read_acr_nema: 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/read_acr_nema - from package: minc-tools

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

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