dconvlum: 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/dconvlum - from package: dcmtk

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

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