Brain Atrophy - Processing Options for Longitudinal Assessment with White-Matter Lesions

Brain Atrophy - Longitudinal with White-Matter Lesions

The picture below shows the setup for assessing brain atrophy at 2 time-points (longitudinally) when there are white-matter (WM) lesions present. You can analyse more than 2 time-points by increasing Spinner to set the number of time points to be analysed . You need both a T₁-weighted image and a FLAIR image acquired at each time-point.

Setup for longitudinal brain atrophy assessment with lesions

The settings will be the same as for cross-sectional analysis with lesions, and the analysis will take commensurately longer because of the increased number of registration and segmentation steps involved.

When the analysis is complete, you will see a pop-up message showing the results:

Results for longitudinal brain atrophy assessment with lesions

These results show, for each time-point:

The grey-matter (GM) lesion volume.
The white-matter (WM) lesion volume.
The total lesion volume.
The probabilistic GM lesion load - an intensity-weighted volume as a percentage of the total GM volume.
The probabilistic WM lesion load - an intensity-weighted volume as a percentage of the total WM volume.
The total probabilisticlesion load - - an intensity-weighted volume as a percentage of the total brain parcenchyma volume.
The GM volume (including GM lesions).
The WM volume (including WM lesions).
The cerebro-spinal fluid (CSF) volume.
The intra-cranial (IC) volume, which is the sum of the volumes of the 3 compartments above.
The brain parenchymal fraction (BPF), which is: (GM Volume + WM Volume) / ICV.
The grey-matter fraction (GMF), which is: GM Volume / ICV.
The white-matter fraction (WMF), which is: WM Volume / ICV.

Also shown for each pair of time-points:

The percentage change in grey-matter volume assessed using the Jacobian integration method.

To make a permanent record of these results, you can:

Write to a text file report. A File chooser will appear, for you to choose a log file name. The default file extension for log files is ".log". If the chosen file already exists, an entry will be appended to the log file.
Write to a PDF file report. A File chooser will appear, for you to choose a PDF file name. If the chosen file already exists, an entry will be appended to the PDF file. A PDF report will also include an illustration the GM/WM/CSF segmentation.

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