3-D speckle tracking for assessment of regional left ventricular function

Speckle tracking in 2-D ultrasound images has become an established tool for assessment of left ventricular function. The recent development of ultrasound systems with capability to acquire real-time full volume data of the left ventricle makes it possible to perform speckle tracking in three dimensions, and thereby track the real motion of the myocardium. This paper presents a method for assessing local strain and rotation from 3-D speckle tracking in apical full-volume datasets. The method has been tested on simulated ultrasound data based on a computer model of the left ventricle, and on patients with myocardial infarction. When applied on simulated ultrasound data, the method showed good agreement with strain and rotation traces calculated from the reference motion, and the method was able to capture segmental differences in the deformation pattern, although the magnitudes of strains were systematically lower than the reference strains. When applied on patients, the method demonstrated reduced strain in the infarcted areas. Bulls-eye plots of regional strains showed good correspondence with wall motion scoring based on 2-D apical images, although the dyskinetic and hypokinetic regions were not apparent in all strain components.