Dose conversion coefficients for paediatric CT examinations with automatic tube current modulation.

abstract：:The purpose of this study was to determine the performance of a single lutetium oxy-orthosilicate (LSO) crystal layer High Resolution Research Tomograph (HRRT) positron emission tomography (PET) scanner. The HRRT is a high resolution PET scanner designed for human brain and small animal imaging. The scanner consists o...

journal_title：Physics in medicine and biology

authors： Boellaard R,Buijs F,de Jong HW,Lenox M,Gremillion T,Lammertsma AA

更新日期：2003-02-21 00:00:00

abstract：:The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic prot...

journal_title：Physics in medicine and biology

authors： Gomà C,Lorentini S,Meer D,Safai S

更新日期：2014-09-07 00:00:00

abstract：:In this study we present a three-dimensional (3D) reconstruction algorithm for magneto-acoustic tomography with magnetic induction (MAT-MI) based on the characteristics of the ultrasound transducer. The algorithm is investigated to solve the blur problem of the MAT-MI acoustic source image, which is caused by the ultr...

journal_title：Physics in medicine and biology

authors： Ma R,Zhou X,Zhang S,Yin T,Liu Z

更新日期：2016-12-21 00:00:00

abstract：:Effects of different scatter compensation methods incorporated in fully 3D iterative reconstruction are investigated. The methods are: (i) the inclusion of an 'ideal scatter estimate' (ISE); (ii) like (i) but with a noiseless scatter estimate (ISE-NF); (iii) incorporation of scatter in the point spread function during...

journal_title：Physics in medicine and biology

authors： Beekman FJ,Kamphuis C,Frey EC

更新日期：1997-08-01 00:00:00

abstract：:The dose-response of LiF:Mg,Ti (TLD-100) exposed to 15 and 35 kVp (8.0 +/- 0.1 and 8.1 +/- 0.1 keV effective energy respectively) x-rays and 60Co gamma-rays has been measured in the dose interval from (1.2-5.4) x 10(3) Gy for x-rays, and from 0.14 to 850 Gy for gamma-rays. In both cases the total TL signal and glow cu...

journal_title：Physics in medicine and biology

authors： Gamboa-deBuen I,Buenfil AE,Ruiz CG,Rodríguez-Villafuerte M,Flores A,Brandan ME

更新日期：1998-08-01 00:00:00

abstract：:The relative biological effectiveness (RBE) of protons varies with multiple physical and biological factors. Phenomenological RBE models have been developed to include such factors in the estimation of a variable RBE, in contrast to the clinically applied constant RBE of 1.1. In this study, eleven published phenomenol...

journal_title：Physics in medicine and biology

authors： Rørvik E,Fjæra LF,Dahle TJ,Dale JE,Engeseth GM,Stokkevåg CH,Thörnqvist S,Ytre-Hauge KS

更新日期：2018-09-13 00:00:00

abstract：:The treatment planning process for patients with head and neck (H&N) cancer is regarded as one of the most complicated due to large target volume, multiple prescription dose levels, and many radiation-sensitive critical structures near the target. Treatment planning for this site requires a high level of human experti...

journal_title：Physics in medicine and biology

authors： Nguyen D,Jia X,Sher D,Lin MH,Iqbal Z,Liu H,Jiang S

更新日期：2019-03-18 00:00:00

abstract：:A theoretical analysis and numerical solutions are presented for viscosity-dominated flow through a uniform, highly distensible tube with a slit-shaped cross section undergoing peristalsis. At flow rates below an intrinsic upper limit to the peristaltic carrying capacity of the tube, provided that there is always at l...

journal_title：Physics in medicine and biology

authors： Griffiths DJ

更新日期：1987-07-01 00:00:00

abstract：:The feasibility of detecting gamma rays with energies below 1.5 MeV by means of a large-volume liquid-filled Cerenkov counter has been examined, together with the characteristics and limitations of an experimental counter. Various liquids (water, glycerol, sodium iodide solution; and glycerol plus a wavelength shifter...

journal_title：Physics in medicine and biology

authors： Hesp R

更新日期：1978-05-01 00:00:00

abstract：:Motion-adaptive radiotherapy aims to deliver a conformal dose to the target tumour with minimal normal tissue exposure by compensating for tumour motion in real time. The prediction as well as the gating of respiratory motion have received much attention over the last two decades for reducing the targeting error of th...

