Figure 2.

Histogram of the mass visibility for 1070 average masses by view identified on the current mammograms and 462 subtle masses by view identified on the prior mammograms. The visibility is evaluated on a 10-point rating scale with 1 representing the most visible masses and 10 the most difficult case relative to the cases seen in their clinical practice. Each mass on a mammogram is rated independently by an experienced MQSA radiologist. There are 60 invisible masses on current mammograms and 124 invisible masses on prior mammograms.