Improving source detection and separation in a spatiotemporal Bayesian inference dipole analysis.

abstract：:Approximately 70% of acute coronary artery disease is caused by unstable (vulnerable) plaques with an inflammation of the overlying cap and high lipid content. A rupturing of the inflamed cap of the plaque results in propagation of the thrombus into the lumen, blockage of the artery and acute ischaemic syndrome or sud...

journal_title：Physics in medicine and biology

authors： Shikhaliev PM,Xu T,Ducote JL,Easwaramoorthy B,Mukherjee J,Molloi S

更新日期：2006-02-21 00:00:00

abstract：:The purpose of this study is to develop an adaptive prior knowledge guided image estimation technique to reduce the scan angle needed in the limited-angle intrafraction verification (LIVE) system for 4D-CBCT reconstruction. The LIVE system has been previously developed to reconstruct 4D volumetric images on-the-fly du...

journal_title：Physics in medicine and biology

authors： Zhang Y,Yin FF,Zhang Y,Ren L

更新日期：2017-05-07 00:00:00

abstract：:A method is presented to predict beam profiles and outputs for wedged asymmetric fields defined by independent collimator jaws allowing fast generation of beam profiles whilst requiring very little additional data to that already used by most treatment planning systems in generating symmetric field isodoses. Symmetric...

journal_title：Physics in medicine and biology

authors： Millin AE,Smith CW

更新日期：1994-01-01 00:00:00

abstract：:Subharmonic contrast imaging promises to improve ultrasound-imaging quality by taking advantage of an increased contrast to tissue signal. However, acoustic pressures beyond the subharmonic generation threshold using common ultrasound pulses may induce significant contrast microbubble destruction. In this work, a chir...

journal_title：Physics in medicine and biology

authors： Zhang D,Gong Y,Gong X,Liu Z,Tan K,Zheng H

更新日期：2007-09-21 00:00:00

abstract：:Monte Carlo simulation was used to calculate correction factors for output factor (OF), percentage depth-dose (PDD), and off-axis ratio (OAR) measurements with the CyberKnife M6 System. These include the first such data for the InCise MLC. Simulated detectors include diodes, air-filled microchambers, a synthetic micro...

journal_title：Physics in medicine and biology

authors： Francescon P,Kilby W,Noll JM,Masi L,Satariano N,Russo S

更新日期：2017-02-07 00:00:00

abstract：:The in-phantom calibration method for radiotherapy kilovoltage x-ray beams requires ionization chamber correction factors. The overall ionization chamber correction factor accounts for changes in the chamber response due to the displacement of water by the chamber cavity and wall, the presence of the stem and the chan...

journal_title：Physics in medicine and biology

authors： Bancheri J,Ketelhut S,Büermann L,Seuntjens J

更新日期：2020-05-11 00:00:00

abstract：:In the current work, EPR (electron paramagnetic resonance) dosimetry using alanine films (134 microm thick) was utilized for dose measurements in inhomogeneous phantoms irradiated with radiotherapy photon beams. The main phantom material was PMMA, while either Styrofoam or aluminium was introduced as an inhomogeneity....

journal_title：Physics in medicine and biology

authors： Osterås BH,Hole EO,Olsen DR,Malinen E

更新日期：2006-12-21 00:00:00

abstract：:This paper contains the recommendations of the high dose rate (HDR) brachytherapy working party of the UK Institute of Physics and Engineering in Medicine (IPEM). The recommendations consist of a Code of Practice (COP) for the UK for measuring the reference air kerma rate (RAKR) of HDR (192)Ir brachytherapy sources. I...

journal_title：Physics in medicine and biology

authors： Bidmead AM,Sander T,Locks SM,Lee CD,Aird EG,Nutbrown RF,Flynn A,IPEM Working Party.

