Optimal material discrimination using spectral x-ray imaging.

abstract：:The purpose of this research is to develop a 4DCBCT-based dose assessment method for calculating actual delivered dose for patients with significant respiratory motion or anatomical changes during the course of SBRT. To address the limitation of 4DCT-based dose assessment, we propose to calculate the delivered dose us...

journal_title：Physics in medicine and biology

authors： Cai W,Dhou S,Cifter F,Myronakis M,Hurwitz MH,Williams CL,Berbeco RI,Seco J,Lewis JH

更新日期：2016-01-21 00:00:00

abstract：:A new hybrid imaging-treatment modality, the MRI-Linac, involves the irradiation of the patient in the presence of a strong magnetic field. This field acts on the charged particles, responsible for depositing dose, through the Lorentz force. These conditions require a dose calculation engine capable of taking into con...

journal_title：Physics in medicine and biology

authors： Hissoiny S,Raaijmakers AJ,Ozell B,Després P,Raaymakers BW

更新日期：2011-08-21 00:00:00

abstract：:The Compton camera is an imaging device which has been proposed to detect prompt gammas (PGs) produced by proton-nuclear interactions within tissue during proton beam irradiation. Compton-based PG imaging has been developed to verify proton ranges because PG rays, particularly characteristic ones, have strong correlat...

journal_title：Physics in medicine and biology

authors： Huang HM,Liu CC,Jan ML,Lee MW

更新日期：2018-04-19 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：:Low-strength anastomoses and thermal damage of tissue are major concerns in laser tissue welding techniques where laser energy is used to induce thermal changes in the molecular structure of the tissues being joined, hence allowing them to bond together. Laser tissue soldering, on the other hand, is a bonding techniqu...

journal_title：Physics in medicine and biology

authors： McNally KM,Sorg BS,Welch AJ,Dawes JM,Owen ER

更新日期：1999-04-01 00:00:00

abstract：:Thermal ablation is a widely applied electrosurgical process in medical treatment of soft biological tissues. Numerical modeling and simulations play an important role in prediction of temperature distribution and damage volume during the treatment planning stage of associated therapies. In this contribution we report...

journal_title：Physics in medicine and biology

authors： Singh S,Melnik R

更新日期：2019-12-13 00:00:00

abstract：:The analysis of (x-ray) mammograms remains qualitative, relying on the judgement of clinicians. We present a novel method to compute a quantitative, normalized measure of tissue radiodensity traversed by the primary beam incident on each pixel of a mammogram, a measure we term the standard attenuation rate (SAR). SAR ...

journal_title：Physics in medicine and biology

authors： Tromans CE,Cocker MR,Brady SM

更新日期：2012-10-21 00:00:00

abstract：:Clinical diffusion MRI (dMRI) is sensitive to micrometer scale spin displacements, but the image resolution is  ∼mm, so the biophysical interpretation of the signal relies on establishing appropriate subvoxel tissue models. A class of two-compartment exchange models originally proposed by Kärger have been used success...

journal_title：Physics in medicine and biology

authors： Naughton NM,Georgiadis JG

更新日期：2019-08-01 00:00:00

abstract：:To increase the scanning speed of cone-beam CT, a scanning configuration with three pairs of x-ray sources and panel detectors was proposed. In this paper, we apply the M-line-based backprojected filtration algorithm to this scanning configuration and propose a fast implementation for this algorithm. Compared with exi...

journal_title：Physics in medicine and biology

authors： Zhao Y,Zhu Y,Zhang P

更新日期：2010-12-07 00:00:00

abstract：:This paper reports a theoretical study on the distribution of blood flow in the human cardiovascular system when one or more blood vessels are affected by stenosis. The analysis employs a mathematical model of the entire system based on the finite element method. The arterial-venous network is represented by a large n...

journal_title：Physics in medicine and biology

authors： Sud VK,Srinivasan RS,Charles JB,Bungo MW

更新日期：1993-03-01 00:00:00

abstract：:Inverse treatment planning in intensity modulated particle therapy (IMPT) with scanned carbon-ion beams is currently based on the optimization of RBE-weighted dose to satisfy requirements of target coverage and limited toxicity to organs-at-risk (OARs) and healthy tissues. There are many feasible IMPT plans that meet ...

