title: Model-based correction of finite aperture effect in photoacoustic tomography.
abstract: In this study, we adopt a model-based correction method to reduce the finite aperture effect in photoacoustic tomography (PAT)--the tangential resolution deteriorates as the imaging point moves away from the circular scanning center. Such degradation in resolution originates from the spatial impulse responses (SIRs) of the used finite-sized unfocused transducer. Based on a linear, discrete PAT imaging model, the proposed method employs a spatiotemporal optimal filter designed in minimum mean square error sense to compensate the SIRs associated with an unfocused transducer at every imaging point; thus retrospective restoration of the tangential resolution can be achieved. Simulation and experimental results demonstrate that this method can substantially improve the degraded tangential resolution for PAT with finite-sized unfocused transducers while retaining the radial resolution.
authors.affiliation: Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan. mlli@ee.nthu.edu.tw
authors.forename: Meng-Lin
authors.initials: ML
authors.lastname: Li
authors.forename: Yi-Chieh
authors.initials: YC
authors.lastname: Tseng
authors.forename: Chung-Chih
authors.initials: CC
authors.lastname: Cheng
mesh_terms: D000465:Algorithms; D016477:Artifacts; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods*; D033401:Microscopy, Acoustic / Q000295:instrumentation* / Q000379:methods*; D014054:Tomography / Q000295:instrumentation* / Q000379:methods*