A motion-incorporated reconstruction method for gated PET studies.

abstract：:Flow visualization, particle image velocimetry and numerical computation have been complementarily performed to study the fluid flow inside a stented lateral aneurysm. The curved afferent vessel had an inner diameter of 5 mm. The diameters of the aneurysmal orifice, neck and fundus were 7 mm, 5 mm and 7.5 mm, respecti...

journal_title：Physics in medicine and biology

authors： Liou TM,Li YC,Wang TC

更新日期：2008-07-21 00:00:00

abstract：:The goal of this study was to assess the impact of set-up uncertainty on compliance with the objectives and constraints of an intensity modulated radiation therapy protocol for early stage cancer of the oropharynx. As the convolution approach to the quantitative study of set-up uncertainties cannot accommodate either ...

journal_title：Physics in medicine and biology

authors： Ploquin N,Song W,Lau H,Dunscombe P

更新日期：2005-08-07 00:00:00

abstract：:Compromises in the design of a positron emission tomography (PET) insert for a magnetic resonance imaging (MRI) system should minimize the deterioration of image quality in both modalities, particularly when simultaneous demanding acquisitions are performed. In this work, the advantages of using individually read-out ...

journal_title：Physics in medicine and biology

authors： Omidvari N,Topping G,Cabello J,Paul S,Schwaiger M,Ziegler SI

更新日期：2018-05-01 00:00:00

abstract：:109Cd K x-ray fluorescence (XRF) measurement systems from two research centres were used to measure tibia lead content in a population (n = 530) of young adults. The group mean bone lead contents (+/-SEM) determined by McMaster University (n = 214) and the University of Maryland (n = 316) were 2.80 +/- 0.51 and 2.33 +...

journal_title：Physics in medicine and biology

authors： McNeill FE,Stokes L,Chettle DR,Kaye WE

更新日期：1999-09-01 00:00:00

abstract：:Recent studies have demonstrated the feasibility of transcranial high-intensity focused ultrasound (HIFU) therapy in the brain using adaptive focusing techniques. However, the complexity of the procedures imposes provision of accurate targeting, monitoring and control of this emerging therapeutic modality in order to ...

journal_title：Physics in medicine and biology

authors： Larrat B,Pernot M,Aubry JF,Dervishi E,Sinkus R,Seilhean D,Marie Y,Boch AL,Fink M,Tanter M

更新日期：2010-01-21 00:00:00

abstract：:The present note addresses the development of a lung tumor position predictor to be used in dynamic tumor tracking radiotherapy, abbreviated as DTT-RT. As there exists 50-500 ms positioning lag in the control of the multi-leaf collimator (MLC) of commercial medical linear accelerators, prediction of future lung tumor ...

journal_title：Physics in medicine and biology

authors： Jiang K,Fujii F,Shiinoki T

更新日期：2019-10-31 00:00:00

abstract：:The derivative at constant direction is frequently used in inversion of cone-beam data. Several algorithms for computing the derivative have been proposed in the literature. The best algorithm to date has been proposed recently by Noo et al (2007 Phys. Med. Biol. 52 5393-414). In this note we propose a new, simple and...

journal_title：Physics in medicine and biology

authors： Katsevich A

更新日期：2011-02-21 00:00:00

abstract：:A method of computing optimized intensity-modulated beam profiles has been further developed and used to generate highly conformal radiotherapy dose distributions. The features of these distributions are shown to be strongly dependent on the tuning built into the algorithm. The optimization aims to achieve a specified...

journal_title：Physics in medicine and biology

authors： Webb S

更新日期：1994-12-01 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：:Patient motion is an important factor affecting the quality of external beam radiotherapy in breast patients. We analyse the motion of a dense set of surface points on breast patients throughout their treatment schedule to assess the magnitude and stability of motion, in particular, with respect to breast volume. We u...

journal_title：Physics in medicine and biology

authors： Price GJ,Sharrock PJ,Marchant TE,Parkhurst JM,Burton D,Jain P,Price P,Moore CJ

更新日期：2009-11-07 00:00:00

abstract：:The treatment planning process for patients with head and neck (H&N) cancer is regarded as one of the most complicated due to large target volume, multiple prescription dose levels, and many radiation-sensitive critical structures near the target. Treatment planning for this site requires a high level of human experti...