journal_title：Physics in medicine and biology

authors： Bukhari W,Hong SM

更新日期：2015-01-07 00:00:00

abstract：:Modern digital radiographic 'flat panel' detectors can exhibit a progressive form of image degradation arising from non-functioning pixels. The effect of these 'dead pixels' on the quantitive image quality measures of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE)...

journal_title：Physics in medicine and biology

authors： Padgett R,Kotre CJ

更新日期：2004-03-21 00:00:00

abstract：:We describe an improved algorithm for localising equivalent sources of biomagnetic fields in the human brain. The algorithm is an improvement over the sphere model in that it considers two distinct surfaces: an ellipsoid, to model the region of the skull on which the sensors are placed, and a sphere as the medium in w...

journal_title：Physics in medicine and biology

authors： Pistella F,Barone P,Narici L,Ocello N,Pizzella V,Romani GL

更新日期：1987-01-01 00:00:00

abstract：:The signal properties of polycrystalline mercuric iodide (HgI2) film detectors, under irradiation conditions relevant to mammographic, radiographic, fluoroscopic and radiotherapy x-ray imaging, are reported. Each film detector consists of an approximately 230 to approximately 460 microm thick layer of HgI2 (fabricated...

journal_title：Physics in medicine and biology

authors： Su Z,Antonuk LE,El-Mohri Y,Hu L,Du H,Sawant A,Li Y,Wang Y,Yamamoto J,Zhao Q

更新日期：2005-06-21 00:00:00

abstract：:Finding fluence maps for intensity-modulated radiation therapy (IMRT) can be formulated as a multi-criteria optimization problem for which Pareto optimal treatment plans exist. To account for the dose-per-fraction effect of fractionated IMRT, it is desirable to exploit radiobiological treatment plan evaluation criteri...

journal_title：Physics in medicine and biology

authors： Hoffmann AL,den Hertog D,Siem AY,Kaanders JH,Huizenga H

更新日期：2008-11-21 00:00:00

abstract：:Diffuse optical tomography is an imaging technique whereby spatial maps of absorption and scattering coefficients are derived from the characteristics of multiply scattered light transmitted through the object. The system described here used four intensity-modulated light sources and measurements of the intensity and ...

journal_title：Physics in medicine and biology

authors： Pogue BW,Patterson MS,Jiang H,Paulsen KD

更新日期：1995-10-01 00:00:00

abstract：:Dynamic contrast enhanced MRI (DCE-MRI) and pharmacokinetic models have been used to measure tumour permeability (K(trans)) and leakage volume (ve) in numerous studies. The construction of pharmacokinetic models describing such tissue properties relies on defining the blood plasma concentration of contrast agent with ...

journal_title：Physics in medicine and biology

authors： Ahearn TS,Staff RT,Redpath TW,Semple SI

更新日期：2004-05-21 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：:A Monte Carlo computer program has been developed for the computation of integral radiation dose to the breast in xeromammography. The results are given in terms of the integral dose per unit area of the breast per unit incident exposure. The calculations have been made for monoenergetic incident photons and the resul...

journal_title：Physics in medicine and biology

authors： Dance DR

更新日期：1980-01-01 00:00:00

abstract：:We are developing a dedicated, combined breast positron emission tomography (PET)-tomosynthesis scanner. Both the PET and digital breast tomosynthesis (DBT) scanners are integrated in a single gantry to provide spatially co-registered 3D PET-tomosynthesis images. The DBT image will be used to identify the breast bound...

journal_title：Physics in medicine and biology

authors： Krishnamoorthy S,Vent T,Barufaldi B,Maidment ADA,Karp JS,Surti S

更新日期：2020-10-28 00:00:00

abstract：:This paper introduces a novel compartmental model describing the excretion of 18F-fluoro-deoxyglucose (FDG) in the renal system and a numerical method based on the maximum likelihood for its reduction. This approach accounts for variations in FDG concentration due to water re-absorption in renal tubules and the increa...

journal_title：Physics in medicine and biology

authors： Garbarino S,Caviglia G,Sambuceti G,Benvenuto F,Piana M

更新日期：2014-05-21 00:00:00

abstract：:Acidic drinks and foodstuffs can demineralize dental hard tissues, leading to a pathological condition known as dental erosion, which is of increasing clinical concern. The first step in enamel dissolution is a demineralization of the outer few micrometres of tissue, which results in a softening of the structure. The ...

