Bulk optical properties of healthy female breast tissue.

abstract：:The cerebral arteries are difficult to reproduce from first principles, featuring interwoven territories, and intricate layers of grey and white matter with differing metabolic demand. The aim of this study was to identify the ideal configuration of arteries required to sustain an entire brain hemisphere based on mini...

journal_title：Physics in medicine and biology

authors： Keelan J,Chung EML,Hague JP

更新日期：2019-06-21 00:00:00

abstract：:We experimentally investigated the SPECT recovery of I-131 activity in multiple spheres located simultaneously at different locations within a cylindrical phantom that had an elliptical cross section. The sphere volumes ranged from 209 cc down to 4.2 cc. A Prism 3000 camera and two types of parallel-hexagonal-hole col...

journal_title：Physics in medicine and biology

authors： Koral KF,Yendiki A,Dewaraja YK

更新日期：2007-02-07 00:00:00

abstract：:Dielectric properties of porcine glandular tissues and gonads (in vivo) and body fluids (in vitro) have been obtained in the frequency range of 50 MHz to 20 GHz. The experimental data were fitted to a two term Cole-Cole expression. The data presented complement the available dielectric properties of tissues in the lit...

journal_title：Physics in medicine and biology

authors： Peyman A,Gabriel C

更新日期：2012-10-07 00:00:00

abstract：:This paper presents finite-difference time-domain (FDTD) calculations of the whole-body averaged SAR in an anatomically realistic voxel model of the human body. This model, NORMAN, consists of approximately 9 million voxels, of 2 mm dimension in the adult phantom, segmented into 37 tissue types. SAR values are present...

journal_title：Physics in medicine and biology

authors： Dimbylow PJ

更新日期：1997-03-01 00:00:00

abstract：:A new multiplicative correction factor for tissue heterogeneities based on an exact expression for homogeneous non-unit-density media is proposed. O'Connor's density scaling theorem is invoked to evaluate the medium-specific tissue-maximum ratios used in the exact formulation. Monte Carlo calculations were performed a...

journal_title：Physics in medicine and biology

authors： Petti PL,Siddon RL,Bjärngard BE

更新日期：1986-10-01 00:00:00

abstract：:Recently, there has been a resurgence of interest in arc-based IMRT, through the use of 'conventional' multileaf collimator (MLC) systems that can treat large tumor volumes in a single, or very few pass(es) of the gantry. Here we present a novel 'burst mode' modulated arc delivery approach, wherein 2000 monitor units ...

journal_title：Physics in medicine and biology

authors： Salter BJ,Sarkar V,Wang B,Shukla H,Szegedi M,Rassiah-Szegedi P

更新日期：2011-04-07 00:00:00

abstract：:Due to high noise levels in the voxel kinetics, development of reliable parametric imaging algorithms remains one of most active areas in dynamic brain PET imaging, which in the vast majority of cases involves receptor/transporter studies with reversibly binding tracers. As such, the focus of this work has been to dev...

journal_title：Physics in medicine and biology

authors： Rahmim A,Zhou Y,Tang J,Lu L,Sossi V,Wong DF

更新日期：2012-02-07 00:00:00

abstract：:Average penetration depths and detour factors of 1-50 MeV electrons in water and plastic materials have been computed by means of analytical calculation, within the continuous-slowing-down approximation and including multiple scattering, and using the Monte Carlo codes ITS and PENELOPE. Results are compared to detour ...

journal_title：Physics in medicine and biology

authors： Fernández-Varea JM,Andreo P,Tabata T

更新日期：1996-07-01 00:00:00

abstract：:We show how the spectral imaging framework should be modified to account for a high fraction of Compton interactions in low Z detector materials such as silicon. Using this framework, where deposited energies differ from actual photon energies, we compare the performance of a silicon strip detector, including the infl...

