title: Imaging Internal Structure of Long Bones Using Wave Scattering Theory.
abstract: An ultrasonic wavefield imaging method is developed to reconstruct the internal geometric properties of long bones using zero-offset data acquired axially on the bone surface. The imaging algorithm based on Born scattering theory is implemented with the conjugate gradient iterative method to reconstruct an optimal image. In the case of a multilayered velocity model, ray tracing through a smooth medium is used to calculate the traveled distance and traveling time. The method has been applied to simulated and real data. The results indicate that the interfaces of the top cortex are accurately imaged and correspond favorably to the original model. The reconstructed bottom cortex below the marrow is less accurate mainly because of the low signal-to-noise ratio. The current imaging method has successfully recovered the top cortical layer, providing a potential tool to investigate the internal structures of long bone cortex for osteoporosis assessment.
authors: Department of Surgery, University of Alberta, Edmonton, Alberta, Canada. Electronic address: rui.zheng@ualberta.ca.
authors: Rui
authors: R
authors: Zheng
authors: Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada. Electronic address: lawrence.le@ualberta.ca.
authors: Lawrence H
authors: LH
authors: Le
authors: Department of Physics, University of Alberta, Edmonton, Alberta, Canada.
authors: Mauricio D
authors: MD
authors: Sacchi
authors: Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada.
authors: Edmond
authors: E
authors: Lou
mesh_terms: D000465:Algorithms; D000818:Animals; D002417:Cattle; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008962:Models, Theoretical; D059629:Signal-To-Noise Ratio; D013977:Tibia / Q000000981:diagnostic imaging*; D014463:Ultrasonography
keywords: Born approximation; Cortical bones; Image reconstruction; Osteoporosis; Ultrasound imaging