abstract：:The reference levels and maximum permissible exposure values for magnetic fields that are currently used have been derived from basic restrictions under the assumption of upright standing body models in a standard posture, i.e. with arms laterally down and without contact with metallic objects. Moreover, if anatomical...

journal_title：Physics in medicine and biology

authors： Schmid G,Hirtl R

更新日期：2016-06-21 00:00:00

abstract：:The electrostimulation excitation threshold of a nerve depends on temporal and frequency parameters of the stimulus. These dependences were investigated in terms of: (1) strength-duration (SD) curve for a single monophasic rectangular pulse, and (2) frequency dependence of the excitation threshold for a continuous sin...

journal_title：Physics in medicine and biology

authors： Šarolić A,Živković Z,Reilly JP

更新日期：2016-06-21 00:00:00

abstract：:This paper evaluates results of a survey of electrostimulation models of myelinated nerve. Participants were asked to determine thresholds of excitation for 18 cases involving different characteristics of the neuron, the stimulation waveform, and the electrode arrangement. Responses were received from 7 investigators ...

journal_title：Physics in medicine and biology

authors： Reilly JP

更新日期：2016-06-21 00:00:00

abstract：:In this work, we propose a framework for optimizing spectral CT imaging parameters and hardware design with regard to material classification tasks. Compared with conventional CT, many more parameters must be considered when designing spectral CT systems and protocols. These choices will impact material classification...

journal_title：Physics in medicine and biology

authors： Rigie DS,La Rivière PJ

更新日期：2016-06-21 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：:As an x-ray beam goes through the human body, it will collect important information via interaction with tissues. Since this interaction is energy-sensitive, the state-of-the-art spectral CT technologies provide higher quality images of biological tissues with x-ray energy information (or spectral information). With e...

journal_title：Physics in medicine and biology

authors： Shi Z,Yang H,Cong W,Wang G

更新日期：2016-06-07 00:00:00

abstract：:A clinical trial named PROMETHEUS is currently ongoing for inoperable hepatocellular carcinoma (HCC) at the Heidelberg Ion Beam Therapy Center (HIT, Germany). In this framework, 4D PET-CT datasets are acquired shortly after the therapeutic treatment to compare the irradiation induced PET image with a Monte Carlo PET p...

journal_title：Physics in medicine and biology

authors： Gianoli C,Kurz C,Riboldi M,Bauer J,Fontana G,Baroni G,Debus J,Parodi K

更新日期：2016-06-07 00:00:00

abstract：:This work investigates the attenuation of a proton beam to reconstruct the map of the linear attenuation coefficient of a material which is mainly caused by the inelastic interactions of protons with matter. Attenuation proton computed tomography (pCT) suffers from a poor spatial resolution due to multiple Coulomb sca...

journal_title：Physics in medicine and biology

authors： Quiñones CT,Létang JM,Rit S

更新日期：2016-05-07 00:00:00

abstract：:In the field of regenerative medicine, there has been a growing interest in studying the combination of bone scaffolds and cells that can maximize newly formed bone. In-line phase-contrast x-ray tomography was used to image porous bone scaffolds (Skelite(©)), seeded with bone forming cells. This technique allows the q...

journal_title：Physics in medicine and biology

authors： Weber L,Langer M,Tavella S,Ruggiu A,Peyrin F

更新日期：2016-05-07 00:00:00

abstract：:Component-based normalization is a method used to compensate for the sensitivity of each of the lines of response acquired in positron emission tomography. This method consists of modelling the sensitivity of each line of response as a product of multiple factors, which can be classified as time-invariant, time-varian...

journal_title：Physics in medicine and biology

authors： Belzunce MA,Reader AJ

更新日期：2016-05-07 00:00:00

abstract：:The purpose of this work is the clinical commissioning of a recently developed in vivo range verification system (IRVS) for treatment of prostate cancer by anterior and anterior oblique proton beams. The IRVS is designed to perform a complete workflow for pre-treatment range verification and adjustment. It contains sp...

