dcmdrle: 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/dcmdrle - from package: dcmtk

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

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