Ultrasound scattering from spherical tumours.

abstract：:Component-based normalization is a method used to compensate for the sensitivity of each of the lines of response acquired in positron emission tomography. This method consists of modelling the sensitivity of each line of response as a product of multiple factors, which can be classified as time-invariant, time-varian...

journal_title：Physics in medicine and biology

authors： Belzunce MA,Reader AJ

更新日期：2016-05-07 00:00:00

abstract：:An algorithm for dynamic multileaf-collimator (dMLC) tracking of a target performing a known a priori, rigid-body motion during volumetric modulated arc therapy (VMAT), has been experimentally validated and applied to investigate the potential of the Agility (Elekta AB, Stockholm, Sweden) multileaf-collimator (MLC) fo...

journal_title：Physics in medicine and biology

authors： Davies GA,Clowes P,Bedford JL,Evans PM,Webb S,Poludniowski G

更新日期：2013-07-07 00:00:00

abstract：:Imaging of the microvasculature is often performed using contrast agents in combination with either ultrasound (US) or magnetic resonance (MR) imaging. Contrast agents are used to enhance medical imaging by highlighting microvascular properties and function. Dynamic signal changes arising from the passage of contrast ...

journal_title：Physics in medicine and biology

authors： Chandrana C,Bevan P,Hudson J,Pang I,Burns P,Plewes D,Chopra R

更新日期：2011-02-07 00:00:00

abstract：:Sensing and enumeration of specific types of circulating cells in small animals is an important problem in many areas of biomedical research. Microscopy-based fluorescence in vivo flow cytometry methods have been developed previously, but these are typically limited to sampling of very small blood volumes, so that ver...

journal_title：Physics in medicine and biology

authors： Zettergren E,Swamy T,Runnels J,Lin CP,Niedre M

更新日期：2012-07-21 00:00:00

abstract：:Positron emission tomography is one of the most mature techniques for monitoring the particles range in hadron therapy, aiming to reduce treatment uncertainties and therefore the extent of safety margins in the treatment plan. In-beam PET monitoring has been already performed using inter-spill and post-irradiation dat...

journal_title：Physics in medicine and biology

authors： Kostara E,Sportelli G,Belcari N,Camarlinghi N,Cerello P,Del Guerra A,Ferrero V,Fiorina E,Giraudo G,Morrocchi M,Pennazio F,Pullia M,Rivetti A,Rolo MD,Rosso V,Wheadon R,Bisogni MG

更新日期：2019-01-21 00:00:00

abstract：:Online proton range/dose verification based on measurements of proton-induced positron emitters is a promising strategy for quality assurance in proton therapy. Because of the nonlinear correlation between the dose distribution and the activity distribution of positron emitters, we aim to establish their relationship ...

journal_title：Physics in medicine and biology

authors： Liu C,Li Z,Hu W,Xing L,Peng H

更新日期：2019-09-04 00:00:00

abstract：:Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry ...

journal_title：Physics in medicine and biology

authors： Afsharpour H,Landry G,D'Amours M,Enger S,Reniers B,Poon E,Carrier JF,Verhaegen F,Beaulieu L

更新日期：2012-06-07 00:00:00

abstract：:At present, there exists few openly available methods for evaluation of simultaneous segmentation and registration algorithms. These methods allow for a combination of both techniques to track the tumor in complex settings such as adaptive radiotherapy. We have produced a quality assurance platform for evaluating this...

journal_title：Physics in medicine and biology

authors： Markel D,Levesque I,Larkin J,Léger P,El Naqa I

更新日期：2016-10-07 00:00:00

abstract：:ICRP Publication 116 on 'Conversion coefficients for radiological protection quantities for external radiation exposures', provides fluence-to-dose conversion coefficients for organ-absorbed doses and effective dose for various types of external exposures (ICRP 2010 ICRP Publication 116). The publication supersedes th...

journal_title：Physics in medicine and biology

authors： Petoussi-Henss N,Bolch WE,Eckerman KF,Endo A,Hertel N,Hunt J,Menzel HG,Pelliccioni M,Schlattl H,Zankl M

更新日期：2014-09-21 00:00:00

abstract：:A method for the calculation of absorbed dose distributions of arbitrarily shaped electron beams is presented. Isodose distributions and output factors of treatment fields can be predicted with good accuracy, without the need for any dose measurement in the actual field. A Gaussian pencil beam model is employed with t...

