ThinkCenter M58 machine with Lenovo MTQ45NK Socket 775 motherboard CAN work with ATI Radeon HD 5450 PCIe graphics card. All you have to do is upgrade the BIOS.
The ThinkCenter product ID in my case is 7360Y1Q, and the serial is LMBDZLX.
I have downloaded and successfully used BIOS available on this link:
My BIOS version now is 5CKT77AUS.