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Author Aguiar, P.; Rafecas, M.; Ortuño, J.E.; Kontaxakis, G.; Santos, A.; Pavia, J.; Rosetti, M. doi  openurl
  Title Geometrical and Monte Carlo projectors in 3D PET reconstruction Type Journal Article
  Year 2010 Publication Medical Physics Abbreviated Journal Med. Phys.  
  Volume 37 Issue 11 Pages 5691-5702  
  Keywords 3D PET; iterative reconstruction; list-mode reconstruction; ray-tracing techniques; Monte Carlo simulation; system response matrix  
  Abstract (up) Purpose: In the present work, the authors compare geometrical and Monte Carlo projectors in detail. The geometrical projectors considered were the conventional geometrical Siddon ray-tracer (S-RT) and the orthogonal distance-based ray-tracer (OD-RT), based on computing the orthogonal distance from the center of image voxel to the line-of-response. A comparison of these geometrical projectors was performed using different point spread function (PSF) models. The Monte Carlo-based method under consideration involves an extensive model of the system response matrix based on Monte Carlo simulations and is computed off-line and stored on disk. Methods: Comparisons were performed using simulated and experimental data of the commercial small animal PET scanner rPET. Results: The results demonstrate that the orthogonal distance-based ray-tracer and Siddon ray-tracer using PSF image-space convolutions yield better images in terms of contrast and spatial resolution than those obtained after using the conventional method and the multiray-based S-RT. Furthermore, the Monte Carlo-based method yields slight improvements in terms of contrast and spatial resolution with respect to these geometrical projectors. Conclusions: The orthogonal distance-based ray-tracer and Siddon ray-tracer using PSF image-space convolutions represent satisfactory alternatives to factorizing the system matrix or to the conventional on-the-fly ray-tracing methods for list-mode reconstruction, where an extensive modeling based on Monte Carlo simulations is unfeasible.  
  Address [Aguiar, Pablo] Univ Santiago de Compostela, Dept Fis Particulas, Complexo Hosp Univ Santiago de Compostela, Fdn IDICHUS IDIS, Santiago De Compostela, Spain, Email: pablo.aguiar.fernandez@sergas.es  
  Corporate Author Thesis  
  Publisher Amer Assoc Physicists Medicine Amer Inst Physics Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0094-2405 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000283747600015 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 338  
Permanent link to this record
 

 
Author Richart, J.; Otal, A.; Rodriguez, S.; Nicolas, A.I.; DePiaggio, M.; Santos, M.; Vijande, J.; Ballester, F.; Perez-Calatayud, J. doi  openurl
  Title A practical MRI-based reconstruction method for a new endocavitary and interstitial gynaecological template Type Journal Article
  Year 2015 Publication Journal of Contemporary Brachytherapy Abbreviated Journal J. Contemp. Brachytherapy  
  Volume 7 Issue 5 Pages 407-414  
  Keywords brachytherapy template; catheter reconstruction; gynecological template; interstitial implants  
  Abstract (up) Purpose: There are perineal templates for interstitial implants such as MUPIT and Syed applicators. Their limitations are the intracavitary component deficit and the necessity to use computed tomography (CT) for treatment planning since both applicators are non-magnetic resonance imaging (MRI) compatibles. To overcome these problems, a new template named Template Benidorm (TB) has been recently developed. Titanium needles are usually reconstructed based on their own artifacts, mainly in T1-weighted sequence, using the void on the tip as the needle tip position. Nevertheless, patient tissues surrounding the needles present heterogeneities that complicate the accurate identification of these artifact patterns. The purpose of this work is to improve the titanium needle reconstruction uncertainty for the TB case using a simple method based on the free needle lengths and typical MRI pellets markers. Material and methods: The proposed procedure consists on the inclusion of three small A-vitamin pellets (hyper-intense on MRI images) compressed by both applicator plates defining the central plane of the plate's arrangement. The needles used are typically 20 cm in length. For each needle, two points are selected defining the straight line. From such line and the plane equations, the intersection can be obtained, and using the free length (knowing the offset distance), the coordinates of the needle tip can be obtained. The method is applied in both T1W and T2W acquisition sequences. To evaluate the inter-observer variation of the method, three implants of T1W and another three of T2W have been reconstructed by two different medical physicists with experience on these reconstructions. Results and conclusions: The differences observed in the positioning were significantly smaller than 1 mm in all cases. The presented algorithm also allows the use of only T2W sequence either for contouring or reconstruction purposes. The proposed method is robust and independent of the visibility of the artifact at the tip of the needle.  
  Address [Richart, Jose; Otal, Antonio; Rodriguez, Silvia; DePiaggio, Marina; Santos, Manuel; Perez-Calatayud, Jose] Benidorm Hosp, Dept Radiotherapy, Alicante, Spain, Email: fballest@uv.es  
  Corporate Author Thesis  
  Publisher Termedia Publishing House Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1689-832x ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000365247600012 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 2476  
Permanent link to this record
 

