title: Shape symmetry analysis of breast tumors on ultrasound images.
abstract: Shape characteristics of malignant and benign breast tumors are significantly different. In this paper, the reflective symmetry of breast tumor shapes on ultrasound images was investigated. A new reflective symmetry measure (RSML) derived from multiscale local area integral invariant was proposed to quantify the shape symmetry of breast tumor, which could be computed directly from the binary mask image without the shape parameterization in terms of arc length. The performance of several symmetry measures for differentiating malignant and benign breast tumors at varying scales was evaluated and compared by receiver operating characteristic (ROC) analysis. RSML with Gaussian kernel at scale 0.04 (related to the maximal diameter) achieved the highest area under the ROC curve (0.85) on the image data of 168 tumors (104 benign and 64 malignant). The experimental results showed that the reflective symmetry of breast tumor shape was capable of providing potential diagnostic information, which could be characterized quantitatively by RSML with the appropriate scale parameter.
authors.affiliation: Department of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. weiyang@sjtu.edu.cn
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Su
authors.initials: S
authors.lastname: Zhang
authors.forename: Yazhu
authors.initials: Y
authors.lastname: Chen
authors.forename: Wenying
authors.initials: W
authors.lastname: Li
authors.forename: Yaqing
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D016011:Normal Distribution; D025341:Principal Component Analysis; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*; D016217:Ultrasonography, Mammary / Q000295:instrumentation / Q000379:methods*