journal_title：Physics in medicine and biology

authors： Nguyen D,Jia X,Sher D,Lin MH,Iqbal Z,Liu H,Jiang S

更新日期：2019-03-18 00:00:00

abstract：:We present a method to include robustness in a multi-criteria optimization (MCO) framework for intensity-modulated proton therapy (IMPT). The approach allows one to simultaneously explore the trade-off between different objectives as well as the trade-off between robustness and nominal plan quality. In MCO, a database...

journal_title：Physics in medicine and biology

authors： Chen W,Unkelbach J,Trofimov A,Madden T,Kooy H,Bortfeld T,Craft D

更新日期：2012-02-07 00:00:00

abstract：:An x-ray fluorescence system with a synchrotron radiation source was used to quantify the levels of iron, copper and zinc in breast tissue specimens. Healthy tissue and breast carcinomas were investigated as an aid to understanding the mechanisms of breast cancer and as a possible complementary diagnostic tool. Eighty...

journal_title：Physics in medicine and biology

authors： Geraki K,Farquharson MJ,Bradley DA

更新日期：2002-07-07 00:00:00

abstract：:In recent years there has been a large amount of research into the potential use of radiation sensitive gels for three-dimensional verification of clinical radiotherapy doses. In this paper we report the use of a MAGIC gel dosimeter (Fong et al 2001 Phys. Med. Biol. 46 3105) for the verification of a specific patient'...

journal_title：Physics in medicine and biology

authors： Trapp JV,Partridge M,Hansen VN,Childs P,Bedford J,Warrington AP,Leach MO,Webb S

更新日期：2004-05-07 00:00:00

abstract：:A multicentre phase II trial of stereotactic body radiotherapy for T1N0M0 non-small cell lung cancer was initiated in Japan as the Japan Clinical Oncology Group trial (JCOG0403). Before starting the trial, a decision was made to evaluate the treatment machine and treatment planning in participating institutions to min...

journal_title：Physics in medicine and biology

authors： Nishio T,Kunieda E,Shirato H,Ishikura S,Onishi H,Tateoka K,Hiraoka M,Narita Y,Ikeda M,Goka T

更新日期：2006-11-07 00:00:00

abstract：:Thermal therapy is an experimental treatment to destroy solid tumours by heating them to temperatures ranging from 55 degrees C to 90 degrees C, inducing thermal coagulation and necrosis of the tumour. We are investigating the feasibility of interstitial microwave thermal therapy as a salvage treatment for prostate ca...

journal_title：Physics in medicine and biology

authors： McCann C,Kumaradas JC,Gertner MR,Davidson SR,Dolan AM,Sherar MD

更新日期：2003-04-21 00:00:00

abstract：:We propose a retrospective respiratory gating algorithm to generate dynamic CT studies. To this end, we compared three different methods of extracting the respiratory signal from the projections of small-animal cone-beam computed tomography (CBCT) scanners. Given a set of frames acquired from a certain axial angle, su...

journal_title：Physics in medicine and biology

authors： Chavarrías C,Vaquero JJ,Sisniega A,Rodríguez-Ruano A,Soto-Montenegro ML,García-Barreno P,Desco M

更新日期：2008-09-07 00:00:00

abstract：:As the use of radiofrequency (RF) electromagnetic (EM) fields has increased along with increased use of wireless communication, the possible related health risks have also been widely discussed. One safety aspect is the interaction of medical implants and RF devices like mobile phones. In the literature, effects on ac...

journal_title：Physics in medicine and biology

authors： Virtanen H,Keshvari J,Lappalainen R

更新日期：2007-03-07 00:00:00

abstract：:The stochastic nature of cavitation implies visualization of the cavitation cloud in real-time and in a discriminative manner for the safe use of focused ultrasound therapy. This visualization is sometimes possible with standard echography, but it strongly depends on the quality of the scanner, and is hindered by diff...

journal_title：Physics in medicine and biology

authors： Arnal B,Baranger J,Demene C,Tanter M,Pernot M

更新日期：2017-02-07 00:00:00

abstract：:We propose a method to compensate for six degree-of-freedom rigid motion in helical CT of the head. The method is demonstrated in simulations and in helical scans performed on a 16-slice CT scanner. Scans of a Hoffman brain phantom were acquired while an optical motion tracking system recorded the motion of the bed an...

