Transrectal contrast-enhanced ultrasound (CEUS) is an important examination for rectal tumors. The inhomogeneity of the CEUS images has important clinical significance. However, there is no objective method to evaluate this index. In this study, a method based on gray-level co-occurrence matrix (GLCM) is proposed to extract texture features of images and grade these images according the inhomogeneity. Specific processes include compressing the gray level of the image, calculating the texture statistics of gray level co-occurrence matrix, combining feature selection and principal component analysis (PCA) for dimensionality reduction, and training and validating quadratic discriminant analysis (QDA). After ten cross-validation, the overall accuracy rate of machine classification was 87.01%, and the accuracy of each level was as follows: Grade Ⅰ 52.94%, Grade Ⅱ 96.48% and Grade Ⅲ 92.35% respectively. The proposed method has high accuracy in judging grade Ⅱ and Ⅲ images, which can help to identify the grade of inhomogeneity of contrast-enhanced ultrasound images of rectal tumors, and may be used to assist clinical doctors in judging the grade of inhomogeneity of contrast-enhanced ultrasound of rectal tumors.
Objective To explore the diagnostic value of contrast-enhanced ultrasonography (CEUS) in axillary and internal mammary lymph node metastasis of invasive breast cancer. Methods A total of 100 patients with invasive breast cancer treated from September 2020 to September 2022 were selected. Preoperative CEUS examination was completed, and the perfusion sequence, enhancement mode and enhancement sequence of lymph nodes were dynamically observed. The CEUS characteristics of metastatic and benign lymph nodes were compared. Using postoperative pathological results as the gold standard, the diagnostic efficacy of CEUS in evaluating lymph node status was analyzed. Results Among the 100 patients, 28 patients were diagnosed with metastatic axillary lymph nodes (ALN) by pathological biopsy. The sensitivity, specificity, accuracy, positive prediction rate and negative prediction rate of CEUS in evaluating ALN status were 71.4%, 87.5%, 83.0%, 69.0% and 88.7%, respectively. In 9 patients, CEUS showed internal mammary lymph node metastasis, and postoperative pathological examination confirmed that 5 patients had internal mammary lymph node metastasis, so the positive predictive rate of CEUS was 55.6%. Conclusion CEUS can evaluate the metastatic status of axillary and internal mammary lymph nodes.