1. A method for determining if an item of media is invalid, the method comprising: providing an ultrasound image of an item of media after the item of media is urged through a magnetic head assembly; determining a plurality of regions of the image that satisfy a predetermined condition indicating that a value associated with the item of media has previously been exhausted regardless of an orientation of the item represented in the ultrasound image; and determining that an item of media is invalid when a location of said regions satisfies a pre-determined condition of multiple discontinuous pinholes punctured in the item of media by identifying the image in the pin holes as bright spots and item locations of the bright spots that are predetermined item locations.