Assessment of Normal Values of Tissue Synchronization Imaging in Normal Healthy Infants and Children

Abstract

SUMMARY T issue Synchronization Imaging (TSI) is a parametric imaging tool based on Tissue Velocity Imaging that provides clinicians with additional image enhancement for assessing delayed cardiac wall motion (Lind et al., 2002). The TSI parametric image analyses the tissue velocity signals within the image to determine the peak velocities within a specified portion of the cardiac cycle since these peaks will occur in relation to overall motion, delayed wall motion will produce a delayed peak velocity (Gorcsan et al., 2004). The amount of delay within the defined area of the cardiac cycle is used to assign a map or color to that location in the image. With TSI, the color represents the amount of tissue motion delay rather than the absolute value of the tissue velocity. When this technique is applied in real time across the 2D image, the variation in color provides both a qualitative and quantitative representation of wall motion delay allowing a trained physician to readily identify and evaluate asynchronous wall motion (Dohi et al., 2005). Sadeghian et al. (2006) studied normal values for intraventricular and interventricular delay by TDI and TSI but only on 25 healthy adult. The aim of this work is to determine the normal values of tissue synchronization imaging in apparently healthy children. The present study conducted on 250 children apparently normal included 43.2% male and 56.8% female who were recruited from the pediatric clinic at Ain Shams Pediatric Hospital. All children included in the study were subjected to: 1- Full history taking laying stress on chest and cardiac symptoms to exclude any cardiac and chest diseases 2- Clinical examination laying stress on chest and cardiac system to exclude any cardiac and chest diseases 3- Investigation including conventional ECHO and TSI that were performed for each child. The age of children ranged from0.6-216months.with mean of 87.37 and SD of 55.87, their weight ranged from 3-79Kg with mean of 23.97 and SD of 13.75, their Ht ranged from51-155 cm. with mean of 112.87 and SD of 27.69. In apical four chamber view as regards the comparison between mean values of B.S time to peak of (B.S, M.S, M.L and B.L), the highest mean value was M.S time to peak (137.68ms) and lowest mean value was M.L time to peak (94.88 ms). And in comparison between mean values of peak velocity of (B.S, M.S, M.L and B.L), the highest mean value was B.L peak velocity (6.5cm/s), and lowest mean value was M.S peak velocity (3.64 cm/s). In apical two chamber as regards the comparison between mean values of peak velocity of (B.I, M.I, M.A and B.A). The highest mean value was B.I peak velocity (6.35cm/s) and lowest mean value was M.I peak velocity (4.18cm/s). In apical two chamber as regards the comparison between mean values of time to peak of (M.I., M.A and B.A). The highest value was M.I time to peak (140.17 ms) and the lowest was M.A time to peak (91.04ms). In apical long axis view as regards the comparison between mean values of peak velocity of (B.P , M.P, M.A.S and B.A.S ), the highest value was B.P peak velocity (5.4cm/s) and lowest M.A.S peak velocity (2.48cm/s) In apical long axis view as regards the comparison between mean values of time to peak of (B.P, M.P, M.A.S and B.A.S). The highest mean value was M.A.S time to peak (137.2ms) and lowest value was M.P time to peak (114.81ms). When we divided our children into two groups, the first group <6 years old and the second group ≥6 years old. The first group included112 child (44.8%) and the second group included138 child (55.2%), we found that mean values of peak velocity OF (B.S,M.L,B.L,M.I,M.A,B.A,M.P,M.A.S)and mean values of time to peak of (B.S, B.L, B.P, M.P, and B.A.S) increase by age.