusion Imaging Reconstruction and Analysis Collection

DIRAC is a collection of tools for rapid and robust processing of diffusion-weighted imaging (DWI) data. Programs are included for both diffusion tensor and HARDI reconstruction and analysis.


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OS-Independent - Version v2.1 Pipeline Workflow

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  • Simple and straightforward with minimal parameters to specify.
  • Adheres to the MiND specification, the standard for storage and sharing of DWI data.
  • Pipeline availability to integrate with existing workflows.
  • HARDI made easy!


DWIDataPacker: Combines an entire diffusion-weighted data set into a single MiND-formatted NIfTI file for input to all subsequent modules.

DWITensorCalculator: Estimates a 2nd-order diffusion tensor using a weighted-least-squares approach.

DWITensorStatistician: Calculates various tensor metrics using the output of DWITensorCalculator.

DWIQBallCalculator: Calculates a diffusion ODF reconstruction using Tuch's q-ball method.

DWISpharmCalculator: Calculates a regularized, spherical harmonics representation of the diffusion ODF.

System Requirements


  • Version: v2.1 Pipeline Workflow
  • Size: 136 KB
  • OS: Any
  • Software: To run the LONI Pipeline, an installation of Sun's Java Runtime Environment, version 1.5 or higher.


Pipeline modules/workflows - extract to a convenient location and open with the LONI Pipeline.


Processing of diffusion-weighted data sets is a complex task. DIRAC simplifies DWI analysis by requiring a minimal number of user-defined parameters for computation. Furthermore, DIRAC avoids the "vendor lock-in" issue common to monolithic software solutions by providing intermediate results to the user, allowing for processing using external tools if desired.