Often measured with framewise displacement by measuring measure rotation and translation from one volume to the next. FD and raw rot and trans values are an output of frmiprep. Useful for all EPI, including dwi, task and Resting State Functional MRI.
In images with a single image (MRSI, anatomical), there is nothing to compare the volume to. Motion still affects quality. In anatomical images this is visible as “ringing”