MIMO Nonlinear Ultrasonic Tomography by Propagation and Backpropagation Method

• Published in: IEEE transactions on image processing 2013-03, Vol.22 (3), p.1056-1069
• Main Authors: Dong, Chengdong, Jin, Yuanwei
• Format: Article
• Language: English
• Subjects: Acoustics; Algorithms; Applied sciences; Back propagation; Equations; Exact sciences and technology; Excitation; Image Enhancement - methods; Image Interpretation, Computer-Assisted - methods; Image processing; Image reconstruction; Imaging; Information, signal and communications theory; Mathematical analysis; Mathematical model; Mathematical models; MIMO; Multiple-input multiple-output (MIMO) waveform signaling; Nonlinear Dynamics; nonlinear ultrasonic tomography; Propagation; propagation and backpropagation (PBP) method; Reproducibility of Results; Sensitivity and Specificity; Signal processing; Studies; Telecommunications and information theory; Tomography; Tomography - methods; Ultrasonic testing; Ultrasonography - methods; Waveforms
• ISSN: 1057-7149; 1941-0042
• DOI: 10.1109/TIP.2012.2226901

This paper develops a fast ultrasonic tomographic imaging method in a multiple-input multiple-output (MIMO) configuration using the propagation and backpropagation (PBP) method. By this method, ultrasonic excitation signals from multiple sources are transmitted simultaneously to probe the objects immersed in the medium. The scattering signals are recorded by multiple receivers. Utilizing the nonlinear ultrasonic wave propagation equation and the received time domain scattered signals, the objects are to be reconstructed iteratively in three steps. First, the propagation step calculates the predicted acoustic potential data at the receivers using an initial guess. Second, the difference signal between the predicted value and the measured data is calculated. Third, the backpropagation step computes updated acoustical potential data by backpropagating the difference signal to the same medium computationally. Unlike the conventional PBP method for tomographic imaging where each source takes turns to excite the acoustical field until all the sources are used, the developed MIMO-PBP method achieves faster image reconstruction by utilizing multiple source simultaneous excitation. Furthermore, we develop an orthogonal waveform signaling method using a waveform delay scheme to reduce the impact of speckle patterns in the reconstructed images. By numerical experiments we demonstrate that the proposed MIMO-PBP tomographic imaging method results in faster convergence and achieves superior imaging quality.