Examples of 50% to 74% mammographic density, moderately dense breast tissue
Indeed, these ARE moderately dense mammogram images with moderately dense breast tissue. I gathered these examples in around the year 2002, so they are admittedly small and poor quality.
Why am I showing these examples? Because its not hard to learn to judge mammographic density. Radiologists don’t get too scientific about it, they just "eyeball it", and you can too. What all these examples have in common, is that the "white" areas of fibroglandular tissue occupy over half ( greater than 50%) of the area inside the breast, whereas the adipose tissue (or fatty tissue) is less than half. These are all normal mammograms, and this pattern of moderately dense fibroglandular tissue is quite common in younger women. As breast tissue becomes this dense, or denser, it becomes harder for mammography to detect breast cancers.