乳房斷層掃描之電腦輔助腫瘤診斷

Abstract

對於全球女性來說，乳癌已經成為最普遍的癌症之一，同時也是癌症致死的主要原因，早期偵測可以提供更好的治療並大幅降低死亡率。早期乳癌篩檢以乳房X光攝影為主要檢查工具，近年發展新型態的乳房斷層攝影是一項三維斷層技術，有助於解決二維乳房X光影像產生的組織重疊問題。因此我們提出一個電腦輔助診斷系統，應用在乳房X光影像以及乳房斷層攝影，並比較它們的效能。電腦輔助診斷系統由二元邏輯回歸分類器建立，從乳房X光影像的ROI或乳房斷層攝影的VOI提取紋理特徵，包含灰階共生矩陣、ranklet轉換、以及Gabor小波轉換。並評估不同特徵組合的效能。電腦輔助診斷系統經由42個良性和82個惡性的腫瘤的資料庫進行驗證。由Gabor小波轉換應用在乳房斷層攝影達成最佳的效能。準確率85.48% (106/124)，靈敏性86.59% (71/82)，特異性83.33% (35/42)，以及ROC曲線面積0.8712。總結來說，乳房斷層攝影搭配Gabor小波轉換特徵相較於乳房X光影像的分類效果更好。

Among female throughout the world, breast cancer has become one of the most common carcinomas and the leading cause of cancer-related death. Early detection can provide a better treatment and significantly reduce mortality. Currently, the most effective tool to diagnose breast cancer is mammography screening. Tomosynthesis as a three dimensional (3-D) tomographic technique can overcome the overlapping problem from superimposed tissues of two dimensional (2-D) mammography. Therefore, we proposed a computer-aided diagnosis (CADx) system implemented in tomosynthesis and also in mammography to compare their performance. The CADx system was built by binary logistic regression classifier. Texture features, including gray-level co-occurrence matrix (GLCM), ranklet, and Gabor, were extracted from user-specified regions of interest (ROIs) in mammograms or volumes of interest (VOIs) in tomosynthesis images. The performance of different combinations of features were evaluated. The CADx system was tested with a dataset of 42 benign and 82 malignant tumors. The best performance was achieved by applying Gabor feature in tomosynthesis with an accuracy of 85.48% (106/124), a sensitivity of 86.59% (71/82), a specificity of 83.33% (35/42), and an Az value of 0.8712. To summarize, tomosynthesis is more effective in classification of breast tumor with Gabor feature than mammography.