Development of the complex permittivity measurement system for high-loss biological samples using the free space method in quasi-millimeter and millimeter wave bands.

abstract：:The measurement of beam data for dynamic wedge dosimetry requires the integration of radiation dose at points across the radiation field during the dose delivery. The different measurement techniques required when using a linear diode array to measure beam profiles and when using ionization chambers to measure depth d...

journal_title：Physics in medicine and biology

authors： Bidmead AM,Garton AJ,Childs PJ

更新日期：1995-03-01 00:00:00

abstract：:Intraoperative x-ray radiography/fluoroscopy is commonly used to assess the placement of surgical devices in the operating room (e.g. spine pedicle screws), but qualitative interpretation can fail to reliably detect suboptimal delivery and/or breach of adjacent critical structures. We present a 3D-2D image registratio...

journal_title：Physics in medicine and biology

authors： Uneri A,De Silva T,Goerres J,Jacobson MW,Ketcha MD,Reaungamornrat S,Kleinszig G,Vogt S,Khanna AJ,Osgood GM,Wolinsky JP,Siewerdsen JH

更新日期：2017-04-21 00:00:00

abstract：:The total ionisation produced by ions stopped in nitrogen, methane and carbon dioxide has been measured in the energy range 25-375 keV using a chamber described previously. The chamber was operated alternately as a proportional counter and as an ionisation chamber to measure respectively the particle rate and the tota...

journal_title：Physics in medicine and biology

authors： Nguyen VD,Chemtob M,Chary J,Posny F,Parmentier N

更新日期：1980-05-01 00:00:00

abstract：:Accurate scatter correction is required to produce high-quality reconstructions of x-ray cone-beam computed tomography (CBCT) scans. This paper describes new scatter kernel superposition (SKS) algorithms for deconvolving scatter from projection data. The algorithms are designed to improve upon the conventional approac...

journal_title：Physics in medicine and biology

authors： Sun M,Star-Lack JM

更新日期：2010-11-21 00:00:00

abstract：:For treatments with dynamic intensity modulated radiotherapy (IMRT), the adjustment of multileaf collimator (MLC) parameters affecting both the optimization algorithm and dose distributions is crucial. The main parameters characterizing the MLC are the transmission (T) and the dosimetric leaf separation (DLS). The aim...

journal_title：Physics in medicine and biology

authors： Chauvet I,Petitfils A,Lehobey C,Kristner JY,Brunet Y,Lembrez R,Gaboriaud G,Mazal A,Zefkili S,Rosenwald JC

更新日期：2005-02-21 00:00:00

abstract：:Usually, Monte Carlo models are validated against experimental data. However, models of multiple Coulomb scattering (MCS) in the Gaussian approximation are exceptional in that we have theories which are probably more accurate than the experiments which have, so far, been done to test them. In problems directly sensiti...

journal_title：Physics in medicine and biology

authors： Makarova A,Gottschalk B,Sauerwein W

更新日期：2017-07-06 00:00:00

abstract：:The effect of temperature on the optical properties of human dermis and subdermis as a function of near-infrared wavelength has been studied between 25 degrees C and 40 degrees C. Measurements were performed ex vivo on a total of nine skin samples taken from the abdomen of three individuals. The results show a reprodu...

journal_title：Physics in medicine and biology

authors： Laufer J,Simpson R,Kohl M,Essenpreis M,Cope M

更新日期：1998-09-01 00:00:00

abstract：:Many applications of electroporation, especially those utilizing electrofusion and in-vivo electroporation, involve cell environments that include close cell-to-cell proximity and a wide range of target cell size. It is important to understand how this kind of environment may alter optimum electroporation electrical p...

journal_title：Physics in medicine and biology

authors： Gaynor PT,Bodger PS

更新日期：2006-06-21 00:00:00

abstract：:In situ and in vivo treatment plan verification and beam monitoring as well as dose control during heavy-ion tumour therapy can be performed in principle by measurements of range distributions of beta(+)-emitting nuclei by means of PET techniques. For this purpose the performance of different types of positron camera ...

