dcmcjpls: 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/dcmcjpls - from package: dcmtk

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

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