Assessment Of Normal Mechanics Parameters In Left Ventricle Using Cardiovascular Magnetic Resonance Based Tissue Tracking

Objective:To investigate the normal values and gender-and age-related differences of mechanical parameters in left ventricle using cardiac magnetic resonance based tissue tracking(CMR-TT),globally and regionally.Methods:100 healthy volunteers(50 males/females)who underwent 1.5 T CMR in University Hospital of Ulm from October 2015 to August 2016 were selected continuously.All volunteers were divided into younger group(?50 yrs)and older group(>50 yrs).Images were acquired with steady-state free precession sequence(SSFP),and the endo-and epicardial borders were delineated semiautomatically.Peak values of strain,strain rate,displacement,velocity,torsion and torsion rate(indexed to left ventricular length)of global and regional(basal,middle,apical)myocardium were assessed by CMR-TT technique in radial,circumferential and longitudinal directions.Gender-and age-related differences of these parameters were tested by t-test or non-parametric test.Results:(1)Females showed higher magnitude of global and regional strain and strain rate than males.(2)Females showed higher magnitude of global and mid-ventricular longitudinal velocity and mid-ventricular longitudinal displacement than males.(3)Older group showed higher magnitude of global and regional strain,but lower circumferential and longitudinal diastolic strain rate than younger group.(4)Older group showed higher magnitude of global and regional radial displacement,but lower longitudinal diastolic velocity than younger group.(5)No gender-and age-related differences existed in torsion and torsion rate.Conclusion:CMR-TT enables the quantitive measurement of myocardial mechanical parameters instantaneously.And some global and regional mechanical parameters of left ventricle showed significant gender-and age-related differences.