A comparative EPR, infrared and Raman study of natural and deproteinated tooth enamel and dentin.

abstract：:A stable cryogel dosimeter was prepared using ferrous benzoic xylenol orange (FBX) in a transparent poly-(vinyl alcohol) (PVA) cryogel matrix. Dose response was evaluated for different numbers of freeze-thaw cycles (FTCs), different concentrations of PVA, and ratios of water/dimethyl sulfoxide. Linear relationships be...

journal_title：Physics in medicine and biology

authors： Eyadeh MM,Farrell TJ,Diamond KR

更新日期：2014-04-07 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 method for the calculation of absorbed dose distributions of arbitrarily shaped electron beams is presented. Isodose distributions and output factors of treatment fields can be predicted with good accuracy, without the need for any dose measurement in the actual field. A Gaussian pencil beam model is employed with t...

journal_title：Physics in medicine and biology

authors： Bruinvis IA,Van Amstel A,Elevelt AJ,Van der Laarse R

更新日期：1983-06-01 00:00:00

abstract：:To achieve accurate and fast deformable image registration (DIR) for pulmonary CT, we proposed a Multi-scale DIR framework with unsupervised Joint training of Convolutional Neural Network (MJ-CNN). MJ-CNN contains three models at multi-scale levels for a coarse-to-fine DIR to avoid being trapped in a local minimum. It...

journal_title：Physics in medicine and biology

authors： Jiang Z,Yin FF,Ge Y,Ren L

更新日期：2020-01-13 00:00:00

abstract：:Various lead attenuation techniques to determine the fast neutron sensitivity kU of a photon dosemeter are reviewed and a modified method is proposed to determine the kU value of a commercially available Geiger--Müller detector. The dependence on the 'effective' photon energy of the gamma-component of the mixed n--gam...

journal_title：Physics in medicine and biology

authors： Hough JH

更新日期：1979-07-01 00:00:00

abstract：:Permanent in vivo verification of IMRT photon beam profiles by a radiation detector with spatial resolution, positioned on the radiation entrance side of the patient, has not been clinically available so far. In this work we present the DAVID system, which is able to perform this quality assurance measurement while th...

journal_title：Physics in medicine and biology

authors： Poppe B,Thieke C,Beyer D,Kollhoff R,Djouguela A,Rühmann A,Willborn KC,Harder D

更新日期：2006-03-07 00:00:00

abstract：:A classical trajectory model has been used to predict total cross sections of single and double ionizing processes (including capture processes) for several ion-biological molecule collisional systems in the intermediate and high energy range. In this work, the systems studied are water, adenine or cytosine targets io...

journal_title：Physics in medicine and biology

authors： Abbas I,Champion C,Zarour B,Lasri B,Hanssen J

更新日期：2008-02-21 00:00:00

abstract：:Elevated interstitial fluid pressure is one of the barriers of drug delivery in solid tumors. Recent studies have shown that normalization of tumor vasculature by anti-angiogenic factors may improve the delivery of conventional cytotoxic drugs, possibly by increasing blood flow, decreasing interstitial fluid pressure,...

journal_title：Physics in medicine and biology

authors： Ozturk D,Yonucu S,Yilmaz D,Unlu MB

更新日期：2015-02-21 00:00:00

abstract：:An open-ended coaxial probe is often used for investigating the dielectric properties of biological tissues. The present study indicates that in addition to the probe size, the penetration of the electromagnetic (EM) fields of an open-ended coaxial probe in contact with the skin is dependent on the applied frequency b...

journal_title：Physics in medicine and biology

authors： Alanen E,Lahtinen T,Nuutinen J

更新日期：1999-07-01 00:00:00

abstract：:Mechanical properties of biological tissues are significant biomarkers for diagnosing various diseases. Assessing the viscoelastic properties of multi-layer tissues has remained challenging for a long time. Some shear wave models have been proposed to estimate thin-layer tissues' viscoelasticity recently. However, the...

journal_title：Physics in medicine and biology

authors： Lu G,Li R,Qian X,Chen R,Jiang L,Chen Z,Shung KK,Humayun MS,Zhou Q

更新日期：2020-11-12 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：:Successful radiotherapy treatment depends heavily upon the accuracy of patient geometry captured during treatment simulation using computed tomography (CT) scans. Radiotherapy patients are often scanned under free breathing, and respiratory motion can cause severe artifacts in CT scans, including shortening, elongatio...

journal_title：Physics in medicine and biology

authors： Lewis JH,Jiang SB

更新日期：2009-02-07 00:00:00

abstract：:A technique is described by which the regional distribution of bone mineral can be determined in bone samples from small animals. The technique employs an Anger camera interfaced to a medical computer. High resolution (less than 1 mm) imaging is possible by producing magnified images of the bone samples. Regional dens...

journal_title：Physics in medicine and biology

authors： LeBlanc A,Evans H,Jhingran S,Johnson P

更新日期：1984-01-01 00:00:00

abstract：:For proton therapy, an accurate conversion of CT HU to relative stopping power (RSP) is essential. Validation of the conversion based on real tissue samples is more direct than the current practice solely based on tissue substitutes and can potentially address variations over the population. Based on a novel dose exti...

