minccalc: command not found

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/bin/minccalc - from package: minc-tools

You may install the required package with command apt-get install {package}

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