The term “breast density” or mammographic density (MD) denotes those components of
breast parenchyma visualised at mammography that are denser than adipose tissue. MD is
composed of a mixture of epithelial and stromal components, notably collagen, in variable
proportions. MD is most commonly assessed in clinical practice with the time-honoured
method of visual estimation of area-based percent density (PMD) on a mammogram, with
categorisation into quartiles. The computerised semi-automated thresholding method …