Simultaneous optimization of RBE-weighted dose and nanometric ionization distributions in treatment planning with carbon ions.

abstract：:Ultrasound Doppler (UD) velocity measurements are commonly used to quantify blood flow velocities in vivo. The aim of our work was to investigate the accuracy of in vivo spectral Doppler measurements of velocity waveforms. Waveforms were derived from spectral Doppler signals and corrected for intrinsic spectral broade...

journal_title：Physics in medicine and biology

authors： Jiang J,Strother C,Johnson K,Baker S,Consigny D,Wieben O,Zagzebski J

更新日期：2011-03-21 00:00:00

abstract：:The total system error (TSE) of a CyberKnife® system was measured using two phantom-based methods and one patient-based method. The standard radiochromic film (RCF) end-to-end (E2E) test using an anthropomorphic head and neck phantom and isocentric treatment delivery was used with the 6Dskull, Fiducial and Xsight® spi...

journal_title：Physics in medicine and biology

authors： Pantelis E,Moutsatsos A,Antypas C,Zoros E,Pantelakos P,Lekas L,Romanelli P,Zourari K,Hourdakis CJ

更新日期：2018-08-20 00:00:00

abstract：:This paper evaluates the performance of two large-area position-sensitive solid-state photomultipliers (PS-SSPM) for use in small animal PET detector designs. Both PS-SSPM device designs are 1 cm² in area, the first being a 2 × 2 tiled array of 5 mm × 5 mm PS-SSPMs and the second being a 10 mm × 10 mm continuous PS-SS...

journal_title：Physics in medicine and biology

authors： Schmall JP,Du J,Yang Y,Dokhale PA,McClish M,Christian J,Shah KS,Cherry SR

更新日期：2012-12-21 00:00:00

abstract：:In radiation therapy, a plan is robust if the calculated and the delivered dose are in agreement, even in the case of different uncertainties. The current practice is to use safety margins, expanding the clinical target volume sufficiently enough to account for treatment uncertainties. This, however, might not be idea...

journal_title：Physics in medicine and biology

authors： Albertini F,Hug EB,Lomax AJ

更新日期：2011-07-21 00:00:00

abstract：:The characteristics of an Elekta Precise treatment machine with a gating interface were investigated. Three detectors were used: a Farmer ionization chamber, a MatriXX ionization chamber array and an in-house, single pulse-measurement ionization chamber (IVC). Measurements were made of dosimetric accuracy, flatness an...

journal_title：Physics in medicine and biology

authors： Evans PM,Symonds-Tayler JR,Colgan R,Hugo GD,Letts N,Sandin C

更新日期：2010-04-21 00:00:00

abstract：:Improving the prevention and detection of preinvasive ductal carcinoma in situ (DCIS) is expected to lower both morbidity and mortality from breast cancer. Transgenic mouse models can be used as a 'test bed' to develop new imaging methods and to evaluate the efficacy of candidate preventive therapies. We hypothesized ...

journal_title：Physics in medicine and biology

authors： Jansen SA,Conzen SD,Fan X,Krausz T,Zamora M,Foxley S,River J,Newstead GM,Karczmar GS

更新日期：2008-10-07 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：:Stereotactic Gamma Knife radiosurgery utilizes ionizing beams from (60)Co sources and relies on a combination of collimator sizes, weighting, etc to generate a high-dose region that is conformal with a designated target volume. Dose computation is typically performed by computer, but in this paper, single collimator d...

journal_title：Physics in medicine and biology

authors： Fenner J,Gwilliam M,Mehrem R,Bird A,Walton L

更新日期：2008-04-21 00:00:00

abstract：:Dynamic PET image reconstruction is a challenging issue due to the low SNR and the large quantity of spatio-temporal data. We propose a robust state-space image reconstruction (SSIR) framework for activity reconstruction in dynamic PET. Unlike statistically-based frame-by-frame methods, tracer kinetic modeling is inco...

journal_title：Physics in medicine and biology

authors： Tong S,Alessio AM,Kinahan PE,Liu H,Shi P

更新日期：2011-04-21 00:00:00

abstract：:Cavity theories are used to relate the dose in a medium to the dose in a cavity. No satisfactory analytical approach exists for the case of intermediate cavities, such as TLDs, when interface effects are important. Burlin proposed a general cavity theory that accounts for the cavity size but which ignores interface ef...

