Biomedical Engineering Graduate Group, University of California, Sacramento, CA 95817, USA.
Med Phys. 2012 Mar;39(3):1435-41. doi: 10.1118/1.3685462.
The purpose of this investigation was to assess the anatomical noise in breast images using a mathematically derived parameter β as a surrogate for detection performance, across the same patient cohort but in different imaging modalities including mammography, tomosynthesis, and breast CT.
Women who were scheduled for breast biopsy were approached for participation in this IRB and HIPPA-compliant investigation. A total of 23 women had all views of each modality and represent the cohort studied in this investigation. Image data sets across all modalities were analyzed using 1000 regions of interest per image data set, and the anatomical noise power spectrum, NPS(a)(f), was computed and averaged for each breast image data set. After windowing the total noise power spectrum NPS(t)(f) to a specific frequency range corresponding to anatomical noise, the power-law slope (β) of the NPS(a)(f) was computed where NPS(a)(f) = α f(-) (β).
The value of β was determined for breast CT data sets, and they were 1.75 (0.424), 1.83 (0.352), and 1.79 (0.397), for the coronal, sagittal, and axial views, respectively. For tomosynthesis, β was 3.06 (0.361) and 3.10 (0.315) for the craniocaudal (CC) and medial lateral oblique (MLO) views, respectively. For mammography, these values were 3.17 (0.226) and 3.30 (0.236), for the CC and MLO views, respectively. The values of β for breast CT were significantly different than those for tomosynthesis and mammography (p < 0.001, all 12 comparisons).
Based on the parameter β which is thought to describe anatomical noise in breast images, breast CT was shown to have a statistically significant lower β than mammography or tomosynthesis. It has been suggested in the literature that a lower β may correspond to increased cancer detection performance; however, this has yet to be demonstrated unequivocally.
本研究旨在评估使用数学衍生参数β作为检测性能替代指标的乳房图像解剖噪声，该参数是在相同的患者队列中，但在不同的成像模式下（包括乳房 X 线摄影、断层合成和乳房 CT）获得的。
本项符合 IRB 和 HIPPA 规定的研究邀请了计划接受乳房活检的女性参与。共有 23 名女性接受了每种模式的所有视图，代表了本研究中研究的队列。使用每个图像数据集 1000 个感兴趣区域分析所有模式的图像数据集，并计算并平均每个乳房图像数据集的解剖噪声功率谱 NPS(a)(f)。在将总噪声功率谱 NPS(t)(f) 窗口化到对应于解剖噪声的特定频率范围后，计算 NPS(a)(f) 的幂律斜率（β），其中 NPS(a)(f) = α f(-) (β)。
确定了乳房 CT 数据集的 β 值，冠状位、矢状位和轴位分别为 1.75（0.424）、1.83（0.352）和 1.79（0.397）。对于断层合成，颅尾（CC）和内外斜（MLO）视图的 β 值分别为 3.06（0.361）和 3.10（0.315）。对于乳房 X 线摄影，这些值分别为 CC 和 MLO 视图的 3.17（0.226）和 3.30（0.236）。乳房 CT 的 β 值与断层合成和乳房 X 线摄影有显著差异（p < 0.001，所有 12 次比较）。
基于被认为描述乳房图像解剖噪声的参数β，与乳房 X 线摄影或断层合成相比，乳房 CT 显示出具有统计学意义的更低的 β 值。文献中曾提出，较低的 β 值可能对应于更高的癌症检测性能；然而，这尚未得到明确证实。
