Ultrasound 2D Strain Estimator Based on Image Registration for Ultrasound Elastography.
In this paper, we present a new approach to calculate 2D strain through the registration of the pre- and post-compression (deformation) B-mode image sequences based on an intensity-based non-rigid registration algorithm (INRA). Compared with the most commonly used cross-correlation (CC) method, our approach is not constrained to any particular set of directions, and can overcome displacement estimation errors introduced by incoherent motion and variations in the signal under high compression. This INRA method was tested using phantom andin vivodata. The robustness of our approach was demonstrated in the axial direction as well as the lateral direction where the standard CC method frequently fails. In addition, our approach copes well under large compression (over 6%). In the phantom study, we computed the strain image under various compressions and calculated the signal-to-noise (SNR) and contrast-to-noise (CNS) ratios. The SNR and CNS values of the INRA method were much higher than those calculated from the CC-based method. Furthermore, the clinical feasibility of our approach was demonstrated with thein vivodata from patients with arm lymphedema.
Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, GA 30322.
Xiaofeng
X
Yang
Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, GA 30322.
Mylin
M
Torres
Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, GA 30322.
Stephanie
S
Kirkpatrick
Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, GA 30322.
Walter J
WJ
Curran
Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, GA 30322.
Tian
T
Liu
Ultrasound; elastography; image registration; strains imaging