Proton computed tomography using a 1D silicon diode array. Issue 10 (29th September 2016)

• Record Type: Journal Article
• Authors: Wang, Peng; Cammin, Jochen; Bisello, Francesca; Solberg, Timothy D.; McDonough, James E.; Zhu, Timothy C.; Menichelli, David; Teo, Boon‐Keng Kevin
• Is Part Of: Medical physics. Volume 43:Issue 10(2016)
• Page Start: 5758
• Page End: 5766
• Publication Date: 2016-09-29
• Subjects: computerised tomography -- diagnostic radiography -- elemental semiconductors -- image reconstruction -- image resolution -- image sampling -- medical image processing -- phantoms -- polymers -- semiconductor diodes -- silicon -- silicon radiation detectors; Computed radiography -- Spatial resolution -- Reconstruction -- Computed tomography; Computerised tomographs -- Biological material, e.g. blood, urine; Haemocytometers -- Digital computing or data processing equipment or methods, specially adapted for specific applications -- Image data processing or generation, in general -- Diodes; proton radiography -- proton computed tomography -- silicon diode detector -- proton treatment planning -- proton range uncertainty; Protons -- Image sensors -- Medical image reconstruction -- Image reconstruction -- Computed tomography -- Calibration -- Image detection systems -- X‐ray scattering -- Spatial resolution; Medical physics -- Periodicals; Medical physics; Geneeskunde; Natuurkunde; Toepassingen; Biophysics; Periodicals; Periodicals; Electronic journals; 610.153
• DOI: 10.1118/1.4963221
• Languages: English
• ISSNs: 0094-2405

Abstract

Abstract : Purpose: Proton radiography (PR) and proton computed tomography (PCT) can be used to measure proton stopping power directly. However, practical and cost effective proton imaging detectors are not widely available. In this study, the authors investigated the feasibility of proton imaging using a silicon diode array. Methods: A one‐dimensional silicon diode detector array (1DSDA) was aligned with the central axis (CAX) of the proton beam. Polymethyl methacrylate (PMMA) slabs were used to find the correspondence between the water equivalent thickness (WET) and 1DSDA channel number. Two‐dimensional proton radiographs were obtained by translation and rotation of a phantom relative to CAX while the proton nozzle and 1DSDA were kept stationary. A PCT image of one slice of the phantom was reconstructed using filtered backprojection. Results: PR and PCT images of the PMMA cube were successfully acquired using the 1DSDA. The WET of the phantom was measured using PR data. The resolution and maximum error in WET measurement are 2.0 and 1.5 mm, respectively. Structures down to 2.0 mm in size could be resolved completely. Reconstruction of a PCT image showed very good agreement with simulation. Limitations in spatial resolution are attributed to limited spatial sampling, beam collimation, and proton scatter. Conclusions: The results demonstrate the feasibility of using silicon diode arrays for proton imaging. Such a device can potentially offer fast image acquisition and high spatial and energy resolution for PR and PCT.