Which mammogram is better digital or old style Xray machine?

My mom just had a standard mammogram done and it showed a suspicious mass in her right breast.  The doctors office called her and advised her to have a digital mammogram done.
What is the difference between the mammograms and is one better then the other??
Earlier this year she had a biopsy done on her left breast and that came back fine just a cysts.
So is there more room for concern or are we jumping the gun?

[barbea]

i'M No doctor, but I believe the digital mammo is far superior to the standard one.  I don't quite understand the order for one mammo over the other if the other has already detected a suspicious mass, but that wasn't your question