 
Author Etxebeste, A.; Barrio, J.; Bernabeu, J.; Lacasta, C.; Llosa, G.; Muñoz, E.; Ros, A.; Oliver, J.F. doi  openurl
  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 (up) 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 NEXT Collaboration (Simon, A. et al); Gomez-Cadenas, J. J.; Alvarez, V.; Benlloch-Rodriguez, J. M.; Botas, A.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Ferrario, P.; Laing, A.; Liubarsky, I.; Lopez-March, N.; Martin-Albo, J.; Martinez, A.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Perez, J.; Querol, M.; Renner, J.; Rodriguez, J.; Sorel, M.; Torrent, J.; Yahlali, N. url  doi
openurl 
  Title Application and performance of an ML-EM algorithm in NEXT Type Journal Article
  Year 2017 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.  
  Volume 12 Issue Pages P08009 - 22pp  
  Keywords Gaseous imaging and tracking detectors; Image reconstruction in medical imaging; Time projection Chambers (TPC); Medical-image reconstruction methods and algorithms; computer-aided software  
  Abstract (up) The goal of the NEXT experiment is the observation of neutrinoless double beta decay in Xe-136 using a gaseous xenon TPC with electroluminescent amplification and specialized photodetector arrays for calorimetry and tracking. The NEXT Collaboration is exploring a number of reconstruction algorithms to exploit the full potential of the detector. This paper describes one of them: the Maximum Likelihood Expectation Maximization (ML-EM) method, a generic iterative algorithm to find maximum-likelihood estimates of parameters that has been applied to solve many different types of complex inverse problems. In particular, we discuss a bi-dimensional version of the method in which the photosensor signals integrated over time are used to reconstruct a transverse projection of the event. First results show that, when applied to detector simulation data, the algorithm achieves nearly optimal energy resolution (better than 0.5% FWHM at the Q value of 136Xe) for events distributed over the full active volume of the TPC.  
  Address [Simon, A.; Gomez-Cadenas, J. J.; Alvarez, V.; Benlloch-Rodriguez, J. M.; Botas, A.; Carcel, S.; Carrion, J. V.; Diaz, J.; Felkai, R.; Ferrario, P.; Laing, A.; Liubarsky, I.; Lopez-March, N.; Martin-Albo, J.; Martinez, A.; Munoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Perez, J.; Querol, M.; Renner, J.; Rodriguez, J.; Sorel, M.; Torrent, J.; Yahlali, N.] CSIC, Inst Fis Corpuscular IFIC, Calle Catedrat Jose Beltran 2, Valencia 46980, Spain, Email: ander.simon@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 1748-0221 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000414159500009 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3358  
Permanent link to this record
 

