Title :
Reconstruction method for compensation of surface effects in transillumination laser CT
Author :
Yuasa, Tetsuya ; Devaraj, Balasigamani ; Tanosaki, Shinji ; Taniguchi, Hiroshi ; Akatsuka, Takao
Author_Institution :
Yamagata Univ., Yonezawa, Japan
fDate :
6/23/1905 12:00:00 AM
Abstract :
A reconstruction method for transillumination laser CT using optical heterodyne detection is proposed. Laser CT does not obey the Radon transform due to surface effects, which occur as a result of refractive index mismatch and bring about an annulus artifact. Optical attenuation with surface effects is described using an affine model. In addition, the constraint derived from the quantitative relationship between projections is introduced in order to obtain a stable solution to the system of equations. This reconstruction produces a least squares problem with the above-mentioned constraint, which is solved via the conjugate gradient method. The method is applied to data from a physical phantom
Keywords :
Radon transforms; computerised tomography; conjugate gradient methods; heterodyne detection; image reconstruction; least squares approximations; light absorption; medical image processing; optical tomography; Radon transform; affine model; annulus artifact; coherent detection imaging; conjugate gradient method; least squares problem; medical diagnosis; optical attenuation; optical heterodyne detection; physical phantom; reconstruction method; refractive index mismatch; surface effects compensation; transillumination laser CT; Laser modes; Optical attenuators; Optical detectors; Optical mixing; Optical refraction; Optical variables control; Reconstruction algorithms; Refractive index; Surface emitting lasers; Surface reconstruction;
Conference_Titel :
Image Processing, 2001. Proceedings. 2001 International Conference on
Conference_Location :
Thessaloniki
Print_ISBN :
0-7803-6725-1
DOI :
10.1109/ICIP.2001.959023
