dcmconv: 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/dcmconv - from package: dcmtk

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

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