 
Author Ros Garcia, A.; Barrio, J.; Etxebeste, A.; Garcia-Lopez, J.; Jimenez-Ramos, M.C.; Lacasta, C.; Muñoz, E.; Oliver, J.F.; Roser, J.; Llosa, G. doi  openurl
  Title MACACO II test-beam with high energy photons Type Journal Article
  Year 2020 Publication Physics in Medicine and Biology Abbreviated Journal Phys. Med. Biol.  
  Volume 65 Issue 24 Pages 245027 - 12pp  
  Keywords Compton imaging; Compton camera; proton therapy; LaBr3; test-beam; image reconstruction  
  Abstract (up) The IRIS group at IFIC Valencia is developing a three-layer Compton camera for treatment monitoring in proton therapy. The system is composed of three detector planes, each made of a LaBr3<i monolithic crystal coupled to a SiPM array. Having obtained successful results with the first prototype (MACACO) that demonstrated the feasibility of the proposed technology, a second prototype (MACACO II) with improved performance has been developed, and is the subject of this work. The new system has an enhanced detector energy resolution which translates into a higher spatial resolution of the telescope. The image reconstruction method has also been improved with an accurate model of the sensitivity matrix. The device has been tested with high energy photons at the National Accelerator Centre (CNA, Seville). The tests involved a proton beam of 18 MeV impinging on a graphite target, to produce 4.4 MeV photons. Data were taken at different system positions of the telescope with the first detector at 65 and 160 mm from the target, and at different beam intensities. The measurements allowed successful reconstruction of the photon emission distribution at two target positions separated by 5 mm in different telescope configurations. This result was obtained both with data recorded in the first and second telescope planes (two interaction events) and, for the first time in beam experiments, with data recorded in the three planes (three interaction events).  
  Address [Ros Garcia, A.; Barrio, J.; Etxebeste, A.; Lacasta, C.; Munoz, E.; Oliver, J. F.; Roser, J.; Llosa, G.] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: arosgar@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:000600803000001 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 4654  
Permanent link to this record
 

 
Author ANTARES Collaboration (Aguilar, J.A. et al); Bigongiari, C.; Dornic, D.; Emanuele, U.; Gomez-Gonzalez, J.P.; Hernandez-Rey, J.J.; Mangano, S.; Ruiz-Rivas, J.; Salesa, F.; Sanchez-Losa, A.; Toscano, S.; Yepes, H.; Zornoza, J.D.; Zuñiga, J. url  doi
openurl 
  Title A method for detection of muon induced electromagnetic showers with the ANTARES detector Type Journal Article
  Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 675 Issue Pages 56-62  
  Keywords Neutrino telescope; Electromagnetic shower identification; High energy muons; Energy reconstruction  
  Abstract (up) The primary aim of ANTARES is neutrino astronomy with upward going muons created in charged current muon neutrino interactions in the detector and its surroundings. Downward going muons are background for neutrino searches. These muons are the decay products of cosmic-ray collisions in the Earth's atmosphere far above the detector. This paper presents a method to identify and count electromagnetic showers induced along atmospheric muon tracks with the ANTARES detector. The method is applied to both cosmic muon data and simulations and its applicability to the reconstruction of muon event energies is demonstrated.  
  Address [Aguilar, J. A.; Bigongiari, C.; Dornic, D.; Emanuele, U.; Gomez-Gonzalez, J. P.; Hernandez-Rey, J. J.; Mangano, S.; Rostovtsev, A.; Ruiz-Rivas, J.; Salesa, F.; Sanchez-Losa, A.; Toscano, S.; Yepes, H.; Zornoza, J. D.; Zuniga, J.] Univ Valencia, IFIC, Inst Fis Corpuscular, CSIC, Valencia 46071, Spain, Email: manganos@ific.uv.es  
  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:000302973600011 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 988  
Permanent link to this record
 

