Single-shot K-edge subtraction x-ray discrete computed tomography with a polychromatic source and the Pixie-III detector.

abstract：:This paper reports a theoretical study on the distribution of blood flow in the human cardiovascular system when one or more blood vessels are affected by stenosis. The analysis employs a mathematical model of the entire system based on the finite element method. The arterial-venous network is represented by a large n...

journal_title：Physics in medicine and biology

authors： Sud VK,Srinivasan RS,Charles JB,Bungo MW

更新日期：1993-03-01 00:00:00

abstract：:This work aims to investigate the dosimetric impact of dental implants on volumetric modulated arc therapy (VMAT) for head-and-neck patients and to evaluate the effectiveness of using the material's electron-density ratio for the correction. An in-house Monte Carlo (MC) code was utilized for the dose calculation to ac...

journal_title：Physics in medicine and biology

authors： Lin MH,Li J,Price RA Jr,Wang L,Lee CC,Ma CM

更新日期：2013-02-21 00:00:00

abstract：:This paper presents calculated specific absorption rate (SAR) dosimetry in 4 and 8 week Japanese pregnant-woman models exposed to plane waves over the frequency range of 10 MHz-1.5 GHz. Two types of 2 mm spatial-resolution pregnant-woman models comprised a woman model, which is similar to the average-sized Japanese ad...

journal_title：Physics in medicine and biology

authors： Kawai H,Nagaoka T,Watanabe S,Saito K,Takahashi M,Ito K

更新日期：2010-01-07 00:00:00

abstract：:This study investigates the dosimetric impact of using population-based Hounsfield units (HUs) and ICRU-based HUs as a function of the number of tissue segments for bulk density assignment toward MRI-based treatment planning in the abdomen. To avoid potential geometric differences between CT and MR images, CT images r...

journal_title：Physics in medicine and biology

authors： Hsu SH,Zawisza I,O'Grady K,Peng Q,Tomé WA

更新日期：2018-07-24 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 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：:The treatment of lung cancer with radiation therapy is hindered by respiratory motion. Real-time adjustments to compensate for this motion are hampered by mechanical system latencies and imaging-rate restrictions. To better understand tumour motion behaviour for adaptive image-guided radiation therapy of lung cancer, ...

journal_title：Physics in medicine and biology

authors： Pepin EW,Wu H,Sandison GA,Langer M,Shirato H

更新日期：2010-06-21 00:00:00

abstract：:The dosimetrical characteristics of a new miniature multileaf collimator (ModuLeaf MLC, MRC Systems GmbH, Heidelberg, Germany) attached to the accessory holder of a Siemens accelerator with 6 MV x-rays (PRIMUS, Siemens OCS, Concord, California, USA) have been investigated. In particular, those parameters which are imp...

journal_title：Physics in medicine and biology

authors： Hartmann GH,Föhlisch F

更新日期：2002-06-21 00:00:00

abstract：:A method is described which offers an alternative to conventional Fourier phase/amplitude imaging for analysing representative LV cycles obtained from first-pass cardiac studies. The method involves applying factor analysis to the data and producing functional images of the first two factor loadings after polar transf...

journal_title：Physics in medicine and biology

authors： Houston AS,Elliott AT,Stone DL

更新日期：1982-10-01 00:00:00

abstract：:The aim of this study is to determine the impact of longitudinal micro-CT imaging on the growth of B16F1 tumours in C57BL/6 mice. Sixty mice received 2 × 10(5) B16F1 cells subcutaneously in the hind flank and were divided into control (no scan), 'low-dose' (80 kVp, 70 mA, 8 s, 0.07 Gy), 'medium-dose' (80 kVp, 50 mA, 3...

journal_title：Physics in medicine and biology

authors： Foster WK,Ford NL

更新日期：2011-01-21 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：:Transcranial direct current stimulation (tDCS) is a neuromodulation scheme where a small current is delivered to the brain via two electrodes attached to the scalp. The electrode design is an important topic, not only as regards efficacy, but also from a safety perspective, as tDCS may be related to skin lesions that ...

