Temperature distribution in atherosclerotic coronary arteries: influence of plaque geometry and flow (a numerical study).

abstract：:Dynamic contrast-enhanced computed tomography (DCE-CT) is an imaging tool that aids in evaluating functional characteristics of tissue at different stages of disease management: diagnostic, radiation treatment planning, treatment effectiveness, and monitoring. Clinical validation of DCE-derived perfusion parameters re...

journal_title：Physics in medicine and biology

authors： Peladeau-Pigeon M,Coolens C

更新日期：2013-09-07 00:00:00

abstract：:In order to optimize external-beam conformal radiotherapy, patient movement during treatment must be minimized. For treatment on the upper torso, the target organs are known to move substantially due to patient respiration. This paper deals with the technical aspects of gating the radiotherapy beam synchronously with ...

journal_title：Physics in medicine and biology

authors： Kubo HD,Hill BC

更新日期：1996-01-01 00:00:00

abstract：:We introduce a novel x-ray imaging approach that yields information about the local texture of structures smaller than the image pixel resolution inside an object. The approach is based on a recently developed x-ray dark-field imaging technique, using scattering from sub-micron structures in the sample. We show that t...

journal_title：Physics in medicine and biology

authors： Jensen TH,Bech M,Bunk O,Donath T,David C,Feidenhans'l R,Pfeiffer F

更新日期：2010-06-21 00:00:00

abstract：:By analyzing the radiobiological model, and the equations derived from the model, it is shown that the main results of the article 'The influence of dose heterogeneity on tumor control probability in fractionated radiation therapy' by Wiklund et al (2011 Phys. Med. Biol. 56 7585-600) are valid only under the condition...

journal_title：Physics in medicine and biology

authors： Grusell E

更新日期：2013-09-21 00:00:00

abstract：:Our study aimed to quantitatively evaluate blood flow in the left ventricle (LV) of apical hypertrophic cardiomyopathy (APH) by combining wall thickness obtained from cardiac magnetic resonance imaging (MRI) and myocardial perfusion from single-photon emission computed tomography (SPECT). In this study, we considered ...

journal_title：Physics in medicine and biology

authors： Fukami T,Sato H,Wu J,Lwin TT,Yuasa T,Kawano S,Iida K,Akatsuka T,Hontani H,Takeda T,Tamura M,Yokota H

更新日期：2007-07-21 00:00:00

abstract：:The purpose of this study is to calculate Pareto surfaces in multi-criteria radiation treatment planning and to analyse the dependency of the Pareto surfaces on the objective functions used for the volumes of interest. We develop a linear approach that allows us to calculate truly Pareto optimal treatment plans, and w...

journal_title：Physics in medicine and biology

authors： Craft D,Halabi T,Bortfeld T

更新日期：2005-12-21 00:00:00

abstract：:In radiation therapy, a plan is robust if the calculated and the delivered dose are in agreement, even in the case of different uncertainties. The current practice is to use safety margins, expanding the clinical target volume sufficiently enough to account for treatment uncertainties. This, however, might not be idea...

journal_title：Physics in medicine and biology

authors： Albertini F,Hug EB,Lomax AJ

更新日期：2011-07-21 00:00:00

abstract：:There are a number of gel dosimeter calibration methods in contemporary usage. The present study is a detailed Monte Carlo investigation into the accuracy of several calibration techniques. Results show that for most arrangements the dose to gel accurately reflects the dose to water, with the most accurate method invo...

journal_title：Physics in medicine and biology

authors： Taylor ML,Franich RD,Johnston PN,Millar RM,Trapp JV

更新日期：2007-07-07 00:00:00

abstract：:Radiation dose distributions have been calculated for 188Re and 32P activity on a coronary artery stent. The doses have been calculated both as a function of position along the stent and of depth into the artery wall. Comparisons of the dose from identical activities of 188Re and 32P on the stent show that the major d...

journal_title：Physics in medicine and biology

authors： Fox RA,Henson PW

更新日期：2000-12-01 00:00:00

abstract：:Recent developments in the technique of constant infusion and in emission computed tomography have provided a new method for quantitative regional flow measurements. This paper re-examines critically the theoretical relationship between flow and radioactivity during constant infusion of short-lived isotopes. Sensitivi...

journal_title：Physics in medicine and biology

authors： Huang SC,Phelps ME,Hoffman EJ,Kuhl DE

更新日期：1979-11-01 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 present note addresses the development of a lung tumor position predictor to be used in dynamic tumor tracking radiotherapy, abbreviated as DTT-RT. As there exists 50-500 ms positioning lag in the control of the multi-leaf collimator (MLC) of commercial medical linear accelerators, prediction of future lung tumor ...

journal_title：Physics in medicine and biology

authors： Jiang K,Fujii F,Shiinoki T

更新日期：2019-10-31 00:00:00

abstract：:Radiotherapy and particle therapy treatment planning require accurate knowledge of the electron density and elemental composition of the tissues in the beam path to predict the local dose deposition. We describe a method for the analysis of dual energy computed tomography (DECT) images that provides the electron densi...

journal_title：Physics in medicine and biology

authors： van Abbema JK,van Goethem MJ,Greuter MJ,van der Schaaf A,Brandenburg S,van der Graaf ER

更新日期：2015-05-07 00:00:00

abstract：:We examined the reasons for the reduction in response of a multidetector radiation counting system when operated at high count-rates and established a convenient method of correction which is accurate to within +/- 1% up to 0-6 X 10(5) counts per second. In its application the method uses the observed count-rates from...