journal_title：Physics in medicine and biology

authors： Barbour ME,Shellis RP

更新日期：2007-02-21 00:00:00

abstract：:Incorrect prediction of skin dose in external beam radiotherapy (EBR) can have normal tissue complication such as acute skin desquamation and skin necrosis. The absorbed dose of skin should be evaluated within basal layer, placed between the epidermis and dermis layers. However, current treatment planning systems (TPS...

journal_title：Physics in medicine and biology

authors： Cheon BW,Yoo DH,Shin WG,Choi HJ,Park HJ,Kim JI,Min CH

更新日期：2019-08-14 00:00:00

abstract：:Picking geometrically relevant atlases from the whole training set is crucial to multi-atlas based image segmentation, especially with extensive data of heterogeneous quality in the Big Data era. Unfortunately, there is very limited understanding of how currently used image similarity criteria reveal geometric relevan...

journal_title：Physics in medicine and biology

authors： Zhao T,Ruan D

更新日期：2016-06-07 00:00:00

abstract：:We have developed deformable and durable optical tissue phantoms with a simple and well-defined microstructure including a novel combination of scatterers and a matrix material. These were developed for speckle and elastography investigations in optical coherence tomography, but should prove useful in many other field...

journal_title：Physics in medicine and biology

authors： Bisaillon CE,Lamouche G,Maciejko R,Dufour M,Monchalin JP

更新日期：2008-07-07 00:00:00

abstract：:By the end of 2002, 33 398 patients worldwide had been treated with proton radiotherapy, 10 829 for eye diseases. The dose prediction algorithms used today for ocular proton therapy treatment planning rely on parameterizations of measured proton dose distributions, i.e., broad-beam and pencil-beam techniques, whose pr...

journal_title：Physics in medicine and biology

authors： Newhauser W,Koch N,Hummel S,Ziegler M,Titt U

更新日期：2005-11-21 00:00:00

abstract：:A simple and fast, but sensitive TLD method for the measurement of energy and homogeneity of therapeutically used electron beams has been developed and tested. This method is based on the fact that when small thicknesses of high-Z absorbers such as lead are interposed in the high-energy electron beams, the transmitted...

journal_title：Physics in medicine and biology

authors： Pradhan AS,Quast U,Sharma PK

更新日期：1994-09-01 00:00:00

abstract：:In multiple plan adaptive radiotherapy (ART) strategies of bladder cancer, a library of plans corresponding to different bladder volumes is created based on images acquired in early treatment sessions. Subsequently, the plan for the smallest PTV safely covering the bladder on cone-beam CT (CBCT) is selected as the pla...

journal_title：Physics in medicine and biology

authors： Chai X,van Herk M,Betgen A,Hulshof M,Bel A

更新日期：2012-06-21 00:00:00

abstract：:Shear wave elastography (SWE) is a potential tool to non-invasively assess cardiac muscle stiffness. This study focused on the effect of the orthotropic material properties and mechanical loading on the performance of cardiac SWE, as it is known that these factors contribute to complex 3D anisotropic shear wave propag...

journal_title：Physics in medicine and biology

authors： Caenen A,Pernot M,Peirlinck M,Mertens L,Swillens A,Segers P

更新日期：2018-03-23 00:00:00

abstract：:Photoacoustic imaging - a hybrid biomedical imaging modality finding its way to clinical practices. Although the photoacoustic phenomenon was known more than a century back, only in the last two decades it has been widely researched and used for biomedical imaging applications. In this review we focus on the developme...

journal_title：Physics in medicine and biology

authors： Das D,Sharma A,Rajendran P,Pramanik M

更新日期：2020-12-23 00:00:00

abstract：:Joint space morphology can be indicative of the risk, presence, progression, and/or treatment response of disease or trauma. We describe a novel methodology of characterizing joint space morphology in high-resolution 3D images (e.g. cone-beam CT (CBCT)) using a model based on elementary electrostatics that overcomes a...

journal_title：Physics in medicine and biology

authors： Cao Q,Thawait G,Gang GJ,Zbijewski W,Reigel T,Brown T,Corner B,Demehri S,Siewerdsen JH

更新日期：2015-02-07 00:00:00