Tourassi Georgia D, Delong David M, Floyd Carey E
Digital Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
Phys Med Biol. 2006 Mar 7;51(5):1299-312. doi: 10.1088/0031-9155/51/5/018. Epub 2006 Feb 15.
Architectural distortion (AD) is a sign of malignancy often missed during mammographic interpretation. The purpose of this study was to explore the application of fractal analysis to the investigation of AD in screening mammograms. The study was performed using mammograms from the Digital Database for Screening Mammography (DDSM). The fractal dimension (FD) of mammographic regions of interest (ROIs) was calculated using the circular average power spectrum technique. Initially, the variability of the FD estimates depending on ROI location, mammographic view and breast side was studied on normal mammograms. Then, the estimated FD was evaluated using receiver operating characteristics (ROC) analysis to determine if it can discriminate ROIs depicting AD from those depicting normal breast parenchyma. The effect of several factors such as ROI size, image subsampling and breast density was studied in detail. Overall, the average FD of the normal ROIs was statistically significantly higher than that of the ROIs with AD. This result was consistent across all factors studied. For the studied set of implementation parameters, the best ROC performance achieved was 0.89 +/- 0.02. The generalizability of these conclusions across different digitizers was also demonstrated.
结构扭曲（AD）是一种在乳腺钼靶检查解读过程中常被遗漏的恶性征象。本研究的目的是探讨分形分析在筛查乳腺钼靶片中AD研究中的应用。该研究使用了来自数字乳腺筛查数据库（DDSM）的乳腺钼靶片。利用圆形平均功率谱技术计算乳腺钼靶感兴趣区域（ROI）的分形维数（FD）。首先，在正常乳腺钼靶片上研究了FD估计值随ROI位置、乳腺钼靶投照位和乳房侧别的变异性。然后，使用受试者工作特征（ROC）分析评估估计的FD，以确定其是否能够区分显示AD的ROI和显示正常乳腺实质的ROI。详细研究了ROI大小、图像二次采样和乳腺密度等几个因素的影响。总体而言，正常ROI的平均FD在统计学上显著高于有AD的ROI。这一结果在所有研究因素中都是一致的。对于所研究的一组实施参数，所达到的最佳ROC性能为0.89±0.02。这些结论在不同数字化仪之间的可推广性也得到了证实。
