title: Fluorescence molecular tomography using a two-step three-dimensional shape-based reconstruction with graphics processing unit acceleration.
abstract: In fluorescence molecular tomography, the accurate and stable reconstruction of fluorescence-labeled targets remains a challenge for wide application of this imaging modality. Here we propose a two-step three-dimensional shape-based reconstruction method using graphics processing unit (GPU) acceleration. In this method, the fluorophore distribution is assumed as the sum of ellipsoids with piecewise-constant fluorescence intensities. The inverse problem is formulated as a constrained nonlinear least-squares problem with respect to shape parameters, leading to much less ill-posedness as the number of unknowns is greatly reduced. Considering that various shape parameters contribute differently to the boundary measurements, we use a two-step optimization algorithm to handle them in a distinctive way and also stabilize the reconstruction. Additionally, the GPU acceleration is employed for finite-element-method-based calculation of the objective function value and the Jacobian matrix, which reduces the total optimization time from around 10 min to less than 1 min. The numerical simulations show that our method can accurately reconstruct multiple targets of various shapes while the conventional voxel-based reconstruction cannot separate the nearby targets. Moreover, the two-step optimization can tolerate different initial values in the existence of noises, even when the number of targets is not known a priori. A physical phantom experiment further demonstrates the method's potential in practical applications.
authors.affiliation: State Key Laboratory of Software Development Environment, Beihang University, Beijing, China.
authors.forename: Daifa
authors.initials: D
authors.lastname: Wang
authors.forename: Huiting
authors.initials: H
authors.lastname: Qiao
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Song
authors.forename: Yubo
authors.initials: Y
authors.lastname: Fan
authors.forename: Deyu
authors.initials: D
authors.lastname: Li
mesh_terms: D003196:Computer Graphics / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D008856:Microscopy, Fluorescence / Q000295:instrumentation*; D057054:Molecular Imaging / Q000295:instrumentation*; D019047:Phantoms, Imaging; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D041622:Tomography, Optical / Q000295:instrumentation*