Ultrasonography is an invaluable and widely used medical imaging tool.
Nevertheless, automatic texture analysis on ultrasound images remains a challenging
issue. This work presents and investigates a texture representation scheme on thyroid
ultrasound images for the detection of hypoechoic and isoechoic thyroid nodules,
which present the highest malignancy risk. The proposed scheme is based on the
Contourlet Transform (CT) and incorporates a thresholding approach for the selection
of the most significant CT coefficients. Then a variety of statistical texture features
are evaluated and the optimal subsets are extracted through a selection process. A
Gaussian kernel Support Vector Machine (SVM) classifier is applied along the
Sequential Floating Forward Selection (SFFS) algorithm, in order to investigate the
most representative set of CT features. For this experimental evaluation, two image
datasets have been utilized: one consisting of hypoechoic nodules and normal thyroid
t...
Stamos Katsigiannis, Eystratios G. Keramidas, Dimi