Measurement of 3D left ventricular strains during diastole using image warping and untagged MRI images

Image-based finite-element analysis of the left ventricle (LV) was used to determine the deformation and strain developed between mid-diastole and end-diastole. The algorithm used volumetric MRI data to create a body force that deforms a finite-element model of the LV in mid-diastole and tracks tissue deformation. A volumetric MRI data set corresponding to mid-diastole was designated as the reference image and an image corresponding to end-diastole was designated as the deformed image. The reference image was manually segmented and a 3D finite-element mesh was created. The warping version of the nonlinear finite-element program NIKE3D (from Lawrence Livermore National Laboratory) was used to analyze the images. Warping results of the left ventricular circumferential stretch measurements at the base and mid-ventricle were compared with direct measurements of the image data set. The warping results showed less than 3% difference between the methods.