Table 1: Summary of representative studies using thresholding based methods for mammographic tissue segmentation. denotes correlation coefficient. Note that () largely identical studies are excluded in the list and () in case of multiple results, only the best reported results are listed.

Study YearNumber of density categoriesModalitiesNumber of viewsNumber of imagesSegmentation evaluationRisk/density estimation accuracy

Global thresholding
Matsubara et al. [25]2000Fatty, mammary gland diffuseness, nonuniform high density, and high densityDigitised SFMMLO148Visually assessed90% (ratios of the four densities)
Saha et al. [26]2001Fatty and denseDigitised SFMMLO and CC174Visually assessed (acceptable)N/A
Sivaramakrishna et al. [27]2001Fatty and denseDigitised SFMCC32Visually assessedSpearman’s = [0.92, 0.95] (automatic-manual)
Olsén and Mukhdoomi [28]2007Fatty and glandularDigitised SFMMLO and CC160 (MIAS + DDSM)Visually assessedN/A
Tzikopoulos et al. [29]2011Fatty and fibroglandularDigitised SFMMLO and CC322 (mini-MIAS)Visually assessed86% (fatty, fatty-glandular, and dense-glandular)
Lu et al. [30]2007Fatty and denseFFDM (raw)CC172Visually assessedintraclass = 0.94 (BI-RADS)
Ferrari et al. [31]2000Fatty and fibroglandularDigitised SFMMLO66 (mini-MIAS)Visually assessed (84% successful)N/A
Ferrari et al. [32]2004Uncompressed-fatty, fatty, nonuniform-dense, and high-denseDigitised SFMMLO84 (mini-MIAS)Visually assessed (81% excellent or good)N/A
El- Zaart [33]2010Fatty and fibroglandularDigitised SFMMLON/AVisually assessedN/A

Adaptive/dynamic thresholding
Zhou et al. [34]2001Fatty and denseDigitised SFMMLO and CC260Visually assessed (94% correct); (CC, MLO) = 0.94, 0.91 (automatic-manual)42% (BI-RADS)
Neyhart et al. [35]2002Radiolucent and radiodenseDigitised SFMMLO and CCN/AVisually assessedN/A
Kim et al. [36]2010Fatty and denseFFDMMLO and CC80Visually assessed; = 0.99 (automated-manual)N/A
Nickson et al. [37]2013Dense and fattyDigitised SFMCC5919 womenVisually assessed; 41% “perfect” agreement (Cumulus-AutoDensity)Pairwise = 0.63 (Cumulus-AutoDensity)