journal_title：Physics in medicine and biology

authors： Bornefalk H,Danielsson M

更新日期：2010-04-07 00:00:00

abstract：:Droplets of liquid perfluorocarbon (PFC) are under study as the next generation of contrast agents for ultrasound (US). These droplets can be selectively vaporized into echogenic gas bubbles in situ by externally applied US, with numerous applications to diagnosis and therapy. However, little is known about the mechan...

journal_title：Physics in medicine and biology

authors： Reznik N,Seo M,Williams R,Bolewska-Pedyczak E,Lee M,Matsuura N,Gariepy J,Foster FS,Burns PN

更新日期：2012-11-07 00:00:00

abstract：:Recently, a new family of low-cost x-radiation detectors have been developed, based on semiconducting polymer diodes, which are easy to process, mechanically flexible, relatively inexpensive, and able to cover large areas. To test their potential for radiotherapy applications such as beam monitors or dosimeters, as an...

journal_title：Physics in medicine and biology

authors： Mills CA,Chan YF,Intaniwet A,Shkunov M,Nisbet A,Keddie JL,Sellin PJ

更新日期：2013-07-07 00:00:00

abstract：:The purpose of this study was to validate the accuracy and reliability of volume measurements obtained using three-dimensional (3D) thoracoscopic ultrasound (US) imaging. Artificial "tumours" were created by injecting a liquid agar mixture into spherical moulds of known volume. Once solidified, the "tumours" were impl...

journal_title：Physics in medicine and biology

authors： Hornblower VD,Yu E,Fenster A,Battista JJ,Malthaner RA

更新日期：2007-01-07 00:00:00

abstract：:A recent paper proposed a novel technique for determining the total body water (TBW) of patients suffering with abnormal hydration levels, using a resonant cavity perturbation method. Current techniques to measure TBW are limited by resolution and technical constraints. However, this new method involves measuring the ...

journal_title：Physics in medicine and biology

authors： Stone DA,Robinson MP

更新日期：2004-05-07 00:00:00

abstract：:Recent measurements of differential elastic and inelastic neutron scattering from oxygen, nitrogen and calcium at 18 less than En less than 26 MeV are presented and analysed in terms of the optical model. These data, together with earlier measurements of scattering and total cross sections, are used to construct model...

journal_title：Physics in medicine and biology

authors： Islam MS,Finlay RW,Petler JS,Rapaport J,Alarcon R,Wierzbicki J

更新日期：1988-03-01 00:00:00

abstract：:Computational phantoms are commonly used in internal radiation dosimetry to assess the amount and distribution pattern of energy deposited in various parts of the human body from different internal radiation sources. Radiation dose assessments are commonly performed on predetermined reference computational phantoms wh...

journal_title：Physics in medicine and biology

authors： Xie T,Kuster N,Zaidi H

更新日期：2017-07-13 00:00:00

abstract：:A multimodal micro-computed tomography (CT) and multi-spectral structured light imaging (SLI) system is introduced and systematically analyzed to test its feasibility to aid in margin delineation during breast conserving surgery (BCS). Phantom analysis of the micro-CT yielded a signal-to-noise ratio of 34, a contrast ...

journal_title：Physics in medicine and biology

authors： McClatchy DM,Rizzo EJ,Meganck J,Kempner J,Vicory J,Wells WA,Paulsen KD,Pogue BW

更新日期：2017-11-10 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：:Intensity-modulated radiation therapy (IMRT) can be delivered by the 'sliding-leaves' dynamic multileaf collimator (DMLC) technique. Intrafraction organ motion can be accommodated by arranging an identical tracking motion for 'breathing leaves'. However, this is only possible for very specific circumstances such as re...

journal_title：Physics in medicine and biology

authors： Webb S,Binnie DM

更新日期：2006-09-21 00:00:00

abstract：:The goal of this study was to assess the impact of set-up uncertainty on compliance with the objectives and constraints of an intensity modulated radiation therapy protocol for early stage cancer of the oropharynx. As the convolution approach to the quantitative study of set-up uncertainties cannot accommodate either ...

