Majanga Vincent, Mnkandla Ernest, Wang Zenghui, Moulla Donatien Koulla
Department of Computer Science, University of South Africa, Preller Street, Muckleneuk Ridge, Pretoria 1709, South Africa.
Bioengineering (Basel). 2025 Jun 12;12(6):642. doi: 10.3390/bioengineering12060642.
Automatic segmentation of nuclei on breast cancer histology images is a basic and important step for diagnosis in a computer-aided diagnostic approach and helps pathologists discover cancer early. Nuclei segmentation remains a challenging problem due to cancer biology and the variability of tissue characteristics; thus, their detection in an image is a very tedious and time-consuming task. In this context, overlapping nuclei objects present difficulties in separating them by conventional segmentation methods; thus, active contours can be employed in image segmentation. A major limitation of the active contours method is its inability to resolve image boundaries/edges of intersecting objects and segment multiple overlapping objects as a single object. Therefore, we present a hybrid active contour (connected component + active contours) method to segment cancerous lesions in unsupervised human breast histology images. Initially, this approach prepares and pre-processes data through various augmentation methods to increase the dataset size. Then, a stain normalization technique is applied to these augmented images to isolate nuclei features from tissue structures. Secondly, morphology operation techniques, namely erosion, dilation, opening, and distance transform, are used to highlight foreground and background pixels while removing overlapping regions from the highlighted nuclei objects on the image. Consequently, the connected components method groups these highlighted pixel components with similar intensity values and assigns them to their relevant labeled component to form a binary mask. Once all binary-masked groups have been determined, a deep-learning recurrent neural network (RNN) model from the Keras architecture uses this information to automatically segment nuclei objects having cancerous lesions on the image via the active contours method. This approach, therefore, uses the capabilities of connected components analysis to solve the limitations of the active contour method. This segmentation method is evaluated on an unsupervised, augmented human breast cancer histology dataset of 15,179 images. This proposed method produced a significant evaluation result of 98.71% accuracy score.
在计算机辅助诊断方法中,对乳腺癌组织学图像上的细胞核进行自动分割是诊断的基础且重要的步骤,有助于病理学家早期发现癌症。由于癌症生物学特性和组织特征的变异性,细胞核分割仍然是一个具有挑战性的问题;因此,在图像中检测细胞核是一项非常繁琐且耗时的任务。在这种情况下,重叠的细胞核对象难以通过传统分割方法进行分离;因此,可以在图像分割中采用活动轮廓模型。活动轮廓模型方法的一个主要局限性在于它无法解析相交对象的图像边界/边缘,也不能将多个重叠对象分割为单个对象。因此,我们提出一种混合活动轮廓(连通分量+活动轮廓)方法,用于在无监督的人类乳腺组织学图像中分割癌性病变。最初,该方法通过各种增强方法准备和预处理数据,以增加数据集的大小。然后,将染色归一化技术应用于这些增强后的图像,以从组织结构中分离出细胞核特征。其次,形态学操作技术,即腐蚀、膨胀、开运算和距离变换,用于突出前景和背景像素,同时从图像上突出显示的细胞核对象中去除重叠区域。因此,连通分量方法将这些具有相似强度值的突出显示的像素分量分组,并将它们分配到其相关的标记分量,以形成一个二值掩码。一旦确定了所有二值掩码组,来自Keras架构的深度学习循环神经网络(RNN)模型就会利用这些信息,通过活动轮廓方法自动分割图像上具有癌性病变的细胞核对象。因此,这种方法利用连通分量分析的能力来解决活动轮廓方法的局限性。该分割方法在一个包含15179张图像的无监督、增强的人类乳腺癌组织学数据集上进行了评估。该方法产生了显著的评估结果,准确率得分达到98.71%。