Tools for imagefile pxi

I am looking for a tool which allows me to compare two imagefiles of the form
filename.pxi (plextor imagefiles), as I want to check if they are identical.
I know I can compare via MS-DOS-Mode (FC/?), but I want a more sophisticated tool which ignores empty spaces before and after the tracks and shows the difference (if existing) graphically.
The tools I know cannot compare pxi-files and cannot compare two imagefiles (only imagefile and the CD). As I use an USB2-burner these tools dont recognize the writer (no drive found)
Thanx for help