更新日期：2010-06-07 00:00:00

abstract：:In recent years, there has been an increase in the popularity of light-emitting diode (LED)-based, battery-powered transilluminators (BPTs) for facilitating transdermal vascular access in adults and neonates. BPTs are believed to have lower potential for inducing skin burns than prior devices based on high-power broad...

journal_title：Physics in medicine and biology

authors： Pfefer TJ,Mehrabi A,James R,Landry R,Weininger S,Chang I,Kaufman D,Miller S

更新日期：2009-11-21 00:00:00

abstract：:A rotary positron-emission computed tomography system has been proposed in which detectors are mounted unequally spaced on a ring, so as to provide fine and uniform linear sampling during a 360 degree rotation of the ring around its centre. The usefulness of a simple iterative method for searching for a suitable arran...

journal_title：Physics in medicine and biology

authors： Yamamoto M

更新日期：1981-05-01 00:00:00

abstract：:Determining plaque vulnerability is critical when selecting the most suitable treatment for patients with atherosclerotic plaque. Currently, clinical non-invasive ultrasound-based methods for plaque characterization are limited to visual assessment of plaque morphology and new quantitative methods are needed. In this ...

journal_title：Physics in medicine and biology

authors： Widman E,Maksuti E,Larsson D,Urban MW,Bjällmark A,Larsson M

更新日期：2015-04-21 00:00:00

abstract：:A method of computing theoretical X-ray spectra in the range 30-150 kV is presented. The theoretical spectra are compared with constant potential, high resolution spectra from a tungsten target measured with a Ge(Li) detector, for a range of target angles, tube voltage and filtrations. Above 100 kV the spectra were al...

journal_title：Physics in medicine and biology

authors： Birch R,Marshall M

更新日期：1979-05-01 00:00:00

abstract：:Ring artifacts in cone beam computed tomography (CBCT) images are caused by pixel gain variations using flat-panel detectors, and may lead to structured non-uniformities and deterioration of image quality. The purpose of this study is to propose a method of general ring artifact removal in CBCT images. This method is ...

journal_title：Physics in medicine and biology

authors： Liang X,Zhang Z,Niu T,Yu S,Wu S,Li Z,Zhang H,Xie Y

更新日期：2017-07-07 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：: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：:Iterative tomographic reconstruction has been established as a viable alternative for data analysis in phase-sensitive x-ray imaging based on the edge-illumination principle. However, previously published approaches did not account for drifts of optical elements during a scan, which can lead to artefacts. Up to now, t...

journal_title：Physics in medicine and biology

authors： Modregger P,Meganck J,Hagen CK,Massimi L,Olivo A,Endrizzi M

更新日期：2019-10-10 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：:Tumour blood flow is one of the important factors limiting the efficacy of radiation therapy (hypoxic radioresistance), chemotherapy (drug delivery) and thermal therapy (heat dissipation) in treating cancer. The modification of tumour blood flow has been an area of intense investigation. In the current study, the arte...

journal_title：Physics in medicine and biology

authors： Purdie TG,Lee TY

更新日期：2003-04-07 00:00:00

abstract：:The origin of the differences in the refractive index observed between normal and tumor tissues using terahertz spectroscopy has been described quantitatively. To estimate water content differences in tissues, we prepared fresh and paraffin-embedded samples from rats. An approximately 5% increase of water content in t...

journal_title：Physics in medicine and biology

authors： Yamaguchi S,Fukushi Y,Kubota O,Itsuji T,Ouchi T,Yamamoto S

更新日期：2016-09-21 00:00:00

abstract：:Monte Carlo (MC) algorithms are recognized as the most accurate methodology for patient dose assessment. For intensity-modulated radiation therapy (IMRT) delivered with dynamic multileaf collimators (DMLCs), accurate dose calculation, even with MC, is challenging. Accurate IMRT MC dose calculations require inclusion o...

