1. Evaluation of carotid plaque echogenicity based on the integral of the cumulative probability distribution using gray-scale ultrasound images
- Author
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Rongqing Zheng, Kelvin K. L. Wong, Ming Qian, Hairong Zheng, Long Meng, Yanling Zhang, Xiaowei Huang, Derek Abbott, and Lili Niu
- Subjects
Carotid Artery Diseases ,Male ,Distribution Curves ,lcsh:Medicine ,Blood Pressure ,030204 cardiovascular system & hematology ,Spearman's rank correlation coefficient ,Vascular Medicine ,Biochemistry ,Diagnostic Radiology ,0302 clinical medicine ,Endocrinology ,Ultrasound Imaging ,Medicine and Health Sciences ,Medicine ,Coronary Heart Disease ,030212 general & internal medicine ,lcsh:Science ,Ultrasonography ,Multidisciplinary ,Radiology and Imaging ,Area under the curve ,Middle Aged ,Lipids ,Plaque, Atherosclerotic ,Cholesterol ,Physical Sciences ,Hypertension ,Probability distribution ,Female ,Radiology ,Research Article ,Statistical Distributions ,medicine.medical_specialty ,Imaging Techniques ,Endocrine Disorders ,Cardiology ,Research and Analysis Methods ,03 medical and health sciences ,Diagnostic Medicine ,Image Interpretation, Computer-Assisted ,Diabetes Mellitus ,Humans ,Aged ,Probability ,Receiver operating characteristic ,business.industry ,Cumulative distribution function ,lcsh:R ,Echogenicity ,Biology and Life Sciences ,Probability Theory ,Probability Distribution ,Gray scale ultrasound ,Coronary heart disease ,Probability Density ,Metabolic Disorders ,lcsh:Q ,business ,Mathematics - Abstract
Objective Carotid plaque echogenicity is associated with the risk of cardiovascular events. Gray-scale median (GSM) of the ultrasound image of carotid plaques has been widely used as an objective method for evaluation of plaque echogenicity in patients with atherosclerosis. We proposed a computer-aided method to evaluate plaque echogenicity and compared its efficiency with GSM. Methods One hundred and twenty-five carotid plaques (43 echo-rich, 35 intermediate, 47 echolucent) were collected from 72 patients in this study. The cumulative probability distribution curves were obtained based on statistics of the pixels in the gray-level images of plaques. The area under the cumulative probability distribution curve (AUCPDC) was calculated as its integral value to evaluate plaque echogenicity. Results The classification accuracy for three types of plaques is 78.4% (kappa value, κ = 0.673), when the AUCPDC is used for classifier training, whereas GSM is 64.8% (κ = 0.460). The receiver operating characteristic curves were produced to test the effectiveness of AUCPDC and GSM for the identification of echolucent plaques. The area under the curve (AUC) was 0.817 when AUCPDC was used for training the classifier, which is higher than that achieved using GSM (AUC = 0.746). Compared with GSM, the AUCPDC showed a borderline association with coronary heart disease (Spearman r = 0.234, p = 0.050). Conclusions Our experimental results suggest that AUCPDC analysis is a promising method for evaluation of plaque echogenicity and predicting cardiovascular events in patients with plaques.
- Published
- 2017