Experimental study on the influence of the central electrode in Farmer-type ionization chambers.

abstract：:Magnetic resonance-guided radiation therapy (MR-GRT) offers great potential to improve radiation treatment outcomes by providing more accurate and patient-tailored therapy. Despite superior soft tissue contrast in MRI, one of the challenges towards MRI-only workflows is that the process often requires some sort of 'MR...

journal_title：Physics in medicine and biology

authors： Nosrati R,Paudel M,Ravi A,Pejovic-Milic A,Morton G,Stanisz GJ

更新日期：2019-07-16 00:00:00

abstract：:A novel radiation targeted therapy is investigated for HER-2 positive breast cancers. The proposed concept combines two known approaches, but never used together for the treatment of advanced, relapsed or metastasized HER-2 positive breast cancers. The proposed radiation binary targeted concept is based on the anti HE...

journal_title：Physics in medicine and biology

authors： Mundy DW,Harb W,Jevremovic T

更新日期：2006-03-21 00:00:00

abstract：:The trend towards conformal, intensity modulated radiotherapy treatments has established the need for a true integrating dosimeter. In traditional radiotherapy, radiographic film dosimetry is commonly used. The accuracy and reproducibility of film optical density as an indicator of dose is influenced by several variab...

journal_title：Physics in medicine and biology

authors： Suchowerska N,Hoban P,Butson M,Davison A,Metcalfe P

更新日期：2001-05-01 00:00:00

abstract：:Currently, standards for the compliance testing of wireless devices are being extended to cover a wider frequency band and different usage patterns of mobile phones as well as of novel body-worn and handheld devices. As a consequence, not only the head but also strongly varying tissue distributions of the body are exp...

journal_title：Physics in medicine and biology

authors： Christ A,Samaras T,Klingenböck A,Kuster N

更新日期：2006-10-07 00:00:00

abstract：:EGSnrc Monte Carlo simulation was used to investigate dose perturbation effects in prostate seed implant brachytherapy using 125I radioactive seeds used in implant brachytherapy. Dose perturbation effects resulting from the seed mutual attenuation in a prostate seed implant consisting of 27 seeds were investigated. Th...

journal_title：Physics in medicine and biology

authors： Mobit P,Badragan I

更新日期：2004-07-21 00:00:00

abstract：:For PET online data acquisition, a centralized coincidence processor (CCP) with a single-thread data processing has been used to select coincidence events for many PET scanners. CCP has the advantage of highly integrated circuit, compact connection between detector front-end and system electronics, and centralized con...

journal_title：Physics in medicine and biology

authors： Cheng X,Hu K,Yang D,Shao Y

更新日期：2021-01-21 00:00:00

abstract：:We experimentally investigated the SPECT recovery of I-131 activity in multiple spheres located simultaneously at different locations within a cylindrical phantom that had an elliptical cross section. The sphere volumes ranged from 209 cc down to 4.2 cc. A Prism 3000 camera and two types of parallel-hexagonal-hole col...

journal_title：Physics in medicine and biology

authors： Koral KF,Yendiki A,Dewaraja YK

更新日期：2007-02-07 00:00:00

abstract：:Four dimensional cone beam computed tomography (4DCBCT) uses a constant gantry speed and imaging frequency that are independent of the patient's breathing rate. Using a technique called respiratory motion guided 4DCBCT (RMG-4DCBCT), we have previously demonstrated that by varying the gantry speed and imaging frequency...

journal_title：Physics in medicine and biology

authors： O'Brien RT,Stankovic U,Sonke JJ,Keall PJ

更新日期：2017-06-07 00:00:00

abstract：:We study threshold-driven optimization methodology for automatically generating a treatment plan that is motivated by a reference DVH for IMRT treatment planning. We present a framework for threshold-driven optimization for reference-based auto-planning (TORA). Commonly used voxel-based quadratic penalties have two co...

