Soft-tissue phase-contrast tomography with an x-ray tube source.

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：:Non-invasively reconstructing the cardiac transmembrane potentials (TMPs) from body surface potentials can act as a regression problem. The support vector regression (SVR) method is often used to solve the regression problem, however the computational complexity of the SVR training algorithm is usually intensive. In t...

journal_title：Physics in medicine and biology

authors： Jiang M,Zhang H,Zhu L,Cao L,Wang Y,Xia L,Gong Y

更新日期：2015-04-21 00:00:00

abstract：:Magnetic particle imaging is a new approach to visualizing magnetic nanoparticles. It is capable of 3D real-time in vivo imaging of particles injected into the blood stream and is a candidate for medical imaging applications. To date, only one particle type has been imaged at a time, however, the ability to separate s...

journal_title：Physics in medicine and biology

authors： Rahmer J,Halkola A,Gleich B,Schmale I,Borgert J

更新日期：2015-03-07 00:00:00

abstract：:The theory of task-based assessment of image quality is reviewed in the context of imaging with ionizing radiation, and objective figures of merit (FOMs) for image quality are summarized. The variation of the FOMs with the task, the observer and especially with the mean number of photons recorded in the image is discu...

journal_title：Physics in medicine and biology

authors： Barrett HH,Myers KJ,Hoeschen C,Kupinski MA,Little MP

更新日期：2015-01-21 00:00:00

abstract：:The dielectric properties of glycerol, propylene glycol, ethylene glycol and dimethyl sulphoxide have been measured in various aqueous concentrations generally sufficient to allow supercooling rather than freezing. The temperature range investigated is from -80 degrees C to +20 degrees C and the frequency range is 100...

journal_title：Physics in medicine and biology

authors： Michelson SC,Evans S

更新日期：1996-10-01 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：:Sensing and enumeration of specific types of circulating cells in small animals is an important problem in many areas of biomedical research. Microscopy-based fluorescence in vivo flow cytometry methods have been developed previously, but these are typically limited to sampling of very small blood volumes, so that ver...

journal_title：Physics in medicine and biology

authors： Zettergren E,Swamy T,Runnels J,Lin CP,Niedre M

更新日期：2012-07-21 00:00:00

abstract：:Computational modeling is an important tool in ultrasound imaging research, but realistic three-dimensional (3D) simulations can exceed the capabilities of serial computers. This paper uses a 3D simulator based on a k-space method that incorporates relaxation absorption and nonreflecting boundary conditions. The simul...

journal_title：Physics in medicine and biology

authors： Daoud MI,Lacefield JC

更新日期：2009-09-07 00:00:00

abstract：:The ion recombination is examined in parallel-plate ionization chambers in scanning proton beams at the Danish Centre for Particle Therapy and the Skandion Clinic. The recombination correction factor k s is investigated for clinically relevant energies between 70 MeV and 244 MeV for dose rates below 400 Gy min-1 in ai...

journal_title：Physics in medicine and biology

authors： Christensen JB,Almhagen E,Stolarczyk L,Liszka M,Hernandez GG,Bassler N,Nørrevang O,Vestergaard A

更新日期：2020-06-05 00:00:00

abstract：:This work compared the impact of x-ray tube performance and automatic dose rate control (ADRC) parameter selection on system imaging efficiency of two Siemens angiography systems: a Siemens Megalix x-ray tube installed on an Artis Zee system (denoted 'MEGALIX') and a newer generation Gigalix x-ray tube installed on an...

journal_title：Physics in medicine and biology

authors： Dehairs M,Bosmans H,Marshall NW

更新日期：2020-11-24 00:00:00

abstract：:Monte Carlo simulation techniques are applied to track the annihilation photons from positron decay, and store the photon histories. Reasonably realistic models of the isotope distribution in the brain and heart during typical PET studies, as well as the traditional phantoms used for measuring PET scanner performance ...

journal_title：Physics in medicine and biology

authors： Thompson CJ,Moreno-Cantu J,Picard Y

更新日期：1992-03-01 00:00:00

abstract：:Quantifying the retention or washout of (99m)Tc-Sestamibi (MIBI) in breast tumours in vivo may provide a basis for predicting the chemotherapy response. The aim of this study is to investigate the variations and limitations of the different methods used to quantify these parameters. A phantom was developed that allowe...

journal_title：Physics in medicine and biology

authors： Marshall C,Griffiths PA

更新日期：2005-05-07 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：:Contrast enhanced ultrasound (CEUS) and dynamic contrast enhanced ultrasound (DCE-US) can be used to provide information about the vasculature aiding diagnosis and monitoring of a number of pathologies including cancer. In the development of a CEUS imaging system, there are many choices to be made, such as whether to ...

journal_title：Physics in medicine and biology

authors： Moghimirad E,Bamber J,Harris E

更新日期：2019-04-23 00:00:00

abstract：:The goal of this study is to demonstrate the feasibility of a novel non-coplanar-arc optimization algorithm (CyberArc). This method aims to reduce the delivery time of conventional CyberKnife treatments by allowing for continuous beam delivery. CyberArc uses a 4 step optimization strategy, in which nodes, beams, and c...

