Local Orientation Imaging for Tissue Structure Using Ultrasound Imaging

Abstract

Cardiovascular diseases and myocardium infarction are main causes of death worldwide. After acute myocardium infarction, remodeling occurs within weeks resulting from a loss of cardiomyocytes in the damaged myocardium, and subsequent changes with regional tissue organization. Imaging methods able to render the local tissue directivity would be useful to detect the lesion and evaluate its extent. In this field, diffusion MRI is the reference. However, because of its long acquisition time, it is not simple to make an image of the moving heart in vivo. For this reason, faster methods using ultrasound were developed. The purpose of this work is to study the spatial coherence method with an ultrasound plane wave ultrafast imaging approach. Simulations have been performed with CREANUIS software on a medium constituted by many angled fibers in order to mimic the orientation changes that appear in the myocardium. Experimental data were also acquired on a wires phantom. The wires of the phantom were set in parallel planes with changing orientation between [−45° and 45°] at a depth between [20 and 40 mm]. Results obtained with the method have permitted to evaluate properly the orientation with RMSE of 11.2° and 16.5° for simulation and experiments, respectively.