journal_title：Physics in medicine and biology

authors： Hoesl M,Deepak S,Moteabbed M,Jassens G,Orban J,Park YK,Parodi K,Bentefour EH,Lu HM

更新日期：2016-04-21 00:00:00

abstract：:Although interventional x-ray angiography (XA) procedures involve relatively high radiation doses that can lead to deterministic tissue reactions in addition to stochastic effects, convenient and accurate estimation of absorbed organ doses has traditionally been out of reach. This has mainly been due to the absence of...

journal_title：Physics in medicine and biology

authors： Omar A,Bujila R,Fransson A,Andreo P,Poludniowski G

更新日期：2016-04-21 00:00:00

abstract：:Burst-tone focused ultrasound exposure in the presence of microbubbles has been demonstrated to be effective at inducing temporal and local opening of the blood-brain barrier (BBB), which promises significant clinical potential to deliver therapeutic molecules into the central nervous system (CNS). Traditional contras...

journal_title：Physics in medicine and biology

authors： Tsai CH,Zhang JW,Liao YY,Liu HL

更新日期：2016-04-07 00:00:00

abstract：:For the treatment planning during intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT), beam fluence maps can be first optimized via fluence map optimization (FMO) under the given dose prescriptions and constraints to conformally deliver the radiation dose to the targets while sparin...

journal_title：Physics in medicine and biology

authors： Gao H

更新日期：2016-04-07 00:00:00

abstract：:This study presents the first observation of shear waves induced remotely within soft tissues. It was performed through the combination of a transcranial magnetic stimulation device and a permanent magnet. A physical model based on Maxwell and Navier equations was developed. Experiments were performed on a cryogel pha...

journal_title：Physics in medicine and biology

authors： Grasland-Mongrain P,Miller-Jolicoeur E,Tang A,Catheline S,Cloutier G

更新日期：2016-03-21 00:00:00

abstract：:Nuclear medicine and radiation therapy, although well established, are still rapidly evolving, by exploiting animal models, aiming to define precise dosimetry in molecular imaging protocols. The purpose of the present study was to create a dataset based on the MOBY phantom for the calculation of organ-to-organ S-value...

journal_title：Physics in medicine and biology

authors： Kostou T,Papadimitroulas P,Loudos G,Kagadis GC

更新日期：2016-03-21 00:00:00

abstract：:Gold nanoparticles (GNPs) have shown potential in recent years as a means of therapeutic dose enhancement in radiation therapy. However, a major challenge in moving towards clinical implementation is the exact characterisation of the dose enhancement they provide. Monte Carlo studies attempt to explore this property, ...

journal_title：Physics in medicine and biology

authors： Koger B,Kirkby C

更新日期：2016-03-07 00:00:00

abstract：:Non-pure positron emitters, with their long half-lives, allow for the tracing of slow biochemical processes which cannot be adequately examined by the commonly used short-lived positron emitters. Most of these isotopes emit high-energy cascade gamma rays in addition to positron decay that can be detected and create a ...

journal_title：Physics in medicine and biology

authors： Lin HH,Chuang KS,Chen SY,Jan ML

更新日期：2016-03-07 00:00:00

abstract：:A pencil beam model for the calculation of the lateral scattering in water of protons for any therapeutic energy and depth is presented. It is based on the full Molière theory, taking into account the energy loss and the effects of mixtures and compounds. Concerning the electromagnetic part, the model has no free para...

journal_title：Physics in medicine and biology

authors： Bellinzona EV,Ciocca M,Embriaco A,Ferrari A,Fontana A,Mairani A,Parodi K,Rotondi A,Sala P,Tessonnier T

更新日期：2016-02-21 00:00:00

abstract：:This is a proof of principle study on an algorithm for optimizing external beam radiotherapy in terms of both photon beamlet energy and fluence. This simultaneous beamlet energy and fluence optimization is denoted modulated photon radiotherapy (XMRT). XMRT is compared with single-energy intensity modulated radiotherap...

