Improved scatter correction using adaptive scatter kernel superposition.

abstract：:The purpose of this work is to develop a validated Geant4 simulation model of a whole-body prototype PET scanner constructed from the four-layer depth-of-interaction detectors developed at the National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Japan. T...

journal_title：Physics in medicine and biology

authors： Ahmed AM,Chacon A,Rutherford H,Akamatsu G,Mohammadi A,Nishikido F,Tashima H,Yoshida E,Yamaya T,Franklin DR,Rosenfeld A,Guatelli S,Safavi-Naeini M

更新日期：2020-12-18 00:00:00

abstract：:A medical research protocol on clinical intravenous coronary angiography has been completed at the European Synchrotron Radiation Facility (ESRF) biomedical beamline. The aim was to investigate the accuracy of intravenous coronary angiography based on the K-edge digital subtraction technique for the detection of in-st...

journal_title：Physics in medicine and biology

authors： Sarnelli A,Nemoz C,Elleaume H,Estève F,Bertrand B,Bravin A

更新日期：2005-02-21 00:00:00

abstract：:Magnetic Particle Imaging (MPI) is a promising medical imaging technique for visualizing the three-dimensional distribution of tracer materials, specifically iron oxide nanoparticles (IONP). The optimization of magnetic nanoparticles (MNP) plays an essential role to improve the image resolution and sensitivity of imag...

journal_title：Physics in medicine and biology

authors： Arsalani S,Loewa N,Kosch O,Radon P,Baffa O,Wiekhorst F

更新日期：2020-11-23 00:00:00

abstract：:The performance of a light sharing and recirculation mechanism that allows the extraction of depth of interaction (DOI) are investigated in this paper, with a particular focus on timing. In parallel, a method to optimize the coincidence time resolution (CTR) of PET detectors by use of the DOI information is proposed a...

journal_title：Physics in medicine and biology

authors： Pizzichemi M,Polesel A,Stringhini G,Gundacker S,Lecoq P,Tavernier S,Paganoni M,Auffray E

更新日期：2019-08-07 00:00:00

abstract：:It has been demonstrated that gas-filled microbubble contrast agents, based on their volume changes, can serve as pressure probes in an MR field. It was recently reported that such an MR-based pressure measurement with microbubbles at 1.5 T must make use of microbubbles that have a volumetric magnetic susceptibility d...

journal_title：Physics in medicine and biology

authors： Dharmakumar R,Plewes DB,Wright GA

更新日期：2005-10-21 00:00:00

abstract：:Cell experiments have shown the proton relative biological effectiveness (RBE) to vary with dose and linear energy transfer (LET), which has led to development of variable RBE models. The RBE is normally estimated from two independent functions, the RBEmax and RBEmin, describing the extreme RBE at low and high doses. ...

journal_title：Physics in medicine and biology

authors： Rørvik E,Thörnqvist S,Ytre-Hauge KS

更新日期：2019-09-23 00:00:00

abstract：:The purpose of this study was to examine the use of three physical image quality metrics in the calibration of an automatic exposure control (AEC) device for chest radiography with a computed radiography (CR) imaging system. The metrics assessed were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and mean ...

journal_title：Physics in medicine and biology

authors： Moore CS,Wood TJ,Avery G,Balcam S,Needler L,Beavis AW,Saunderson JR

更新日期：2014-05-07 00:00:00

abstract：:A mathematical transcription of the intrinsic circuit of the CA1 region of the rat dorsal hippocampus was made and the model parameters adjusted according to experimental data from intracellular recordings and single channel kinetics. This model was able to simulate well the profile of the field potentials recorded ex...

journal_title：Physics in medicine and biology

authors： Almeida AC,Fernandes de Lima VM,Infantosi AF

更新日期：1998-09-01 00:00:00

abstract：:A technique is described for examining the mode of operation of radiation detectors and estimating the losses and gains caused by random summing effects in spectra acquired at high counting rates. The technique is applied to estimating the errors caused by random summing when measuring the amounts of carbon and nitrog...

journal_title：Physics in medicine and biology

authors： Yankuba S,Oldroyd B,Metcalfe SC,Godfrey JE,Oxby CB

更新日期：1989-08-01 00:00:00

abstract：:Cone-beam computed tomography (CBCT) has rapidly become a clinically useful imaging modality for image-guided radiation therapy. Unfortunately, CBCT images of the thorax are susceptible to artefacts due to scattered photons, beam hardening, lag in data acquisition, and respiratory motion during a slow scan. These limi...

