dcmscale: command not found

Have You tried accessing the binary with the full path?

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/dcmscale - from package: dcmtk

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