Tissue strain rate estimator using ultrafast IQ complex data

Redouane Ternifi , Melouka Elkateb Hachemi , Jean-Pierre Remenieras

Pulsatile motion of brain parenchyma results from cardiac and breathing cycles. In this study, transient motion of brain tissue was estimated using an Aixplorer® imaging system allowing an ultrafast 2D acquisition mode. The strain was computed directly from the ultrafast IQ complex data using the extended autocorrelation strain estimator (EASE), which provides great SNRs regardless of depth. The EASE first evaluates the autocorrelation function at each depth over a set of successive IQ pairs. This estimates the mean change in phase over time, which is proportional to the velocity. A second autocorrelation is evaluated on the results of the first autocorrelation. This estimates the mean change in phase over depth, which is proportional to the strain rate. The developed algorithm was first validated on “in vivo” data acquired at 7.5MHz from the carotid. Tissue velocity and strain rate were estimated on artery wall and adjacent regions. The estimated displacement velocity and displacement of the wall artery were 2.5 cm/s, and 150 µm respectively. The displacement velocity and displacement of the region near the surface were 1 cm/s and 30 µm respectively.

Mots clés: Ultrasound Imaging; Tissue motion estimation; Strain; IQ Data

Domaines: Acoustique [physics.class-ph]

Redouane Ternifi, Melouka Elkateb Hachemi, Jean-Pierre Remenieras. Tissue strain rate estimator using ultrafast IQ complex data. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810913⟩