Ultrasonic tissue characterization with integrated backscatter. Acute myocardial ischemia, reperfusion, and stunned myocardium in patients.

Abstract

We have previously shown in studies of experimental animals that myocardium exhibits a cardiac cycle-dependent variation of integrated backscatter that reflects regional myocardial contractile performance and that is blunted promptly after arterial occlusion and recovers after reperfusion. To define the clinical utility of ultrasonic tissue characterization with integrated backscatter for detection of acute myocardial infarction and reperfusion, 21 patients (14 men and seven women) were studied in the cardiac care unit within the first 24 hours (mean time, 11.3 hours; range, 3.5-23.8 hours) after the onset of symptoms indicative of acute myocardial infarction with conventional two-dimensional and M-mode echocardiography and with analysis of integrated backscatter. The magnitude of cyclic variation of integrated backscatter was measured from several sites within acute infarct regions and normal regions remote from the infarct zone for each patient. The average magnitude of cyclic variation among all patients (n=21) was 4.8±0.5 dB in normal regions compared with 0.8±0.3 dB in infarct regions (p<0.05) within the first 24 hours after the onset of symptoms. Among the patients who had two studies, 15 (mean, 7.1 days; range, 2-31 days for second study) underwent coronary arteriography to define vessel patency. In patients with vessels with documented patency (n = 10), the magnitude of cyclic variation in infarct regions increased over time from 1.3±0.6 to 2.5±0.5 dB from the initial to final study (p<0.05). Patients with occluded infarct-related arteries (n=5) exhibited no significant recovery of cyclic variation (0.3±0.3-0.6+0.3 dB

Relation of ultrasonic tissue characterization with integrated backscatter to contractile reserve in patients with chronic coronary artery disease

“…11 Studies in humans with reperfused myocardial infusion have shown that the persistence of defective CVIB within the infarcted area allowed accurate delineation of reversible from irreversible tissue injury. 5,7 The results of the present investigation extend the earlier observations to the situation of patients with chronic left ventricular ischemic dysfunction. We chose septum and posterior dysfunctional wall for investigation because the ultrasound beam can be perpendicular to the muscle fiber only in these parts of the left ventricle.…”

“…Previous studies have indicated that the magnitude of cardiac cycle-dependent variations of integrated backscatter (CVIB) is smaller in the infarct or myopathic myocardium than in normal myocardium. [5][6][7][8] We hypothesized that myocardial segments with contractile reserve would demonstrate preserved CVIB in patients with CAD. The aim of the present study was to establish a noninvasive method for assessing contractile reserve in the dysfunctional segments by using a technique of ultrasonic myocardial tissue characterization.…”

Ultrasonic tissue characterization of infarcted myocardium by scanning acoustic microscopy

“…Wall-motion abnormalities, during and after myocardial infarction, can be detected by M-mode echocardiography or by centerline analysis of the two-dimensional echocardiogram (Hikichi and Tanaka 198 la;Moinihan et al 1980;Parisi et al 1980). Ultrasonic tissue characterization of myocardium is also under development (Lattanzi et al 1991(Lattanzi et al , 1992Miller et al 1985;Milunski et al 1989;Mimbs et al 1977;Picano et al 1990Picano et al , 1993Scorton et al 1983). The need to evaluate local myocardial function has increased in proportion to the progress of interven- (Ellis et al 1995;Hannan et al 1994).…”

Myocardial integrated ultrasonic backscatter for early detection of cardiac involvement in patients with Wilson disease

“…Diagnosis of Wilson disease was made on the basis of clinical manifestations, family history of neuropsychiatric manifestations, jaundice, premature death attributable to Wilson disease, evidence of KayserFleischer rings on slit-lamp examination, low serum copper and ceruloplasmin levels, and increased 24-h urinary excretion of copper. Radiologic investigations included a cranial computed tomography scan with or without iodinated contrast and/or magnetic resonance imaging and radiography of long bones, pelvis, and chest to evaluate skeletal abnormalities (15). The diagnosis was confirmed by liver biopsy and quantitative liver copper assay.…”

“…Quantitative characterization of myocardial texture by IBS imaging has been experimentally (6-9) and clinically (10)(11)(12)(13) shown to be useful for detecting the pathologic changes affecting the myocardium, such as an aging heart (14), myocardial ischemia (15), hypertrophic and dilated cardiomyopathy (16,17), hypertensive heart disease (18), and acute cardiac rejection (19), resulting in alterations in its fundamental physical properties.…”