Global point signature for shape analysis of carpal bones.

abstract：:The original concept of the echo mechanism in diagnostic medical ultrasound--of step impedance discontinuities--is investigated in terms of the numerical implications of more refined models. The effect of a discontinuity in the attenuation coefficients is found to have as much significance as the impedance discontinui...

journal_title：Physics in medicine and biology

authors： Chivers RC,Santosa F

更新日期：1986-08-01 00:00:00

abstract：:Simultaneous dual-radionuclide myocardial perfusion/innervation SPECT imaging can provide important information about the mismatch between scar tissue and denervated regions. The Siemens IQ-SPECT system developed for cardiac imaging uses a multifocal SMARTZOOM collimator to achieve a four-fold sensitivity for the card...

journal_title：Physics in medicine and biology

authors： Du Y,Bhattacharya M,Frey EC

更新日期：2014-06-07 00:00:00

abstract：:A comparative study was performed to reveal differences and relative figures of merit of seven different calculation algorithms for photon beams when applied to inhomogeneous media. The following algorithms were investigated: Varian Eclipse: the anisotropic analytical algorithm, and the pencil beam with modified Batho...

journal_title：Physics in medicine and biology

authors： Fogliata A,Vanetti E,Albers D,Brink C,Clivio A,Knöös T,Nicolini G,Cozzi L

更新日期：2007-03-07 00:00:00

abstract：:In radiofrequency (RF) ablation or hyperthermia, internal temperature measurements and tissue property imaging are important to control their outputs and assess the treatment effect. Recently, magnetic resonance electrical impedance tomography (MREIT), as a non-invasive imaging method of internal conductivity distribu...

journal_title：Physics in medicine and biology

authors： Oh TI,Kim HJ,Jeong WC,Chauhan M,Kwon OI,Woo EJ

更新日期：2013-04-21 00:00:00

abstract：:Scattered doses, e.g. neutron doses in proton therapy, are of concern in radiation therapy. Although measured data are the gold standard, Monte Carlo simulations allow a more realistic consideration of patient anatomy via whole-body phantoms. When calculating neutron doses with Monte Carlo techniques, the dose can be ...

journal_title：Physics in medicine and biology

authors： Jarlskog CZ,Paganetti H

更新日期：2008-09-07 00:00:00

abstract：:In carbon-ion radiotherapy, single-beam delivery each day in alternate directions has been common practice for efficient operation, taking advantage of the Bragg peak and the relative biological effectiveness (RBE) for uniform dose conformation to a tumor. Treatments are usually fractionated and treatment plans are ev...

journal_title：Physics in medicine and biology

authors： Kanematsu N,Inaniwa T

更新日期：2017-02-07 00:00:00

abstract：:This paper introduces a spatial-diversity method for speckle suppression in optical coherence microscopy. The method is based on combining interference signals from an array of detectors placed in the back focal plane of the objective lens, such that elements receive light backscattered from the sample volume at diffe...

journal_title：Physics in medicine and biology

authors： Schmitt JM

更新日期：1997-07-01 00:00:00

abstract：:Optical experiments are described for measuring the attenuation characteristics of breast tissues at visible and near-infrared wavelengths. Total attenuation coefficients post mortem were measured directly in thin tissue sections. They are usually within the range from 10 to 30 mm-1, are rather higher in fat than in f...

journal_title：Physics in medicine and biology

authors： Key H,Davies ER,Jackson PC,Wells PN

更新日期：1991-05-01 00:00:00

abstract：:Monte Carlo simulation of radiation transport is considered to be one of the most accurate methods of radiation therapy dose calculation. With the rapid development of computer technology, Monte Carlo based treatment planning for radiation therapy is becoming practical. A basic requirement for Monte Carlo treatment pl...

journal_title：Physics in medicine and biology

authors： Ma CM,Jiang SB

更新日期：1999-12-01 00:00:00

abstract：:Depth-dose distributions were calculated for thermal and epithermal neutron fluence and capture gamma ray dose rates using a two-dimensional neutron-coupled gamma-ray transport code (DOT 3.5) for gadolinium neutron capture therapy. The results show that (i) a capture gamma-ray dose rate of 10 Gy h-1 was obtained with ...