journal_title：Physics in medicine and biology

authors： Kearney V,Cheung JP,McGuinness C,Solberg TD

更新日期：2017-06-26 00:00:00

abstract：:Optical experiments are described for measuring the attenuation characteristics of breast tissues at visible and near-infrared wavelengths. Total attenuation coefficients post mortem were measured directly in thin tissue sections. They are usually within the range from 10 to 30 mm-1, are rather higher in fat than in f...

journal_title：Physics in medicine and biology

authors： Key H,Davies ER,Jackson PC,Wells PN

更新日期：1991-05-01 00:00:00

abstract：:An ESTRO booklet and a report of the Netherlands Commission on Radiation Dosimetry have been published recently describing empirical methods for monitor unit (MU) calculations in symmetrical high-energy photon beams. Both documents support the same basic ideas; firstly the separation of head scatter and volume scatter...

journal_title：Physics in medicine and biology

authors： Georg D

更新日期：1999-12-01 00:00:00

abstract：:In electron beam dosimetry using parallel-plate chambers solid phantoms are sometimes necessary. To obtain the dose to water from the ionization obtained in the solid phantom, fluence correction factors and perturbation factors have to be applied. In this study fluence factors in a perturbation free geometry have been...

journal_title：Physics in medicine and biology

authors： Nilsson B,Montelius A,Andreo P,Johansson J

更新日期：1997-11-01 00:00:00

abstract：:We investigated the physical characteristics of two complementary metal oxide semiconductor (CMOS) mammography detectors. The detectors featured 14-bit image acquisition, 50 microm detector element (del) size and an active area of 5 cm x 5 cm. One detector was a passive-pixel sensor (PPS) with signal amplification per...

journal_title：Physics in medicine and biology

authors： Elbakri IA,McIntosh BJ,Rickey DW

更新日期：2009-03-21 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：:A modified sector-integration method is presented that can predict the output factors of irregular shaped electron fields even in the case of extended source to surface distance (SSD). The model takes as input measured output factors for circular inserts of various radii. These circular fields were measured at SSDs of...

journal_title：Physics in medicine and biology

authors： Choi DR,Wolters J,Mason D,Baillie A

更新日期：2000-11-01 00:00:00

abstract：:Proton therapy is very sensitive to daily density changes along the pencil beam paths. The purpose of this study is to develop and evaluate an automated method for adaptation of IMPT plans to compensate for these daily tissue density variations. A two-step restoration method for 'densities-of-the-day' was created: (1)...

journal_title：Physics in medicine and biology

authors： Jagt T,Breedveld S,van de Water S,Heijmen B,Hoogeman M

更新日期：2017-06-07 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：:The purpose of this study is to evaluate a new method to improve performance of computer-aided detection (CAD) schemes of screening mammograms with two approaches. In the first approach, we developed a new case based CAD scheme using a set of optimally selected global mammographic density, texture, spiculation, and st...

journal_title：Physics in medicine and biology

authors： Tan M,Aghaei F,Wang Y,Zheng B

更新日期：2017-01-21 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：:Until now, no matrix transducer has been realized for 3D transesophageal echocardiography (TEE) in pediatric patients. In 3D TEE with a matrix transducer, the biggest challenges are to connect a large number of elements to a standard ultrasound system, and to achieve a high volume rate (>200 Hz). To address these issu...

journal_title：Physics in medicine and biology

authors： Bera D,Raghunathan SB,Chen C,Chen Z,Pertijs MAP,Verweij MD,Daeichin V,Vos HJ,van der Steen AFW,de Jong N,Bosch JG

更新日期：2018-03-29 00:00:00

abstract：:The variety of treatment options for cancer patients has increased significantly in recent years. Not only do we combine radiation with surgery and chemotherapy, new therapeutic approaches such as immunotherapy and targeted therapies are starting to play a bigger role. Physics has made significant contributions to rad...

journal_title：Physics in medicine and biology

authors： Grassberger C,Paganetti H

更新日期：2016-11-07 00:00:00

abstract：:Elastography, which uses ultrasound to image the tissue strain that results from an applied displacement, can display tumours and heat-ablated tissue with high contrast. However, its application to liver in vivo may be problematic due to the presence of respiratory and cardiovascular sources of displacement. The aim o...

journal_title：Physics in medicine and biology

authors： Kolen AF,Miller NR,Ahmed EE,Bamber JC

更新日期：2004-09-21 00:00:00

abstract：:In carbon ion therapy treatment planning, the relative biological effectiveness (RBE) is accounted for by optimization of the RBE-weighted dose (biological dose). The RBE calculation methods currently applied clinically in carbon ion therapy are derived from the microdosimetric kinetic model (MKM) in Japan and the loc...

journal_title：Physics in medicine and biology

authors： Dahle TJ,Magro G,Ytre-Hauge KS,Stokkevåg CH,Choi K,Mairani A

更新日期：2018-11-12 00:00:00

abstract：:Effective use of the [Formula: see text] decay chain in targeted internal radioimmunotherapy requires the retention of both [Formula: see text] and progeny isotopes at the target site. Imaging-based pharmacokinetic tests of these pharmaceuticals must therefore separately yet simultaneously image multiple isotopes that...

journal_title：Physics in medicine and biology

authors： Robertson AKH,Ramogida CF,Rodríguez-Rodríguez C,Blinder S,Kunz P,Sossi V,Schaffer P

更新日期：2017-06-07 00:00:00