Study of the PTW microLion chamber temperature dependence.

abstract：:Prompt γ-ray imaging with a knife-edge shaped slit camera provides the possibility of verifying proton beam range in tumor therapy. Dedicated experiments regarding the characterization of the camera system have been performed previously. Now, we aim at implementing the prototype into clinical application of monitoring...

journal_title：Physics in medicine and biology

authors： Priegnitz M,Barczyk S,Nenoff L,Golnik C,Keitz I,Werner T,Mein S,Smeets J,Vander Stappen F,Janssens G,Hotoiu L,Fiedler F,Prieels D,Enghardt W,Pausch G,Richter C

更新日期：2016-11-21 00:00:00

abstract：:Image reconstruction of ultrasound computed tomography based on the wave equation is able to show much more structural details than simpler ray-based image reconstruction methods. However, to invert the wave-based forward model is computationally demanding. To address this problem, we develop an efficient fully learne...

journal_title：Physics in medicine and biology

authors： Zhao W,Wang H,Gemmeke H,van Dongen KWA,Hopp T,Hesser J

更新日期：2020-11-27 00:00:00

abstract：:Beam hardening is inevitable due to the polychromatic X-ray spectrum and energy-dependent attenuation coefficients of materials, leading to the underestimation of artifacts arising from projection data, especially on metal regions. State-of-the-art research on beam-hardening artifacts is based on a numerical method th...

journal_title：Physics in medicine and biology

authors： Hur J,Kim D,Shin YG,Lee H

更新日期：2021-01-26 00:00:00

abstract：:The automatic calibration in Fourier-domain optical coherence tomography (FD-OCT) systems allows for high resolution imaging with precise depth ranging functionality in many complex imaging scenarios, such as microsurgery. However, the accuracy and speed of the existing automatic schemes are limited due to the functio...

journal_title：Physics in medicine and biology

authors： Ratheesh KM,Seah LK,Murukeshan VM

更新日期：2016-11-07 00:00:00

abstract：:A novel digital x-ray detector has been assembled. The imaging system is based on a phosphor-coated charge-coupled device (CCD) obtained by direct deposition of a gadolinium oxysulphide scintillator onto the detector surface. The modulation transfer function has been measured along the two directions of the digital co...

journal_title：Physics in medicine and biology

authors： Gambaccini M,Taibi A,Del Guerra A,Marziani M,Tuffanelli A

更新日期：1996-12-01 00:00:00

abstract：:The cerebral arteries are difficult to reproduce from first principles, featuring interwoven territories, and intricate layers of grey and white matter with differing metabolic demand. The aim of this study was to identify the ideal configuration of arteries required to sustain an entire brain hemisphere based on mini...

journal_title：Physics in medicine and biology

authors： Keelan J,Chung EML,Hague JP

更新日期：2019-06-21 00:00:00

abstract：:The aim of this study was to develop a model exploiting artificial neural networks (ANNs) to correlate dosimetric and clinical variables with late rectal bleeding in prostate cancer patients undergoing radical radiotherapy and to compare the ANN results with those of a standard logistic regression (LR) analysis. 718 m...

journal_title：Physics in medicine and biology

authors： Tomatis S,Rancati T,Fiorino C,Vavassori V,Fellin G,Cagna E,Mauro FA,Girelli G,Monti A,Baccolini M,Naldi G,Bianchi C,Menegotti L,Pasquino M,Stasi M,Valdagni R

更新日期：2012-03-07 00:00:00

abstract：:The authors have developed an apparatus able to generate ID intensity-modulated beams, using only one moving absorber within the irradiation field. A procedure for deriving optimized absorber-speed profiles in order to produce the desired fluence/dose profiles has been suggested. Experimental tests show that the syste...

journal_title：Physics in medicine and biology

authors： Fiorino C,Lev A,Fusca M,Cattaneo GM,Rudello F,Calandrino R

更新日期：1995-02-01 00:00:00

abstract：:The medical imaging and therapeutic technologies that are based on the use of radiation are reviewed briefly, with special emphasis on the recent developments of synchrotron radiation (SR) methods. New results have been achieved in all of these areas since the last comprehensive reviews were written in this field. Thi...

journal_title：Physics in medicine and biology

authors： Suortti P,Thomlinson W

更新日期：2003-07-07 00:00:00

abstract：:Although the calculation of the surface average of the low-frequency current density distribution over a cross-section of 1 cm2 is required by ICNIRP guidelines, no reference averaging algorithm is indicated, neither in the ICNIRP guidelines nor in the Directive 2004/40/EC that is based on them. The lack of a general ...

journal_title：Physics in medicine and biology

authors： Zoppetti N,Andreuccetti D

更新日期：2009-08-07 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：: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：: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：:All radiation therapy treatment planning relies on accurate dose calculation. Uncertainties in dosimetric prediction can significantly degrade an otherwise optimal plan. In this work, we introduce a robust optimization method which handles dosimetric errors and warrants for high-quality IMRT plans. Unlike other dose e...

journal_title：Physics in medicine and biology

authors： Nohadani O,Seco J,Martin BC,Bortfeld T

更新日期：2009-06-07 00:00:00

abstract：:The purpose of this work is to develop a validated Geant4 simulation model of a whole-body prototype PET scanner constructed from the four-layer depth-of-interaction detectors developed at the National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Japan. T...

journal_title：Physics in medicine and biology

authors： Ahmed AM,Chacon A,Rutherford H,Akamatsu G,Mohammadi A,Nishikido F,Tashima H,Yoshida E,Yamaya T,Franklin DR,Rosenfeld A,Guatelli S,Safavi-Naeini M