journal_title：Physics in medicine and biology

authors： Oxby CB,Oldroyd B,Appleby DB

更新日期：1976-01-01 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：:Computed tomography images have been acquired using an experimental (low atomic number (Z) insert) megavoltage cone-beam imaging system. These images have been compared with standard megavoltage and kilovoltage imaging systems. The experimental system requires a simple modification to the 4 MeV electron beam from an E...

journal_title：Physics in medicine and biology

authors： Roberts DA,Hansen VN,Thompson MG,Poludniowski G,Niven A,Seco J,Evans PM

更新日期：2011-07-21 00:00:00

abstract：:In vivo neutron activation analysis was used to measure total body sodium and chlorine in 18 male and 18 female normal adults. Corrections for body size were developed. Normalisation factors were derived which enable the prediction of the normal levels of sodium and chlorine in a subject. The coefficient of variation ...

journal_title：Physics in medicine and biology

authors： Kennedy NS,Eastell R,Smith MA,Tothill P

更新日期：1983-03-01 00:00:00

abstract：:Many applications in medical imaging include image registration for matching of images from the same or different modalities. In the case of full data sampling, the respective reconstructed images are usually of such a good image quality that standard deformable volume-to-volume (3D-3D) registration approaches can be ...

journal_title：Physics in medicine and biology

authors： Flach B,Brehm M,Sawall S,Kachelrieß M

更新日期：2014-12-21 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：: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：:Positron emission tomography (PET) iterative 3D reconstruction is a very computational demanding task. One of the main issues of the iterative reconstruction concerns the management of the system response matrix (SRM). The SRM models the relationship between the projection and the voxel space and its memory footprint ...

journal_title：Physics in medicine and biology

authors： Camarlinghi N,Sportelli G,Guerra AD,Belcari N

更新日期：2018-09-28 00:00:00

abstract：:Ultrasound-based elastography including strain elastography, acoustic radiation force impulse (ARFI) imaging, point shear wave elastography and supersonic shear imaging (SSI) have been used to differentiate breast tumors among other clinical applications. The objective of this study is to extend a previously published...

journal_title：Physics in medicine and biology

authors： Wang Y,Peng B,Jiang J

更新日期：2017-03-07 00:00:00

abstract：:The measurand relevant for the dosimetry for radiation therapy is the absorbed dose to water, DW. The Physikalisch-Technische Bundesanstalt (PTB) is establishing a secondary standard for DW for high-energy photon and electron radiation based on electron spin resonance (ESR) of the amino acid alanine. For practical app...

journal_title：Physics in medicine and biology

authors： Anton M

更新日期：2008-03-07 00:00:00

abstract：:Micro-CT is widely used in preclinical studies, generating substantial interest in extending its capabilities in functional imaging applications such as blood perfusion and cardiac function. However, imaging cardiac structure and function in mice is challenging due to their small size and rapid heart rate. To overcome...

journal_title：Physics in medicine and biology

authors： Holbrook M,Clark DP,Badea CT

更新日期：2018-01-09 00:00:00

abstract：:Random coincidences can contribute substantially to the background in positron emission tomography (PET). Several estimation methods are being used for correcting them. The goal of this study was to investigate the validity of techniques for random coincidence estimation, with various low-energy thresholds (LETs). Sim...

journal_title：Physics in medicine and biology

authors： Torres-Espallardo I,Rafecas M,Spanoudaki V,McElroy DP,Ziegler SI

更新日期：2008-05-07 00:00:00

abstract：:In order to analyse the respective roles of ion concentration and fractional volume of the interstitial compartment as determinants of the impedance, Z, of renal medullary tissue, a model was needed in which both these factors could be varied independently. An array of blood cell suspensions ions in saline (different ...

journal_title：Physics in medicine and biology

authors： Niewiadomski W,Sadowski J,Badzyńska B,Rasmussen SN

更新日期：1990-11-01 00:00:00

abstract：:Crucial to all cancer therapy modalities is a strong correlation between treatment and effect. Predictability of therapy success/failure allows for the optimization of treatment protocol and aids in the decision of whether additional treatment is necessary to prevent tumour progression. This work evaluated the relatio...

journal_title：Physics in medicine and biology

authors： Hrycushko BA,Ware S,Li S,Bao A

更新日期：2011-09-07 00:00:00

abstract：:The aim of the present work was to investigate how the native signal observed in the electron paramagnetic resonance (EPR) spectrum of tooth enamel and dentin is associated with the organic content of the two tissues. This was achieved by comparing the EPR native signal and the optical bands (Raman and infrared, IR) a...

journal_title：Physics in medicine and biology

authors： Fattibene P,Carosi A,De Coste V,Sacchetti A,Nucara A,Postorino P,Dore P

更新日期：2005-03-21 00:00:00

abstract：:The function of the placenta is challenging to characterize and as a result is understudied, despite the growing awareness of the impact of the placental environment on human health and development. Medical imaging has the potential to improve our ability to screen for diseases associated with placental insufficiency,...

journal_title：Physics in medicine and biology

authors： Wu C,Bayer CL

更新日期：2018-07-09 00:00:00

abstract：:The lipid disordering effect of aspirin on the liposomal membrane of dipalmitoyl phosphatidyl choline has recently been studied using the fluorescence polarization method. From the anisotropy-temperature curve, we have calculated here the associated change in van't Hoff enthalpy. Since the fluorescence technique requi...

journal_title：Physics in medicine and biology

authors： De S,Ghosh AK,Basu R,Nandy P

更新日期：1996-03-01 00:00:00