Applied Computing Group, Federal University of Maranhão - UFMA, NCA, Av. dos Portugueses, SN, Bacanga, São Luís, MA 65085-580, Brazil.
Pontifical Catholic University of Rio de Janeiro - PUC - Rio, R. São Vicente, 225, Gávea, Rio de Janeiro, RJ, 22453-900, Brazil.
Comput Methods Programs Biomed. 2018 Mar;156:191-207. doi: 10.1016/j.cmpb.2018.01.007. Epub 2018 Jan 11.
The processing of medical image is an important tool to assist in minimizing the degree of uncertainty of the specialist, while providing specialists with an additional source of detect and diagnosis information. Breast cancer is the most common type of cancer that affects the female population around the world. It is also the most deadly type of cancer among women. It is the second most common type of cancer among all others. The most common examination to diagnose breast cancer early is mammography. In the last decades, computational techniques have been developed with the purpose of automatically detecting structures that maybe associated with tumors in mammography examination. This work presents a computational methodology to automatically detection of mass regions in mammography by using a convolutional neural network.
The materials used in this work is the DDSM database. The method proposed consists of two phases: training phase and test phase. The training phase has 2 main steps: (1) create a model to classify breast tissue into dense and non-dense (2) create a model to classify regions of breast into mass and non-mass. The test phase has 7 step: (1) preprocessing; (2) registration; (3) segmentation; (4) first reduction of false positives; (5) preprocessing of regions segmented; (6) density tissue classification (7) second reduction of false positives where regions will be classified into mass and non-mass.
The proposed method achieved 95.6% of accuracy in classify non-dense breasts tissue and 97,72% accuracy in classify dense breasts. To detect regions of mass in non-dense breast, the method achieved a sensitivity value of 91.5%, and specificity value of 90.7%, with 91% accuracy. To detect regions in dense breasts, our method achieved 90.4% of sensitivity and 96.4% of specificity, with accuracy of 94.8%.
According to the results achieved by CNN, we demonstrate the feasibility of using convolutional neural networks on medical image processing techniques for classification of breast tissue and mass detection.
医学图像处理是协助降低专家不确定性程度的重要工具,同时为专家提供额外的检测和诊断信息来源。乳腺癌是影响全球女性人群最常见的癌症类型。它也是女性中最致命的癌症类型。它是所有其他癌症类型中第二常见的类型。早期诊断乳腺癌最常见的检查是乳房 X 光摄影。在过去几十年中,已经开发了计算技术,目的是自动检测乳房 X 光摄影检查中可能与肿瘤相关的结构。这项工作提出了一种使用卷积神经网络自动检测乳房 X 光摄影中肿块区域的计算方法。
这项工作使用的材料是 DDSM 数据库。所提出的方法包括两个阶段:训练阶段和测试阶段。训练阶段有两个主要步骤:(1)创建一个模型,将乳房组织分类为致密和非致密;(2)创建一个模型,将乳房区域分类为肿块和非肿块。测试阶段有七个步骤:(1)预处理;(2)配准;(3)分割;(4)第一次减少假阳性;(5)对分割的区域进行预处理;(6)致密组织分类;(7)第二次减少假阳性,将区域分类为肿块和非肿块。
所提出的方法在分类非致密乳房组织方面达到了 95.6%的准确率,在分类致密乳房组织方面达到了 97.72%的准确率。在非致密乳房中检测肿块区域,该方法的灵敏度值为 91.5%,特异性值为 90.7%,准确率为 91%。在致密乳房中检测区域,我们的方法达到了 90.4%的灵敏度和 96.4%的特异性,准确率为 94.8%。
根据 CNN 获得的结果,我们证明了使用卷积神经网络进行医学图像处理技术在乳房组织分类和肿块检测方面的可行性。