journal_title：Physics in medicine and biology

authors： Matsumoto T

更新日期：1992-01-01 00:00:00

abstract：:Tumour histological grade has prognostic implications in breast cancer. Tumour features in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and T2-weighted (T2W) imaging can provide related and complementary information in the analysis of breast lesions to improve MRI-based histological status prediction...

journal_title：Physics in medicine and biology

authors： Fan M,Liu Z,Xie S,Xu M,Wang S,Gao X,Li L

更新日期：2019-10-23 00:00:00

abstract：:Images of the human retina are routinely used in clinical practice for the diagnosis and management of eye disease. Increased permeability of retinal blood vessels, which is a clinically significant feature, can be visualized with a process known as fluorescein angiography as leakage of fluorescence dye into the surro...

journal_title：Physics in medicine and biology

authors： Cree MJ,Olson JA,McHardy KC,Sharp PF,Forrester JV

更新日期：1999-01-01 00:00:00

abstract：:For conventional irradiation devices, the radiation isocenter accuracy is determined by star shot measurements on films. In magnetic resonance (MR)-guided radiotherapy devices, the results of this test may be altered by the magnetic field and the need to align the radiation and imaging isocenter may require a modifica...

journal_title：Physics in medicine and biology

authors： Dorsch S,Mann P,Lang C,Haering P,Runz A,Karger CP

更新日期：2018-05-29 00:00:00

abstract：:A method has been developed which, by using the geometric information from treatment sample cases, selects from a given data set an initial treatment plan as a step for treatment plan optimization. The method uses an artificial neural network (ANN) classification technique to select a best matching plan from the 'opti...

journal_title：Physics in medicine and biology

authors： Hosseini-Ashrafi ME,Bagherebadian H,Yahaqi E

更新日期：1999-06-01 00:00:00

abstract：:Computer aided detection (CADe) for breast lesion can provide an important reference for radiologists in breast cancer screening. Architectural distortion (AD) is a type of breast lesion that is difficult to detect. A majority of CADe methods focus on detecting the radial pattern, which is a main characteristic of typ...

journal_title：Physics in medicine and biology

authors： Li Y,He Z,Lu Y,Ma X,Guo Y,Xie Z,Xu Z,Chen W,Chen H

更新日期：2020-06-02 00:00:00

abstract：:We report on a novel method for simultaneous biological optimization of treatment plans for hypoxic tumors using multiple ion species. Our previously introduced kill painting approach, where the overall cell killing is optimized on biologically heterogeneous targets, was expanded with the capability of handling differ...

journal_title：Physics in medicine and biology

authors： Sokol O,Krämer M,Hild S,Durante M,Scifoni E

更新日期：2019-02-08 00:00:00

abstract：:Over the last decade, the performance of benchtop x-ray fluorescence computed tomography (XFCT) systems has been significantly enhanced through hardware and software optimizations. Recent studies have indicated the need of energy-resolving pixelated/array detectors in the x-ray detection component to further improve t...

journal_title：Physics in medicine and biology

authors： Moktan H,Ahmed MF,Jayarathna S,Deng L,Cho SH

更新日期：2020-08-31 00:00:00

abstract：:Dynamic positron emission tomography (PET) imaging can provide information about metabolic changes over time, used for kinetic analysis and auxiliary diagnosis. Existing deep learning-based reconstruction methods have too many trainable parameters and poor generalization, and require mass data to train the neural netw...

journal_title：Physics in medicine and biology

authors： Wang B,Liu H

更新日期：2020-10-13 00:00:00

abstract：:The standard mammogram form (SMF) representation of an x-ray mammogram is a standardized, quantitative representation of the breast from which the volume of non-fat tissue and breast density can be easily estimated, both of which are of significant interest in determining breast cancer risk. Previous theoretical analy...

