Quantification of myocardial perfusion by contrast echocardiography

Two-dimensional echocardiography allows identification of myocardial perfusion defects due to coronary artery occlusion by detection of regional wall motion abnormalities and absence of myocardial echocontrast enhancement after injection of echocontrast agents into the aortic root. In the current study twelve anesthetized closed chest dogs were examined before and after balloon occlusion of a coronary vessel. Size of perfusion defects was determined morphologically by Evans blue staining, while the circumferential extent of regional wall motion abnormality was calculated using radial wall motion analysis of the two-dimensional echocardiogram. Four mL of SH U 454 were injected into the aortic root for echocontrast studies. Perfusion defects in the echocardiogram were determined planimetrically in the analog two-dimensional echocardiographic image. In addition, perfusion defects in the contrast echocardiogram were estimated by a digital image processing technique along a circumferential mid-wall line. Along this line the time-intensity curves of the myocardial echocontrast were also calculated. There was a linear correlation between morphological determination of perfusion defects and their planimetric estimate in the contrast echocardiogram. The linear regression equation was y = 0.98x + 4.63, r = 0.92, and the standard error of estimate for the echocardiographic examination was SEE = 4.4%. Digital image processing did not increase accuracy in determining the size of perfusion defects (r = 0.88; y = 1.01x + 3.33; SEE = 5.7%). By comparing the extent of regional wall motion abnormalities with the size of anatomic perfusion defects there was a correlation of r = 0.85; SEE = 6.2%; y = 0.71x + 10.50.(ABSTRACT TRUNCATED AT 250 WORDS)