DIFFUSION IMAGING RECONSTRUCTION AND
ANALYSIS COLLECTION (DIRAC)
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.
DWIDataPacker: Combines an entire diffusion-weighted data set into a single MiND-formatted NIf TI 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.
• 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
OS: Any, Other: 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.
This work was supported by:
NIH-NCRR U54 RR021813