journal_title：Physics in medicine and biology

authors： McGeachy P,Villarreal-Barajas JE,Zinchenko Y,Khan R

更新日期：2016-02-21 00:00:00

abstract：:Fluorescence diffuse optical tomography (fDOT) provides 3D images of fluorescence distributions in biological tissue, which represent molecular and cellular processes. The image reconstruction problem is highly ill-posed and requires regularisation techniques to stabilise and find meaningful solutions. Quadratic regul...

journal_title：Physics in medicine and biology

authors： Correia T,Koch M,Ale A,Ntziachristos V,Arridge S

更新日期：2016-02-21 00:00:00

abstract：:The in vivo electric conductivity (σ) values of tissue are essential for accurate electromagnetic simulations and specific absorption rate (SAR) assessment for applications such as thermal dose computations in hyperthermia. Currently used σ-values are mostly based on ex vivo measurements. In this study the conductivit...

journal_title：Physics in medicine and biology

authors： Balidemaj E,de Boer P,van Lier AL,Remis RF,Stalpers LJ,Westerveld GH,Nederveen AJ,van den Berg CA,Crezee J

更新日期：2016-02-21 00:00:00

abstract：:In modern radiotherapy the verification of complex treatments plans is often performed in inhomogeneous or even anthropomorphic phantoms. For dose verification small detectors are necessary and therefore alanine detectors are most suitable. Though the response of alanine for a wide range of clinical photon energies in...

journal_title：Physics in medicine and biology

authors： von Voigts-Rhetz P,Anton M,Vorwerk H,Zink K

更新日期：2016-02-07 00:00:00

abstract：:To address the quality assurance (QA) of a MR-linac which is an MRI combined with a linear accelerator (linac), the traditional linac QA-tests need to be redesigned, since the presence of the static magnetic field in the MR-linac alters the electron trajectory. The latter causes the asymmetry in the dose kernel which ...

journal_title：Physics in medicine and biology

authors： van Zijp HM,van Asselen B,Wolthaus JW,Kok JM,de Vries JH,Ishakoglu K,Beld E,Lagendijk JJ,Raaymakers BW

更新日期：2016-02-07 00:00:00

abstract：:Time-of-flight (TOF) positron emission tomography (PET) technology has recently regained popularity in clinical PET studies for improving image quality and lesion detectability. Using TOF information, the spatial location of annihilation events is confined to a number of image voxels along each line of response, there...

journal_title：Physics in medicine and biology

authors： Mehranian A,Kotasidis F,Zaidi H

更新日期：2016-02-07 00:00:00

abstract：:The purpose of this work is to provide an evaluation of the mean glandular dose (MGD) for breast computed tomography (CT) with synchrotron radiation in an axial scanning configuration with a partial or total organ volume irradiation, for the in vivo program of breast CT ongoing at the ELETTRA facility (Trieste, Italy)...

journal_title：Physics in medicine and biology

authors： Mettivier G,Fedon C,Di Lillo F,Longo R,Sarno A,Tromba G,Russo P

更新日期：2016-01-21 00:00:00

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：:In response to the recognized fragility of reactor-produced (99)Mo supply, direct production of (99m)Tc via (100)Mo(p,2n)(99m)Tc reaction using medical cyclotrons has been investigated. However, due to the existence of other Molybdenum (Mo) isotopes in the target, in parallel with (99m)Tc, other technetium (Tc) radioa...

journal_title：Physics in medicine and biology

authors： Hou X,Tanguay J,Buckley K,Schaffer P,Bénard F,Ruth TJ,Celler A

更新日期：2016-01-21 00:00:00

abstract：:In proton therapy, the relative biological effectiveness (RBE) depends on various types of parameters such as linear energy transfer (LET). An analytical model for LET calculation exists (Wilkens' model), but secondary particles are not included in this model. In the present study, we propose a correction factor, L se...

journal_title：Physics in medicine and biology

authors： Marsolat F,De Marzi L,Pouzoulet F,Mazal A

更新日期：2016-01-21 00:00:00

abstract：:Novel x-ray medical imaging sensors, such as photon counting detectors (PCDs) and large area CCD and CMOS cameras can involve irregular and/or sparse sampling of the detector plane. Application of such detectors to CT involves undersampling that is markedly different from the commonly considered case of sparse angular...

