Analyses of multi-irradiation film for system alignments in stereotactic radiotherapy (SRT) and radiosurgery (SRS).

abstract：:Non-pure positron emitters, with their long half-lives, allow for the tracing of slow biochemical processes which cannot be adequately examined by the commonly used short-lived positron emitters. Most of these isotopes emit high-energy cascade gamma rays in addition to positron decay that can be detected and create a ...

journal_title：Physics in medicine and biology

authors： Lin HH,Chuang KS,Chen SY,Jan ML

更新日期：2016-03-07 00:00:00

abstract：:We report on a radiographic measurement of an ex vivo human knee using a grating-based phase-contrast imaging setup and a medical x-ray tube at a tube voltage of 70 kV. The measurement has been carried out using a Talbot-Lau setup that is suitable to achieve a high visibility in the energy regime of medical imaging. I...

journal_title：Physics in medicine and biology

authors： Horn F,Gelse K,Jabari S,Hauke C,Kaeppler S,Ludwig V,Meyer P,Michel T,Mohr J,Pelzer G,Rieger J,Riess C,Seifert M,Anton G

更新日期：2017-08-01 00:00:00

abstract：:The purpose of this study was to improve the performance of a small gamma camera, utilizing a NaI(Tl) plate and a 5" position sensitive PMT. We attempted to build a NaI(Tl) plate crystal system which retained all its advantages, while at the same time integrating some of the advantages inherent in an array-type scinti...

journal_title：Physics in medicine and biology

authors： Jeong MH,Choi Y,Chung YH,Song TY,Jung JH,Hong KJ,Min BJ,Choe YS,Lee KH,Kim BT

更新日期：2004-11-07 00:00:00

abstract：:The aim of the study is to assess the staging value of the tumor heterogeneity characterized by texture features and other commonly used semi-quantitative indices extracted from (18)F-FDG PET images of cervical cancer (CC) patients. Forty-two patients suffering CC at different stages were enrolled in this study. First...

journal_title：Physics in medicine and biology

authors： Mu W,Chen Z,Liang Y,Shen W,Yang F,Dai R,Wu N,Tian J

更新日期：2015-07-07 00:00:00

abstract：:This paper extends the kernel method that was proposed previously for dynamic PET reconstruction, to incorporate anatomical side information into the PET reconstruction model. In contrast to existing methods that incorporate anatomical information using a penalized likelihood framework, the proposed method incorporate...

journal_title：Physics in medicine and biology

authors： Hutchcroft W,Wang G,Chen KT,Catana C,Qi J

更新日期：2016-09-21 00:00:00

abstract：:A multimodal micro-computed tomography (CT) and multi-spectral structured light imaging (SLI) system is introduced and systematically analyzed to test its feasibility to aid in margin delineation during breast conserving surgery (BCS). Phantom analysis of the micro-CT yielded a signal-to-noise ratio of 34, a contrast ...

journal_title：Physics in medicine and biology

authors： McClatchy DM,Rizzo EJ,Meganck J,Kempner J,Vicory J,Wells WA,Paulsen KD,Pogue BW

更新日期：2017-11-10 00:00:00

abstract：:Proton therapy with active scanning beam delivery has significant advantages compared to conventional radiotherapy. However, so far only static targets have been treated in this way, since moving targets potentially lead to interplay effects. For 4D treatment planning, information on the target motion is needed to cal...

journal_title：Physics in medicine and biology

authors： Zhang Y,Boye D,Tanner C,Lomax AJ,Knopf A

更新日期：2012-04-07 00:00:00

abstract：:Awake and/or freely moving small animal single photon emission imaging allows the continuous study of molecules exhibiting slow kinetics without the need to restrain or anaesthetise the animals. Estimating motion free projections in freely moving small animal planar imaging can be considered as a limited angle tomogra...

journal_title：Physics in medicine and biology

authors： Angelis GI,Ryder WJ,Gillam JE,Boisson F,Kyme AZ,Fulton RR,Meikle SR,Kench PL

更新日期：2017-05-21 00:00:00

abstract：:This paper describes end-to-end test procedures as the last fundamental step of medical commissioning before starting clinical operation of the MedAustron synchrotron-based pencil beam scanning (PBS) therapy facility with protons. One in-house homogeneous phantom and two anthropomorphic heterogeneous (head and pelvis)...

journal_title：Physics in medicine and biology

authors： Carlino A,Gouldstone C,Kragl G,Traneus E,Marrale M,Vatnitsky S,Stock M,Palmans H

更新日期：2018-02-26 00:00:00

abstract：:This paper describes an accurate and time-efficient method for the determination of total body potassium via a combination of measurements in the Birmingham whole body counter and the use of the Monte Carlo n-particle (MCNP) simulation code. In developing this method, MCNP has also been used to derive values for some ...

