mk_adni_phantom: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/lib/cmtk/bin/mk_adni_phantom - from package: cmtk

You may install the required package with command apt-get install {package}
Error in other languages:
mk_adni_phantom: bevel nie gevind nie
mk_adni_phantom: comandă negăsită
mk_adni_phantom: comando não encontrado
mk_adni_phantom: commande introuvable
mk_adni_phantom: command not found
mk_adni_phantom: käsku ei ole
mk_adni_phantom: không tìm thấy lệnh
mk_adni_phantom: komanda nerasta
mk_adni_phantom: Kommando nicht gefunden.
mk_adni_phantom: kommandot finns inte
mk_adni_phantom: komut yok
mk_adni_phantom: nie znaleziono polecenia
mk_adni_phantom: níor aimsíodh an t-ordú
mk_adni_phantom: no se encontró la orden
mk_adni_phantom: no s'ha trobat l'ordre
mk_adni_phantom: opdracht niet gevonden
mk_adni_phantom: parancs nem található
mk_adni_phantom: perintah tidak ditemukan
mk_adni_phantom: príkaz nenájdený
mk_adni_phantom: příkaz nenalezen
mk_adni_phantom: команда не найдена
mk_adni_phantom: командата не е открита
mk_adni_phantom: 命令找不到
mk_adni_phantom: コマンドが見つかりません