journal_title：Physics in medicine and biology

authors： Disher B,Hajdok G,Wang A,Craig J,Gaede S,Battista JJ

更新日期：2013-06-21 00:00:00

abstract：:Optically stimulated luminescent dosimeters (OSLDs) are becoming increasingly popular for measuring an absorbed dose in clinical radiotherapy. OSLDs have known energy dependence, and this is accounted for by either calibrating the OSLD with a specific nominal energy, or using a standard energy correction factor to acc...

journal_title：Physics in medicine and biology

authors： Scarboro SB,Followill DS,Kerns JR,White RA,Kry SF

更新日期：2012-05-07 00:00:00

abstract：:Proton therapy with active scanning beam delivery has significant advantages compared to conventional radiotherapy. However, so far only static targets have been treated in this way, since moving targets potentially lead to interplay effects. For 4D treatment planning, information on the target motion is needed to cal...

journal_title：Physics in medicine and biology

authors： Zhang Y,Boye D,Tanner C,Lomax AJ,Knopf A

更新日期：2012-04-07 00:00:00

abstract：:In this paper, Novikov's inversion formula of the attenuated two-dimensional (2D) Radon transform is applied to the reconstruction of attenuated fan-beam projections acquired with equal detector spacing and of attenuated cone-beam projections acquired with a flat planar detector and circular trajectory. The derivation...

journal_title：Physics in medicine and biology

authors： Huang Q,Zeng GL,You J,Gullberg GT

更新日期：2005-05-21 00:00:00

abstract：:A recently described, computer aided method of attenuation analysis has been applied to free-air chamber measurements of the attenuation by up to 30mm A1 of the exposure rate of a narrow beam of X-radiation excited at a thick W target in a Be window tube by constant potentials of 60, 80, 100, 120 and 140 kV. It has ...

journal_title：Physics in medicine and biology

authors： Soole BW

更新日期：1977-03-01 00:00:00

abstract：:Detectors used for positron emission tomography (PET) provide fast, randomly distributed signals that need to be digitized for further processing. One possibility is to sample the signals at the peak initiated by a trigger from a constant fraction discriminator (CFD). For PET detectors, simultaneous acquisition of man...

journal_title：Physics in medicine and biology

authors： Judenhofer MS,Pichler BJ,Cherry SR

更新日期：2005-01-07 00:00:00

abstract：:Radionuclides which decay by electron capture accompanied by Auger electron cascades, or by beta emission are thought to be excessively damaging when incorporated into the molecular structure of mammalian cell nuclei and thereby pose a radiation hazard which is not assessable by conventional dosimetry. Survival data, ...

journal_title：Physics in medicine and biology

authors： Younis AR,Watt DE

更新日期：1989-07-01 00:00:00

abstract：:A circular scanning trajectory is and will likely remain a popular choice of trajectory in computed tomography (CT) imaging because it is easy to implement and control. Filtered-backprojection (FBP)-based algorithms have been developed previously for approximate and exact reconstruction of the entire image or a region...

journal_title：Physics in medicine and biology

authors： Pan X,Xia D,Zou Y,Yu L

更新日期：2004-09-21 00:00:00

abstract：:An ultrahigh-resolution full-field optical coherence tomography (OCT) system has been developed for cellular-level imaging of biological media. The system is based on a Linnik interference microscope illuminated with a tungsten halogen lamp, associated with a high-resolution CCD camera. En face tomographic images are ...

journal_title：Physics in medicine and biology

authors： Dubois A,Moneron G,Grieve K,Boccara AC

更新日期：2004-04-07 00:00:00

abstract：:Transcranial direct current stimulation (tDCS) is a neuromodulation scheme where a small current is delivered to the brain via two electrodes attached to the scalp. The electrode design is an important topic, not only as regards efficacy, but also from a safety perspective, as tDCS may be related to skin lesions that ...

journal_title：Physics in medicine and biology

authors： Gomez-Tames J,Sugiyama Y,Laakso I,Tanaka S,Koyama S,Sadato N,Hirata A

更新日期：2016-12-21 00:00:00

abstract：:The device developed by the authors and described here enables the user to measure the depth from the water surface to the point of measurement for a cylindrical ion chamber with a waterproof plastic cap in a water phantom, free of surface-tension error with a high precision. The device seeks vertical orientation and ...

