Correlation graph between PSD on GSPECT and Ts - SD 12 and Ts - Diff 12 on TSI G iá t rị t s s d 20 40 60 80 100 Giá trị spect-psd Giá trị tssd12 Đường hồi quy (tssd12= 13 + 0.62 * spect-psd, R-square=0.3) (r =0.57, p<0.01) G iá t rị t s d if f1 20 40 60 80 100 Giá trị spect-psd Giá trị tsd iff12 Đườn g hồi quy (tsd iff12= 46 .99 + 1.54 * spect-psd, R-square=0.36) (r =0.6391, p<0.01) 15 There is a positive linear correlation between the PSD and the standard deviation of time to reach the maximum speed of 12 regions in the systolic (Ts - SD 12) (r = 0.57; p <0.01) and Ts - Diff (Ts - Diff 12) with r = 0.64; p <0.01.