II. Quality Check

There are 3 methods can be used to quickly check whether the data is affected by artifacts like motion, instability, etc.

1. Variance map

An easy way to check the stability and time-varying fluctuations is to look at the temporal standard deviation. In the PreProcessing menu, you can display 1) temporal standard deviation (SD map), 2) temporal standard deviation divided by temporal mean (SD/mean map), and 3) the temporal peak-to-peak divided by mean (p-p/mean).

2. Center-of-Mass Detection

An easy way to check gross head/brain movement is look at the center of mass of the head/brain. This tool can be found also in PreProcessing menu. To exclude the non-brain region, a suitable background threshold has to be entered. Usually, gross movement larger than 0.1 pixel will be difficult to compensate and the data may need to be discarded.

3. CINE

Another way to detect head movement is to visually see the motion by playing the time-series images as a movie. This function can be found in View.