Decorrelation-based blood flow velocity estimation: effect of spread of flow velocity, linear flow velocity gradients, and parabolic flow

Abstract

In recent years, a new method to measure transverse blood flow, based on the decorrelation of the radio frequency (RF) signals has been developed. In this paper, we investigated the influence of nonuniform flow on the velocity estimation. The decorrelation characteristics of transverse blood flow using an intravascular ultrasound (IVUS) array catheter are studied by means of computer modeling. Blood was simulated as a collection of randomly located point scatterers; moving this scattering medium transversally across the acoustical beam represented flow. First-order statistics were evaluated, and the signal-to-noise ratio from the signals were measured. The correlation coefficient method was used to present the results. Three velocity profiles were simulated: random spread of blood-flow velocity, linear blood-flow velocity gradient, and parabolic bloodflow. Radio frequency and envelope signals were used to calculate the decorrelation pattern. The results were compared to the mean decorrelation pattern for plug blood-flow. The RF signals decorrelation patterns were in good agreement with those obtained for plug blood flow. Envelope decorrelation patterns show a close agreement with the one for plug blood flow. For axial blood flow, there is a discrepancy between decorrelation patterns. The results presented here suggest that the decorrelation properties of an IVUS array catheter for measuring quantitative transverse blood flow probably will not be affected by different transverse blood-flow conditions.

P2A-7 A Robust Deformable Simplex Mesh Model with Temporal Signal Decorrelation Constraints in Echocardiography

“…Due to the motion of the red blood cells the signal will decorrelate over time, in contrary to the heart muscle that is relatively stable for data collected at high pulse repetition frequencies. This phenomenon was already developed [1] and validated [2] for intravascular applications. In these studies, the flow through the artery was estimated using the decorrelation of the ultrasound signal.…”

“…The simplex mesh deforms under the Newtonian law of motion, discretized as P t+1 = P t + α(F tangent + F normal ) + γF temp (2) where P t is the current mesh point and P t+1 the subsequent mesh point…”

Dependence of ultrasound decorrelation on urine scatter particle concentration for a non-invasive diagnosis of bladder outlet obstruction

“…The correlation coefficients in each correlation image were transformed to a normal distribution using the Fisher Z-transformation defined as. 16 Z ¼ lnð1 þ rÞ À lnð1 À rÞ 2 ðA2Þ…”

Blood Flow Estimation Error with Intravascular Ultrasound Due to In-Plane Component of Flow

“…De fin ing B(r, w) as the Fou rier trans form of the N-point an gle-de pend ent sam pled sequence of the beam pat tern with re spect to n at ini tial depth r, the tilted slow-time spec trum of a scat terer mov ing at a con stant ve loc ity v at an an gle Y is the con vo lu tion of the spec trum of Eq. (19) with that in Eq. (14), which can be ex tended for a dis tri bu tion of scat ter ers.…”

“…[1][2][3] When in serted into an ar tery or vein, [3][4][5] blood gen er ally flows per pen dic u lar to the im age plane, which makes Dopp ler tech niques im prac ti cal. Frame-to-frame cor re la tion 4,[6][7][8][9][10][11] and decorrelation [12][13][14][15][16][17][18][19][20][21] tech niques have been pro posed and used to ob tain quan ti ta tive blood flow mea sure ments. 13 The main draw back of cor re la tion tech niques is the com pu ta tional cost and lack of real-time func tion al ity un less very ex pen sive, ded i cated hard ware is used.…”