title: Assessment of regional myocardial blood flow with myocardial contrast echocardiography: an experimental study.
abstract: OBJECTIVE
  The aim of this study was to verify the accuracy of using myocardial contrast echocardiography (MCE), to quantify regional myocardial blood flow (MBF), and to evaluate myocardial viability in comparison to that measured by radiolabeled microsphere and pathologic examination.
  
  
  METHODS
  Epicardial MCE was obtained in five myocardial ischemic dogs with constant microbubble intravenous infusion. After the video intensity (VI, y) versus pulsing interval plots derived from each myocardial pixel were fitted to an exponential function: y = A(1 - e(-beta t)), the MBF was calculated as the product of A (microvascular cross-sectional area or myocardial blood volume) and beta (mean myocardial microbubble velocity). The MBF was also obtained by radiolabeled microsphere method.
  
  
  RESULTS
  The MBF derived by radiolabeled microsphere method in the normal, ischemic, and infarcted region was 1.5 +/- 0.3, 0.7 +/- 0.3, and 0.3 +/- 0.2 ml/min per gram, respectively; P < 0.01. The product of A and beta in those regions was 52.5 +/- 15.1, 24.4 +/- 3.9, and 3.7 +/- 3.8, respectively; P < 0.01. The normalized product of A and beta correlated well with normalized MBF (r = 0.81, P = 0.001).
  
  
  CONCLUSIONS
  Our initial study demonstrated that MCE has an ability to assess MBF in ischemic myocardium in the experimental model. It may provide a potential capability to detect viable myocardium noninvasively after total persistent coronary occlusion in the clinical setting.
authors.affiliation: Department of Cardiology, Nanfang Hospital, The First Military Medical University, Guangzhou, People's Republic of China.
authors.forename: Wen Zhu
authors.initials: WZ
authors.lastname: Zhang
authors.forename: Dao Gang
authors.initials: DG
authors.lastname: Zha
authors.forename: Guan Xun
authors.initials: GX
authors.lastname: Cheng
authors.forename: Shao Qin
authors.initials: SQ
authors.lastname: Yang
authors.forename: Xiao Bo
authors.initials: XB
authors.lastname: Huang
authors.forename: Jian Xin
authors.initials: JX
authors.lastname: Qin
authors.forename: Yi Li
authors.initials: YL
authors.lastname: Liu
mesh_terms: D000818:Animals; D003326:Coronary Circulation / Q000502:physiology; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology; D004285:Dogs; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008854:Microscopy, Electron; D008863:Microspheres; D023421:Models, Animal; D008955:Models, Cardiovascular; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000473:pathology* / Q000648:ultrastructure*; D012039:Regional Blood Flow / Q000502:physiology; D013223:Statistics as Topic