Monte Carlo and experimental evaluation of accuracy and noise properties of two scatter correction methods for SPECT.

abstract：:The inadequate visibility of microcalcifications-small calcium deposits that cue radiologists to early stages of cancer-is a major limitation in current designs of dedicated breast computed tomography (bCT). This limitation has previously been attributed to the constituent components, spatial resolution, and utilized ...

journal_title：Physics in medicine and biology

authors： Ghazi P

更新日期：2020-12-04 00:00:00

abstract：:A system is described in which large superficial areas of tissue may be heated using a single plane ultrasonic transducer scanned in a raster fashion. The shape of the heated area is determined by the movement of a microswitch which is activated when it strikes the rigid edge of a hole of the required shape cut in a p...

journal_title：Physics in medicine and biology

authors： ter Haar G,Hopewell JW

更新日期：1985-12-01 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 temperature sensitivities of absorption and reduced scattering coefficients in the range 700-1000 nm are determined for the liquid phantom Intralipid using spatially resolved continuous wave measurements. The measurements were conducted on a 10 L heated volume of 1% Intralipid subjected to a 40-30 degrees C coolin...

journal_title：Physics in medicine and biology

authors： McGlone VA,Martinsen P,Künnemeyer R,Jordan B,Cletus B

更新日期：2007-05-07 00:00:00

abstract：:A new system has been designed and built to validate the concept of 3D computerized angiography (CA). This system can acquire a set of 2D digital subtracted angiography images while rotating around a patient and then, using these images, reconstruct a 3D representation of the opacified vasculature. The design principl...

journal_title：Physics in medicine and biology

authors： Saint-Félix D,Trousset Y,Picard C,Ponchut C,Roméas R,Rougée A

更新日期：1994-03-01 00:00:00

abstract：:Ultrasound-based elastography including strain elastography, acoustic radiation force impulse (ARFI) imaging, point shear wave elastography and supersonic shear imaging (SSI) have been used to differentiate breast tumors among other clinical applications. The objective of this study is to extend a previously published...

journal_title：Physics in medicine and biology

authors： Wang Y,Peng B,Jiang J

更新日期：2017-03-07 00:00:00

abstract：:We propose a regularized least-squares method for reconstructing 2D velocity vector fields within the left ventricular cavity from single-view color Doppler echocardiographic images. Vector flow mapping is formulated as a quadratic optimization problem based on an [Formula: see text]-norm minimization of a cost functi...

journal_title：Physics in medicine and biology

authors： Assi KC,Gay E,Chnafa C,Mendez S,Nicoud F,Abascal JFPJ,Lantelme P,Tournoux F,Garcia D

更新日期：2017-08-11 00:00:00

abstract：:We propose a hybrid multiobjective (MO) evolutionary optimization algorithm (MOEA) for intensity-modulated radiotherapy inverse planning and apply it to optimize the number of incident beams, their orientations and intensity profiles. The algorithm produces a set of efficient solutions, which represent different clini...

journal_title：Physics in medicine and biology

authors： Schreibmann E,Lahanas M,Xing L,Baltas D

更新日期：2004-03-07 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：: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：:The relative stopping power (RSP) uncertainty is the largest contributor to the range uncertainty in proton therapy. The purpose of this work was to develop a systematic method that yields accurate and patient-specific RSPs by combining (1) pre-treatment x-ray CT and (2) daily proton radiography of the patient. The me...

journal_title：Physics in medicine and biology

authors： Collins-Fekete CA,Brousmiche S,Hansen DC,Beaulieu L,Seco J

更新日期：2017-08-03 00:00:00

abstract：:The National Physical Laboratory (NPL) provides a high-energy photon calibration service using 4-19 MV x-rays and 60Co gamma-radiation for secondary standard dosemeters in terms of absorbed dose to water. The primary standard used for this service is a graphite calorimeter and so absorbed dose calibrations must be con...

journal_title：Physics in medicine and biology

authors： Nutbrown RF,Duane S,Shipley DR,Thomas RA

更新日期：2002-02-07 00:00:00

abstract：:Monolithic scintillation detectors for positron emission tomography and single-photon emission computed tomography (SPECT) imaging have many advantages over pixelated detectors. The use of monolithic crystals allows for reducing the scintillator cost per unit volume and increasing the sensitivity along with the energy...

journal_title：Physics in medicine and biology

authors： España S,Deprez K,Van Holen R,Vandenberghe S

更新日期：2013-07-21 00:00:00

abstract：:X-ray fluorescence computed tomography (XFCT) is a relatively new synchrotron-based imaging modality aiming at reconstructing the distribution of nonradiative elements within a sample irradiated with high-intensity monochromatic x-rays. In a recent paper La Rivière (2004 Phys. Med. Biol. 49 2391-405) presented an appr...

journal_title：Physics in medicine and biology

authors： Miqueles EX,De Pierro AR

更新日期：2010-02-21 00:00:00

abstract：:Injection of gas into the eye, followed by face-down positioning, is a common protocol for the reseating of the retina in posterior and superior retinal tears and breaks. The physical mechanism by which injected gas helps reattach retinal flaps is often ascribed to the 'buoyancy' force of the injected gas bubble. The ...

journal_title：Physics in medicine and biology

authors： Foster WJ,Chou T

更新日期：2004-07-07 00:00:00

abstract：:A parametric model for the x-ray linear attenuation coefficient is used to describe the compositional dependence of Hounsfield numbers measured by medical CT scanners. Measurements with materials of known density and composition, that span and evenly sample the compositional range of tissues, are written as linear sim...

