title: Correlation of RF signals during angular compounding.
abstract: A theoretical analysis of the correlation between radio-frequency (RF) echo signal data acquired from the same location but at different angles is presented. The accuracy of the theoretical results is verified with computer simulations. Refinements to previous analyses of the correlation of RF signals originating from the same spatial location at different angular positions are made. We extend the analysis to study correlation of RF signals coming from different spatial locations and eventually correlation of RF signal segments that intersect at the same spatial location. The theory predicts a faster decorrelation with a change in the insonification angle for longer RF echo signal segments. As the RF signal segment becomes shorter, the decorrelation rate with angle is slower and approaches the limit corresponding to the correlation of RF signals originating from the same spatial location. Theoretical results provide a clear understanding of angular compounding techniques used to improve the signal-to-noise ratio in ultrasonic parametric imaging and in elastography.
authors.affiliation: Department of Medical Physics, The University of Wisconsin-Madison, Madison, WI-53706, USA.
authors.forename: Quan
authors.initials: Q
authors.lastname: Chen
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Gerig
authors.forename: Udomchai
authors.initials: U
authors.lastname: Techavipoo
authors.forename: James A
authors.initials: JA
authors.lastname: Zagzebski
authors.forename: Tomy
authors.initials: T
authors.lastname: Varghese
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods*; D008954:Models, Biological; D015233:Models, Statistical; D011846:Radio Waves; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D014463:Ultrasonography / Q000379:methods*