A novel technique for measuring the low-dose envelope of pencil-beam scanning spot profiles.

abstract：:This paper introduces a novel compartmental model describing the excretion of 18F-fluoro-deoxyglucose (FDG) in the renal system and a numerical method based on the maximum likelihood for its reduction. This approach accounts for variations in FDG concentration due to water re-absorption in renal tubules and the increa...

journal_title：Physics in medicine and biology

authors： Garbarino S,Caviglia G,Sambuceti G,Benvenuto F,Piana M

更新日期：2014-05-21 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：:Dose measurements following 10 min irradiations with a portable x-ray fluorescence spectrometer composed of a miniature x-ray tube and a silicon PiN diode detector were performed using thermoluminescent dosimeters consisting of LiF:Mg,Ti chips of 3 mm diameter and 0.4 mm thickness. The table-top setup of the spectrome...

journal_title：Physics in medicine and biology

authors： Gherase MR,Mader JE,Fleming DE

更新日期：2010-09-21 00:00:00

abstract：:Deformable image registration is widely used in various radiation therapy applications including daily treatment planning adaptation to map planned tissue or dose to changing anatomy. In this work, a simple and efficient inverse consistency deformable registration method is proposed with aims of higher registration ac...

journal_title：Physics in medicine and biology

authors： Yang D,Li H,Low DA,Deasy JO,El Naqa I

更新日期：2008-11-07 00:00:00

abstract：:We developed and validated a Monte-Carlo-based application (RAYDOSE) to generate patient-specific 3D dose maps on the basis of pre-treatment imaging studies. A CT DICOM image is used to model patient geometry, while repeated PET scans are employed to assess radionuclide kinetics and distribution at the voxel level. In...

journal_title：Physics in medicine and biology

authors： Marcatili S,Pettinato C,Daniels S,Lewis G,Edwards P,Fanti S,Spezi E

更新日期：2013-04-21 00:00:00

abstract：:Dosimetry of proton beams is generally evaluated in liquid water, or alternatively in solid phantoms via water equivalent ratios (WER). WER is defined as the ratio of proton range in liquid water to that in a phantom of certain material. Presently, WER is not available in the literature neither for a wide range of ene...

journal_title：Physics in medicine and biology

authors： Safigholi H,Song WY

更新日期：2018-07-27 00:00:00

abstract：:Tumour histological grade has prognostic implications in breast cancer. Tumour features in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and T2-weighted (T2W) imaging can provide related and complementary information in the analysis of breast lesions to improve MRI-based histological status prediction...

journal_title：Physics in medicine and biology

authors： Fan M,Liu Z,Xie S,Xu M,Wang S,Gao X,Li L

更新日期：2019-10-23 00:00:00

abstract：:Radionuclides which decay by electron capture accompanied by Auger electron cascades, or by beta emission are thought to be excessively damaging when incorporated into the molecular structure of mammalian cell nuclei and thereby pose a radiation hazard which is not assessable by conventional dosimetry. Survival data, ...

journal_title：Physics in medicine and biology

authors： Younis AR,Watt DE

更新日期：1989-07-01 00:00:00

abstract：:Computer tomographic (CT) scans are used to correct for tissue inhomogeneities in radiotherapy treatment planning. In order to guarantee a precise treatment, it is important to obtain the relationship between CT Hounsfield units and electron densities (or proton stopping powers for proton radiotherapy), which is the b...

journal_title：Physics in medicine and biology

authors： Schneider U,Pedroni E,Lomax A

更新日期：1996-01-01 00:00:00

abstract：:Kilovoltage intratreatment monitoring (KIM) is a novel real-time localization modality where the tumor position is continuously measured during intensity modulated radiation therapy (IMRT) or intensity modulated arc therapy (IMAT) by a kilovoltage (kV) x-ray imager. Adding kV imaging during therapy adds radiation dose...

journal_title：Physics in medicine and biology

authors： Ng JA,Booth J,Poulsen P,Kuncic Z,Keall PJ

更新日期：2013-09-07 00:00:00

abstract：:This paper describes the development and characterization of a fully automated in vitro cell irradiator using an electronic brachytherapy source to perform radiation sensitivity bioassays. This novel irradiator allows complex variable dose and dose rate schemes to be delivered to multiple wells of 96-well culture plat...

