In vivo assessment of regional myocardial work in normal canine hearts using 3D tagged MRI.
A non-invasive method for assessing regional myocardial work is presented. The method utilizes tagged magnetic resonance images (MRI) obtained from two sets of orthogonal planes to mark and reconstruct 24 small myocardial cuboids at end-diastole (ED) and end-systole (ES) in the in vivo left ventricle (LV). Regional myocardial work is assessed by calculating the area enclosed by the endocardial wall tension-area (T-A) loop of each studied cuboid. The method was applied to six normal canine hearts. In addition, a global myocardial work index was obtained from the corresponding estimated pressure-volume (P-V) loops. The average work index calculated using the T-A loop was 0.242 +/- 0.088 J/100gr/beat, in agreement with the average index obtained from the P-V loop: 0.296 +/- 0.089 J/100gr/beat. The two indices correlate linearly with a correlation coefficient of 0.82.
Azhari
H
H
Department of Biomedical Engineering, Technion-IIT Haifa, Israel.
Weiss
J L
JL
Shapiro
E P
EP
D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs; D004734:Energy Metabolism; D006321:Heart / Q000033:anatomy & histology / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008433:Mathematics; D009200:Myocardial Contraction