更新日期：2020-12-18 00:00:00

abstract：:We present a method based on spectral theory for the shape analysis of carpal bones of the human wrist. We represent the cortical surface of the carpal bone in a coordinate system based on the eigensystem of the two-dimensional Helmholtz equation. We employ a metric--global point signature (GPS)--that exploits the sca...

journal_title：Physics in medicine and biology

authors： Chaudhari AJ,Leahy RM,Wise BL,Lane NE,Badawi RD,Joshi AA

更新日期：2014-02-21 00:00:00

abstract：:It is not feasible to define very small or complex organs and tissues in the current voxel-type adult reference computational phantoms of the International Commission on Radiological Protection (ICRP), which limit dose coefficients for weakly penetrating radiations. To address the problem, the ICRP is converting the v...

journal_title：Physics in medicine and biology

authors： Kim HS,Yeom YS,Nguyen TT,Choi C,Han MC,Lee JK,Kim CH,Zankl M,Petoussi-Henss N,Bolch WE,Lee C,Qiu R,Eckerman K,Chung BS

更新日期：2017-03-21 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：:Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is a valuable tool for assessing treatment response to novel cancer therapeutics. With appropriate data acquisition, quantitative functional parameter estimates can be obtained by fitting a model to the data. This research focuses on applying a dual-input ...

journal_title：Physics in medicine and biology

authors： Orton MR,Miyazaki K,Koh DM,Collins DJ,Hawkes DJ,Atkinson D,Leach MO

更新日期：2009-04-07 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：:Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B. The purpose of this study is to system...

journal_title：Physics in medicine and biology

authors： Pojtinger S,Dohm OS,Kapsch RP,Thorwarth D

更新日期：2018-06-07 00:00:00

abstract：:We combine two near-infrared diffuse optical techniques to study variations of blood flow, haemoglobin concentration, and blood oxygen saturation in the functioning rat brain. Diffuse correlation spectroscopy (or flowmetry) monitors changes in the cerebral blood flow, without the use of the principles of tracer cleara...

journal_title：Physics in medicine and biology

authors： Cheung C,Culver JP,Takahashi K,Greenberg JH,Yodh AG

更新日期：2001-08-01 00:00:00

abstract：:Refraction contrast of simple objects obtained using diffraction enhanced imaging (DEI) was studied and compared to conventional radiographic contrast. Lucite cylinders and nylon wires were imaged using monochromatic synchrotron radiation at the National Synchrotron Light Source (http://nslsweb. nsls.bnl.gov/nsls/Defa...

journal_title：Physics in medicine and biology

authors： Kiss MZ,Sayers DE,Zhong Z

更新日期：2003-02-07 00:00:00

abstract：:In vivo neutron activation analysis was used to measure total body sodium and chlorine in 18 male and 18 female normal adults. Corrections for body size were developed. Normalisation factors were derived which enable the prediction of the normal levels of sodium and chlorine in a subject. The coefficient of variation ...

journal_title：Physics in medicine and biology

authors： Kennedy NS,Eastell R,Smith MA,Tothill P

更新日期：1983-03-01 00:00:00

abstract：:Corrections for room scatter, [ksc(d, H)]RM, were derived using Monte Carlo methods for rooms of various sizes, including the brachytherapy treatment room, in which primary air kerma strength standardization of a remote afterloading microSelectron 192Ir HDR source was carried out, using a 60 cm3 spherical graphite ion...

journal_title：Physics in medicine and biology

authors： Selvam TP,Rajan KN,Nagarajan PS,Sethulakshmi P,Bhatt BC

更新日期：2001-09-01 00:00:00

abstract：:We explore how the radioactive background from naturally occurring 176Lu affects single photon transmission imaging for lutetium orthosilicate (LSO) scintillator-based PET cameras by estimating the transmission noise equivalent count rate (NECR) including this background. Assuming a typical PET camera geometry (80 cm ...

journal_title：Physics in medicine and biology

authors： Huber JS,Moses WW,Jones WF,Watson CC

更新日期：2002-10-07 00:00:00

abstract：:The purpose of this study was to examine the use of three physical image quality metrics in the calibration of an automatic exposure control (AEC) device for chest radiography with a computed radiography (CR) imaging system. The metrics assessed were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and mean ...

journal_title：Physics in medicine and biology

authors： Moore CS,Wood TJ,Avery G,Balcam S,Needler L,Beavis AW,Saunderson JR

更新日期：2014-05-07 00:00:00

abstract：:Respiratory induced resonance offset (RIRO) is a periodic disturbance of a magnetic field due to breathing. Such disturbance handicaps the accuracy of the proton resonance frequency shift (PRFS) method of MRI temperature mapping in anatomies situated nearby the lungs and chest wall. In this work, we propose a method c...

journal_title：Physics in medicine and biology

authors： Shmatukha AV,Bakker CJ

更新日期：2006-09-21 00:00:00

abstract：:Two novel materials have been developed to simulate the dielectric properties of human muscle and fat at 1000 MHz. These materials, which are based on ethanediol set with gelatine, are easily made and have good mechanical properties. The complex permittivity, epsilon *, of each material was measured with an open-ended...

journal_title：Physics in medicine and biology

authors： Robinson MP,Richardson MJ,Green JL,Preece AW

更新日期：1991-12-01 00:00:00

abstract：:An alternative to gamma (gamma) histograms for ROI-based quantitative comparisons of dose distributions using the gamma concept is proposed. The method provides minimum values of dose difference and distance-to-agreement such that a pre-set fraction of the region of interest passes the gamma test. Compared to standard...

journal_title：Physics in medicine and biology

authors： Dvorak P

更新日期：2009-06-21 00:00:00