journal_title：Physics in medicine and biology

authors： Fowler TL,Fulkerson RK,Micka JA,Kimple RJ,Bednarz BP

更新日期：2014-03-21 00:00:00

abstract：:We consider several inverse problems motivated by elastography. Given the (possibly transient) displacement field measured everywhere in an isotropic, compressible, linear elastic solid, and given density rho, determine the Lamé parameters lambda and mu. We consider several special cases of this problem: (a) for mu kn...

journal_title：Physics in medicine and biology

authors： Barbone PE,Oberai AA

更新日期：2007-03-21 00:00:00

abstract：:A novel approach to read out radiochromic film was introduced recently by the manufacturer of GafChromic film. In this study, the performance of this triple-channel film dosimetry method was compared against the conventional single-red-channel film dosimetry procedure, with and without inclusion of a pre-irradiation (...

journal_title：Physics in medicine and biology

authors： van Hoof SJ,Granton PV,Landry G,Podesta M,Verhaegen F

更新日期：2012-07-07 00:00:00

abstract：:A motorized electron multileaf collimator (eMLC) was developed as an add-on device to the Varian linac for delivery of advanced electron beam therapy. It has previously been shown that electron beams collimated by an eMLC have very similar penumbra to those collimated by applicators and cutouts. Thus, manufacturing pa...

journal_title：Physics in medicine and biology

authors： Eldib A,Jin L,Li J,Ma CM

更新日期：2013-08-21 00:00:00

abstract：:Modern effort in radiotherapy to address the challenges of tumor localization and motion has led to the development of MRI guided radiotherapy technologies. Accurate dose calculations must properly account for the effects of the MRI magnetic fields. Previous work has investigated the accuracy of a deterministic linear...

journal_title：Physics in medicine and biology

authors： Zelyak O,Fallone BG,St-Aubin J

更新日期：2017-12-14 00:00:00

abstract：:A mathematical transcription of the intrinsic circuit of the CA1 region of the rat dorsal hippocampus was made and the model parameters adjusted according to experimental data from intracellular recordings and single channel kinetics. This model was able to simulate well the profile of the field potentials recorded ex...

journal_title：Physics in medicine and biology

authors： Almeida AC,Fernandes de Lima VM,Infantosi AF

更新日期：1998-09-01 00:00:00

abstract：:Accurate scatter correction is especially important for high-resolution 3D positron emission tomographies (PETs) such as high-resolution research tomograph (HRRT) due to large scatter fraction in the data. To address this problem, a fully 3D iterative scatter-corrected ordered subset expectation maximization (OSEM) in...

journal_title：Physics in medicine and biology

authors： Kim KS,Ye JC

更新日期：2011-08-07 00:00:00

abstract：:Respiratory gating based on external surrogates is performed in many clinics. We have developed a new technique for treatment verification using an electronic portal imaging device (EPID) in cine mode for gated 3D conformal therapy. Implanted radiopaque fiducial markers inside or near the target are required for this ...

journal_title：Physics in medicine and biology

authors： Berbeco RI,Neicu T,Rietzel E,Chen GT,Jiang SB

更新日期：2005-08-21 00:00:00

abstract：:Inverse treatment planning in intensity modulated particle therapy (IMPT) with scanned carbon-ion beams is currently based on the optimization of RBE-weighted dose to satisfy requirements of target coverage and limited toxicity to organs-at-risk (OARs) and healthy tissues. There are many feasible IMPT plans that meet ...

journal_title：Physics in medicine and biology

authors： Burigo LN,Ramos-Méndez J,Bangert M,Schulte RW,Faddegon B

更新日期：2019-01-04 00:00:00

abstract：:The purpose of this paper for four-dimensional (4D) computed tomography (CT) is threefold. (1) A new spatiotemporal model is presented from the matrix perspective with the row dimension in space and the column dimension in time, namely the robust PCA (principal component analysis)-based 4D CT model. That is, instead o...

journal_title：Physics in medicine and biology

authors： Gao H,Cai JF,Shen Z,Zhao H

更新日期：2011-06-07 00:00:00

abstract：:A hybrid differential and spatially resolved spectroscopy (SRS) technique has been developed to measure absolute absorption coefficient (mu(a)), reduced scattering coefficient (mu'(s)) and cerebral blood volume (CBV) in the adult human head. A spectrometer with both differential and SRS capabilities has been used to c...