journal_title：Physics in medicine and biology

authors： Long T,Chen M,Jiang S,Lu W

更新日期：2018-02-08 00:00:00

abstract：:In this letter the authors highlight the presence of an error appearing in the discussion of the note 'The use of the Henyey-Greenstein phase function in Monte Carlo simulations in biomedical optics' previously published by them (Binzoni et al 2006 Phys. Med. Biol. 51 N313). In the light of this error, the discussion ...

journal_title：Physics in medicine and biology

authors： Binzoni T,Leung TS,Gandjbakhche AH,Rüfenacht D,Delpy DT

更新日期：2006-11-21 00:00:00

abstract：:We present a new method for automated characterization of atherosclerotic plaque composition in ex vivo MRI. It uses MRI intensities as well as four other types of features: smoothed, gradient magnitude and Laplacian images at several scales, and the distances to the lumen and outer vessel wall. The ground truth for f...

journal_title：Physics in medicine and biology

authors： van Engelen A,Niessen WJ,Klein S,Groen HC,Verhagen HJ,Wentzel JJ,van der Lugt A,de Bruijne M

更新日期：2012-01-07 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：:This paper presents a method to experimentally validate the beam quality correction factors (kQ) tabulated in IAEA TRS-398 for proton beams and to determine the kQ of non-tabulated ionization chambers (based on the already tabulated values). The method is based exclusively on ionometry and it consists in comparing the...

journal_title：Physics in medicine and biology

authors： Gomà C,Hofstetter-Boillat B,Safai S,Vörös S

更新日期：2015-04-21 00:00:00

abstract：:The objective of this paper is to evaluate an iterative maximum likelihood (ML) cone-beam computed tomography (CBCT) reconstruction with total variation (TV) regularization with respect to the robustness of the algorithm due to data inconsistencies. Three different and (for clinical application) typical classes of err...

journal_title：Physics in medicine and biology

authors： Stsepankou D,Arns A,Ng SK,Zygmanski P,Hesser J

更新日期：2012-10-07 00:00:00

abstract：:Magnetic Resonance Electrical Impedance Tomography (MREIT) is an MRI method that enables mapping of internal conductivity and/or current density via measurements of magnetic flux density signals. The MREIT measures only the z-component of the induced magnetic flux density B = (Bx, By, Bz) by external current injection...

journal_title：Physics in medicine and biology

authors： Jeong WC,Chauhan M,Sajib SZ,Kim HJ,Serša I,Kwon OI,Woo EJ

更新日期：2014-09-07 00:00:00

abstract：:Ultraviolet (UV) treatment dose is determined by the length of time that a patient spends in a phototherapy cabin. The output from UV fluorescent lamps declines with use and a method is needed to compensate for the change in irradiance and to identify and replace any lamps that fail. The decline in lamp output with ag...

journal_title：Physics in medicine and biology

authors： Amatiello H,Martin CJ

更新日期：2006-01-21 00:00:00

abstract：:Computer aided detection (CADe) for breast lesion can provide an important reference for radiologists in breast cancer screening. Architectural distortion (AD) is a type of breast lesion that is difficult to detect. A majority of CADe methods focus on detecting the radial pattern, which is a main characteristic of typ...

journal_title：Physics in medicine and biology

authors： Li Y,He Z,Lu Y,Ma X,Guo Y,Xie Z,Xu Z,Chen W,Chen H

更新日期：2020-06-02 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：:Monte Carlo simulations were used to investigate large-angle x-ray scatter at design energy of 25 keV during small field of view (9.6 cm × 5 cm) differential phase contrast imaging of the breast using Talbot-Lau interferometry. Homogenous, adipose and fibroglandular breasts of uniform thickness ranging from 2 to 8 cm ...

journal_title：Physics in medicine and biology

authors： Vedantham S,Shi L,Karellas A

更新日期：2014-11-07 00:00:00

abstract：:Several methods of flip angle mapping for magnetic resonance imaging have been proposed. We evaluated the accuracy of five methods of flip angle measurement in the presence of measurement noise. Our analysis was performed in a closed form by propagation of probability density functions (PDFs). The flip angle mapping m...