journal_title：Physics in medicine and biology

authors： Tailor RC,Tello VM

更新日期：1995-08-01 00:00:00

abstract：:The electron pencil-beam redefinition algorithm (PBRA), which is used to calculate electron beam dose distributions, assumes that the virtual source of each pencil beam is identical to that of the broad beam incident on the patient. In the present work, a virtual source specific for each pencil beam is modelled by inc...

journal_title：Physics in medicine and biology

authors： Boyd RA,Hogstrom KR,White RA,Starkschall G

更新日期：2001-11-01 00:00:00

abstract：:Margins are employed in radiotherapy treatment planning to mitigate the dosimetric effects of geometric uncertainties for the clinical target volume (CTV). Unfortunately, whilst the use of margins can increase the probability that sufficient dose is delivered to the CTV, it can also result in delivering high dose of r...

journal_title：Physics in medicine and biology

authors： Tsang HS,Kamerling CP,Ziegenhein P,Nill S,Oelfke U

更新日期：2018-10-29 00:00:00

abstract：:Few quantitative data are available on the kinetics of polymerization reactions in polymer gel (PAG) dosimeters and their long-term stability. Post-irradiation polymerization reactions have been found to continue for several weeks, posing questions regarding dosimeter stability and its achievement. In this paper we re...

journal_title：Physics in medicine and biology

authors： McJury M,Oldham M,Leach MO,Webb S

更新日期：1999-08-01 00:00:00

abstract：:The measurand relevant for the dosimetry for radiation therapy is the absorbed dose to water, DW. The Physikalisch-Technische Bundesanstalt (PTB) is establishing a secondary standard for DW for high-energy photon and electron radiation based on electron spin resonance (ESR) of the amino acid alanine. For practical app...

journal_title：Physics in medicine and biology

authors： Anton M

更新日期：2008-03-07 00:00:00

abstract：:Preclinical positron emission tomography, combined with magnetic resonance imaging (PET/MRI), is increasingly used as a tool to simultaneously characterize functional processes in vivo. Many emerging preclinical applications, however, are limited by PET detection sensitivity, especially when generating short imaging f...

journal_title：Physics in medicine and biology

authors： Selfridge AR,Cherry SR,Judenhofer MS

更新日期：2018-12-06 00:00:00

abstract：:A number of heating sources are available for minimally invasive thermal therapy of tumours. The purpose of this work was to compare, theoretically, the heating characteristics of interstitial microwave, laser and ultrasound sources in three tissue sites: breast, brain and liver. Using a numerical method, the heating ...

journal_title：Physics in medicine and biology

authors： Skinner MG,Iizuka MN,Kolios MC,Sherar MD

更新日期：1998-12-01 00:00:00

abstract：:Determining accurate in vivo dosimetry in brachytherapy treatment with high dose gradients is challenging. Here we introduce, investigate, and characterize a novel in vivo dosimeter and readout technique with the potential to address this problem. A cylindrical (4 mm × 20 mm) tissue equivalent radiochromic dosimeter P...

journal_title：Physics in medicine and biology

authors： Vidovic AK,Juang T,Meltsner S,Adamovics J,Chino J,Steffey B,Craciunescu O,Oldham M

更新日期：2014-07-21 00:00:00

abstract：:The peak CT number (CT) and full width at half maximum (FWHM) were obtained from the image profiles of aluminium of thickness ranging from 0.1-9.5 mm. The scans were performed at different fields of view (FOVs) and with different reconstruction algorithms ('bone' and 'standard'). Above 3 mm, CT and FWHM provide measur...

journal_title：Physics in medicine and biology

authors： Newman DL,Dougherty G,al Obaid A,al Hajrasy H

更新日期：1998-03-01 00:00:00

abstract：:Current dosimetry protocols recommend the use of plane-parallel ionization chambers for the dosimetry of clinical electron beams. The necessary perturbation corrections p(wall) and p(cav) are assumed to be unity, independent of the depth of measurement and the energy of the primary electrons. To verify these assumptio...

journal_title：Physics in medicine and biology

authors： Zink K,Wulff J

更新日期：2009-04-21 00:00:00

abstract：:Advanced radiotherapeutical techniques like intensity-modulated radiation therapy (IMRT) are based on an accurate knowledge of the location of the radiation target. An accurate dose delivery, therefore, requires a method to account for the inter- and intrafractional target motion and the target deformation occurring d...

journal_title：Physics in medicine and biology

authors： Tacke M,Nill S,Oelfke U

更新日期：2007-11-21 00:00:00