An in vivo validation study of ultrasonic strain imaging: a comparison of strain derived by ultrasonic strain rate imaging, gray-scale M-mode and MRI

Strain rate imaging (SRI) is a new method to quantify regional myocardial deformation. It has been validated against other technique. However, these studies have been limited to validating peak strain values. As the temporal evolution of the strain curve is believed to contain important information on the functional consequences of regional pathology, we compared the complete strain curve as measured by SRI with the curves obtained by ultrasound gray-scale M-mode and magnetic resonance imaging (MRI). In 10 healthy volunteers and 20 patients with chronic ischaemic heart disease, radial deformation of the infero-lateral segment of the left ventricle was measured by ultrasound SRI, ultrasound M-mode and MRI. The correspondence of the temporal characteristics of these strain curves were compared by defining an intra-class correlation coefficient. In normal volunteers, an overall good agreement was found between the different methods. In patients with abnormal segmented deformation and low peak strain values, the agreement was less. However it remained within clinical acceptable limits. SRI, measuring myocardial deformation, thus provides an appropriate tool for the non-invasive assessment of regional myocardial deformation throughout the complete cardiac cycle.