journal_title：Physics in medicine and biology

authors： Leung TS,Tachtsidis I,Smith M,Delpy DT,Elwell CE

更新日期：2006-02-07 00:00:00

abstract：:We used a real-skull phantom head to investigate the performances of representative methods for EEG source localization when considering various head models. We describe several experiments using a montage with current sources located at multiple positions and orientations inside a human skull filled with a conductive...

journal_title：Physics in medicine and biology

authors： Baillet S,Riera JJ,Marin G,Mangin JF,Aubert J,Garnero L

更新日期：2001-01-01 00:00:00

abstract：:A near-field probe is described that enables high spatial resolution imaging with terahertz (THz) pulses. The spatial resolution capabilities of the system lie in the range of few microns and we demonstrate a resolution of 7 microm using broad-banded THz pulses with an intensity maximum near 0.5 THz. We present a stud...

journal_title：Physics in medicine and biology

authors： Federici JF,Mitrofanov O,Lee M,Hsu JW,Brener I,Harel R,Wynn JD,Pfeiffer LN,West KW

更新日期：2002-11-07 00:00:00

abstract：:Finding fluence maps for intensity-modulated radiation therapy (IMRT) can be formulated as a multi-criteria optimization problem for which Pareto optimal treatment plans exist. To account for the dose-per-fraction effect of fractionated IMRT, it is desirable to exploit radiobiological treatment plan evaluation criteri...

journal_title：Physics in medicine and biology

authors： Hoffmann AL,den Hertog D,Siem AY,Kaanders JH,Huizenga H

更新日期：2008-11-21 00:00:00

abstract：:Joint space morphology can be indicative of the risk, presence, progression, and/or treatment response of disease or trauma. We describe a novel methodology of characterizing joint space morphology in high-resolution 3D images (e.g. cone-beam CT (CBCT)) using a model based on elementary electrostatics that overcomes a...

journal_title：Physics in medicine and biology

authors： Cao Q,Thawait G,Gang GJ,Zbijewski W,Reigel T,Brown T,Corner B,Demehri S,Siewerdsen JH

更新日期：2015-02-07 00:00:00

abstract：:Rheumatoid arthritis is one of the most common epidemic diseases in the world. For some patients, the treatment with steroids or nonsteroidal anti-inflammatory drugs is not effective, thus necessitating physical removal of the inflamed synovium. Alternative approaches other than surgery will provide appropriate diseas...

journal_title：Physics in medicine and biology

authors： Wu J,Chang SJ,Chuang KS,Hsueh YW,Yeh KC,Wang JN,Tsai WP

更新日期：2007-03-21 00:00:00

abstract：:Volumetric scintillation dosimetry has the potential to provide fast, high-resolution, three-dimensional radiation dosimetry. However, scintillators exhibit a nonlinear response at the high linear energy transfer (LET) values characteristic of proton Bragg peaks. The purpose of this study was to develop a quenching co...

journal_title：Physics in medicine and biology

authors： Robertson D,Mirkovic D,Sahoo N,Beddar S

更新日期：2013-01-21 00:00:00

abstract：:Low-strength anastomoses and thermal damage of tissue are major concerns in laser tissue welding techniques where laser energy is used to induce thermal changes in the molecular structure of the tissues being joined, hence allowing them to bond together. Laser tissue soldering, on the other hand, is a bonding techniqu...

journal_title：Physics in medicine and biology

authors： McNally KM,Sorg BS,Welch AJ,Dawes JM,Owen ER

更新日期：1999-04-01 00:00:00

abstract：:This study presents a combined small animal holding fixture system, termed a 'bridge capsule', which provides for small animal re-fixation with positional reproducibility. This system comprises separate holding fixtures for the head and lower body and a connecting part to a gas anesthesia system. A mouse is fixed in p...

journal_title：Physics in medicine and biology

authors： Kokuryo D,Kimura Y,Obata T,Yamaya T,Kawamura K,Zhang MR,Kanno I,Aoki I

更新日期：2010-07-21 00:00:00

abstract：:Determination of the cardiorespiratory phase of the heart has numerous applications during cardiac imaging. In this article we propose a novel view-angle independent near-real time cardiorespiratory motion gating and coronary sinus (CS) catheter tracking technique for x-ray fluoroscopy images that are used to guide ca...

journal_title：Physics in medicine and biology

authors： Panayiotou M,Rhode KS,King AP,Ma Y,Cooklin M,O'Neill M,Gill J,Rinaldi CA,Housden RJ

更新日期：2015-10-21 00:00:00