journal_title：Physics in medicine and biology

authors： Gomez-Tames J,Sugiyama Y,Laakso I,Tanaka S,Koyama S,Sadato N,Hirata A

更新日期：2016-12-21 00:00:00

abstract：:Scatter correction is an essential technique to improve the image quality of cone-beam CT (CBCT). Although different scatter correction methods have been proposed in the literature, a standard solution is still being studied due to the limitations including accuracy, computation efficiency and generalization. In this ...

journal_title：Physics in medicine and biology

authors： Jiang Y,Yang C,Yang P,Hu X,Luo C,Xue Y,Xu L,Hu X,Zhang L,Wang J,Sheng K,Niu T

更新日期：2019-07-11 00:00:00

abstract：:We study the treatment plan optimization problem for volumetric modulated arc therapy (VMAT). We propose a new column-generation-based algorithm that takes into account bounds on the gantry speed and dose rate, as well as an upper bound on the rate of change of the gantry speed, in addition to MLC constraints. The alg...

journal_title：Physics in medicine and biology

authors： Peng F,Jia X,Gu X,Epelman MA,Romeijn HE,Jiang SB

更新日期：2012-07-21 00:00:00

abstract：:In charged particle therapy with pencil beam scanning (PBS), localization of the dose in the Bragg peak makes dose distributions sensitive to lateral tissue heterogeneities. The sensitivity of a PBS plan to lateral tissue heterogeneities can be reduced by selecting appropriate beam angles. The purpose of this study is...

journal_title：Physics in medicine and biology

authors： Toramatsu C,Inaniwa T

更新日期：2016-12-21 00:00:00

abstract：:The combined build-up and attenuation factor, B exp (-mu r), of point isotropic photon sources in a water medium has been calculated using the Monte Carlo method, for energies (20-1500 keV) and distances (1-10 cm) relevant in brachytherapy. For the transport of photons and electrons, up-to-date and self-consistent tot...

journal_title：Physics in medicine and biology

authors： Angelopoulos A,Perris A,Sakellariou K,Sakelliou L,Sarigiannis K,Zarris G

更新日期：1991-06-01 00:00:00

abstract：:This study investigates the oxygen mass transport in the region around the human carotid bifurcation, particularly addressing the effects of bifurcation geometry and pulsatile blood flow on the oxygen transport between the blood flow and artery wall tissue, coupled with the metabolic oxygen consumption and oxygen diff...

journal_title：Physics in medicine and biology

authors： Tada S

更新日期：2010-07-21 00:00:00

abstract：:To increase the scanning speed of cone-beam CT, a scanning configuration with three pairs of x-ray sources and panel detectors was proposed. In this paper, we apply the M-line-based backprojected filtration algorithm to this scanning configuration and propose a fast implementation for this algorithm. Compared with exi...

journal_title：Physics in medicine and biology

authors： Zhao Y,Zhu Y,Zhang P

更新日期：2010-12-07 00:00:00

abstract：:Range verification is one of the most relevant tasks in ion beam therapy. In the case of carbon ion therapy, positron emission tomography (PET) is the most widely used method for this purpose, which images the [Formula: see text]-activation following nuclear interactions of the ions with the tissue nuclei. Since the p...

journal_title：Physics in medicine and biology

authors： Hofmann T,Fochi A,Parodi K,Pinto M

更新日期：2019-05-21 00:00:00

abstract：:In magnetic particle imaging (MPI), the relation between the particle distribution and the measurement signal can be described by a linear system of equations. For 1D imaging, it can be shown that the system matrix can be expressed as a product of a convolution matrix and a Chebyshev transformation matrix. For multidi...

journal_title：Physics in medicine and biology

authors： Weber A,Knopp T

更新日期：2015-05-21 00:00:00

abstract：:Nuclear emulsions of the Ilford K series, exposed to X-rays from 15 to 150 kVp and systematically underdeveloped, exhibit supralinear blackness--exposure curves ranging from 1- to 4-hit in character, and whose shape is the same at all excitation voltages. Processing can be so adjusted that the curve shape is well repr...

