Tu and Yuen Center for Functional Onco-imaging, University of California, Irvine, California 92697, USA.
Med Phys. 2010 Jan;37(1):217-26. doi: 10.1118/1.3271346.
Mammographic density and breast parenchymal patterns (the relative distribution of fatty and fibroglandular tissue) have been shown to be associated with the risk of developing breast cancer. Percent breast density as determined by mammography is a well-established risk factor, but on the other hand, studies on parenchymal pattern have been scarce, possibly due to the lack of reliable quantitative parameters that can be used to analyze parenchymal tissue distribution. In this study the morphology of fibroglandular tissue distribution was analyzed using three-dimensional breast MRI, which is not subject to the tissue overlapping problem.
Four parameters, circularity, convexity, irregularity, and compactness, which are sensitive to the shape and margin of segmented fibroglandular tissue, were analyzed for 230 patients. Cases were assigned to one of two distinct parenchymal breast patterns: Intermingled pattern with intermixed fatty and fibroglandular tissue (Type I, N = 141), and central pattern with confined fibroglandular tissue inside surrounded by fatty tissue outside (Type C, N = 89). For each analyzed parameter, the differentiation between these two patterns was analyzed using a two-tailed t-test based on transformed parameters to normal distribution, as well as distribution histograms and ROC analysis.
These two groups of patients were well matched both in age (50 +/- 11 vs 50 +/- 11) and in fibroglandular tissue volume (Type I: 104 +/- 62 cm3 vs Type C: 112 +/- 73 cm3). Between Type I and Type C breasts, all four morphological parameters showed significant differences that could be used to differentiate between the two breast types. In the ROC analysis, among all four parameters, the "compactness" could achieve the highest area under the curve of 0.84, and when all four parameters were combined, the AUC could be further increased to 0.94.
The results suggest that these morphological parameters analyzed from 3D MRI can be used to distinguish between intermingled and central dense tissue distribution patterns, and hence may be used to characterize breast parenchymal pattern quantitatively. The availability of these quantitative morphological parameters may facilitate the investigation of the relationship between parenchymal pattern and breast cancer risk.
乳腺密度和乳腺实质模式（脂肪和纤维腺体组织的相对分布）已被证明与乳腺癌发病风险相关。通过乳房 X 光摄影确定的乳腺密度百分比是一个成熟的风险因素，但另一方面，关于实质模式的研究却很少，这可能是因为缺乏可用于分析实质组织分布的可靠定量参数。在这项研究中，使用不受组织重叠问题影响的三维乳房 MRI 分析纤维腺体组织分布的形态。
对 230 名患者的四种参数（圆形度、凸度、不规则度和紧凑度）进行了分析，这些参数对分割的纤维腺体组织的形状和边缘敏感。将病例分为两种不同的实质乳腺模式之一：混杂模式（脂肪和纤维腺体组织混合，N=141）和中央模式（纤维腺体组织局限于中央，周围为脂肪组织，N=89）。对于每个分析的参数，基于转换为正态分布的参数、分布直方图和 ROC 分析，使用双侧 t 检验分析这两种模式之间的差异。
这两组患者在年龄（50±11 岁 vs 50±11 岁）和纤维腺体组织体积（混杂模式：104±62cm3 vs 中央模式：112±73cm3）方面匹配良好。在混杂模式和中央模式的乳腺之间，所有四个形态学参数都存在显著差异，可以用来区分两种乳腺类型。在 ROC 分析中，在所有四个参数中，“紧凑度”可以获得最高的曲线下面积 0.84，当四个参数结合使用时，AUC 可以进一步提高到 0.94。
这些结果表明，从 3D MRI 分析的这些形态学参数可用于区分混杂型和中央密集型组织分布模式，因此可用于定量描述乳腺实质模式。这些定量形态学参数的可用性可能有助于研究实质模式与乳腺癌风险之间的关系。
