Session PB7.7

A Validation Study of Left Ventricular Contraction and Relaxation Model

WC Hu*, JJ Wang, LY Shyu, CC Lin, HM Tsao

Chung Yaun Christian University
Chung Li, Taiwan

Multiple Slice Computer Tomography (MSCT) Cardiac Images have become the major methodology for evaluating myocardial and ventricular function. Observations are made before, during, and after exercise and stress. Such procedure creates myocardial perfusion dysfunction and corresponding wall motion abnormalities in regional ventricular wall supplied by critically stenosis coronary arteries. Yet, the function of ventricle and property of myocardium are still to be identified. To reconstruct 4D view of beating heart model using MSCT cardiac images is complicated. However, the 4D view of beating heart may be useful in diagnosis. The study was using 10 phases of MSCT cardiac images to model the dynamic 3D left ventricle that is reconstructing a 4D view of ventricle. Furthermore, functional parameters extracted from volume-time relationship will be extracted from the model for evaluation of ventricular function and the motion of ventricle. The motion and the deformation of ventricular shape were modeled using the spiral function that was governed by two equations. The periodic function of shortening and lengthening of the ventricular long axis was modeled using information extracted from reconstructed MSCT cardiac images. The motion of thickening of myocardium in contraction and thinning the ventricular wall in relaxation was modeled using spiral function to motion of ventricle wall in contraction and relaxation to emulate the motion of wall thickening and thinning. To validate the functional model of ventricle, the time-volume curve was compared in twenty 4D data set. The validation of the left ventricular contraction model was checked against the volume time curve of the patient’s data. The result showed that the different of the ejection volume was average of 5.2±0.5 c.c. along the contraction of the heart beat. The different of the filling volume was average of 7.96±2.89 c.c. along the relaxation of the heart beat. These results showed that modeling the motion of left ventricular contraction is more accurate than modeling the motion of relaxation.

(Abstract Control Number: 210)