journal_title：Physics in medicine and biology

authors： Katz R,Pennington EC

更新日期：1978-11-01 00:00:00

abstract：:Monte Carlo simulation with PENELOPE (version 2003) is applied to calculate Leksell Gamma Knife dose distributions for heterogeneous phantoms. The usual spherical water phantom is modified with a spherical bone shell simulating the skull and an air-filled cube simulating the frontal or maxillary sinuses. Different sim...

journal_title：Physics in medicine and biology

authors： Al-Dweri FM,Rojas EL,Lallena AM

更新日期：2005-12-07 00:00:00

abstract：:A technique is described by which the regional distribution of bone mineral can be determined in bone samples from small animals. The technique employs an Anger camera interfaced to a medical computer. High resolution (less than 1 mm) imaging is possible by producing magnified images of the bone samples. Regional dens...

journal_title：Physics in medicine and biology

authors： LeBlanc A,Evans H,Jhingran S,Johnson P

更新日期：1984-01-01 00:00:00

abstract：:Multileaf collimators (MLCs) have been in clinical use for many years and meanwhile are commonly used to deliver intensity-modulated radiotherapy (IMRT) beams. For this purpose it is important to know their dosimetric properties precisely, one of them being inter- and intraleaf leakage. The Siemens 160 MLC features a ...

journal_title：Physics in medicine and biology

authors： Klüter S,Sroka-Perez G,Schubert K,Debus J

更新日期：2011-01-21 00:00:00

abstract：:Energy and spatial projection distributions were simulated for gamma camera imaging of multiple order Compton scattered photons. SPECT imaging of a line source of radioactivity located in a water filled cylindrical phantom was modelled using Monte Carlo techniques. Photon trajectories were followed from emission to de...

journal_title：Physics in medicine and biology

authors： Floyd CE,Jaszczak RJ,Harris CC,Coleman RE

更新日期：1984-10-01 00:00:00

abstract：:A photoluminescent thermometer, based on the transient emission response of a europium-activated calcium sulphide phosphor, is described in detail. This optical thermometry system has special advantages for temperature measurements in microwave and RF fields and potential application in electromagnetically induced cli...

journal_title：Physics in medicine and biology

authors： Samulski TV,Chopping PT,Haas B

更新日期：1982-01-01 00:00:00

abstract：:The UK and European protocols for mammographic dosimetry use conversion factors that relate incident air kerma to the mean glandular dose (MGD) within the breast. The conversion factors currently used were obtained by computer simulation of a model breast with a composition of 50% adipose and 50% glandular tissues by ...

journal_title：Physics in medicine and biology

authors： Dance DR,Skinner CL,Young KC,Beckett JR,Kotre CJ

更新日期：2000-11-01 00:00:00

abstract：:Sparse phased array ultrasound transducers with millimetre length scale elements have previously been proposed for generating hyperthermia but not for imaging. Numerical simulation with a pseudospectral solver was used to investigate: (a) how the position of the maximum pressure in the focal region changed with elemen...

journal_title：Physics in medicine and biology

authors： Wilson AJ

更新日期：2018-07-16 00:00:00

abstract：:Voxel phantoms are human models based on computed tomographic or magnetic resonance images obtained from high-resolution scans of a single individual. They consist of a huge number of volume elements (voxels) and are at the moment the most precise representation of the human anatomy. The purpose of this paper is to in...

journal_title：Physics in medicine and biology

authors： Petoussi-Henss N,Zanki M,Fill U,Regulla D

更新日期：2002-01-07 00:00:00

abstract：:Computed tomography images have been acquired using an experimental (low atomic number (Z) insert) megavoltage cone-beam imaging system. These images have been compared with standard megavoltage and kilovoltage imaging systems. The experimental system requires a simple modification to the 4 MeV electron beam from an E...

journal_title：Physics in medicine and biology

authors： Roberts DA,Hansen VN,Thompson MG,Poludniowski G,Niven A,Seco J,Evans PM

更新日期：2011-07-21 00:00:00