Proton Radiographic Detection of Strokes

Steward, V. W.; Koehler, Andreas

doi:10.1038/245038a0

Cited by 48 publications

(18 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Directly behind the metal object, the fluence enhancements and depletions are observed near the edge of the metal object. This well-understood effect is sometimes called the edge enhancement effect (Koehler, 1968; Schneider and Pedroni, 1995; Steward and Koehler, 1973a, b). The lateral deflections are predominated by multiple Coulomb scattering.…”

Section: Dicussionmentioning

confidence: 99%

Benchmark measurements and simulations of dose perturbations due to metallic spheres in proton beams

Newhauser¹,

Rechner

Mirković

et al. 2013

Radiation Measurements

View full text Add to dashboard Cite

Monte Carlo simulations are increasingly used for dose calculations in proton therapy due to its inherent accuracy. However, dosimetric deviations have been found using Monte Carlo code when high density materials are present in the proton beam line. The purpose of this work was to quantify the magnitude of dose perturbation caused by metal objects. We did this by comparing measurements and Monte Carlo predictions of dose perturbations caused by the presence of small metal spheres in several clinical proton therapy beams as functions of proton beam range, spread-out Bragg peak width and drift space. Monte Carlo codes MCNPX, GEANT4 and Fast Dose Calculator (FDC) were used. Generally good agreement was found between measurements and Monte Carlo predictions, with the average difference within 5% and maximum difference within 17%. The modification of multiple Coulomb scattering model in MCNPX code yielded improvement in accuracy and provided the best overall agreement with measurements. Our results confirmed that Monte Carlo codes are well suited for predicting multiple Coulomb scattering in proton therapy beams when short drift spaces are involved.

show abstract

Section: Dicussionmentioning

confidence: 99%

Benchmark measurements and simulations of dose perturbations due to metallic spheres in proton beams

Newhauser¹,

Rechner

Mirković

et al. 2013

Radiation Measurements

View full text Add to dashboard Cite

show abstract

“…Alongside the long-term development of X-ray imaging, much effort has been spent to produce images by use of proton stopping [e.g. [102][103][104][105]. Radiographies and tomographies using proton beams from conventional accelerators were demonstrated in close context with charged particle therapy of cancer.…”

Section: Radiographic Imagingmentioning

confidence: 99%

“…1.3) represents the first and well studied scenario. Early trials using very monochromatic proton beams from conventional accelerators used exactly this property for ultra-high contrast proton-absorption-imaging of biological samples [102][103][104] by simply assessing the number/fraction of transmitted ions. The obvious disadvantage is, that contrast for a fixed proton energy is produced only for a small range of effective object thickness.…”

Section: Some Ideas On Proton Radiographymentioning

confidence: 99%

Relativistically Intense Laser–Microplasma Interactions

Ostermayr

2019

Springer Theses

View full text Add to dashboard Cite

Diese Arbeit behandelt verschiedene Aspekte der Interaktion von relativistisch intensiven Laserpulsen mit Mikroplasmen. Dafür wurde zunächst eine Paul-Falle entwickelt, welche vollständig isolierte und definierte Mikrokugeln als Ziel für Experimente mit fokussierten Peta-Watt Laser-Pulsen bereitstellt. Solche Interaktionen wurden dann in der Theorie, in numerischen Simulationen und in einer Serie von Experimenten untersucht. Die erste wichtige Beobachtung hierbei war die Erzeugung manipulierbarer Protonenstrahlen mit kinetischen Energienüber 10 MeV. Die Modifikation in den spektralen und räumlichen Verteilungen erfolgte durch die Variation des Beschleunigungsmechanismus. Dies beinhaltet das Auftreten von Protonenstrahlen mit begrenzter spektraler Bandbreite, welcheähnliche Lasergetriebene Quellen in kinetischer Energie und/oder Teilchenfluenzübertreffen. Die relative Bandbreite von 20-25% wird durch die (isotrope) Coulomb Explosion oder durch gerichtete Beschleunigungsprozesse erreicht (Abb. 1a, sec. 5.3 und 5.4). Im zweiten Teil der Ar-Abbildung 1 | Zentrale Ergebnisse. a. Ionenquellen mit limitierter spektraler Bandbreite in dieser Arbeit (rot) im Kontext früherer Experimente mit Laser-Ionen-Beschleunigern (Quellen: [1-10]). Markiert ist je das spektrale Maximum, Fehlerbalken markieren die spektrale Breite (volle Breite bei halbem Maximalwert). b. Beispiel eines bimodalen Röntgen-und Protonenbildes (übereinander registriert). Der Skalenbalken entspricht 1 cm. Intensitäten sind in relativen Skalen angegeben und das Protonenbild wird zu 40% transparent dargestellt. beit wurden Mikronadeln mit Peta-Watt Laser-Pulsen beschossen um Röntgen-und Protonenstrahlen mit jeweils nur einigen Mikrometern effektiver Quellgröße zu erzeugen. Im Röntgenspektrum wurde ein Maximum um 6 keV und messbares Signal bisüber 10 keV beobachtet. Das Protonenspektrum zeigte erneut die quasi-monoenergetische Verteilung mit Peak-Energienüber 10 MeV (Abb. 1a, sec. 6.1). Nach der Charakterisierung der Quelle wurde diese für Bildgebung genutzt. Dabei konnte insbesondere die gleichzeitige Aufnahme von Röntgen-und Protonenbildern mit einem einzelnen Laserschuß gezeigt werden (Abb. 1b). Die Besonderheiten der Quelle erlaubten zudem Röntgenaufnahmen mit starkem Phasen-Kontrast Anteil, sowie die Untersuchung von quantitativen Einzelschuß Protonen-Radiographien.

show abstract

“…The concept of the range-edge proton radiography was proposed by Koehler in 1968 [1]. Subsequently, Koehler and others [2][3][4][5] demonstrated that the high-contrast images obtained by proton radiography can provide improved imaging of low contrast lesions in human specimens over conventional x-ray techniques. Hanson described a proton CT method in 1981 [6,7], in which projections necessary for computer tomography (CT) reconstructions were obtained by measuring the proton energy losses.…”

Section: Introductionmentioning

confidence: 97%

Concept and design of charged particle optics using energy Fourier plane collimation

Gao

Tao

Zhou

et al. 2014

Phys. Rev. ST Accel. Beams

View full text Add to dashboard Cite

Charged particle radiography has become a promising new approach in the field of transmission radiography because of the invention of the magnetic imaging lens. The using of the imaging lens makes it possible for thick objects to get significantly improved transmission radiography. Currently, the conventional charged particle radiography only uses the information of the flux attenuation and the angular scattering of the transmitted particles to determine the properties of the sample. However, the energy loss of the incident particles introduced by ionizations throughout the object limits the spatial resolution of the image because of the chromatic blur. In this paper a new concept of imaging lens that uses the information of the energy loss is proposed. With a specially designed imaging lens, the information of the energy loss could result in apparent contrast in the final image. This design procedure of the energy loss imaging lens is presented, and a preliminary design is verified by numerical simulations. Experimental demonstration is also expected on a cyclotron at the Institute of Fluid Physics, CAEP.

show abstract

Proton Radiographic Detection of Strokes

Cited by 48 publications

References 6 publications

Benchmark measurements and simulations of dose perturbations due to metallic spheres in proton beams

Benchmark measurements and simulations of dose perturbations due to metallic spheres in proton beams

Relativistically Intense Laser–Microplasma Interactions

Concept and design of charged particle optics using energy Fourier plane collimation

Contact Info

Product

Resources

About