journal_title：Physics in medicine and biology

authors： Ploquin N,Song W,Lau H,Dunscombe P

更新日期：2005-08-07 00:00:00

abstract：:We investigate an optimization-based reconstruction, with an emphasis on image-artifact reduction, from data collected in C-arm cone-beam computed tomography (CBCT) employed in image-guided interventional procedures. In the study, an image to be reconstructed is formulated as a solution to a convex optimization progra...

journal_title：Physics in medicine and biology

authors： Xia D,Langan DA,Solomon SB,Zhang Z,Chen B,Lai H,Sidky EY,Pan X

更新日期：2016-10-21 00:00:00

abstract：:An expression for the noise power spectrum of images reconstructed by the discrete filtered backprojection algorithm has been derived. The formulation explicitly includes sampling within the projections, angular sampling, and the two-dimensional sampling implicit in the discrete representation of the image. The effect...

journal_title：Physics in medicine and biology

authors： Kijewski MF,Judy PF

更新日期：1987-05-01 00:00:00

abstract：:We used a real-skull phantom head to investigate the performances of representative methods for EEG source localization when considering various head models. We describe several experiments using a montage with current sources located at multiple positions and orientations inside a human skull filled with a conductive...

journal_title：Physics in medicine and biology

authors： Baillet S,Riera JJ,Marin G,Mangin JF,Aubert J,Garnero L

更新日期：2001-01-01 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 work investigated the differences between multileaf collimator (MLC) positioning accuracy determined using either log files or electronic portal imaging devices (EPID) and then assessed the possibility of reducing patient specific quality control (QC) via phantom-less methodologies. In-house software was develope...

journal_title：Physics in medicine and biology

authors： Agnew A,Agnew CE,Grattan MW,Hounsell AR,McGarry CK

更新日期：2014-05-07 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：:Diffusion tensor tractography (DTT) allows one to explore axonal connectivity patterns in neuronal tissue by linking local predominant diffusion directions determined by diffusion tensor imaging (DTI). The majority of existing tractography approaches use continuous coordinates for calculating single trajectories throu...

journal_title：Physics in medicine and biology

authors： Bodammer NC,Kaufmann J,Kanowski M,Tempelmann C

更新日期：2009-02-21 00:00:00

abstract：:The purpose of this study is to develop a new global mammographic image feature analysis based computer-aided detection (CAD) scheme and evaluate its performance in detecting positive screening mammography examinations. A dataset that includes images acquired from 1896 full-field digital mammography (FFDM) screening e...

journal_title：Physics in medicine and biology

authors： Tan M,Qian W,Pu J,Liu H,Zheng B

更新日期：2015-06-07 00:00:00

abstract：:A 4D ordered-subsets maximum a posteriori (OSMAP) algorithm for dynamic SPECT is described which uses a temporal prior that constrains each voxel's behaviour in time to conform to a compartmental model. No a priori limitations on kinetic parameters are applied; rather, the parameter estimates evolve as the algorithm i...

journal_title：Physics in medicine and biology

authors： Kadrmas DJ,Gullberg GT

更新日期：2001-05-01 00:00:00

abstract：:Measurement of the dielectric properties of ocular tissues up to 110 GHz was performed by the coaxial probe method. A coaxial sensor was fabricated to allow the measurement of small amounts of biological tissues. Four-standard calibration was applied in the dielectric property measurement to obtain more accurate data ...

journal_title：Physics in medicine and biology

authors： Sasaki K,Isimura Y,Fujii K,Wake K,Watanabe S,Kojima M,Suga R,Hashimoto O

更新日期：2015-08-21 00:00:00

abstract：:Partial volume effects (PVEs) are consequences of the limited spatial resolution in emission tomography. They lead to a loss of signal in tissues of size similar to the point spread function and induce activity spillover between regions. Although PVE can be corrected for by using algorithms that provide the correct ra...

journal_title：Physics in medicine and biology

authors： Boussion N,Hatt M,Lamare F,Bizais Y,Turzo A,Cheze-Le Rest C,Visvikis D

更新日期：2006-04-07 00:00:00