High performance computing for three dimensional proton computed tomography (HPC-pCT)
A proton computed tomography (pCT) detector system, including two tracking detectors in sequence on a first side of an object to be imaged, two tracking detectors in sequence on an opposite side of the object to be imaged, a calorimeter, and a computer cluster, wherein the tracking detectors include plastic scintillation fibers. All fibers in the detector system are read out by Silicon Photomultipliers (SiPM). A method of imaging an object by emitting protons from a source through two tracking detectors, through and around the object, and through two opposite tracking detectors, detecting energy of the protons with a calorimeter, and imaging the object.
1. A proton computed tomography (pCT) detector system, comprising:
a first set of tracking detectors on a first side of an object to be imaged;
a second set of tracking detectors on an opposite side of the object to be imaged;
an imaging source configured to emit protons through the first set of tracking detectors, through and around the object, and through the second set of tracking detectors;
a calorimeter configured to detect proton energy emitted from the imaging source;
a computer cluster configured to reconstruct an image based on data recorded by the first set of tracking detectors, second set of tracking detectors and calorimeter; and
wherein at least one of the first set of said tracking detectors and the second set of tracking detectors include plastic scintillation fibers packed in a row covering the full area of an imaging field and silicon photomultipliers.
2. The system of claim 1 , wherein the calorimeter includes silicon photomultipliers attached to wavelength shifting (WLS) fibers.
3. The system of claim 1 , wherein the computer cluster includes a cluster of multiple computers and graphic processing units.
4. The system of claim 3 , wherein the computer cluster is configured to acquire the data from the first set of tracking detectors, second set of tracking detectors and calorimeter with a Message Passing Interface (MPI) standard.
5. The system of claim 1 , wherein the computer cluster is configured to use a compact memory representation to reconstruct the image.
6. The system of claim 5 , wherein the computer cluster is configured to solve an entire 3D image space at a single time.
7. The system of claim 1 , wherein the computer cluster includes at least one foreman computer and multiple worker computers.
8. The system of claim 7 , wherein the foreman computer is configured to distribute substantially equal amounts of proton histories to the worker computers.
9. The system of claim 7 , wherein the computer cluster is configured to compute an Integrated Electron Density (IED) and Most Likely Path (MLP), solve for a solution vector and storing on computer readable memory, send copies of the solution vector to the foreman computer, combine the solution vectors of the worker computers and the foreman computer and store the combined solution vector on computer readable media, test the combined solution vector, and if the combined solution vector is done, produce an image of the object.
10. The system of claim 9 , wherein if the combined solution vector is not done, the computer cluster is configured to transmit the combined solution vector to the worker computers and produce an image of the object.
11. The system of claim 1 , wherein said plastic scintillation fibers have a 1 mm diameter.
12. The system of claim 1 , wherein said imaging field is approximately 27 by 36 cm.
13. The system of claim 1 , wherein said plastic scintillation fibers are arranged in a plane, and one or more of the first set of tracking detectors and the second set of tracking detectors include at least two stacked planes.
14. The system of claim 13 , wherein said stacked planes are oriented in X and Y directions.
15. The system of claim 14 , further including a foam-like material between said two stacked planes.
16. The system of claim 1 , wherein said plastic scintillation fibers have a cross-sectional shape chosen from the group consisting of a square, circle, and hexagon.
17. The system of claim 1 , wherein one or more of said first set of tracking detectors and the second set of tracking detectors further include a mechanical support for supporting the fibers.
18. The system of claim 1 , wherein said plastic scintillation fibers comprise polystyrene with cladding of PMMA (Poly(methyl methacrylate)).
19. The system of claim 1 , wherein said calorimeter includes a stack of scintillator plates, and wherein each scintillator plate includes one SiPM and one WLS.
20. The system of claim 1 , further comprising a rotating stage for rotating the object.