journal_title：Physics in medicine and biology

authors： Pawelke J,Byars L,Enghardt W,Fromm WD,Geissel H,Hasch BG,Lauckner K,Manfrass P,Schardt D,Sobiella M

更新日期：1996-02-01 00:00:00

abstract：:This study presents a new approach to accurately account for the medium-dependent effect in model-based dose calculations for kilovoltage (kV) x-rays. This approach is based on the hypothesis that the correction factors needed to convert dose from model-based dose calculations to absorbed dose-to-medium depend on both...

journal_title：Physics in medicine and biology

authors： Pawlowski JM,Ding GX

更新日期：2011-07-07 00:00:00

abstract：:Ho-166 is a combined beta-gamma emitter of which the betas can be used therapeutically. From the 81 keV gammas of Ho-166, SPECT images can be obtained, which give opportunities to guide Ho-166 therapy. Accurate reconstruction of Ho-166 images is currently hampered by photopeak-scatter in the patient, down-scatter in t...

journal_title：Physics in medicine and biology

authors： de Wit TC,Xiao J,Nijsen JF,van het Schip FD,Staelens SG,van Rijk PP,Beekman FJ

更新日期：2006-10-07 00:00:00

abstract：:In addition to being a powerful clinical tool, Positron emission tomography (PET) is also used in small laboratory animal research to visualize and track certain molecular processes associated with diseases such as cancer, heart disease and neurological disorders in living small animal models of disease. However, dosi...

journal_title：Physics in medicine and biology

authors： Xie T,Zaidi H

更新日期：2013-01-07 00:00:00

abstract：:We implemented a hybrid scatter-correction method for 3D PET that combines two scatter-correction methods in a complementary way. The implemented scheme uses a method based on the discrimination of the energy of events (the estimation of trues method (ETM)) and an auxiliary method (the single scatter simulation method...

journal_title：Physics in medicine and biology

authors： Ferreira NC,Trébossen R,Lartizien C,Brulon V,Merceron P,Bendriem B

更新日期：2002-05-07 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：:All available imaging devices in nuclear medicine have finite energy resolution. This leads to inclusion of scattered radiation, which in turn degrades the image quality. Different scatter correction schemes therefore try to eliminate the effect of scattered radiation. On the other hand, improvement of the camera's in...

journal_title：Physics in medicine and biology

authors： Wirth V

更新日期：1989-01-01 00:00:00

abstract：:Microcalcification is one of the earliest and main indicators of breast cancer. Because dual-energy digital mammography could suppress the contrast between the adipose and glandular tissues of the breast, it is considered a promising technique that will improve the detection of microcalcification. In dual-energy digit...

journal_title：Physics in medicine and biology

authors： Mou X,Chen X,Sun L,Yu H,Ji Z,Zhang L

更新日期：2008-11-21 00:00:00

abstract：:In external beam radiation therapy, radioactive beams offer the best clinical solution to simultaneously treat and in vivo monitor the dose delivery and tumor response using PET or PET-CT imaging. However, difficulties mainly linked to the low production efficiency have so far limited their use. This study is devoted ...

journal_title：Physics in medicine and biology

authors： Lazzeroni M,Brahme A

更新日期：2011-03-21 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：:Over the last 50 years, diagnostic imaging has grown from a state of infancy to a high level of maturity. Many new imaging modalities have been developed. However, modern medical imaging includes not only image production but also image processing, computer-aided diagnosis (CAD), image recording and storage, and image...

journal_title：Physics in medicine and biology

authors： Doi K

更新日期：2006-07-07 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：:Kilo-voltage (KV) cone-beam computed tomography (CBCT) unit mounted onto a linear accelerator treatment system, often referred to as on-board imager (OBI), plays an increasingly important role in image-guided radiation therapy. While the FDK algorithm is currently used for reconstructing images from clinical OBI data,...

