Dielectric properties of porcine glands, gonads and body fluids.

abstract：:Over the last 50 years, diagnostic imaging has grown from a state of infancy to a high level of maturity. Many new imaging modalities have been developed. However, modern medical imaging includes not only image production but also image processing, computer-aided diagnosis (CAD), image recording and storage, and image...

journal_title：Physics in medicine and biology

authors： Doi K

更新日期：2006-07-07 00:00:00

abstract：:This work aims to contribute to the study of the radiation dose distribution delivered to the hands of medical staff members during a general computed tomographic (CT) fluoroscopic guided procedure. In this study, both Monte Carlo simulations and measurements were performed. For free-in-air and computed tomography dos...

journal_title：Physics in medicine and biology

authors： Figueira C,Becker F,Blunck C,DiMaria S,Baptista M,Esteves B,Paulo G,Santos J,Teles P,Vaz P

更新日期：2013-08-21 00:00:00

abstract：:The purpose of this study was the evaluation of the impact of a variable relative biological effectiveness (RBE) compared to a constant RBE value of 1.1 in proton therapy prostate trials due to uncertainties in α/β ratio. Twenty patients receiving passive scattered proton therapy (PSPT) and fifteen patients receiving ...

journal_title：Physics in medicine and biology

authors： Marteinsdottir M,Paganetti H

更新日期：2019-06-05 00:00:00

abstract：:Proton therapy is very sensitive to daily density changes along the pencil beam paths. The purpose of this study is to develop and evaluate an automated method for adaptation of IMPT plans to compensate for these daily tissue density variations. A two-step restoration method for 'densities-of-the-day' was created: (1)...

journal_title：Physics in medicine and biology

authors： Jagt T,Breedveld S,van de Water S,Heijmen B,Hoogeman M

更新日期：2017-06-07 00:00:00

abstract：:This work is a follow-up study for a recently-proposed 3D radiochromic gel dosimeter that contains a tetrazolium salt and a physical gel matrix made of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (Pluronic F-127). Several tetrazolium salts were examined in this work, including tetrazoli...

journal_title：Physics in medicine and biology

authors： Kwiatos K,Maras P,Kadlubowski S,Stempień Z,Dudek M,Kozicki M

更新日期：2018-05-04 00:00:00

abstract：:A non-contact approach for diffuse optical tomography (DOT) has been developed for on-demand image updates using surgical navigation technology. A stereoscopic optical tracker provides real-time localization of reflective spheres mounted to a laser diode and near-infrared camera. Standard camera calibration is combine...

journal_title：Physics in medicine and biology

authors： Daly MJ,Wilson BC,Irish JC,Jaffray DA

更新日期：2019-07-05 00:00:00

abstract：:Peripheral neural stimulation is a major problem in current gradient coil designs. Induced current problems in patients relate directly to gradient strength and modulation frequency. Present designs of gradient coil tend to limit ultra-high-speed imaging methods such as echo-planar imaging (EPI) and echo-volumar imagi...

journal_title：Physics in medicine and biology

authors： Mansfield P,Haywood B

更新日期：2008-04-07 00:00:00

abstract：:This paper describes the algorithm and examines the performance of an intensity-modulated radiation therapy (IMRT) beam-angle optimization (BAO) system. In this algorithm successive sets of beam angles are selected from a set of predefined directions using a fast simulated annealing (FSA) algorithm. An IMRT beam-profi...

journal_title：Physics in medicine and biology

authors： Djajaputra D,Wu Q,Wu Y,Mohan R

更新日期：2003-10-07 00:00:00

abstract：:This study investigated the relationship between the specific absorption rate and temperature elevation in an anatomically-based model named NORMAN for exposure to radio-frequency far fields in the ICNIRP guidelines (1998 Health Phys. 74 494-522). The finite-difference time-domain method is used for analyzing the elec...

journal_title：Physics in medicine and biology

authors： Hirata A,Asano T,Fujiwara O

更新日期：2007-08-21 00:00:00

abstract：:The variety of treatment options for cancer patients has increased significantly in recent years. Not only do we combine radiation with surgery and chemotherapy, new therapeutic approaches such as immunotherapy and targeted therapies are starting to play a bigger role. Physics has made significant contributions to rad...

