| Objective Myocardial contrast echocardiography (MCE) can reflect regional myocardial blood flow, the method for quantitative assessment of myocardial blood flow (MBF) with MCE include radio frequency method and video frequency one. The aim of this study was to perform a comparison between video frequency method and radio frequency one in quantitative analysis of MBF with contrast echocardiography. Methods In nine open-chest dogs(average weight 14.8±2.5Kg), the heart was exposed through a left lateral thoracotomy and suspended in a pericardial cradle. Two grades of left anterior descending coronary artery (LAD) stenoses were created. Stenoses reduced resting LAD flow by 60%, 100% of baseline with flow probe. QUANFUXIAN (aperflurocarbon contrast agent made by NanFang Hospital) was diluted to 20 folds by normal saline solution and pumped into femoral vein with constant velocity (2ml/min). MCE was performed during varying ECG gated pulsing intervals from 1:1 to 1:12. The parameters of time-intensity curve (TIC) were obtained with "DFY quantitative analysis system" and "Acoustic Densitometry technique", respectively. Peak intensity (A) , the slope of the curve βwhich reflects the rise rate of peak intensity were obtained and A·β reflects myocardial blood flow were derived from the TIC curves. Results Among the parameters derived from TIC, peak echo-intensity(PEI),peak integrated backscatter(PIBS) ,β and A·βwere decreased when coronary stenosis (p<0.05) or occlusion (p<0.05). Conclusions Both two methods (video frequency method and radio frequency method) are reliable and accurate in quantitative assessment of myocardial blood flow with contrast echocardiography.KEY WORDS: Myocardial Contrast Echocardiography,Video Frequency Method,Radio Frequency Method... |
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