journal_title：Physics in medicine and biology

authors： Siebers JV,Keall PJ,Kim JO,Mohan R

更新日期：2002-09-07 00:00:00

abstract：:Output normalized dose profiles for asymmetric open photon fields has been calculated using a commercial treatment planning system (TPS) based on a dose-to-energy-fluence concept. The model does not require any additional measurements for off-axis fields. Calculations are compared with measurements for quadratic field...

journal_title：Physics in medicine and biology

authors： Hurkmans C,Knöös T,Nilsson P

更新日期：1996-08-01 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：:A cost-effective method employing polysulphone, nalidixic acid, 8-methoxypsoralen and phenothiazine as UV dosimeters is presented for evaluating the UV spectrum. The exposure measured by each dosimeter is a function of the source spectrum and the spectral response of the material. Each material has a different spectra...

journal_title：Physics in medicine and biology

authors： Parisi AV,Wong JC,Moore GI

更新日期：1997-01-01 00:00:00

abstract：:Photosensitizer fluorescence excited by photodynamic therapy (PDT) treatment light can be used to monitor the in vivo concentration of the photosensitizer and its photobleaching. The temporal integral of the product of in vivo photosensitizer concentration and light fluence is called PDT dose, which is an important do...

journal_title：Physics in medicine and biology

authors： Ong YH,Kim MM,Finlay JC,Dimofte A,Singhal S,Glatstein E,Cengel KA,Zhu TC

更新日期：2017-12-29 00:00:00

abstract：:In stereotactic radiosurgery, a seven-irradiation film was used to define any discrepancy between the beam and target centres. A mathematical model based on the linac alignment and target set-up was developed to diagnose the discrepancies of the seven-irradiation film between the beam and simulation target centres. Fr...

journal_title：Physics in medicine and biology

authors： Tsai JS

更新日期：1996-09-01 00:00:00

abstract：:An in vivo probe was compared with a gamma camera for the task of detecting radiolabelled tumour models in a water phantom. The probe, which contained a 1 cm diameter NaI(T1) detector, was designed and used by us for surgical staging studies of gynaecological patients. Tumours were spherical sources of different sizes...

journal_title：Physics in medicine and biology

authors： Barber HB,Barrett HH,Woolfenden JM,Myers KJ,Hickernell TS

更新日期：1989-06-01 00:00:00

abstract：:Multi-atlas segmentation (MAS) has been widely used to automate the delineation of organs at risk (OARs) for radiotherapy. Label fusion is a crucial step in MAS to cope with the segmentation variabilities among multiple atlases. However, most existing label fusion methods do not consider the potential dosimetric impac...

journal_title：Physics in medicine and biology

authors： Chang J,Tian Z,Lu W,Gu X,Chen M,Jiang SB

更新日期：2017-05-07 00:00:00

abstract：:This paper presents a description of tests carried out to compare the behaviour of five algorithms in inverse radiation therapy planning: (1) The Dynamically Penalized Likelihood (DPL), an algorithm based on statistical estimation theory; (2) an accelerated version of the same algorithm: (3) a new fast adaptive simula...

journal_title：Physics in medicine and biology

authors： Llacer J,Solberg TD,Promberger C

更新日期：2001-10-01 00:00:00

abstract：:Coronary flow rate remains complex to assess in clinical practice using non-invasive, non-ionizing imaging tools. In this study, we introduce 3D ultrafast Doppler coronary angiography (3D UDCA), an ultrasound-based method to assess coronary blood flows in three-dimensions at high volume-rate and in one single heartbea...

journal_title：Physics in medicine and biology

authors： Correia M,Maresca D,Goudot G,Villemain O,Bizé A,Sambin L,Tanter M,Ghaleh B,Pernot M

更新日期：2020-06-05 00:00:00

abstract：:A method of measuring the image quality of medical imaging equipment is considered within the framework of statistical decision theory. In this approach, images are regarded as random vectors and image quality is defined in the context of the image information available for performing a specified detection or discrimi...

journal_title：Physics in medicine and biology

authors： Tapiovaara MJ,Wagner RF

更新日期：1993-01-01 00:00:00