journal_title：Physics in medicine and biology

authors： Highnam R,Pan X,Warren R,Jeffreys M,Davey Smith G,Brady M

更新日期：2006-06-07 00:00:00

abstract：:Novel methods are presented which allow the estimation of the effect of stereotactic fiducial marker localization on target localization in a stereotactic surgery planning program based on the integration of image data from various modalities. The results of simulations are presented. A method for the evaluation of th...

journal_title：Physics in medicine and biology

authors： Lemieux L,Jagoe R

更新日期：1994-11-01 00:00:00

abstract：:The dependence of boron-dose enhancer (BDE) characteristics on dose protocol and 10B concentration was evaluated for BNCT using near-threshold 7Li(p,n)7Be direct neutrons. The treatable protocol depth (TPD) was utilized as an evaluation index. MCNP calculations were performed for near-threshold 7Li(p,n)7Be at a proton...

journal_title：Physics in medicine and biology

authors： Tanaka K,Kobayashi T,Bengua G,Nakagawa Y,Endo S,Hoshi M

更新日期：2005-01-07 00:00:00

abstract：:Electrical properties (EP), namely conductivity and permittivity, can provide endogenous contrast for tissue characterization. Using electrical property tomography (EPT), maps of EP can be generated from conventional MRI data. This report investigates the feasibility and accuracy of EPT at 21.1 T for multiple RF coils...

journal_title：Physics in medicine and biology

authors： Amouzandeh G,Mentink-Vigier F,Helsper S,Bagdasarian FA,Rosenberg JT,Grant SC

更新日期：2020-02-28 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：: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：:It is difficult to test near-infrared spectrophotometry instruments in vivo. Therefore we constructed a liquid phantom which mimics the neonatal head. It consists of a spherical 3.5 mm thick layer of silicone rubber simulating skin and bone and a 0.5 mm thick clear layer of polypropylene imitating cerebrospinal fluid....

journal_title：Physics in medicine and biology

authors： Wolf M,Keel M,Dietz V,von Siebenthal K,Bucher HU,Baenziger O

更新日期：1999-07-01 00:00:00

abstract：:Several recent reports agree that the potentially dangerous heating around extended wires or coaxial cables inside the bodycoil of a magnetic resonance imager is related to resonant effects. No quantitative description of this idea has been given so far. We analyse a simplified situation, where a straight metallic wir...

journal_title：Physics in medicine and biology

authors： Pictet J,Meuli R,Wicky S,van der Klink JJ

更新日期：2002-08-21 00:00:00

abstract：:Both inhomogeneity in the main magnetic field and non-linearity in the gradient fields introduce errors in NMR images reconstructed from projections. It is found that the image artefacts caused by these two sources are separable. The inhomogeneous main field blurs the image while the nonlinear gradients distort the im...

journal_title：Physics in medicine and biology

authors： Lai CM

更新日期：1983-08-01 00:00:00

abstract：:Temporal regularization plays a critical role in cardiac gated dynamic SPECT reconstruction, of which the goal is to obtain an image sequence from a single acquisition which simultaneously shows both cardiac motion and tracer distribution change over the course of imaging (termed 5D). In our recent work, we explored t...

journal_title：Physics in medicine and biology

authors： Niu X,Yang Y,King MA

更新日期：2012-09-07 00:00:00

abstract：:Two new detectors (0.015 cm3 ion chamber from PTW, 0.6 mm diameter diode from Scanditronix AB) designed specifically for use in small stereotactic fields were compared against similar, more routine, detectors (0.125 cm3 ion chamber, parallel plate chamber, shielded and unshielded diodes and film). Percentage depth dos...

journal_title：Physics in medicine and biology

authors： McKerracher C,Thwaites DI

更新日期：1999-09-01 00:00:00

abstract：:This paper presents a computerized method for the selection of an irregular region of interest (ROI) in broadband ultrasound attenuation (BUA) images. A region growing algorithm searches an initial region in the posterior part of the calcaneus until the pixel with the lowest attenuation value is found; this is the sta...

journal_title：Physics in medicine and biology

authors： Damilakis J,Stratakis J,Perisinakis K,Gourtsoyiannis N

更新日期：2002-01-21 00:00:00