journal_title：Physics in medicine and biology

authors： Sisniega A,Zbijewski W,Stayman JW,Xu J,Taguchi K,Fredenberg E,Lundqvist M,Siewerdsen JH

更新日期：2016-01-07 00:00:00

abstract：:This paper presents a method to obtain the pencil-beam kernels that characterize a megavoltage photon beam generated in a flattening filter free (FFF) linear accelerator (linac) by deconvolution from experimental measurements at different depths. The formalism is applied to perform independent dose calculations in mod...

journal_title：Physics in medicine and biology

authors： Azcona JD,Barbés B,Wang L,Burguete J

更新日期：2016-01-07 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：:Wafer-scale CMOS active pixel sensors (APSs) have been developed recently for x-ray imaging applications. The small pixel pitch and low noise are very promising properties for medical imaging applications such as digital breast tomosynthesis (DBT). In this work, we evaluated experimentally and through modeling the ima...

journal_title：Physics in medicine and biology

authors： Zhao C,Konstantinidis AC,Zheng Y,Anaxagoras T,Speller RD,Kanicki J

更新日期：2015-12-07 00:00:00

abstract：:In digital breast tomosynthesis (DBT), image characteristics of projection views and reconstructed volume are different and both have the advantage of detecting breast masses, e.g. reconstructed volume mitigates a tissue overlap, while projection views have less reconstruction blur artifacts. In this paper, an improve...

journal_title：Physics in medicine and biology

authors： Kim DH,Kim ST,Ro YM

更新日期：2015-11-21 00:00:00

abstract：:In CT imaging, a variety of applications exist which are strongly SNR limited. However, in some cases redundant data of the same body region provide additional quanta. Examples in dual energy CT, the spatial resolution has to be compromised to provide good SNR for material decomposition. However, the respective spectr...

journal_title：Physics in medicine and biology

authors： Bruder H,Raupach R,Sunnegardh J,Allmendinger T,Klotz E,Stierstorfer K,Flohr T

更新日期：2015-11-07 00:00:00

abstract：:Determination of the cardiorespiratory phase of the heart has numerous applications during cardiac imaging. In this article we propose a novel view-angle independent near-real time cardiorespiratory motion gating and coronary sinus (CS) catheter tracking technique for x-ray fluoroscopy images that are used to guide ca...

journal_title：Physics in medicine and biology

authors： Panayiotou M,Rhode KS,King AP,Ma Y,Cooklin M,O'Neill M,Gill J,Rinaldi CA,Housden RJ

更新日期：2015-10-21 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：:In this study, the safety compliance for nonuniform field exposures is discussed using coupling factor concepts. The coupling factor, which is defined in the International Electrotechnical Commission 62311 standard, is extended to consider the effects of harmonics and also to apply to the specific absorption rate (for...

journal_title：Physics in medicine and biology

authors： Sunohara T,Hirata A,Laakso I,De Santis V,Onishi T

更新日期：2015-10-21 00:00:00

abstract：:Breast-conserving surgery is a standard option for the treatment of patients with early-stage breast cancer. This form of surgery may result in incomplete excision of the tumor. Iodine-125 labeled titanium seeds are currently used in clinical practice to reduce the number of incomplete excisions. It seems likely that ...

journal_title：Physics in medicine and biology

authors： Arsenali B,de Jong HW,Viergever MA,Dickerscheid DB,Beijst C,Gilhuijs KG

更新日期：2015-10-07 00:00:00

abstract：:There is a need to verify the accuracy of general purpose Monte Carlo codes like EGSnrc, which are commonly employed for investigations of dosimetric problems in radiation therapy. A number of experimental benchmarks have been published to compare calculated values of absorbed dose to experimentally determined values....

journal_title：Physics in medicine and biology

authors： Renner F,Wulff J,Kapsch RP,Zink K

更新日期：2015-10-07 00:00:00