Yes it's possible, there is no official global ROM, but you can use this time xiaomi.eu, only you have to do is to flash TWRP recovery and install the ROM, but just make sure you have the original Bootloader type and the Bootloader unlocked, you can know more about Bootloadrr and its types here http://en.miui.com/forum.php?mod=viewthread&tid=840402&extra=page=1&mobile=2
EDIT: Sorry this only works with unlocked Bootloader
And it's not possible without unlocjun Bootloader