טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentVitek Nili
SubjectQuantifying the Spatial and Temporal Distribution of
Myocardial Strain by Ultrasound
DepartmentDepartment of Biomedical Engineering
Supervisors Professor Emeritus Dan Adam
Professor Rafael Beyar


Abstract

The non invasive quantification of regional myocardial function is an important goal in clinical cardiology, since it can provide significant information such as velocity, strain and strain rate.

The ventricular wall may be segmented into three layers, which roughly correspond to the endocardium, mesocardium and epicardium. Previous MRI and ultrasound studies have reported a nonuniform distribution of intra-myocardial velocities in the presence of ischemia. It was shown that the sub-endocardium undergoes greater thickening and shortening than the epicardium, and that functional changes occur in the epi- and endocardium layers during ischemia.

The purpose of this study was to improve the current quantification of myocardial regional function, by improving its locality across the cardiac wall.

This study is based on the regional velocity information retrieved from the B mode cine loops using raw data produced by a speckle tracking algorithm (GE EchoPAC). By applying smoothing operations to the velocities - spatial and temporal filtration using a Wavelet shrinkage method, more reliable and local data can be obtained.

The study was validated using a computer simulated model of the heart motion, and also by comparing the processed clinical data with angiographic results and with evaluations performed by an expert echocardiograph.

The results show good and beneficial ability to diagnose local minor infarcts, with high accuracy confirmed by the significant correlation with the evaluation of experts, as well as with the angiographic findings.