journal_title：Physics in medicine and biology

authors： Grassberger C,Paganetti H

更新日期：2016-11-07 00:00:00

abstract：:The purpose of this paper for four-dimensional (4D) computed tomography (CT) is threefold. (1) A new spatiotemporal model is presented from the matrix perspective with the row dimension in space and the column dimension in time, namely the robust PCA (principal component analysis)-based 4D CT model. That is, instead o...

journal_title：Physics in medicine and biology

authors： Gao H,Cai JF,Shen Z,Zhao H

更新日期：2011-06-07 00:00:00

abstract：:Pinhole SPECT is rapidly gaining popularity for imaging laboratory animals using gamma-emitting molecules. Penetration and scattering of gamma radiation in the pinhole edge material can account for a significant fraction of the total number of photons detected, particularly if the pinholes have small diameters. This s...

journal_title：Physics in medicine and biology

authors： van der Have F,Beekman FJ

更新日期：2004-04-21 00:00:00

abstract：:A dual-ended readout PET detector based on two Hamamatsu 16 × 16 arrays of 1 × 1 mm2 SiPMs coupled to both ends of a 25 × 25 array of 0.69 × 0.69 × 20 mm3 polished LYSOs was evaluated in terms of flood histogram, energy resolution, timing resolution, and DOI resolution. The SiPM arrays have a pitch size of 1.2 mm. Eac...

journal_title：Physics in medicine and biology

authors： Du J,Bai X,Cherry SR

更新日期：2020-08-19 00:00:00

abstract：:The interest in positron emission tomography (PET) and particularly in hybrid integrated PET/CT systems has significantly increased in the last few years due to the improved quality of the obtained images. Nevertheless, one of the most important limits of the PET imaging technique is still its poor spatial resolution ...

journal_title：Physics in medicine and biology

authors： Rapisarda E,Bettinardi V,Thielemans K,Gilardi MC

更新日期：2010-07-21 00:00:00

abstract：:The purpose of this paper is to evaluate the ability of a prototype Compton camera (CC) to measure prompt gamma rays (PG) emitted during delivery of clinical proton pencil beams for prompt gamma imaging (PGI) as a means of providing in vivo verification of the delivered proton radiotherapy beams. A water phantom was i...

journal_title：Physics in medicine and biology

authors： Polf JC,Avery S,Mackin DS,Beddar S

更新日期：2015-09-21 00:00:00

abstract：:Most tissue characterization methods use RF data originating from backscattering processes in the insonified tissue. Characterization of the tissue of a thin layer (e.g., an artery wall) poses problems because of the small amount of data available. The tissue layer may be so thin that there are no RF data that are not...

journal_title：Physics in medicine and biology

authors： Linssen FM,Hoeks AP,Brands PJ

更新日期：1991-10-01 00:00:00

abstract：:Coincidence resolving time (CRT) is one of the most important physical-performance measures for positron emission tomography (PET), as reconstruction with accurate time-of-flight information enhances the lesion detectability in patient studies. Accordingly, various PET detector designs and high-performance front-end r...

journal_title：Physics in medicine and biology

authors： Park H,Lee S,Ko GB,Lee JS

更新日期：2018-12-10 00:00:00

abstract：:A cost-effective method employing polysulphone, nalidixic acid, 8-methoxypsoralen and phenothiazine as UV dosimeters is presented for evaluating the UV spectrum. The exposure measured by each dosimeter is a function of the source spectrum and the spectral response of the material. Each material has a different spectra...

journal_title：Physics in medicine and biology

authors： Parisi AV,Wong JC,Moore GI

更新日期：1997-01-01 00:00:00

abstract：:The (83)Kr magnetic resonance (MR) relaxation time T(1) of krypton gas in contact with model surfaces was previously found to be highly sensitive to surface composition, surface-to-volume ratio, and surface temperature. The work presented here explored aspects of pulmonary (83)Kr T(1) relaxation measurements in excise...

journal_title：Physics in medicine and biology

authors： Stupic KF,Elkins ND,Pavlovskaya GE,Repine JE,Meersmann T

更新日期：2011-07-07 00:00:00

abstract：:Over the course of radiation therapy, a patient's anatomy may change substantially. The relatively recent addition of frequent in-room imaging to assist with patient localization has provided a database of images that may be used to recalculate dose distributions for adaptive radiotherapy purposes. The TomoTherapy Hi-...

