title: Measurement of myocardial perfusion and infarction size using computer-aided diagnosis system for myocardial contrast echocardiography.
abstract: Proper evaluation of myocardial microvascular perfusion and assessment of infarct size is critical for clinicians. We have developed a novel computer-aided diagnosis (CAD) approach for myocardial contrast echocardiography (MCE) to measure myocardial perfusion and infarct size. Rabbits underwent 15 min of coronary occlusion followed by reperfusion (group I, n = 15) or 60 min of coronary occlusion followed by reperfusion (group II, n = 15). Myocardial contrast echocardiography was performed before and 7 d after ischemia/reperfusion, and images were analyzed with the CAD system on the basis of eliminating particle swarm optimization clustering analysis. The myocardium was quickly and accurately detected using contrast-enhanced images, myocardial perfusion was quantitatively calibrated and a color-coded map calibrated by contrast intensity and automatically produced by the CAD system was used to outline the infarction region. Calibrated contrast intensity was significantly lower in infarct regions than in non-infarct regions, allowing differentiation of abnormal and normal myocardial perfusion. Receiver operating characteristic curve analysis documented that -54-pixel contrast intensity was an optimal cutoff point for the identification of infarcted myocardium with a sensitivity of 95.45% and specificity of 87.50%. Infarct sizes obtained using myocardial perfusion defect analysis of original contrast images and the contrast intensity-based color-coded map in computerized images were compared with infarct sizes measured using triphenyltetrazolium chloride staining. Use of the proposed CAD approach provided observers with more information. The infarct sizes obtained with myocardial perfusion defect analysis, the contrast intensity-based color-coded map and triphenyltetrazolium chloride staining were 23.72 ± 8.41%, 21.77 ± 7.8% and 18.21 ± 4.40% (% left ventricle) respectively (p > 0.05), indicating that computerized myocardial contrast echocardiography can accurately measure infarct size. On the basis of the results, we believe the CAD method can quickly and automatically measure myocardial perfusion and infarct size and will, it is hoped, be very helpful in clinical therapeutics.
authors.affiliation: Ultrasound Department, Second Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Guo-Qing
authors.initials: GQ
authors.lastname: Du
authors.affiliation: Department of Cardiology, First Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Jing-Yi
authors.initials: JY
authors.lastname: Xue
authors.affiliation: School of Science, St. Thomas University, Miami Gardens, Florida, USA.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Ultrasound Department, Second Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Chen
authors.affiliation: Ultrasound Department, Second Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Du
authors.affiliation: Ultrasound Department, Second Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Ultrasound Department, Second Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Yu-Hang
authors.initials: YH
authors.lastname: Wang
authors.affiliation: Ultrasound Department, Second Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Li-Qiu
authors.initials: LQ
authors.lastname: Zong
authors.affiliation: Ultrasound Department, Second Affiliated Hospital of Harbin Medical University, Harbin, China. Electronic address: jiaweitian@126.com.
authors.forename: Jia-Wei
authors.initials: JW
authors.lastname: Tian
mesh_terms: D000465:Algorithms; D000818:Animals; D001783:Blood Flow Velocity; D003326:Coronary Circulation; D004452:Echocardiography / Q000379:methods*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Computer-aided diagnosis; Infarct size; Myocardial contrast echocardiography; Myocardial infarction; Myocardial perfusion