journal_title：Physics in medicine and biology

authors： Burigo LN,Ramos-Méndez J,Bangert M,Schulte RW,Faddegon B

更新日期：2019-01-04 00:00:00

abstract：:Four-dimensional volumetric modulated arc therapy (4D VMAT) is a treatment strategy for lung cancers that aims to exploit relative target and tissue motion to improve organ at risk (OAR) sparing. The algorithm incorporates the entire patient respiratory cycle using 4D CT data into the optimization process. Resulting t...

journal_title：Physics in medicine and biology

authors： Chin E,Loewen SK,Nichol A,Otto K

更新日期：2013-02-21 00:00:00

abstract：:The dose distribution near a non-radioactive gold seed under a 6 MV photon beam was measured using radiographic film, water equivalent bolus and solid water slabs. This type of small seed is typically used as a marker in target positional verification using a portal imager for conformal prostate treatment such as inte...

journal_title：Physics in medicine and biology

authors： Chow JC,Grigorov GN

更新日期：2005-09-21 00:00:00

abstract：:Ultrasoft x-rays of 0.3-5 keV have provided a unique tool for the investigation of intracellular mechanisms of radiation action in biological organisms, including mammalian cells. However, their use presents unique practical problems in dosimetry and experimental design. Detailed interpretation of the biological resul...

journal_title：Physics in medicine and biology

authors： Hoshi M,Goodhead DT,Brenner DJ,Bance DA,Chmielewski JJ,Paciotti MA,Bradbury JN

更新日期：1985-10-01 00:00:00

abstract：:Measurements of lung nodule volume with multi-detector computed tomography (MDCT) have been shown to be more accurate and precise compared to conventional lower dimensional measurements. Quantifying the size of lesions is potentially more difficult when the object-to-background contrast is low as with lesions in the l...

journal_title：Physics in medicine and biology

authors： Li Q,Gavrielides MA,Zeng R,Myers KJ,Sahiner B,Petrick N

更新日期：2015-01-21 00:00:00

abstract：:This study aims at investigating in real-time the structural and dynamical changes occurring in an ex vivo tissue during a microwave thermal ablation (MTA) procedure. The experimental set-up was based on ex vivo liver tissue inserted in a dedicated box, in which 3 fibre-optic (FO) temperature probes were introduced to...

journal_title：Physics in medicine and biology

authors： Strigari L,Minosse S,D'Alessio D,Farina L,Cavagnaro M,Cassano B,Pinto R,Vallati G,Lopresto V

更新日期：2019-05-31 00:00:00

abstract：:In this letter the authors highlight the presence of an error appearing in the discussion of the note 'The use of the Henyey-Greenstein phase function in Monte Carlo simulations in biomedical optics' previously published by them (Binzoni et al 2006 Phys. Med. Biol. 51 N313). In the light of this error, the discussion ...

journal_title：Physics in medicine and biology

authors： Binzoni T,Leung TS,Gandjbakhche AH,Rüfenacht D,Delpy DT

更新日期：2006-11-21 00:00:00

abstract：:The Jacobian of the deformation field of elastic registration between images taken during radiotherapy is a measure of inter-fraction local deformation. The histogram of the Jacobian values (Jac) within an organ was introduced (JVH-Jacobian-volume-histogram) and first applied in quantifying parotid shrinkage. MVCTs of...

journal_title：Physics in medicine and biology

authors： Fiorino C,Maggiulli E,Broggi S,Liberini S,Cattaneo GM,Dell'oca I,Faggiano E,Di Muzio N,Calandrino R,Rizzo G

更新日期：2011-06-07 00:00:00

abstract：:Gold nanoparticle (GNP) radio-enhancement is a promising technique to increase the dose deposition in a tumor while sparing neighboring healthy tissue. Previous experimental studies showed effects on cell survival and tumor control for keV x-rays but surprisingly also for MV-photons, proton and carbon-ion beams. In a ...

journal_title：Physics in medicine and biology

authors： Rudek B,McNamara A,Ramos-Méndez J,Byrne H,Kuncic Z,Schuemann J

更新日期：2019-08-28 00:00:00

abstract：:Monte Carlo simulation with PENELOPE (version 2003) is applied to calculate Leksell Gamma Knife dose distributions for heterogeneous phantoms. The usual spherical water phantom is modified with a spherical bone shell simulating the skull and an air-filled cube simulating the frontal or maxillary sinuses. Different sim...