journal_title：Physics in medicine and biology

authors： Pukala J,Meeks SL,Bova FJ,Langen KM

更新日期：2011-12-21 00:00:00

abstract：:The use of deformable image registration methods in the context of adaptive radiotherapy leads to uncertainties in the simulation of the administered dose distributions during the treatment course. Evaluation of these methods is a prerequisite to decide if a plan adaptation will improve the individual treatment. Curre...

journal_title：Physics in medicine and biology

authors： Teske H,Bartelheimer K,Meis J,Bendl R,Stoiber EM,Giske K

更新日期：2017-06-21 00:00:00

abstract：:The interactions between energetic ions and biological and/or organic target materials have recently attracted theoretical and experimental attention, due to their implications for detector and device technologies, and for therapeutic applications. Most of the attention has focused on detection of the primary ionizati...

journal_title：Physics in medicine and biology

authors： Falzone N,Myhra S,Chakalova R,Hill MA,Thomson J,Vallis KA

更新日期：2013-11-07 00:00:00

abstract：:Within an epidemiological study regarding the correlation between skin pathologies and personal ultraviolet (UV) exposure due to solar radiation, 14 field campaigns using polysulphone (PS) dosemeters were carried out at three different Italian sites (urban, semi-rural and rural) in every season of the year. A polysulp...

journal_title：Physics in medicine and biology

authors： Casale GR,Borra M,Colosimo A,Colucci M,Militello A,Siani AM,Sisto R

更新日期：2006-09-07 00:00:00

abstract：:The aim of this study is to investigate the feasibility of using conventional jaws to deliver inverse planned intensity-modulated radiotherapy (IMRT) plans for patients with prostate cancer. For ten patients, each had one three-dimensional conformal plan (3D plan) and seven inverse IMRT plans using direct aperture opt...

journal_title：Physics in medicine and biology

authors： Kim Y,Verhey LJ,Xia P

更新日期：2007-04-21 00:00:00

abstract：:A method for simulating spot-scanned delivery to a moving tumour was developed which uses patient-specific image and plan data. The magnitude of interplay effects was investigated for two patient cases under different fractionation and respiratory motion variation scenarios. The use of volumetric rescanning for motion...

journal_title：Physics in medicine and biology

authors： Kraus KM,Heath E,Oelfke U

更新日期：2011-10-21 00:00:00

abstract：:Distributions of linear pathlength measurements have been utilized in skeletal dosimetry of internally emitted short-range particles for over 30 years. This work reviews the methods for coupling these distributions to range-energy data. A revised methodology is presented for handling the insertion of the additional do...

journal_title：Physics in medicine and biology

authors： Jokisch DW,Rajon DA,Patton PW,Bolch WE

更新日期：2011-05-07 00:00:00

abstract：:An algorithm is described for three-dimensional whole-body (3DWB) image reconstruction in positron emission tomography. For whole-body applications, improvements to the popular fixed-axial-acceptance-angle technique are achieved by combining axially adjacent projection data available with a long-axis data set. Time-co...

journal_title：Physics in medicine and biology

authors： Cutler PD,Xu M

更新日期：1996-08-01 00:00:00

abstract：:The application of thermal modelling for hyperthermia and thermal ablation is severely hampered by lack of information about perfusion and vasculature. However, recently, with the advent of sophisticated angiography and dynamic contrast enhanced (DCE) imaging techniques, it has become possible to image small vessels a...

journal_title：Physics in medicine and biology

authors： Van den Berg CA,Van de Kamer JB,De Leeuw AA,Jeukens CR,Raaymakers BW,van Vulpen M,Lagendijk JJ

更新日期：2006-02-21 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：:Cavity theories are used to relate the dose in a medium to the dose in a cavity. No satisfactory analytical approach exists for the case of intermediate cavities, such as TLDs, when interface effects are important. Burlin proposed a general cavity theory that accounts for the cavity size but which ignores interface ef...

journal_title：Physics in medicine and biology

authors： Frujinoiu C

更新日期：2001-04-01 00:00:00