|   | 
Details
   web
Records
Author (up) Becker, R.; Buck, A.; Casella, C.; Dissertori, G.; Fischer, J.; Howard, A.; Ito, M.; Khateri, P.; Lustermann, W.; Oliver, J.F.; Roser, U.; Warnock, G.; Weber, B.
Title The SAFIR experiment: Concept, status and perspectives Type Journal Article
Year 2017 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 845 Issue Pages 648-651
Keywords Positron Emission Tomography (PET); Hybrid PET/MRI; SiPM
Abstract The SAFIR development represents a novel Positron Emission Tomography (PET) detector, conceived for preclinical fast acquisitions inside the bore of a Magnetic Resonance Imaging (MRI) scanner. The goal is hybrid and simultaneous PET/MRI dynamic studies at unprecedented temporal resolutions of a few seconds. The detector relies on matrices of scintillating LSO-based crystals coupled one-to-one with SiPM arrays and readout by fast ASIC5 with excellent timing resolution and high rate capabilities. The paper describes the detector concept and the initial results in terms of simulations and characterisation measurements.
Address [Becker, Robert; Casella, Chiara; Dissertori, Gunther; Fischer, Jannis; Howard, Alexander; Ito, Mikiko; Khateri, Parisa; Lustermann, Werner; Roeser, Ulf] Swiss Fed Inst Technol, Inst Particle Phys, Zurich, Switzerland, Email: chiara.casella@cern.ch
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000394556300153 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2957
Permanent link to this record
 

 
Author (up) Blume, M.; Martinez-Moller, A.; Keil, A.; Navab, N.; Rafecas, M.
Title Joint Reconstruction of Image and Motion in Gated Positron Emission Tomography Type Journal Article
Year 2010 Publication IEEE Transactions on Medical Imaging Abbreviated Journal IEEE Trans. Med. Imaging
Volume 29 Issue 11 Pages 1892-1906
Keywords Gating; motion compensation; positron emission tomography (PET); reconstruction
Abstract We present a novel intrinsic method for joint reconstruction of both image and motion in positron emission tomography (PET). Intrinsic motion compensation methods exclusively work on the measured data, without any external motion measurements. Most of these methods separate image from motion estimation: They use deformable image registration/optical flow techniques in order to estimate the motion from individually reconstructed gates. Then, the image is estimated based on this motion information. With these methods, a main problem lies in the motion estimation step, which is based on the noisy gated frames. The more noise is present, the more inaccurate the image registration becomes. As we show both visually and quantitatively, joint reconstruction using a simple deformation field motion model can compete with state-of-the-art image registration methods which use robust multilevel B-spline motion models.
Address [Blume, Moritz; Rafecas, Magdalena] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain, Email: moritz.blume@cs.tum.edu
Corporate Author Thesis
Publisher Ieee-Inst Electrical Electronics Engineers Inc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0278-0062 ISBN Medium
Area Expedition Conference
Notes ISI:000283941800007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 340
Permanent link to this record
 

 
Author (up) Brzezinski, K. et al
Title Detection of range shifts in proton beam therapy using the J-PET scanner: a patient simulation study Type Journal Article
Year 2023 Publication Physics in Medicine and Biology Abbreviated Journal Phys. Med. Biol.
Volume 68 Issue 14 Pages 145016 - 17pp
Keywords proton therapy; positron emission tomography; in vivo range verification; J-PET; Monte Carlo
Abstract Objective. The Jagiellonian positron emission tomography (J-PET) technology, based on plastic scintillators, has been proposed as a cost effective tool for detecting range deviations during proton therapy. This study investigates the feasibility of using J-PET for range monitoring by means of a detailed Monte Carlo simulation study of 95 patients who underwent proton therapy at the Cyclotron Centre Bronowice (CCB) in Krakow, Poland. Approach. Discrepancies between prescribed and delivered treatments were artificially introduced in the simulations by means of shifts in patient positioning and in the Hounsfield unit to the relative proton stopping power calibration curve. A dual-layer, cylindrical J-PET geometry was simulated in an in-room monitoring scenario and a triple-layer, dual-head geometry in an in-beam protocol. The distribution of range shifts in reconstructed PET activity was visualized in the beam's eye view. Linear prediction models were constructed from all patients in the cohort, using the mean shift in reconstructed PET activity as a predictor of the mean proton range deviation. Main results. Maps of deviations in the range of reconstructed PET distributions showed agreement with those of deviations in dose range in most patients. The linear prediction model showed a good fit, with coefficient of determination r (2) = 0.84 (in-room) and 0.75 (in-beam). Residual standard error was below 1 mm: 0.33 mm (in-room) and 0.23 mm (in-beam). Significance. The precision of the proposed prediction models shows the sensitivity of the proposed J-PET scanners to shifts in proton range for a wide range of clinical treatment plans. Furthermore, it motivates the use of such models as a tool for predicting proton range deviations and opens up new prospects for investigations into the use of intra-treatment PET images for predicting clinical metrics that aid in the assessment of the quality of delivered treatment.
Address [Brzezinski, Karol; Gajewski, Jan; Kopec, Renata; Olko, Pawel; Stasica, Paulina; Rucinski, Antoni] Polish Acad Sci, Inst Nucl Phys, Krakow, Poland, Email: karol.brzezinski@ific.uv.es
Corporate Author Thesis
Publisher IOP Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9155 ISBN Medium
Area Expedition Conference
Notes WOS:001026535700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5616
Permanent link to this record
 