journal_title：Physics in medicine and biology

authors： Zhang R,Baer E,Jee KW,Sharp GC,Flanz J,Lu HM

更新日期：2017-06-23 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

abstract：:Silicon photomultipliers (SiPMs) are widely used in positron emission tomography (PET), however, SiPMs from different vendors vary in their performance characteristics. In addition, the specifications provided by the manufacturers are measured under different operating conditions and using different test setups, makin...

journal_title：Physics in medicine and biology

authors： Du J,Bai X,Cherry SR

更新日期：2019-08-07 00:00:00

abstract：:The possible use of fluorescence bronchoscopy for localization of bronchogenic tumours at the carcinoma in situ stage has been investigated. The target lesion is 80 micrometer thick with a mass of 250 microgram, containing 250 pg of haematoporphyrin derivative. The injected haematoporphyrin-derivative is preferentiall...

journal_title：Physics in medicine and biology

authors： Profio AE,Doiron DR

更新日期：1977-09-01 00:00:00

abstract：:Intraoperative x-ray radiography/fluoroscopy is commonly used to assess the placement of surgical devices in the operating room (e.g. spine pedicle screws), but qualitative interpretation can fail to reliably detect suboptimal delivery and/or breach of adjacent critical structures. We present a 3D-2D image registratio...

journal_title：Physics in medicine and biology

authors： Uneri A,De Silva T,Goerres J,Jacobson MW,Ketcha MD,Reaungamornrat S,Kleinszig G,Vogt S,Khanna AJ,Osgood GM,Wolinsky JP,Siewerdsen JH

更新日期：2017-04-21 00:00:00

abstract：:The measured attenuation correction technique is widely used in cardiac positron tomographic studies. However, the success of this technique is limited because of insufficient counting statistics achievable in practical transmission scan times, and of the scattered radiation in transmission measurement which leads to ...

journal_title：Physics in medicine and biology

authors： Yu SK,Nahmias C

更新日期：1996-10-01 00:00:00

abstract：:Magnetoencephalography (MEG) is a non-invasive functional imaging modality based on the measurement of the external magnetic field produced by neural current sources within the brain. The reconstruction of the underlying sources is a severely ill-posed inverse problem typically tackled using either low-dimensional par...

journal_title：Physics in medicine and biology

authors： Jerbi K,Mosher JC,Baillet S,Leahy RM

更新日期：2002-02-21 00:00:00

abstract：:The purpose of this work was to create a computational platform for studying motion in intensity modulated radiotherapy (IMRT). Specifically, the non-uniform rational B-spline (NURB) cardiac and torso (NCAT) phantom was modified for use in a four-dimensional Monte Carlo (4D-MC) simulation system to investigate the eff...

journal_title：Physics in medicine and biology

authors： McGurk R,Seco J,Riboldi M,Wolfgang J,Segars P,Paganetti H

更新日期：2010-03-07 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：: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：:This paper discusses the effect of blood perfusion on the ablation of rat liver tissue with high-intensity focused ultrasound (HIFU). For this study a practical method has been developed, in which the liver blood flow can be reduced by ligation of the hepatic artery and portal vein. During the treatment the rat liver ...

journal_title：Physics in medicine and biology

authors： Chen L,ter Haar G,Hill CR,Dworkin M,Carnochan P,Young H,Bensted JP

更新日期：1993-11-01 00:00:00

abstract：:The purpose of this paper is to evaluate the ability of a prototype Compton camera (CC) to measure prompt gamma rays (PG) emitted during delivery of clinical proton pencil beams for prompt gamma imaging (PGI) as a means of providing in vivo verification of the delivered proton radiotherapy beams. A water phantom was i...

journal_title：Physics in medicine and biology

authors： Polf JC,Avery S,Mackin DS,Beddar S

更新日期：2015-09-21 00:00:00

abstract：:Grating interferometry is advantageous over conventional x-ray absorption imaging because it enables the detection of samples constituted by low atomic number elements (low-Z materials). Therefore, it has a potential application in biological science and medical diagnostics. The grating interferometry has some critica...

journal_title：Physics in medicine and biology

authors： Du Y,Lei Y,Liu X,Huang J,Zhao Z,Guo J,Li J,Niu H

更新日期：2016-12-07 00:00:00

abstract：:The geometry of a permanent prostate implant varies over time. Seeds can migrate and edema of the prostate affects the position of seeds. Seed movements directly influence dosimetry which relates to treatment quality. We present a method that tracks all individual seeds over time allowing quantification of seed moveme...

journal_title：Physics in medicine and biology

authors： Westendorp H,Nuver TT,Moerland MA,Minken AW

更新日期：2015-10-21 00:00:00

abstract：:A novel meshless reconstruction algorithm for digital tomosynthesis (DT) is presented and assessed against experimental data. The algorithm does not require a three-dimensional grid or mesh allocation and performs a slice-by-slice reconstruction where each slice position can be chosen at runtime. The methodology is ba...

journal_title：Physics in medicine and biology

authors： Soloviev VY,Renforth KL,Dirckx CJ,Wells SG

更新日期：2020-04-20 00:00:00

abstract：:Ultrasound may provide a quantitative technique for the characterization of cartilage changes typical of early osteoarthrosis. In this study, specific changes in bovine articular cartilage were induced using collagenase and chondroitinase ABC, enzymes that selectively degrade collagen fibril network and digest proteog...

journal_title：Physics in medicine and biology

authors： Töyräs J,Rieppo J,Nieminen MT,Helminen HJ,Jurvelin JS

更新日期：1999-11-01 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