Assessment of regional myocardial strain using cardiac elastography: distinguishing infarcted from non-infarcted myocardium

Abstract

Estimation of the regional mechanical properties of the cardiac muscle has been shown to play a crucial role in the detection of cardiovascular disease. Current echocardiography-based cardiac motion estimation techniques, such as Doppler Myocardial Imaging (DMI), are limited due to angle dependence. By contrast, elastography, a method designed and used for the detection of tumors, measures displacement and strain by comparing echoes before and after (not during) a deformation and thus is not angle-dependent. Therefore, the feasibility of cardiac elastography to provide reliable and reproducible displacement and strain estimates from multiple sonographic views was recently demonstrated utilizing RF data from a normal human heart in vivo. In this paper, we demonstrate this technique utilizing 2D B-scan data in a patient with a known myocardial infarction. Envelope-detected sonographic data was used to estimate regional wall motion and deformation. Displacement and strain estimates were obtained in both non-infarcted, normally contracting and infarcted regions. By obtaining cine-loop and M-Mode elastograms from both regions, the ischemic regions could be identified. In conclusion, elastography may be a clinically viable method for detection of abnormalities of regional wall motion throughout the cardiac cycle.