ViSTa QC

Written by Dr. Hunter Moss

It is vital to inspect the output image called vista.nii for artifacts or other anomalies. To do this, examples of good and bad outputs are provided below. Empirically, it is found that windowing the ViSTa apparent myelin water fraction (aMWF) output between 0 and either 0.15 or 0.2

typically provides good contrast to check for artifacts. Additionally, the aMWF from ViSTa is really only valid in white matter, where typical values range between 0.1 and 0.2

Below is an ideal example of a raw ViSTa image, the corresponding reference image, and the aMWF map from a 33-year-old volunteer typically provides good contrast to check for artifacts. Additionally, the aMWF from ViSTa is really only valid in white matter, where typical values range between 0.1 and 0.2

Below is an ideal example of a raw ViSTa image, the corresponding reference image, and the aMWF map from a 33-year-old volunteer:

Due to motion or other factors, various image distortions and artifacts can arise in the processed aMWF map. Some examples are provided below (note, these are middle to older age subjects):