On the spectral properties of Doppler thread phantoms.
It is shown that some of the threads used in Doppler phantoms have a repetitive structure which leads to peaks in the angular distribution of the backscattered power at beam axis-to-flow angles of theta = 90 degrees and approximately theta = 70 degrees. This nonuniform scattering does not significantly interfere with modelling the Doppler spectrum peak as a function of velocity and beam-to-thread angle, but makes it impossible to model the spectral width as a function of these parameters. A new plaited structure is described which has a periodicity too small to lead to subsidiary reflection peaks, and which has a more uniform backscattering profile than the other threads studied.
Cathignol
D
D
Inserm, Unité 281, Lyon, France.
Dickerson
K
K
Newhouse
V L
VL
Faure
P
P
Chapelon
J Y
JY
D001783:Blood Flow Velocity; D004301:Doppler Effect; D008961:Models, Structural; D014465:Ultrasonics