journal_title：Physics in medicine and biology

authors： Kim JH,Nuyts J,Kyme A,Kuncic Z,Fulton R

更新日期：2015-03-07 00:00:00

abstract：:We comment on a recent article (Gomà et al 2014 Phys. Med. Biol. 59 4961-71) which compares different routes of reference dosimetry for the energy dependent beam monitor calibration in scanned proton beams. In this article, a 3% discrepancy is reported between a Faraday cup and a plane-parallel ionization chamber in t...

journal_title：Physics in medicine and biology

authors： Palmans H,Vatnitsky SM

更新日期：2016-09-07 00:00:00

abstract：:In this paper we describe measurements of the contrast transfer function, modulation transfer function and point-spread function of an optical coherence tomography (OCT) imaging system through scattering layers having a dimension-less scattering depth over the range 0.2-6.9. The results were found to be insensitive to...

journal_title：Physics in medicine and biology

authors： Woolliams PD,Tomlins PH

更新日期：2011-05-07 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：:The architecture of multi-layer imagers (MLIs) can be exploited to provide megavoltage spectral imaging (MVSPI) for specific imaging tasks. In the current work, we investigated bone suppression and gold fiducial contrast enhancement as two clinical tasks which could be improved with spectral imaging. A method based on...

journal_title：Physics in medicine and biology

authors： Myronakis M,Hu YH,Fueglistaller R,Wang A,Baturin P,Huber P,Morf D,Star-Lack J,Berbeco R

更新日期：2018-05-10 00:00:00

abstract：:Distributions of linear pathlength measurements have been utilized in skeletal dosimetry of internally emitted short-range particles for over 30 years. This work reviews the methods for coupling these distributions to range-energy data. A revised methodology is presented for handling the insertion of the additional do...

journal_title：Physics in medicine and biology

authors： Jokisch DW,Rajon DA,Patton PW,Bolch WE

更新日期：2011-05-07 00:00:00

abstract：:Biomedical fibre-optic sensors are attractive for the measurement of physical, chemical and biochemical parameters and for spectral measurements directly performed on the patient. An overview of fibre-optic sensors for in vivo monitoring is given, with particular attention paid to the advantages that these sensors are...

journal_title：Physics in medicine and biology

authors： Mignani AG,Baldini F

更新日期：1997-05-01 00:00:00

abstract：:Two experimental investigations of the electromagnetic method to measure body composition are presented. In the first experiment, the impedance of a single-loop transmitting antenna, located at the centre of a 150 m helical receiving coil, was observed to have a sharp minimum at 2.40 MHz. The impedance of the antenna ...

journal_title：Physics in medicine and biology

authors： Sutcliffe JF,Smye SW,Smith MA

更新日期：1995-04-01 00:00:00

abstract：:A micro beam synchrotron x-ray fluorescence (muSRXRF) technique has been used to determine the localization of metals in primary invasive ductal carcinoma of breast. Nine samples were examined, all of which were formalin fixed tissues arranged as micro arrays of 1.0 mm diameter and 10 microm thickness. Cu was the part...

journal_title：Physics in medicine and biology

authors： Farquharson MJ,Al-Ebraheem A,Falkenberg G,Leek R,Harris AL,Bradley DA

更新日期：2008-06-07 00:00:00

abstract：:We model the heterogeneous response to radiation of multicellular tumour spheroids assuming position- and volume-dependent radiosensitivity. We propose a method to calculate the overall radiosensitivity parameters to obtain the surviving fraction of tumours. A mathematical model of a spherical tumour with a hypoxic co...

journal_title：Physics in medicine and biology

authors： Horas JA,Olguin OR,Rizzotto MG

更新日期：2005-04-21 00:00:00

abstract：:This work studies the effect of age on lung dose commitments arising from the inhalation of an atmosphere containing radionuclides of varying half-lives and physical sizes. This dependence is significant in many cases, approaching a ratio of 2 in several instances when the maximum dose at a given age is compared with ...

journal_title：Physics in medicine and biology

authors： Crawford DJ

更新日期：1982-04-01 00:00:00