Goh Yi Ling Eileen, Lee Zhen Yu, Lai Christopher
Health and Social Sciences, Singapore Institute of Technology, 10 Dover Drive, Singapore 138683, Singapore.
Life (Basel). 2021 Jun 3;11(6):516. doi: 10.3390/life11060516.
(1) Background: Mammographic breast density (MBD) and older age are classical breast cancer risk factors. Normally, MBDs are not evenly distributed in the breast, with different women having different spatial distribution and clustering patterns. The presence of MBDs makes tumors and other lesions challenging to be identified in mammograms. The objectives of this study were: (i) to quantify the amount of MBDs-in the whole (overall), different sub-regions, and different zones of the breast using an image segmentation method; (ii) to investigate the spatial distribution patterns of MBD in different sub-regions of the breast. (2) Methods: The image segmentation method was used to quantify the overall amount of MBDs in the whole breast (overall percentage density (PD)), in 48 sub-regions (regional PDs), and three different zones (zonal PDs) of the whole breast, and the results of the amount of MBDs in 48 sub-regional PDs were further analyzed to determine its spatial distribution pattern in the breast using Moran's I values (spatial autocorrelation). (3) Results: The overall PD showed a negative correlation with age ( = 0.008); the younger women tended to have denser breasts (higher overall PD in breasts). We also found a higher proportion ( < 0.001) of positive autocorrelation pattern in the less dense breast group than in the denser breast group, suggesting that MBDs in the less dense breasts tend to be clustered together. Moreover, we also observed that MBDs in the mature women (<65 years old) tended to be clustered in the middle zone, while in older women (>64 years old) they tended to be clustered in both the posterior and middle zones. (4) Conclusions: There is an inverse relationship between the amount of MBD (overall PD in the breast) and age, and a different clustering pattern of MBDs between the older and mature women.
(1) 背景：乳腺钼靶密度（MBD）和高龄是经典的乳腺癌风险因素。通常，MBD在乳腺中分布不均，不同女性具有不同的空间分布和聚集模式。MBD的存在使得在乳腺钼靶片中识别肿瘤和其他病变具有挑战性。本研究的目的是：（i）使用图像分割方法量化乳腺整体、不同子区域和不同区域的MBD量；（ii）研究乳腺不同子区域中MBD的空间分布模式。(2) 方法：使用图像分割方法量化整个乳腺的MBD总量（整体百分比密度（PD））、48个子区域（区域PD）和整个乳腺的三个不同区域（区域PD），并进一步分析48个子区域PD中MBD量的结果，使用莫兰指数I值（空间自相关）确定其在乳腺中的空间分布模式。(3) 结果：整体PD与年龄呈负相关（ = 0.008）；年轻女性的乳房往往更致密（乳房的整体PD更高）。我们还发现，密度较低的乳腺组中正向自相关模式的比例高于密度较高的乳腺组（ < 0.001），这表明密度较低的乳腺中的MBD倾向于聚集在一起。此外，我们还观察到，成熟女性（<65岁）的MBD倾向于聚集在中间区域，而老年女性（>64岁）的MBD则倾向于聚集在后部和中间区域。(4) 结论：MBD量（乳腺中的整体PD）与年龄之间存在反比关系，老年女性和成熟女性的MBD聚集模式不同。