journal_title：Physics in medicine and biology

authors： Han X,Pearson E,Pelizzari C,Al-Hallaq H,Sidky EY,Bian J,Pan X

更新日期：2015-06-21 00:00:00

abstract：:Methods based on magnetic resonance imaging for the measurement of three-dimensional distributions of radiation dose are highly developed. However, relatively little work has been done on optical computed tomography (OCT). This paper describes a new OCT scanner based on a broad beam light source and a two-dimensional ...

journal_title：Physics in medicine and biology

authors： Doran SJ,Koerkamp KK,Bero MA,Jenneson P,Morton EJ,Gilboy WB

更新日期：2001-12-01 00:00:00

abstract：:Non-invasive evaluation of the Achilles tendon elastic properties may enhance diagnosis of tendon injury and the assessment of recovery treatments. Shear wave elastography has shown to be a powerful tool to estimate tissue mechanical properties. However, its applicability to quantitatively evaluate tendon stiffness is...

journal_title：Physics in medicine and biology

authors： Brum J,Bernal M,Gennisson JL,Tanter M

更新日期：2014-02-07 00:00:00

abstract：:With the development of laser technology, laser-driven proton acceleration provides a new method for proton tumor therapy. However, it has not been applied in practice because of the wide and decreasing energy spectrum of laser-accelerated proton beams. In this paper, we propose an analytical model to reconstruct the ...

journal_title：Physics in medicine and biology

authors： Tao L,Zhu K,Zhu J,Xu X,Lin C,Ma W,Lu H,Zhao Y,Lu Y,Chen JE,Yan X

更新日期：2017-07-07 00:00:00

abstract：:Quantification in cardiac mouse positron emission tomography (PET) imaging is limited by the imaging spatial resolution. Spillover of left ventricle (LV) myocardial activity into adjacent organs results in partial volume (PV) losses leading to underestimation of myocardial activity. A PV correction method was develope...

journal_title：Physics in medicine and biology

authors： Dumouchel T,Thorn S,Kordos M,DaSilva J,Beanlands RS,deKemp RA

更新日期：2012-07-07 00:00:00

abstract：:In this paper, we use a more realistic head model with ovoid geometry for approximation of a human head. By inverting the Geselowitz equation, some analytic results on the inverse MEG problem are presented in homogenous ovoid geometry. On one hand, some information about the components of primary current is shown by t...

journal_title：Physics in medicine and biology

authors： Peng L,Cheng J,Jin L

更新日期：2006-11-07 00:00:00

abstract：:Numerous studies have reported the measurements of the dielectric properties of the skin. Clarifying the manner in which the human body interacts with electromagnetic waves is essential for medical research and development, as well as for the safety assessment of electromagnetic wave exposure. The skin comprises sever...

journal_title：Physics in medicine and biology

authors： Sasaki K,Wake K,Watanabe S

更新日期：2014-08-21 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：:Ultrasoft x-rays of 0.3-5 keV have provided a unique tool for the investigation of intracellular mechanisms of radiation action in biological organisms, including mammalian cells. However, their use presents unique practical problems in dosimetry and experimental design. Detailed interpretation of the biological resul...

journal_title：Physics in medicine and biology

authors： Hoshi M,Goodhead DT,Brenner DJ,Bance DA,Chmielewski JJ,Paciotti MA,Bradbury JN

更新日期：1985-10-01 00:00:00

abstract：:In magnetic resonance (MR) guided radiotherapy, the magnetic field-dependent change in the dose response of ionization chambers is typically included by means of a correction factor [Formula: see text]. This factor can be determined experimentally or calculated by means of Monte Carlo (MC) simulations. To date, a smal...

journal_title：Physics in medicine and biology

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

更新日期：2019-07-04 00:00:00