Three-dimensional visualization of pulmonary blood flow velocity profiles in lambs.
For a better understanding of the characteristics of blood flow in the pulmonary artery, we constructed three-dimensional images of velocity profiles of blood flow in the pulmonary artery from pulsed Doppler ultrasound recordings in 14 lambs aged 28-40 days. In 8 lambs, pulmonary hypertension was created by the central venous injection of monocrotaline pyrrole. Six lambs served as unaltered controls. The velocity data were sampled in 2 mm increments along both an anterior-posterior axis and a right-left orthogonal axis in the main pulmonary artery. Using a computer-generated cross-sectional velocity matrix consisting of 0.25 mm square grids, the velocity of blood flow was estimated at each intersection. The cross-sectional velocity matrices were generated at 5 msec intervals during the entire cardiac cycle. In all animals, significant velocity reversal was detected near the posterior wall. In 7 of 14 animals, the peak forward velocity was located near the posterior wall. Three of 8 hypertensive models showed reacceleration during the mid-systolic phase at the center of the velocity waveform, but one reacceleration disappeared at a point only 2 mm away from the center of the vessel toward the posterior wall. Acceleration time correlated well with the mean pulmonary arterial pressure (PAP) (r = -0.85) and the log10 PAP (r = -0.86). Corrected acceleration time (acceleration time divided by the square root of the cardiac cycle length) also correlated with PAP (r = -0.78) and the log10 PAP (r = -0.81).
Katayama
H
H
Department of Pediatrics, School of Medicine, University of North Carolina, Chapel Hill 27599-7220.
Henry
G W
GW
Lucas
C L
CL
Ha
B
B
Ferreiro
J I
JI
Frantz
E G
EG
Krzeski
R
R
D000818:Animals; D001783:Blood Flow Velocity; D001794:Blood Pressure; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging / Q000503:physiopathology; D007091:Image Processing, Computer-Assisted; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000502:physiology* / Q000503:physiopathology; D012756:Sheep; D014463:Ultrasonography