journal_title：Physics in medicine and biology

authors： O'Hehir S,Green S,Beddoe AH

更新日期：2006-09-07 00:00:00

abstract：:Over the last two years we have evaluated paediatric patient doses in projection radiography derived from exposure level (EL) in computed radiography (CR) in a large university hospital. Entrance surface air kerma (ESAK) for 3501 paediatric examinations was calculated from the EL, which is a dose index parameter relat...

journal_title：Physics in medicine and biology

authors： Vano E,Martinez D,Fernandez JM,Ordiales JM,Prieto C,Floriano A,Ten JI

更新日期：2008-06-21 00:00:00

abstract：:The purpose of this investigation is to propose new compensator design strategies for protons and heavier particles which are based on pencil-beam (PB) dose calculations and which significantly reduce the dose to tissues downstream from the target, yet provide acceptable target coverage under conditions of patient mot...

journal_title：Physics in medicine and biology

authors： Petti PL

更新日期：1997-07-01 00:00:00

abstract：:Assessment of radiation absorbed dose to internal organs of the body from the intake of radionuclides or, in the medical setting through the injection of radiopharmaceuticals, is generally performed based upon reference biokinetic models or patient imaging data, respectively. Biokinetic models estimate the time course...

journal_title：Physics in medicine and biology

authors： Schwarz BC,Godwin WJ,Wayson MB,Dewji SA,Jokisch DW,Lee C,Bolch WE

更新日期：2020-11-03 00:00:00

abstract：:Delivery of pencil beam scanning (PBS) requires the on-line measurement of several beam parameters. If the measurement is outside of specified tolerances and a binary threshold algorithm is used, the beam will be paused. Given instrumentation and statistical noise such a system can lead to many pauses which could incr...

journal_title：Physics in medicine and biology

authors： Clasie BM,Kooy HM,Flanz JB

更新日期：2016-01-07 00:00:00

abstract：:This study examines the effectiveness of a single, first-order Arrhenius process in accurately modelling the thermally induced changes in the optical properties, particularly the reduced scattering coefficient, mu(s)', and the absorption coefficient, mu(a), of ex vivo rat prostate. Recent work has shown that mu(s)' ca...

journal_title：Physics in medicine and biology

authors： Skinner MG,Everts S,Reid AD,Vitkin IA,Lilge L,Sherar MD

更新日期：2000-05-01 00:00:00

abstract：:Magnetic Particle Imaging (MPI) is a promising medical imaging technique for visualizing the three-dimensional distribution of tracer materials, specifically iron oxide nanoparticles (IONP). The optimization of magnetic nanoparticles (MNP) plays an essential role to improve the image resolution and sensitivity of imag...

journal_title：Physics in medicine and biology

authors： Arsalani S,Loewa N,Kosch O,Radon P,Baffa O,Wiekhorst F

更新日期：2020-11-23 00:00:00

abstract：:Voltage-sensitive dyes are an important tool in visualizing electrical activity in cardiac tissue. Until today, they have mainly been applied in cardiac electrophysiology to subsurface imaging. In the present study, we assess different imaging methods used in optical tomography with respect to their effectiveness in v...

journal_title：Physics in medicine and biology

authors： Bernus O,Wellner M,Mironov SF,Pertsov AM

更新日期：2005-01-21 00:00:00

abstract：:A full-field speckle interferometry method for non-contact and prospectively high speed Photoacoustic Tomography is introduced and evaluated as proof of concept. Thermoelastic pressure induced changes of the objects topography are acquired in a repetitive mode without any physical contact to the object. In order to ob...

journal_title：Physics in medicine and biology

authors： Horstmann J,Spahr H,Buj C,Münter M,Brinkmann R

更新日期：2015-05-21 00:00:00

abstract：:The Monte Carlo method is the most accurate method for radiotherapy dose calculations, if used correctly. However, any Monte Carlo dose calculation is burdened with statistical noise. In this paper, denoising of Monte Carlo dose distributions with a three-dimensional adaptive anisotropic diffusion method was investiga...

journal_title：Physics in medicine and biology

authors： Miao B,Jeraj R,Bao S,Mackie TR

更新日期：2003-09-07 00:00:00

abstract：:In (19)F MRI oximetry, a method used to image tumour hypoxia, perfluorocarbons serve as oxygenation markers. The goal of this study is to evaluate the impact of perfluorocarbon distribution and concentration in (19)F MRI oximetry through a computer simulation. The simulation studies the correspondence between (19)F me...

