Regional variations of ultrasonic integrated backscatter in normal and myopathicleft ventricles. A new multi-view approach

Abstract

The purpose of the present study was to determine whether the cyclic variation of integrated backscatter is measurable and quantifiable in all left ventricular walls and whether the information obtained using both parasternal and apical transducer positions can be used to identify changes in myocardial structure and contractility. The cyclic variation of integrated backscatter was measured from the parasternal long-axis, apical four-chamber and two-chamber views in 26 patients with idiopathic dilated cardiomyopathy (mean age 58 +/- 9 years; ejection fraction 29 +/- 10%) and compared with information obtained from 30 aged-matched healthy volunteers. For each subject, the cyclic variation of integrated backscatter was calculated from 16 predetermined regions-of-interest located within the myocardium of the basal and mid-segments of the left ventricle imaged from the long-axis view and also the basal mid and apical left ventricular segments imaged from the two apical views. The cyclic variation of integrated backscatter was found to be present in 100% of the analysed regions-of-interest in healthy volunteers and in 87.5% of the analysed regions-of-interest in patients with idiopathic dilated cardiomyopathy. The mean value of cyclic variation of integrated backscatter, averaged from all regions-of-interest in the idiopathic dilated cardiomyopathy group, was significantly reduced compared to that in the healthy volunteers group (3.2 +/- 2.5 dB [mean +/- SD] vs 4.8 +/- 2.9 dB, P < 0.0001). Additionally, the healthy volunteers group demonstrated marked regional variability in the magnitude of cyclic variation of integrated backscatter which closely followed the regional changes in the contractile function of the normal heart. These regional differences in the magnitude of the cyclic variation of integrated backscatter were only partially retained in the idiopathic dilated cardiomyopathy group, and suggest that a multi-view approach of the recording of cyclic variation of integrated backscatter can be of value to differentiate normal from myopathic myocardium and to quantify regional differences in myocardial contractile performance throughout the left ventricular walls.

Detection of TIMI-3 Flow Before Mechanical Reperfusion With Ultrasonic Tissue Characterization in Patients With Anterior Wall Acute Myocardial Infarction

“…CV of IBS is dependent on the angle between fiber orientation and ultrasonic beam, called anisotropy. 17 We measured CV only in anterior and posterior (control) wall in the short-axis view, in which myocardial fiber is oriented nearly perpendicular to the ultrasound beam, to avoid problems with anisotropy as possible. It is unclear whether the results in the present study could be applied to inferior or lateral wall infarction because of anisotropy.…”

“…Measurement of CV on apical views might be also useful for detecting coronary reperfusion to reduce anisotropy. 17 The quality of echocardiographic images also could affect analysis of IBS, and approximately 10% of the study patients were excluded because of inadequate echocardiographic images. This method might also not be inapplicable for the patients having prior myocardial infarction, bundle branch block, paced rhythm, or cardiomyopathy.…”

Serum markers of angiogenesis and myocardial ultrasonic tissue characterization in patients with dilated cardiomyopathy

“…Recently, the analysis of IB and strain rate imaging have been used to detect myocardial structural and functional abnormalities in various cardiac conditions, and it has been shown that IB analysis has a higher ability to assess myocardial fibrosis in comparison with strain rate imaging [13]. Previous studies have demonstrated that the analysis of IB has the potential to assess myocardial interstitial fibrosis and intrinsic myocardial contractility in DCM [9,10]. These clinical observations have revealed an increased calibrated IB and a reduced CV-IB in patients with DCM, and it has been reported that both parameters correlate with a histologic estimate of myocardial fibrosis in the biopsy specimen of DCM patients [14].…”

“…Previous studies have investigated ultrasonic tissue characterization in patients with DCM, and have shown that the analysis of IB has the potential to assess the myocardial interstitial fibrosis and intrinsic myocardial contractility in DCM [9,10]. We have thus hypothesized that a close relationship should exist between the activity of angiogenic factors and alterations in myocardial texture in DCM.…”

Early Detection of Doxorubicin-Induced Myocardial Damage by Ultrasound Tissue Characterization With Integrated Backscatter

“…The cyclic variation of integrated backscatter (CV-IBS) decreases with myocardial cell injury, a property that assists in detecting subclinical myocardial damage. [15][16][17][18][19][20] In the current study, we measured the acoustic properties of the myocardium in patients with normal left ventricular contractile function who were receiving DXR to determine the feasibility of using CV-IBS for detecting an early phase of DXR-induced myocardial damage.…”