journal_title：Physics in medicine and biology

authors： Bruinvis IA,Van Amstel A,Elevelt AJ,Van der Laarse R

更新日期：1983-06-01 00:00:00

abstract：:In modern radiotherapy, it is vitally important to monitor the performance of all linac components including the collimation system. In this study, a simple measurement method and accurate algorithm are introduced for investigation of the secondary and tertiary collimator sag during radiotherapy arc treatments. The me...

journal_title：Physics in medicine and biology

authors： Rowshanfarzad P,Sabet M,O'Connor DJ,Greer PB

更新日期：2012-06-21 00:00:00

abstract：:Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B. The purpose of this study is to system...

journal_title：Physics in medicine and biology

authors： Pojtinger S,Dohm OS,Kapsch RP,Thorwarth D

更新日期：2018-06-07 00:00:00

abstract：:Many models exist for predicting toxicities based on dose-volume histograms (DVHs) or dose-surface histograms (DSHs). This approach has several drawbacks as firstly the reduction of the dose distribution to a histogram results in the loss of spatial information and secondly the bins of the histograms are highly correl...

journal_title：Physics in medicine and biology

authors： Buettner F,Gulliford SL,Webb S,Partridge M

更新日期：2011-04-07 00:00:00

abstract：:For angiography using synchrotron radiation we measured the absorbed dose distribution in inhomogeneous phantoms with thin LiF:Mg, Cu, P, LiF:Mg, Ti thermoluminescent dosimeters (TLDs) in tissue and lung substitutes, and with Mg2SiO4:Tb TLDs in bone substitute for 33.32 keV monoenergetic photons from synchrotron radia...

journal_title：Physics in medicine and biology

authors： Nariyama N,Namito Y,Ban S,Hirayama H

更新日期：2001-03-01 00:00:00

abstract：:Many applications of electroporation, especially those utilizing electrofusion and in-vivo electroporation, involve cell environments that include close cell-to-cell proximity and a wide range of target cell size. It is important to understand how this kind of environment may alter optimum electroporation electrical p...

journal_title：Physics in medicine and biology

authors： Gaynor PT,Bodger PS

更新日期：2006-06-21 00:00:00

abstract：:Earlier work on the dielectric properties of cryoprotectant agents is extended using a modified measuring cell and method of data reduction yielding results more efficiently over a temperature range from -75 to +25 degrees C at frequencies from 27 MHz to 3 GHz. Dimethyl sulphoxide and butanediol are investigated at lo...

journal_title：Physics in medicine and biology

authors： Evans S,bin Azeman A

更新日期：1998-10-01 00:00:00

abstract：:The spatial resolution of 2D detector arrays equipped with ionization chambers or diodes, used for the dose verification of IMRT treatment plans, is limited by the size of the single detector and the centre-to-centre distance between the detectors. Optimization criteria with regard to these parameters have been develo...

journal_title：Physics in medicine and biology

authors： Poppe B,Djouguela A,Blechschmidt A,Willborn K,Rühmann A,Harder D

更新日期：2007-05-21 00:00:00

abstract：:There are three ways to determine the spectrum of a clinical photon beam: direct measurement, modelling the source and reconstruction from ion-chamber measurements. We focus on reconstruction because the necessary equipment is readily available and it provides independent confirmation of source models for a given mach...

journal_title：Physics in medicine and biology

authors： Armbruster B,Hamilton RJ,Kuehl AK

更新日期：2004-11-21 00:00:00

abstract：:In order (i) to evaluate the dose uncertainty of the mouthpiece in daily use during intensity-modulated radiotherapy of patients with head and neck cancer, and (ii) to present a system for in vivo dosimetry of the oral mucosa, we equipped the mouthpiece with alanine dosimeter probes for in vivo dosimetry. The aim was ...

journal_title：Physics in medicine and biology

authors： Wagner D,Anton M,Vorwerk H

更新日期：2011-03-07 00:00:00

abstract：:Intra-fractional motion is a concern during prostate radiation therapy, as it may cause deviations between planned and delivered radiation doses. Because accurate motion information during treatment delivery is critical to address dose deviation, we developed the projection marker matching method (PM3), a novel method...

journal_title：Physics in medicine and biology

authors： Chi Y,Rezaeian NH,Shen C,Zhou Y,Lu W,Yang M,Hannan R,Jia X

更新日期：2017-07-07 00:00:00

abstract：:In vitro dielectric properties of ageing porcine tissues were measured in the frequency range of 50 MHz-20 GHz, and the total combined uncertainties of the measurements were assessed. The results show statistically significant reduction with age in both permittivity and conductivity of 10 out of 15 measured tissues. A...

