Quantitative analysis of myocaridal perfusion in rabbits by tansthoracic real-time myocardial contrast echocardiography

Abstract

To evaluate the feasibility of real-time myocardial contrast echocardiography (RTMCE) by quantitative analysis of myocardial perfusion in rabbits, transthoracic RTMCE was performed in 10 healthy rabbits by using continuous infusion of SonoVue into the auricular vein. The short axis view at the papillary muscle level was obtained. The duration of the time that the contrast took to appear in right heart, left heart and myocardium was recorded. The regional myocardial signal intensity (SI) versus refilling time plots were fitted to an exponential function: y(t) =A(1-e^{−β(t−t0)}) + C, where y is SI at any given time, A is the SI plateau that reflects myocardial blood volume, and β is the slope of the refilling curve that reflects myocardial microbubble velocity. The A, β and A×β values at different infusion rate of SonoVue were analyzed and the A, β and A×β values in each segment in the short axis view at the papillary muscle level were compared. All the animal experiments were successful and high-quality images were obtained. The best intravenous infusion rate for SonoVue was 30 mL/h. The contrast appeared in right heart, left heart and myocardium at 7.5±2.2 s, 9.1±2.4 s and 12.2±1.6 s respectively. After 16.6±2.3s, myocardial opacification reached a steady state. The mean A, β and A×β value in the short axis view at the papillary muscle level were 9.8±3.0 dB, 1.4±0.5 s⁻¹ and 13.5±3.6 dB×s⁻¹ respectively. A, β and A×β values showed no significant differences among 6 segments. It was suggested that RTMCE was feasible for quantitative analysis of myocardial perfusion in rabbits. It provides a non-invasive method to evaluate the myocardial perfusion in rabbit disease models.

Keywords

myocardial contrast echocardiography / real-time / myocardial perfusion / rabbit

References

[1] ElhendyA., PorterT.R.. Assessment of myocardial perfusion with real-time myocardial contrast echocardiography: methodology and clinical applications. J Nucl Cardiol, 2005, 12(5): 582-590

[2] KaufmannB.A., WeiK., LindnerJ.R.. Contrast echocardiography. Curr Probl Cardiol, 2007, 32(2): 51-96

[3] YaoG.H., ZhangY., ShiS.Z., et al.. Quantitative assessment of myocardial perfusion using real-time myocardial contrast echocardiography. Chin J Ultrasonogr, 2004, 13(2): 124-126

[4] ToledoE., LangR.M., CollinsK.A., et al.. Imaging and quantification of myocardial perfusion using real-time three-dimensional echocardiography. J Am Coll Cardiol, 2006, 47(1): 146-154

[5] RussellJ.C., ProctorS.D.. Small animal models of cardiovascular disease: tools for the study of the roles of metabolic syndrome, dyslipidemia, and atherosclerosis. Cardiovasc Pathol, 2006, 15(6): 318-330

[6] GeistA., MarxJ., MüllerS., et al.. Combination of enoxaparin and fibroblast growth factor-1 increases myocardial blood flow and capillary density after myocardial infarction in rabbits. Eur Surg Res, 2005, 37(4): 191-198

[7] TakabaK., JiangC., NemotoS., et al.. A combination of omental flap and growth factor therapy induces arteriogenesis and increases myocardial perfusion in chronic myocardial ischemia: evolving concept of biologic coronary artery bypass grafting. J Thorac Cardiovasc Surg, 2006, 132(4): 891-899

[8] MarianA.J.. Beta-adrenergic receptors signaling and heart failure in mice, rabbits and humans. J Mol Cell Cardiol, 2006, 41(1): 11-13

[9] WeinsteinH., ReinhardtC.P., LeppoJ.A.. Direct detection of regional myocardial ischemia with technetium-99m nitroimidazole in rabbits. J Nucl Med, 1998, 39(4): 598-607

[10] ReederS.B., HolmesA.A., McverghE.R., et al.. Simultaneous noninvasive determination of regional myocardial perfusion and oxygen content in rabbits: toward direct measurement of myocardial oxygen consumption at MR imaging. Radiology, 1999, 212(3): 739-747

[11] FrenchB.A., LiY., KlibanovA.L., et al.. 3D perfusion mapping in post-infarct mice using myocardial contrast echocardiography. Ultrasound Med Biol, 2006, 32(6): 805-815

[12] AkiyamaM., AkasakaT., FujimotoK., et al.. Heterogeneity of myocardial perfusion in distal coronary embolism with different particle sizes. J Am Soc Echocardiogr, 2006, 19(1): 55-63

[13] ThibaultH., LafitteS., TimperleyJ., et al.. Quantitative analysis of myocardial perfusion in rats by contrast echocardiography. J Am Soc Echocardiogr, 2005, 18(12): 1321-1328

[14] MalmS., FrigstadS., HellandF., et al.. Quantification of resting myocardial blood flow velocity in normal humans using real-time contrast echocardiography. A feasibility study. Cardiovasc Ultrasound, 2005, 16(6): 3-16

[15] DijkmansP.A., KnaapenP., SieswerdaG.T.J., et al.. Quantification of myocardial perfusion using intravenous myocardial contrast echocardiography in healthy volunteers: comparison with positron emission tomography. J Am Soc Echocardiogr, 2006, 19(3): 285-293

[16] CorreasJ.M., BurnsP.N., LaiX., et al.. Infusion versus bolus of an ultrasound contrast agent: in vivo dose-response measurements of BR1. Invest Radiol, 2000, 35(1): 72-79

[17] HanZ.H., QianY.Q., SuH.L.. Experimental study on canine normal myocardial perfusion with intravenous real-time myocardial contrast enhancement imaging. Chin J Ultrasound (Chinese), 2001, 17(3): 89-92

[18] ThibaultH., TimperleyJ., EhlgenA., et al.. Can contrast dobutamine stress echocardiography be performed with standardized imaging settings for everybody?. J Am Soc Echocardiogr, 2005, 18(11): 1194-1202