Assessment of wall velocity gradient and thrombi detection using test-phantom

A new phantom has been designed to gain a better understanding of tissue Doppler imaging (TDI) applied to the myocardium velocity gradient measurements and thrombi detection. The phantom mimics left ventricle and is made of fine grade sponge material with thrombi-like structures attached to internal surface of the phantom. Theoretical analysis of the phantom wall movements helped to explain the velocity gradients developing across the heart walls. All in vitro thrombi were easily detected with DTI demonstrating the different color to that of the adjacent moving wall. The result of computer simulation of the phantom wall movement was found to be in good agreement with TDI recordings. It was also found that DTI is a promising, more sensitive method of imaging the left ventricle thrombi.