title: Understanding symptomatology of atherosclerotic plaque by image-based tissue characterization.
abstract: Characterization of carotid atherosclerosis and classification into either symptomatic or asymptomatic is crucial in terms of diagnosis and treatment planning for a range of cardiovascular diseases. This paper presents a computer-aided diagnosis (CAD) system (Atheromatic) that analyzes ultrasound images and classifies them into symptomatic and asymptomatic. The classification result is based on a combination of discrete wavelet transform, higher order spectra (HOS) and textural features. In this study, we compare support vector machine (SVM) classifiers with different kernels. The classifier with a radial basis function (RBF) kernel achieved an average accuracy of 91.7% as well as a sensitivity of 97%, and specificity of 80%. Thus, it is evident that the selected features and the classifier combination can efficiently categorize plaques into symptomatic and asymptomatic classes. Moreover, a novel symptomatic asymptomatic carotid index (SACI), which is an integrated index that is based on the significant features, has been proposed in this work. Each analyzed ultrasound image yields on SACI number. A high SACI value indicates that the image shows symptomatic and low value indicates asymptomatic plaques. We hope this SACI can support vascular surgeons during routine screening for asymptomatic plaques.
authors.affiliation: Department of Electrical and Computer Engineering, Ann Polytechnic, Singapore 599489, Singapore.
authors.forename: U Rajendra
authors.initials: UR
authors.lastname: Acharya
authors.forename: Oliver
authors.initials: O
authors.lastname: Faust
authors.forename: Vinitha Sree
authors.initials: VS
authors.lastname: S
authors.forename: A P C
authors.initials: AP
authors.lastname: Alvin
authors.forename: Ganapathy
authors.initials: G
authors.lastname: Krishnamurthi
authors.forename: José C R
authors.initials: JC
authors.lastname: Seabra
authors.forename: João
authors.initials: J
authors.lastname: Sanches
authors.forename: Jasjit S
authors.initials: JS
authors.lastname: Suri
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016893:Carotid Stenosis / Q000145:classification / Q000175:diagnosis / Q000000981:diagnostic imaging; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000145:classification / Q000175:diagnosis / Q000000981:diagnostic imaging*; D060388:Support Vector Machine; D014463:Ultrasonography; D058067:Wavelet Analysis