 
Author (up) Etxebeste, A.; Barrio, J.; Bernabeu, J.; Lacasta, C.; Llosa, G.; Muñoz, E.; Ros, A.; Oliver, J.F.
Title Study of sensitivity and resolution for full ring PET prototypes based on continuous crystals and analytical modeling of the light distribution Type Journal Article
Year 2019 Publication Physics in Medicine and Biology Abbreviated Journal Phys. Med. Biol.
Volume 64 Issue 3 Pages 035015 - 17pp
Keywords continuous crystals; NEMA NU 4-2008; positron emission tomography (PET); Monte Carlo simulations; image reconstruction; depth of interaction
Abstract Sensitivity and spatial resolution are the main parameters to maximize in the performance of a PET scanner. For this purpose, detectors consisting of a combination of continuous crystals optically coupled to segmented photodetectors have been employed. With the use of continuous crystals the sensitivity is increased with respect to the pixelated crystals. In addition, spatial resolution is no longer limited to the crystal size. The main drawback is the difficulty in determining the interaction position. In this work, we present the characterization of the performance of a full ring based on cuboid continuous crystals coupled to SiPMs. To this end, we have employed the simulations developed in a previous work for our experimental detector head. Sensitivity could be further enhanced by using tapered crystals. This enhancement is obtained by increasing the solid angle coverage, reducing the wedge-shaped gaps between contiguous detectors. The performance of the scanners based on both crystal geometries was characterized following NEMA NU 4-2008 standardized protocol in order to compare them. An average sensitivity gain over the entire axial field of view of 13.63% has been obtained with tapered geometry while similar performance of the spatial resolution has been proven with both scanners. The activity at which NECR and true peak occur is smaller and the peak value is greater for tapered crystals than for cuboid crystals. Moreover, a higher degree of homogeneity was obtained in the sensitivity map due to the tighter packing of the crystals, which reduces the gaps and results in a better recovery of homogeneous regions than for the cuboid configuration. Some of the results obtained, such as spatial resolution, depend on the interaction position estimation and may vary if other method is employed.
Address [Etxebeste, Ane; Barrio, John; Bernabeu, Jose; Lacasta, Carlos; Llosa, Gabriela; Munoz, Enrique; Ros, Ana; Oliver, Josef F.] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: ane.etxebeste@ific.uv.es
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9155 ISBN Medium
Area Expedition Conference
Notes WOS:000457182500004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3897
Permanent link to this record
 

 
Author (up) Gillam, J.E.; Solevi, P.; Oliver, J.F.; Casella, C.; Heller, M.; Joram, C.; Rafecas, M.
Title Sensitivity recovery for the AX-PET prototype using inter-crystal scattering events Type Journal Article
Year 2014 Publication Physics in Medicine and Biology Abbreviated Journal Phys. Med. Biol.
Volume 59 Issue 15 Pages 4065-4083
Keywords positron emission tomography (PET); inter-crystal scattering; sensitivity
Abstract The development of novel detection devices and systems such as the AX-positron emission tomography (PET) demonstrator often introduce or increase the measurement of atypical coincidence events such as inter-crystal scattering (ICS). In more standard systems, ICS events often go undetected and the small measured fraction may be ignored. As the measured quantity of such events in the data increases, so too does the importance of considering them during image reconstruction. Generally, treatment of ICS events will attempt to determine which of the possible candidate lines of response (LoRs) correctly determine the annihilation photon trajectory. However, methods of assessment often have low success rates or are computationally demanding. In this investigation alternative approaches are considered. Experimental data was taken using the AX-PET prototype and a NEMA phantom. Three methods of ICS treatment were assessed-each of which considered all possible candidate LoRs during image reconstruction. Maximum likelihood expectation maximization was used in conjunction with both standard (line-like) and novel (V-like in this investigation) detection responses modeled within the system matrix. The investigation assumed that no information other than interaction locations was available to distinguish between candidates, yet the methods assessed all provided means by which such information could be included. In all cases it was shown that the signal to noise ratio is increased using ICS events. However, only one method, which used full modeling of the ICS response in the system matrix-the V-like model-provided enhancement in all figures of merit assessed in this investigation. Finally, the optimal method of ICS incorporation was demonstrated using data from two small animals measured using the AX-PET demonstrator.
Address [Gillam, John E.; Solevi, Paola; Oliver, Josep F.; Rafecas, Magdalena] Univ Valencia, CSIC, IFIC, Valencia, Spain, Email: john.gillam@sydney.edu.au
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9155 ISBN Medium
Area Expedition Conference
Notes WOS:000340056800006 Approved no
Is ISI yes International Collaboration
Call Number IFIC @ pastor @ Serial 1879
Permanent link to this record