journal_title：Physics in medicine and biology

authors： Al-Dweri FM,Rojas EL,Lallena AM

更新日期：2005-12-07 00:00:00

abstract：:Discrete implanted liver tumours in the rat have been exposed to arrays of 1.7 MHz ultrasound lesions. Focal peak intensities in the range 1.4-3.5 k Wcm-2 were used for an exposure time of 10 s. It has been demonstrated that where the whole tumour volume was exposed to the focused ultrasound beam, no evidence of tumou...

journal_title：Physics in medicine and biology

authors： ter Haar G,Rivens I,Chen L,Riddler S

更新日期：1991-11-01 00:00:00

abstract：:Although field area and object thickness are important parameters in comparisons of techniques for optimal reduction of scattered radiation to the image, they are in practice seldom varied. For this reason, we suggest that contrast degradation (CDF) and contrast improvement (CIF) factors be more frequently used and ap...

journal_title：Physics in medicine and biology

authors： Carlsson GA,Carlsson CA,Nielsen B,Persliden J

更新日期：1986-07-01 00:00:00

abstract：:3D acquisition and reconstruction in positron emission tomography (PET) produce data with improved signal-to-noise ratios compared with conventional 2D slice-oriented methods. However, the sensitivity increase is accompanied by an increase in the number of scattered photons and random coincidences detected. This paper...

journal_title：Physics in medicine and biology

authors： Bailey DL,Meikle SR

更新日期：1994-03-01 00:00:00

abstract：:The external radiation exposure from an overhead plume containing gamma emitting radionuclides can contribute substantial dose to the ground receptor during normal operations as well as accidental release conditions of nuclear facilities. In order to estimate the effective dose conversion coefficients (DCCs) directly,...

journal_title：Physics in medicine and biology

authors： Dey R,Patni HK,Deo Singh K,Kulkarni MS,Anand S

更新日期：2019-08-01 00:00:00

abstract：:The purpose of this study was the characterization of local magnetic susceptibility deviations by spectral analysis of their induced magnetic field inhomogeneities. Magnetic resonance spectra and related signal decay curves of local susceptibility deviations were simulated for different volume fractions and compositio...

journal_title：Physics in medicine and biology

authors： Seppenwoolde JH,van Zijtveld M,Bakker CJ

更新日期：2005-01-21 00:00:00

abstract：:This study examines the effectiveness of a single, first-order Arrhenius process in accurately modelling the thermally induced changes in the optical properties, particularly the reduced scattering coefficient, mu(s)', and the absorption coefficient, mu(a), of ex vivo rat prostate. Recent work has shown that mu(s)' ca...

journal_title：Physics in medicine and biology

authors： Skinner MG,Everts S,Reid AD,Vitkin IA,Lilge L,Sherar MD

更新日期：2000-05-01 00:00:00

abstract：:Usually, Monte Carlo models are validated against experimental data. However, models of multiple Coulomb scattering (MCS) in the Gaussian approximation are exceptional in that we have theories which are probably more accurate than the experiments which have, so far, been done to test them. In problems directly sensiti...

journal_title：Physics in medicine and biology

authors： Makarova A,Gottschalk B,Sauerwein W

更新日期：2017-07-06 00:00:00

abstract：:Lymphedema is a common condition involving an abnormal accumulation of lymphatic fluid in the interstitial space that causes swelling, most often in the arm(s) and leg(s). Lymphedema is a significant lifelong concern that can be congenital or develop following cancer treatment or cancer metastasis. Common methods of e...

journal_title：Physics in medicine and biology

authors： Righetti R,Garra BS,Mobbs LM,Kraemer-Chant CM,Ophir J,Krouskop TA

更新日期：2007-11-07 00:00:00

abstract：:Delivery of pencil beam scanning (PBS) requires the on-line measurement of several beam parameters. If the measurement is outside of specified tolerances and a binary threshold algorithm is used, the beam will be paused. Given instrumentation and statistical noise such a system can lead to many pauses which could incr...

journal_title：Physics in medicine and biology

authors： Clasie BM,Kooy HM,Flanz JB

更新日期：2016-01-07 00:00:00

abstract：:Using MRI for radiotherapy treatment planning and image guidance is appealing as it provides superior soft tissue information over CT scans and avoids possible systematic errors introduced by aligning MR to CT images. This study presents a method that generates Synthetic CT (MRCT) volumes by performing probabilistic t...

journal_title：Physics in medicine and biology

authors： Liu L,Jolly S,Cao Y,Vineberg K,Fessler JA,Balter JM

更新日期：2017-04-21 00:00:00