The version is 1.2.4, fvar4img, add Gaussian noise to PET images. fvar4img is a program for adding Gaussian noise to dynamic PET images in ECAT 6.3 or 7.x format. Here is an example for this utility: fvar4img simulated.v 0.5 noisy.v. So, if you were looking for a program to help you work with ECAT files, take fvar4imgfor a spin...