Haasler G B, Rhyne T L, Komorowski R, Boerboom L E, Sagar K B
Department of Pathology, Medical College of Wisconsin, Milwaukee 53226.
Ultrason Imaging. 1993 Jan;15(1):25-35. doi: 10.1177/016173469301500103.
The effects of coronary blood flow, tissue water content and hematocrit variation on the Integrated Myocardial Backscatter Rayleigh 5 (IBR5) and Fourier coefficient of amplitude modulation (FAM, an index of cardiac cycle-dependent variation in IBR5) were measured in five open chest dogs. Data were obtained at baseline, during adenosine infusion and after two hours of crystalloid hemodilution (Hct 15%). IBR5 of -46.4 +/- .94 dB at baseline did not change significantly during adenosine infusion (-45 +/- .85 dB) and after hemodilution (-46.4 +/- 2.0 dB). FAM at baseline was (4.0 +/- 1.0 dB) (3.8 +/- -1.0 dB) during adenosine infusion and after hemodilution (5.0 +/- 1.8 dB). Myocardial water content increased significantly (p < .05) from 78 +/- .20% at baseline to 80.7 +/- .17% after hemodilution. Coronary blood flow demonstrated a three-fold increase with adenosine and two-fold increase with hemodilution. Electronmicroscopy demonstrated an increase in intracellular and extracellular water content. In conclusion, IBR5 and FAM did not change significantly despite significant increases in coronary blood flow and myocardial water content. Myocardial cellular derangements seen with nonischemic cell swelling, increased blood flow and a fall in hematocrit are insufficient to affect integrated backscatter.
在五只开胸犬身上测量了冠状动脉血流量、组织含水量和血细胞比容变化对心肌背向散射积分瑞利5（IBR5）和调幅傅里叶系数（FAM，IBR5中依赖心动周期变化的一个指标）的影响。在基线、腺苷输注期间以及晶体液血液稀释两小时后（血细胞比容15%）获取数据。基线时IBR5为-46.4±0.94dB，腺苷输注期间（-45±0.85dB）和血液稀释后（-46.4±2.0dB）无显著变化。基线时FAM为（4.0±1.0dB），腺苷输注期间为（3.8±-1.0dB），血液稀释后为（5.0±1.8dB）。心肌含水量从基线时的78±0.20%显著增加（p<0.05）至血液稀释后的80.7±0.17%。冠状动脉血流量在腺苷作用下增加了三倍，在血液稀释作用下增加了两倍。电子显微镜显示细胞内和细胞外含水量增加。总之，尽管冠状动脉血流量和心肌含水量显著增加，但IBR5和FAM无显著变化。非缺血性细胞肿胀、血流增加和血细胞比容下降所见的心肌细胞紊乱不足以影响背向散射积分。