journal_title：Physics in medicine and biology

authors： Baete SH,Vandecasteele J,De Deene Y

更新日期：2011-04-21 00:00:00

abstract：:Elastography, which uses ultrasound to image the tissue strain that results from an applied displacement, can display tumours and heat-ablated tissue with high contrast. However, its application to liver in vivo may be problematic due to the presence of respiratory and cardiovascular sources of displacement. The aim o...

journal_title：Physics in medicine and biology

authors： Kolen AF,Miller NR,Ahmed EE,Bamber JC

更新日期：2004-09-21 00:00:00

abstract：:Practical dosimeters in brachytherapy, such as thermoluminescent dosimeters (TLD) and diodes, are usually calibrated against low-energy megavoltage beams. To measure absolute dose rate near a brachytherapy source, it is necessary to establish the energy response of the detector relative to that of the calibration ener...

journal_title：Physics in medicine and biology

authors： Das RK,Li Z,Perera H,Williamson JF

更新日期：1996-06-01 00:00:00

abstract：:A new multiplicative correction factor for tissue heterogeneities based on an exact expression for homogeneous non-unit-density media is proposed. O'Connor's density scaling theorem is invoked to evaluate the medium-specific tissue-maximum ratios used in the exact formulation. Monte Carlo calculations were performed a...

journal_title：Physics in medicine and biology

authors： Petti PL,Siddon RL,Bjärngard BE

更新日期：1986-10-01 00:00:00

abstract：:The layer-stacking method can provide three-dimensional conformal dose distributions to the target based on a passive scattering method using mini-spread-out Bragg peak (SOBP). The purpose of this work is to demonstrate the effectiveness of a new weight optimization algorithm that can enhance the robustness of dose di...

journal_title：Physics in medicine and biology

authors： Sakamoto Y,Maeda Y,Yamada Y,Ikeda M,Tameshige Y,Sasaki M,Shibata S,Yamamoto K

更新日期：2020-09-28 00:00:00

abstract：:Existing studies have suggested some debate on whether the quality of radiation that delivers dose outside of the primary field of a radiotherapy photon beam can be considered the same as that inside the primary field. We used a Monte Carlo approach to simulate the electron fluence differential in energy inside a wate...

journal_title：Physics in medicine and biology

authors： Kirkby C,Field C,MacKenzie M,Syme A,Fallone BG

更新日期：2007-06-21 00:00:00

abstract：:This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical obs...

journal_title：Physics in medicine and biology

authors： Lee TS,Frey EC,Tsui BM

更新日期：2015-04-07 00:00:00

abstract：:The aim of this study was to measure entrance skin doses on patients undergoing cone-beam computed tomography (CBCT) examinations, to establish conversion factors between skin and organ doses, and to estimate cancer risk from CBCT exposures. 266 patients (age 8-83) were included, involving three imaging centres. CBCT ...

journal_title：Physics in medicine and biology

authors： Pauwels R,Cockmartin L,Ivanauskaité D,Urbonienė A,Gavala S,Donta C,Tsiklakis K,Jacobs R,Bosmans H,Bogaerts R,Horner K,SEDENTEXCT Project Consortium.

更新日期：2014-07-21 00:00:00

abstract：:The in-phantom calibration method for radiotherapy kilovoltage x-ray beams requires ionization chamber correction factors. The overall ionization chamber correction factor accounts for changes in the chamber response due to the displacement of water by the chamber cavity and wall, the presence of the stem and the chan...

journal_title：Physics in medicine and biology

authors： Bancheri J,Ketelhut S,Büermann L,Seuntjens J

更新日期：2020-05-11 00:00:00

abstract：:In this study, we explore the potential of compressed sensing (CS) accelerated broadband 3D phase-encoded turbo spin-echo (3D-PE-TSE) for the purpose of geometrically undistorted imaging in the presence of field inhomogeneities. To achieve this goal 3D-PE-SE and 3D-PE-TSE sequences with broadband rf pulses and dedicat...

journal_title：Physics in medicine and biology

authors： van Gorp JS,Bakker CJ,Bouwman JG,Smink J,Zijlstra F,Seevinck PR

更新日期：2015-01-21 00:00:00

abstract：:The dose-calculation accuracy of the tomotherapy Hi-Art II(R) (Tomotherapy, Inc., Madison, WI) treatment planning system (TPS) in the presence of low-density lung media was investigated. In this evaluation, a custom-designed heterogeneous phantom mimicking the mediastinum geometry was used. Gammex LN300 and balsa wood...

journal_title：Physics in medicine and biology

authors： Chaudhari SR,Pechenaya OL,Goddu SM,Mutic S,Rangaraj D,Bradley JD,Low D

更新日期：2009-04-21 00:00:00