journal_title：Physics in medicine and biology

authors： Morrell GR,Schabel MC

更新日期：2010-10-21 00:00:00

abstract：:It seems likely that long term patency of small bore vascular prostheses is dependent upon, among other things, the mechanical properties of their walls. Arteries are visco-elastic but there is no accurate method of measuring the visco-elasticity of arterial substitutes in vivo. The most successful vascular substitute...

journal_title：Physics in medicine and biology

authors： Chapman BL,Charlesworth D

更新日期：1983-09-01 00:00:00

abstract：:New values of the factors required to convert the reading of a radiation dosemeter calibrated in terms of air kerma (or exposure) into absorbed dose to water for medium-energy x-radiation were given in a code of practice published by the IAEA in 1987. These are not considered to possess sufficient support from other s...

journal_title：Physics in medicine and biology

authors：

更新日期：1991-08-01 00:00:00

abstract：:Noise equivalent count rate (NECR) and image noise are two different but related metrics that have been used to predict and assess image quality, respectively. The aim of this study is to investigate, using patient studies, the relationships between injected dose (ID), body mass index (BMI) and scanner type on NECR an...

journal_title：Physics in medicine and biology

authors： Chang T,Chang G,Kohlmyer S,Clark JW,Rohren E,Mawlawi OR

更新日期：2011-08-21 00:00:00

abstract：:Blood and blood products are irradiated with gamma rays to reduce the risk of graft versus host disease (GVHD). A simple technique using electron beams produced by a medical linear accelerator has been studied to evaluate irradiation of blood and blood products. Variations in applied doses for a single field 20 MeV el...

journal_title：Physics in medicine and biology

authors： Butson MJ,Cheung T,Yu PK,Stokes MJ

更新日期：2000-11-01 00:00:00

abstract：:The aim of this study is the evaluation of on-the-fly volume of intersection computation for system's geometry modelling in 3D PET image reconstruction. For this purpose we propose a simple geometrical model in which the cubic image voxels on the given Cartesian grid are approximated with spheres and the rectangular t...

journal_title：Physics in medicine and biology

authors： Lougovski A,Hofheinz F,Maus J,Schramm G,Will E,van den Hoff J

更新日期：2014-02-07 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 silicon semiconductor photodiode was used to measure the TL-signal of TLD-300 (CaF2:Tm) detectors irradiated with 60Co gamma rays and 226Ra alpha particles. The applied dose values varied from 0.12 to 14.3 Gy for gamma rays and from about 50 to 300 Gy for alpha particles. Because of the infrared sensitivity of the p...

journal_title：Physics in medicine and biology

authors： Meissner P,Jacob M,Rassow J

更新日期：1988-12-01 00:00:00

abstract：:The elastic and hyperelastic properties of biological soft tissues have been of interest to the medical community. There are several biomedical applications where parameters characterizing such properties are critical for a reliable clinical outcome. These applications include surgery planning, needle biopsy and brach...

journal_title：Physics in medicine and biology

authors： O'Hagan JJ,Samani A

更新日期：2009-04-21 00:00:00

abstract：:Recent developments in the technique of constant infusion and in emission computed tomography have provided a new method for quantitative regional flow measurements. This paper re-examines critically the theoretical relationship between flow and radioactivity during constant infusion of short-lived isotopes. Sensitivi...

journal_title：Physics in medicine and biology

authors： Huang SC,Phelps ME,Hoffman EJ,Kuhl DE

更新日期：1979-11-01 00:00:00

abstract：:Chronic liver disease (CLD) is currently one of the major causes of death worldwide. If not treated, it may lead to cirrhosis, hepatic carcinoma and death. Ultrasound (US) shear wave elastography (SWE) is a relatively new, popular, non-invasive technique among radiologists. Although many studies have been published va...

journal_title：Physics in medicine and biology

authors： Kagadis GC,Drazinos P,Gatos I,Tsantis S,Papadimitroulas P,Spiliopoulos S,Karnabatidis D,Theotokas I,Zoumpoulis P,Hazle JD

更新日期：2020-11-05 00:00:00