Hi Isobel,The middle number is the number of non-zero voxels in your image - from the fslstats help:-V : output <voxels> <volume> (for nonzero voxels)-m : output mean-M : output mean (for nonzero voxels)Cheers,PaulOn 25 August 2017 at 06:02, Isobel French <[log in to unmask]> wrote:Dear Experts,May I know what the middle value means when I key in the following command on fslstats?[neuros-iMac-3:17661/P26.bedpostX/P26PPNR] neuro% fslstats test.nii.gz -M -V 0.109732 62 10.343285Thank you.Best regards,Isobel FrenchResearcherNeurosurgery Research Unit, Division of NeurosurgeryDepartment of Surgery, Faculty of MedicineUniversity MalayaSuite 15 T8-4aLevel 4, Menara TimurUniversity of Malaya Medical Center016-793760503-79493138