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Title: SU-C-207A-03: Development of Proton CT Imaging System Using Thick Scintillator and CCD Camera

Abstract

Purpose: In the treatment planning of proton therapy, Water Equivalent Length (WEL), which is the parameter for the calculation of dose and the range of proton, is derived by X-ray CT (xCT) image and xCT-WEL conversion. However, about a few percent error in the accuracy of proton range calculation through this conversion has been reported. The purpose of this study is to construct a proton CT (pCT) imaging system for an evaluation of the error. Methods: The pCT imaging system was constructed with a thick scintillator and a cooled CCD camera, which acquires the two-dimensional image of integrated value of the scintillation light toward the beam direction. The pCT image is reconstructed by FBP method using a correction between the light intensity and residual range of proton beam. An experiment for the demonstration of this system was performed with 70-MeV proton beam provided by NIRS cyclotron. The pCT image of several objects reconstructed from the experimental data was evaluated quantitatively. Results: Three-dimensional pCT images of several objects were reconstructed experimentally. A finestructure of approximately 1 mm was clearly observed. The position resolution of pCT image was almost the same as that of xCT image. And the error of proton CTmore » pixel value was up to 4%. The deterioration of image quality was caused mainly by the effect of multiple Coulomb scattering. Conclusion: We designed and constructed the pCT imaging system using a thick scintillator and a CCD camera. And the system was evaluated with the experiment by use of 70-MeV proton beam. Three-dimensional pCT images of several objects were acquired by the system. This work was supported by JST SENTAN Grant Number 13A1101 and JSPS KAKENHI Grant Number 15H04912.« less

Authors:
;  [1]; ;  [2];  [3];  [4]
  1. The University of Tokyo, Tokyo (Japan)
  2. Hiroshima University, Hiroshima (Japan)
  3. Rikkyo University, Tokyo (Japan)
  4. Tokai University, Isehara (Japan)
Publication Date:
OSTI Identifier:
22624338
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 43; Journal Issue: 6; Other Information: (c) 2016 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; 61 RADIATION PROTECTION AND DOSIMETRY; ACCURACY; BIOMEDICAL RADIOGRAPHY; CAMERAS; CHARGE-COUPLED DEVICES; COMPUTERIZED TOMOGRAPHY; CORRECTIONS; COULOMB SCATTERING; ERRORS; EVALUATION; NIRS CYCLOTRON; PLANNING; PROTON BEAMS; RADIATION DOSES; RADIOTHERAPY; SCINTILLATIONS; FUNDAMENTAL INTERACTIONS

Citation Formats

Tanaka, S, Uesaka, M, Nishio, T, Tsuneda, M, Matsushita, K, and Kabuki, S. SU-C-207A-03: Development of Proton CT Imaging System Using Thick Scintillator and CCD Camera. United States: N. p., 2016. Web. doi:10.1118/1.4955578.
Tanaka, S, Uesaka, M, Nishio, T, Tsuneda, M, Matsushita, K, & Kabuki, S. SU-C-207A-03: Development of Proton CT Imaging System Using Thick Scintillator and CCD Camera. United States. doi:10.1118/1.4955578.
Tanaka, S, Uesaka, M, Nishio, T, Tsuneda, M, Matsushita, K, and Kabuki, S. 2016. "SU-C-207A-03: Development of Proton CT Imaging System Using Thick Scintillator and CCD Camera". United States. doi:10.1118/1.4955578.
@article{osti_22624338,
title = {SU-C-207A-03: Development of Proton CT Imaging System Using Thick Scintillator and CCD Camera},
author = {Tanaka, S and Uesaka, M and Nishio, T and Tsuneda, M and Matsushita, K and Kabuki, S},
abstractNote = {Purpose: In the treatment planning of proton therapy, Water Equivalent Length (WEL), which is the parameter for the calculation of dose and the range of proton, is derived by X-ray CT (xCT) image and xCT-WEL conversion. However, about a few percent error in the accuracy of proton range calculation through this conversion has been reported. The purpose of this study is to construct a proton CT (pCT) imaging system for an evaluation of the error. Methods: The pCT imaging system was constructed with a thick scintillator and a cooled CCD camera, which acquires the two-dimensional image of integrated value of the scintillation light toward the beam direction. The pCT image is reconstructed by FBP method using a correction between the light intensity and residual range of proton beam. An experiment for the demonstration of this system was performed with 70-MeV proton beam provided by NIRS cyclotron. The pCT image of several objects reconstructed from the experimental data was evaluated quantitatively. Results: Three-dimensional pCT images of several objects were reconstructed experimentally. A finestructure of approximately 1 mm was clearly observed. The position resolution of pCT image was almost the same as that of xCT image. And the error of proton CT pixel value was up to 4%. The deterioration of image quality was caused mainly by the effect of multiple Coulomb scattering. Conclusion: We designed and constructed the pCT imaging system using a thick scintillator and a CCD camera. And the system was evaluated with the experiment by use of 70-MeV proton beam. Three-dimensional pCT images of several objects were acquired by the system. This work was supported by JST SENTAN Grant Number 13A1101 and JSPS KAKENHI Grant Number 15H04912.},
doi = {10.1118/1.4955578},
journal = {Medical Physics},
number = 6,
volume = 43,
place = {United States},
year = 2016,
month = 6
}
  • New third generation x-ray sources such as the Advanced Photon Source have created a need for a detector that can provide multiple frames of detailed x-ray images on the millisecond time scale. Such detectors will prove invaluable in applications such as time-resolved x-ray diffraction, x-ray microtomography, as well as materials science applications like polymer processing. Currently, detectors capable of acquiring high resolution x-ray images at such high speed do not exist, thus limiting progress in many of these important areas of research. To address these needs the authors have developed a prototype fast x-ray imaging system, using a structured CsI(Tl)more » scintillator coupled to a fast-frame 1K x 1K CCD. The system has been successfully employed to capture 1024 x 64 pixel x-rays images at a rate of 1000 frames per second (fps) with a 12 bit dynamic range. The system exceeds the capabilities of the current high speed x-ray imaging systems which typically operate at the rate of 30 fps. Fabrication of a large area detector is currently underway, using a microstructured CsI(Tl) scintillator coupled to a fast-frame CCD with a 3:1 fiberoptic taper. The camera will operate in a burst mode, acquiring 8 1K x 1K images at rates up to 1000 frames per second with 12 bit dynamic range. Higher image capture speeds can be accomplished by reducing the image area. This paper will discuss the specific characteristics of the CsI(Tl) screens, experimental details of the prototype and the new design for the large area detector being developed specifically for time-resolved x-ray diffraction experiments in structural biology.« less
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