gdcmconv: 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/gdcmconv - from package: libgdcm-tools

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

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