journal_title：Physics in medicine and biology

authors： Peyman A,Gabriel C,Grant EH,Vermeeren G,Martens L

更新日期：2009-01-21 00:00:00

abstract：:The UK, European and IAEA protocols for breast dosimetry in mammography use tabulations of conversion factors, which relate measurements of incident air kerma to the mean glandular dose to the breast. To supplement the existing tabulations, a Monte Carlo computer program has been used to calculate conversion factors f...

journal_title：Physics in medicine and biology

authors： Dance DR,Young KC

更新日期：2014-05-07 00:00:00

abstract：:Although interventional x-ray angiography (XA) procedures involve relatively high radiation doses that can lead to deterministic tissue reactions in addition to stochastic effects, convenient and accurate estimation of absorbed organ doses has traditionally been out of reach. This has mainly been due to the absence of...

journal_title：Physics in medicine and biology

authors： Omar A,Bujila R,Fransson A,Andreo P,Poludniowski G

更新日期：2016-04-21 00:00:00

abstract：:This study evaluates the performance of the Bruker positron emission tomograph (PET) insert combined with a BioSpec 70/30 USR magnetic resonance imaging (MRI) scanner using the manufacturer acceptance protocol and the NEMA NU 4-2008 for small animal PET. The PET insert is made of 3 rings of 8 monolithic LYSO crystals ...

journal_title：Physics in medicine and biology

authors： Gsell W,Molinos C,Correcher C,Belderbos S,Wouters J,Junge S,Heidenreich M,Vande Velde G,Rezaei A,Nuyts J,Cawthorne C,Cleeren F,Nannan L,Deroose CM,Himmelreich U,González Martínez AJ

更新日期：2020-06-26 00:00:00

abstract：:Current dosimetry protocols (AAPM, IAEA, DIN) recommend the use of parallel-plate ionization chambers for the measurement of absorbed dose-to-water in clinical electron beams. For well-guarded plane-parallel chambers, it is assumed that the perturbation correction pQ is unity for all electron energies. In this study, ...

journal_title：Physics in medicine and biology

authors： Zink K,Wulff J

更新日期：2008-03-21 00:00:00

abstract：:Prompt gamma (PG) imaging is widely investigated for spot-by-spot in vivo range verification for proton therapy. Previous studies pointed out that the accuracy of prompt gamma imaging is affected by the statistics (number of protons delivered per pencil beam) of the proton beams and the conformity between prompt gamma...

journal_title：Physics in medicine and biology

authors： Tian L,Landry G,Dedes G,Pinto M,Kamp F,Belka C,Parodi K

更新日期：2020-04-29 00:00:00

abstract：:The free space method using a pair of lens antennas was modified for the complex permittivity measurement of biological samples from 20 to 110 GHz. Two methodologies were used to obtain the complex permittivities by the free space method, which were based on the reflection and transmission coefficients. The measuremen...

journal_title：Physics in medicine and biology

authors： Sasaki K,Segawa H,Mizuno M,Wake K,Watanabe S,Hashimoto O

更新日期：2013-03-07 00:00:00

abstract：:The whole prostatic volume (PV) is an important indicator for benign prostate hyperplasia. Correlating the PV with other clinical parameters in a population-based prospective cohort study (SHIP-2) requires valid prostate segmentation in a large number of whole-body MRI scans. The axial proton density fast spin echo fa...

journal_title：Physics in medicine and biology

authors： Habes M,Schiller T,Rosenberg C,Burchardt M,Hoffmann W

更新日期：2013-09-07 00:00:00

abstract：:The development of alpha-emitting radiopharmaceuticals using 211At requires quantitative determination of the time-dependent nature of the 211At biodistribution. However, imaging-based methods for acquiring this information with 211At have not found wide-spread use because of its low abundance of decay emissions suita...

journal_title：Physics in medicine and biology

authors： Crawford JR,Robertson AKH,Yang H,Rodríguez-Rodríguez C,Esquinas PL,Kunz P,Blinder S,Sossi V,Schaffer P,Ruth TJ

更新日期：2018-02-21 00:00:00

abstract：:The enormous advances in the understanding of human anatomy, physiology and pathology in recent decades have led to ever-improving methods of disease prevention, diagnosis and treatment. Many of these achievements have been enabled, at least in part, by advances in ionizing radiation detectors. Radiology has been tran...

journal_title：Physics in medicine and biology

authors： Seco J,Clasie B,Partridge M

更新日期：2014-10-21 00:00:00