Prediction of image noise contributions in proton computed tomography and comparison to measurements

Abstract Proton beam therapy can potentially offer improved treatment for cancers of the head and neck and in paediatric patients. There has been asharp uptake of proton beam therapy in recent years as improved delivery techniques and patient benefits are observed. However, treatments are currently planned using conventional x-ray CT images due to the absence of devices able to perform high quality proton computed tomography(pCT) under realistic clinical conditions. A new plastic-scintillator-based range telescope concept, named ASTRA, is proposed here to measure the proton’s energy loss in a pCT system. Simulations conducted using GEANT4 yield an expected energy resolution of 0.7%. If calorimetric information is used the energy resolution could be further improved to about 0.5%. In addition, the ability of ASTRA to track multiple protons simultaneously is presented. Due to its fast components, ASTRA is expected to reach unprecedented data collection rates, similar to 10^8 protons/s.The performance of ASTRA has also been tested by simulating the imaging of phantoms. The results show excellent image contrast and relative stopping power reconstruction.

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Fast and Accurate Proton Computed Tomography Image Reconstruction for Applications in Proton Therapy

IFMBE Proceedings - World Congress on Medical Physics and Biomedical Engineering, September 7 - 12, 2009, Munich, Germany ◽

10.1007/978-3-642-03474-9_61 ◽

2009 ◽

pp. 213-216

Author(s):

S. N. Penfold ◽

R. W. Schulte ◽

V. Bashkirov ◽

A. B. Rosenfeld

Keyword(s):

Computed Tomography ◽

Image Reconstruction ◽

Proton Therapy ◽

Proton Computed Tomography ◽

Tomography Image ◽

Computed Tomography Image

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Image Noise And Smoothing In Computed Tomography (CT) Scanners

Optical Engineering ◽

10.1117/12.7972250 ◽

1978 ◽

Vol 17 (4) ◽

pp. 174396 ◽

Cited By ~ 8

Author(s):

Peter M. Joseph

Keyword(s):

Computed Tomography ◽

Image Noise ◽

Ct Scanners

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Application of fluence field modulation to proton computed tomography for proton therapy imaging

Physics in Medicine and Biology ◽

10.1088/1361-6560/aa7734 ◽

2017 ◽

Vol 62 (15) ◽

pp. 6026-6043 ◽

Cited By ~ 13

Author(s):

G Dedes ◽

L De Angelis ◽

S Rit ◽

D Hansen ◽

C Belka ◽

...

Keyword(s):

Computed Tomography ◽

Proton Therapy ◽

Proton Computed Tomography ◽

Field Modulation

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Image Quality Assessment of Low-Dose CT using Hybrid Iterative Reconstruction

Journal of Imaging Science and Technology ◽

10.2352/j.imagingsci.technol.2022.66.1.010504 ◽

2021 ◽

Author(s):

Qiao Zhang ◽

Jinhua Sheng ◽

Bin Chen

Keyword(s):

Computed Tomography ◽

Noise Reduction ◽

Iterative Reconstruction ◽

Low Dose ◽

Low Frequency ◽

Image Noise ◽

Observer Performance ◽

Human Observer ◽

X Ray ◽

Hybrid Iterative Reconstruction

Background: X-ray computed tomography is the first imaging technology that supports accurate nondestructive interior image reconstruction of an object from sufficient projection data. Low-dose computed tomography (LDCT) has been considered to relieve the harm to patients caused by X-ray radiation. However, LDCT images can be degraded by quantum noise and streak artifacts. Methods: The objective of the authors’ study is to evaluate the optimal level of the hybrid iterative reconstruction (HIR) that generates images with the best diagnostic quality on different dose and noise levels. HIR with optimizations is proposed to reduce image noise and provide better performance at a low dose. The Catphan R 504 phantom is employed to assess various image qualities (IQ). Results: For any given scanning protocols, there is linear noise reduction and linear increase of contrast-to- noise ratio (CNR) using optimal HIR. The evidence from various module tests demonstrates that the shape of the noise power spectrum is continuously shifted to low frequency with increasing HIR levels compared with that of filtered-back-projection (FBP). This may describe the difference between the human observer performance and features of the ideal low-contrast objects. Conclusion: Optimal HIR is clearly demonstrated to be a superior method for reducing image noise and improving CNR compared to FBP. Optimal HIR also inhibits texture change or spectrum shift compared with the pure IR method. Even though there are continuous noise reduction and CNR increase with HIR at increasing levels, the human observer performance does not seem to improve simultaneously due to coarser noise (low-frequency noise). HIR level 3 to 5 is optimal for their study. It is possible for the optimal HIR to offer equivalent diagnostic IQ at a lower dose compared with FBP at a routine dose.

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