Data Types

Raw Data

vIST/e can read the data stored in "raw" format (if the volume has a header file along with the raw binary data file or files). Header file is a simple text file for all kinds of data. There is only one data file for a scalar image or 6 data files for DTI or 15 data files for HARDI data in spherical harmonics representation of order 15.

The data file for a scalar volume, consists the data as a one dimensional binary array. Here is the contents of the header file of the 28350 Kb binary data file mri_brain.raw :

Contents of the header file mri_brain.vol:

Data.FileName = mri_brain.raw
Data.Type = raw
Data.Dimensions = 288 288 175
Data.PixelSpacing = 1.000000 1.000000 1.000000
Data.NrBits = 16
Data.NrComponents = 1
Data.Transformation = -0.0533617 -0.0038837 -0.998567 207.012
-0.998005 0.0340125 0.0531993 244.837
0.0337572 0.999414 -0.00569091 -103.771
0 0 0 1

In case of DTI , vIST/e uses the header file which includes the names of 7 binary volume files ( a binary volume for each component of DTI tensor and an intensity volume) and 3 values for spacing. Hence each component of the tensor must be in another 3d raw volume file.

• DTI BMT header file format for raw binary
  T
  float
  XX XX.dat
  YY YY.dat
  ZZ ZZ.dat
  XY XY.dat
  XZ XZ.dat
  YZ YZ.dat
  I II.dat
  1.796875 1.796875 1.800000

Since vIST/e has a HARDIConverter plugin which converts Discrete Sphere representations to Spherical Harmonis or vice versa, the Spherical Harmonics modelled HARDI data attached to the vIST/e distribution can be converted to Discrete Sphere model data.

VTK

vIST/e can read DTI volumes and scalar volumes stored in .vti format.

Nifti and Nifti with Mind Extentions

• vIST/e can read DTI data or Scalar volumes in single or double file(with a seperated header file) Nifti format.
• If DTI data or HARDI data ( ie. with ODF reconstructions in Spherical Harmonics or Discrete Sphere coefficients) are stored in LONI MIND format, vIST/e can also read these files. For a few sample files: http://mind.loni.ucla.edu/tools/sample-files/ .