journal_title：Physics in medicine and biology

authors： Midgley SM

更新日期：2014-12-07 00:00:00

abstract：:We have numerically modelled the thermal effects of yellow (577 or 578 nm) light illumination on the ectatic blood vessels of port wine stains. We investigated the effect of the laser treatment parameters of light irradiance and illumination time on the extent of coagulation (coagulation thickness) of the endothelial ...

journal_title：Physics in medicine and biology

authors： Pickering JW,Butler PH,Ring BJ,Walker EP

更新日期：1989-09-01 00:00:00

abstract：:The purpose of this work was to use Monte Carlo simulations to verify the accuracy of the dose distributions from a commercial treatment planning optimization system (Corvus, Nomos Corp., Sewickley, PA) for intensity-modulated radiotherapy (IMRT). A Monte Carlo treatment planning system has been implemented clinically...

journal_title：Physics in medicine and biology

authors： Ma CM,Pawlicki T,Jiang SB,Li JS,Deng J,Mok E,Kapur A,Xing L,Ma L,Boyer AL

更新日期：2000-09-01 00:00:00

abstract：:Assessment of image quality for digital x-ray mammography systems used in European screening programs relies mainly on contrast-detail CDMAM phantom scoring and requires the acquisition and analysis of many images in order to reduce variability in threshold detectability. Part II of this study proposes an alternative ...

journal_title：Physics in medicine and biology

authors： Monnin P,Marshall NW,Bosmans H,Bochud FO,Verdun FR

更新日期：2011-07-21 00:00:00

abstract：:Current dosimetry protocols (AAPM, IAEA, DIN) recommend the use of parallel-plate ionization chambers for the measurement of absorbed dose-to-water in clinical electron beams. For well-guarded plane-parallel chambers, it is assumed that the perturbation correction pQ is unity for all electron energies. In this study, ...

journal_title：Physics in medicine and biology

authors： Zink K,Wulff J

更新日期：2008-03-21 00:00:00

abstract：:At low and intermediate frequencies, the strength of the induced electric field is used as dosimetric quantity for human protection in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. To compute the induced electric field, numerical methods based on anatomically realistic voxel mo...

journal_title：Physics in medicine and biology

authors： Soldati M,Laakso I

更新日期：2020-01-10 00:00:00

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：:A software program, SpekCalc, is presented for the calculation of x-ray spectra from tungsten anode x-ray tubes. SpekCalc was designed primarily for use in a medical physics context, for both research and education purposes, but may also be of interest to those working with x-ray tubes in industry. Noteworthy is the p...

journal_title：Physics in medicine and biology

authors： Poludniowski G,Landry G,DeBlois F,Evans PM,Verhaegen F

更新日期：2009-10-07 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：:Positron emission tomography is one of the most mature techniques for monitoring the particles range in hadron therapy, aiming to reduce treatment uncertainties and therefore the extent of safety margins in the treatment plan. In-beam PET monitoring has been already performed using inter-spill and post-irradiation dat...

journal_title：Physics in medicine and biology

authors： Kostara E,Sportelli G,Belcari N,Camarlinghi N,Cerello P,Del Guerra A,Ferrero V,Fiorina E,Giraudo G,Morrocchi M,Pennazio F,Pullia M,Rivetti A,Rolo MD,Rosso V,Wheadon R,Bisogni MG

更新日期：2019-01-21 00:00:00

abstract：:A method for registering images acquired from a prototype flat panel mobile C-arm, capable of kilovoltage (kV) cone-beam computed tomography (CT), to a linear accelerator (LINAC) isocenter is presented. A calibration procedure is performed which involves locating reflective markers placed on the C-arm and a phantom in...

journal_title：Physics in medicine and biology

authors： Sorensen S,Mitschke M,Solberg T

更新日期：2007-06-21 00:00:00

abstract：:When dosimetric effects in time-dependent geometries are studied, usually either the results of individual three-dimensional (3D) calculations are combined or probability-based approaches are applied. These methods may become cumbersome and time-consuming if high time resolution is required or if the geometry is compl...

journal_title：Physics in medicine and biology

authors： Paganetti H,Jiang H,Trofimov A

更新日期：2005-03-07 00:00:00

abstract：:Dual spectral computed tomography (DSCT) has a superior material distinguishability than the conventional single spectral computed tomography (SSCT). However, the decomposition process is an illposed problem, which is sensitive to noise. Thus, the decomposed image quality is degraded, and the corresponding signal-to-n...

journal_title：Physics in medicine and biology

authors： Wang Q,Zhu Y,Yu H

更新日期：2017-10-19 00:00:00

abstract：:A hybrid differential and spatially resolved spectroscopy (SRS) technique has been developed to measure absolute absorption coefficient (mu(a)), reduced scattering coefficient (mu'(s)) and cerebral blood volume (CBV) in the adult human head. A spectrometer with both differential and SRS capabilities has been used to c...

journal_title：Physics in medicine and biology

authors： Leung TS,Tachtsidis I,Smith M,Delpy DT,Elwell CE

更新日期：2006-02-07 00:00:00

abstract：:Factors affecting the accuracy of the in vivo measurement of cutaneous pigments and blood oxygenation by reflectance spectrophotometry have been examined. It was found that stray light, the amounts of haemoglobin and melanin, and the level of blood oxygenation all contributed to the measured reflectance and had to be ...

journal_title：Physics in medicine and biology

authors： Hajizadeh-Saffar M,Feather JW,Dawson JB

更新日期：1990-09-01 00:00:00