Abstract:
A comparative interpretation of mammograms has become increasingly important, and it is crucial to develop subtraction processing and registration methods for mammograms. However, nonrigid image registration has seldom been applied to subjects constructed with soft tissue only, such as mammograms. We examined whether subtraction processing for the comparative interpretation of mammograms can be performed using nonrigid image registration. As a preliminary study, we evaluated the results of subtraction processing by applying nonrigid image registration to normal mammograms, assuming a comparative interpretation between the left and right breasts. Mediolateral-oblique-view mammograms were taken from noncancer patients and divided into 1000 cases for training, 100 cases for validation, and 500 cases for testing. Nonrigid image registration was applied to align the horizontally flipped left-breast mammogram with the right one. We compared the sum of absolute differences (SAD) of the difference of bilateral images (Difference Image) with and without the application of nonrigid image registration. Statistically, the average SAD was significantly lower with the application of nonrigid image registration than without it (without: 0.0692; with: 0.0549 (p < 0.001)). In four subgroups using the breast area, breast density, compressed breast thickness, and Difference Image without nonrigid image registration, the average SAD of the Difference Image was also significantly lower with nonrigid image registration than without it (p < 0.001). Nonrigid image registration was found to be sufficiently useful in aligning bilateral mammograms, and it is expected to be an important tool in the development of a support system for the comparative interpretation of mammograms.
摘要:
乳房X光检查的比较解释变得越来越重要,发展乳房X线照片的减法处理和配准方法至关重要。然而,非刚性图像配准很少应用于仅用软组织构造的受试者,比如乳房X线照片.我们检查了是否可以使用非刚性图像配准来执行用于乳房X线照片比较解释的减法处理。作为一项初步研究,我们通过将非刚性图像配准应用于正常乳房X光检查来评估减法处理的结果,假设左乳和右乳之间的比较解释。中外侧斜视乳房X线照片取自非癌症患者,并分为1000例进行训练,100例用于验证,和500个案例进行测试。应用非刚性图像配准以将水平翻转的左乳房乳房X线照片与右乳房X线照片对齐。我们比较了在应用和不应用非刚性图像配准的情况下,双边图像(DifferenceImage)差异的绝对差异之和(SAD)。统计上,应用非刚性图像配准后的平均SAD显著低于未应用非刚性图像配准的平均SAD(无:0.0692;有:0.0549(p<0.001)).在使用乳房区域的四个亚组中,乳腺密度,压缩乳房厚度,和没有非刚性图像配准的差异图像,在非刚性图像配准的情况下,差异图像的平均SAD也显著低于无刚性图像配准的情况(p<0.001)。发现非刚性图像配准在对齐双侧乳房X线照片中足够有用,预计它将成为开发乳房X线照片比较解释支持系统的重要工具。