DTIInfo

MLModule
genre DTIImageProcessing
author Jan Klein
package FMEwork/Release
dll MLDTI
definition MLDTI.def
keywords DTI, DTIInfo, DTI, Diffusion, Tensor, gradient

Purpose

The module DTIInfo displays the following information based on DICOM tags. Note that the full information will only be given for Siemens DTI data.

  • the number of excitations (NEX), also know as the number of repetitions, or number of measurements.
  • the number of gradients.
  • the scanner manufacturer.
  • the gradient scheme.

Usage

Connect image data to input. Note that you have previously used the DecodeVendorSpecificDicomTags module.

Tips

If using the SubImage to crop the t-dimension, the corresponding gradient information is not cropped. Furthermore, if using the DTIInfo, the number of excitations will also show the original number before cropping.

Windows

Default Panel

../../../Projects/MLDiffusionMRI/Modules/MLDTI/mhelp/Images/Screenshots/DTIInfo._default.png

Input Fields

input0

name: input0, type: Image

Diffusion weighed image.

Parameter Fields

Field Index

careUnusalDataSorting: Bool
Excitations (before any cropping of t-dim): Integer
Gradients: Integer
List of gradients: String
Remove each x-th gradient: Integer

The module shows additionally the a list showing all gradient vectors.

Visible Fields

Gradients

name: numberOfGradients, type: Integer, default: 0

Shows the number of gradients used during the acquisition process.

In other words, it shows the number of repetitions that have been made of the data.

Excitations (before any cropping of t-dim)

name: numberOfMeasurings, type: Integer, default: 0

Shows the number of excitations used in the acquisition process. If using the SubImage, this will not influence the result.

In other words, it shows the number of repetitions that have been made of the data.

List of gradients

name: gradients, type: String

List of gradient vectors sorted by x,y,z.

Remove each x-th gradient

name: removeEachXthGradient, type: Integer, default: 0

Some newer diffusion-weighted sequences, e.g. from Philips, store intermediate B0 images during the DTI acquisition. Those B0 images are also attached with a gradient. However, the DiffusionTensorAnalysis module does not directly work with these kinds of data and gradient tables. Thus, this option easily allows for removing each x-th gradient which might correspond to an intermediate B0 image.

Hidden Fields

careUnusalDataSorting

name: careUnusalDataSorting, type: Bool, default: TRUE

If this field is set to True AND if 'B' or 'C' or ' ' or '' are at the end of the gradient string, then the number of gradients is reduced by one. Usually, this happens only for wrongly implemented DICOM standards. Thus, this value is set to True as default.