 
Author Aiola, S.; Amhis, Y.; Billoir, P.; Jashal, B.K.; Henry, L.; Oyanguren, A.; Marin Benito, C.; Polci, F.; Quagliani, R.; Schiller, M.; Wang, M. url  doi
openurl 
  Title Hybrid seeding: A standalone track reconstruction algorithm for scintillating fibre tracker at LHCb Type Journal Article
  Year 2021 Publication Computer Physics Communications Abbreviated Journal Comput. Phys. Commun.  
  Volume 260 Issue Pages 107713 - 5pp  
  Keywords Track reconstruction; Pattern Recognition; LHCb  
  Abstract (up) We describe the Hybrid seeding, a stand-alone pattern recognition algorithm aiming at finding charged particle trajectories for the LHCb upgrade. A significant improvement to the charged particle reconstruction efficiency is accomplished by exploiting the knowledge of the LHCb magnetic field and the position of energy deposits in the scintillating fibre tracker detector. Moreover, we achieve a low fake rate and a small contribution to the overall timing budget of the LHCb real-time data processing.  
  Address [Billoir, P.; Polci, F.; Quagliani, R.] Sorbonne Univ, Paris Diderot Sorbonne Paris Cite, LPNHE, CNRS IN2P3, Paris, France, Email: louis.henry@cern.ch;  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0010-4655 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000608243400007 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4685  
Permanent link to this record
 

 
Author Albiol, F.; Corbi, A.; Albiol, A. doi  openurl
  Title Geometrical Calibration of X-Ray Imaging With RGB Cameras for 3D Reconstruction Type Journal Article
  Year 2016 Publication IEEE Transactions on Medical Imaging Abbreviated Journal IEEE Trans. Med. Imaging  
  Volume 35 Issue 8 Pages 1952-1961  
  Keywords 3D reconstruction; camera system; geometric calibration; visible fiducials; X-ray imaging  
  Abstract (up) We present a methodology to recover the geometrical calibration of conventional X-ray settings with the help of an ordinary video camera and visible fiducials that are present in the scene. After calibration, equivalent points of interest can be easily identifiable with the help of the epipolar geometry. The same procedure also allows the measurement of real anatomic lengths and angles and obtains accurate 3D locations from image points. Our approach completely eliminates the need for X-ray-opaque reference marks (and necessary supporting frames) which can sometimes be invasive for the patient, occlude the radiographic picture, and end up projected outside the imaging sensor area in oblique protocols. Two possible frameworks are envisioned: a spatially shifting X-ray anode around the patient/object and a moving patient that moves/rotates while the imaging system remains fixed. As a proof of concept, experiences with a device under test (DUT), an anthropomorphic phantom and a real brachytherapy session have been carried out. The results show that it is possible to identify common points with a proper level of accuracy and retrieve three-dimensional locations, lengths and shapes with a millimetric level of precision. The presented approach is simple and compatible with both current and legacy widespread diagnostic X-ray imaging deployments and it can represent a good and inexpensive alternative to other radiological modalities like CT.  
  Address [Albiol, Francisco; Corbi, Alberto] Univ Valencia, Consejo Super Invest Cient, Inst Fis Corpuscular IFIC, Paterna 46980, Spain, Email: kiko@ific.uv.es;  
  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 WOS:000381436000016 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 2781  
Permanent link to this record
 

 
Author Blume, M.; Martinez-Moller, A.; Keil, A.; Navab, N.; Rafecas, M. doi  openurl
  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 (up) 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 Boronat, M.; Fuster, J.; Garcia, I.; Ros, E.; Vos, M. url  doi
openurl 
  Title A robust jet reconstruction algorithm for high-energy lepton colliders Type Journal Article
  Year 2015 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 750 Issue Pages 95-99  
  Keywords Jet reconstruction; Sequential recombination algorithm; Future lepton colliders; ILC; CLIC  
  Abstract (up) We propose a new sequential jet reconstruction algorithm for future lepton colliders at the energy frontier. The Valencia algorithm combines the natural distance criterion for lepton colliders with the greater robustness against backgrounds of algorithms adapted to hadron colliders. Results on a detailed Monte Carlo simulation of t (t) over tilde and ZZ production at future linear e(+)e(-) colliders (ILC and CLIC) with a realistic level of background overlaid, show that it achieves better performance in the presence of background than the classical algorithms used at previous e(+)e(-) colliders.  
  Address [Boronat, M.; Fuster, J.; Garcia, I.; Ros, E.; Vos, M.] IFIC CSIC UVEG, Valencia, Spain, Email: marcel.vos@ific.uv.es  
  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 0370-2693 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000364250600018 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 2468  
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