title: Reducing the effects of acoustic heterogeneity with an iterative reconstruction method from experimental data in microwave induced thermoacoustic tomography.
abstract: OBJECTIVE
  An iterative reconstruction method has been previously reported by the authors of this paper. However, the iterative reconstruction method was demonstrated by solely using the numerical simulations. It is essential to apply the iterative reconstruction method to practice conditions. The objective of this work is to validate the capability of the iterative reconstruction method for reducing the effects of acoustic heterogeneity with the experimental data in microwave induced thermoacoustic tomography.
  
  
  METHODS
  Most existing reconstruction methods need to combine the ultrasonic measurement technology to quantitatively measure the velocity distribution of heterogeneity, which increases the system complexity. Different to existing reconstruction methods, the iterative reconstruction method combines time reversal mirror technique, fast marching method, and simultaneous algebraic reconstruction technique to iteratively estimate the velocity distribution of heterogeneous tissue by solely using the measured data. Then, the estimated velocity distribution is used subsequently to reconstruct the highly accurate image of microwave absorption distribution. Experiments that a target placed in an acoustic heterogeneous environment are performed to validate the iterative reconstruction method.
  
  
  RESULTS
  By using the estimated velocity distribution, the target in an acoustic heterogeneous environment can be reconstructed with better shape and higher image contrast than targets that are reconstructed with a homogeneous velocity distribution.
  
  
  CONCLUSIONS
  The distortions caused by the acoustic heterogeneity can be efficiently corrected by utilizing the velocity distribution estimated by the iterative reconstruction method. The advantage of the iterative reconstruction method over the existing correction methods is that it is successful in improving the quality of the image of microwave absorption distribution without increasing the system complexity.
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China.
authors.forename: Jinguo
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China.
authors.forename: Zhiqin
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Song
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China.
authors.forename: Guoping
authors.initials: G
authors.lastname: Chen
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China.
authors.forename: Zaiping
authors.initials: Z
authors.lastname: Nie
authors.affiliation: Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708.
authors.forename: Qing-Huo
authors.initials: QH
authors.lastname: Liu
mesh_terms: D000162:Acoustics / Q000295:instrumentation; D000273:Adipose Tissue / Q000033:anatomy & histology / Q000502:physiology; D000818:Animals; D016477:Artifacts; D001940:Breast / Q000033:anatomy & histology / Q000502:physiology; D001943:Breast Neoplasms / Q000473:pathology / Q000503:physiopathology; D004867:Equipment Design; D006801:Humans; D008872:Microwaves; D009132:Muscles / Q000033:anatomy & histology / Q000502:physiology; D019047:Phantoms, Imaging; D011312:Pressure; D013552:Swine; D014054:Tomography / Q000295:instrumentation / Q000379:methods*