journal_title：Physics in medicine and biology

authors： Frujinoiu C

更新日期：2001-04-01 00:00:00

abstract：:In modern radiotherapy the verification of complex treatments plans is often performed in inhomogeneous or even anthropomorphic phantoms. For dose verification small detectors are necessary and therefore alanine detectors are most suitable. Though the response of alanine for a wide range of clinical photon energies in...

journal_title：Physics in medicine and biology

authors： von Voigts-Rhetz P,Anton M,Vorwerk H,Zink K

更新日期：2016-02-07 00:00:00

abstract：:Uncemented prosthetic joint implants used in orthopaedic surgery are usually coated with a porous surface to encourage bone ingrowth. Better contact between the endosteal bone and the porous surface improves ingrowth, and such contact may be increased if the joint further subsides into position in the first weeks foll...

journal_title：Physics in medicine and biology

authors： Berry E,Langkamer VG,Jackson PC,Snow M,Goddard PR,Wells PN

更新日期：1993-02-01 00:00:00

abstract：:Most solid-state detectors, including 3D dosimeters, show lower signal in the Bragg peak than expected, a process termed quenching. The purpose of this study was to investigate how variation in chemical composition of a recently developed radiochromic, silicone-based 3D dosimeter influences the observed quenching in p...

journal_title：Physics in medicine and biology

authors： Høye EM,Skyt PS,Balling P,Muren LP,Taasti VT,Swakoń J,Mierzwińska G,Rydygier M,Bassler N,Petersen JB

更新日期：2017-02-21 00:00:00

abstract：:We are developing a three-dimensional (3D) position-sensitive detector with isotropic spatial resolution, the X'tal cube. Originally, our design consisted of a crystal block for which all six surfaces were covered with arrays of multi-pixel photon counters (MPPCs). In this paper, we examined the feasibility of reducin...

journal_title：Physics in medicine and biology

authors： Hirano Y,Inadama N,Yoshida E,Nishikido F,Murayama H,Watanabe M,Yamaya T

更新日期：2013-03-07 00:00:00

abstract：:We tested the ability of a single Compton camera (CC) to produce 3-dimensional (3D) images of prompt gammas (PGs) emitted during the irradiation of a tissue-equivalent plastic phantom with proton pencil beams for clinical doses delivered at clinical dose rates. PG measurements were made with a small prototype CC place...

journal_title：Physics in medicine and biology

authors： Draeger E,Mackin D,Peterson S,Chen H,Avery S,Beddar S,Polf JC

更新日期：2018-01-30 00:00:00

abstract：:The 'EXACT3D' positron tomograph, which is now in routine clinical research use, was developed with the aim of achieving unprecedented sensitivity, high spatial and temporal resolution and simplicity of design using proven detector technology. It consists of six rings of standard detector blocks (CTI/Siemens EXACT HR+...

journal_title：Physics in medicine and biology

authors： Spinks TJ,Jones T,Bloomfield PM,Bailey DL,Miller M,Hogg D,Jones WF,Vaigneur K,Reed J,Young J,Newport D,Moyers C,Casey ME,Nutt R

更新日期：2000-09-01 00:00:00

abstract：:Segmentation of liver in abdominal computed tomography (CT) is an important step for radiation therapy planning of hepatocellular carcinoma. Practically, a fully automatic segmentation of liver remains challenging because of low soft tissue contrast between liver and its surrounding organs, and its highly deformable s...

journal_title：Physics in medicine and biology

authors： Qin W,Wu J,Han F,Yuan Y,Zhao W,Ibragimov B,Gu J,Xing L

更新日期：2018-05-04 00:00:00

abstract：:Mean glandular dose is the quantity used for dosimetry in mammography and depends on breast-related characteristics, such as thickness and density, and on the x-ray spectrum used for breast imaging. This work aims to present an experimentally-based method to derive polyenergetic normalized glandular dose coefficients ...

journal_title：Physics in medicine and biology

authors： Santos JC,Tomal A,de Barros N,Costa PR

更新日期：2019-05-10 00:00:00

abstract：:The National Physical Laboratory (NPL) provides a high-energy photon calibration service using 4-19 MV x-rays and 60Co gamma-radiation for secondary standard dosemeters in terms of absorbed dose to water. The primary standard used for this service is a graphite calorimeter and so absorbed dose calibrations must be con...

journal_title：Physics in medicine and biology

authors： Nutbrown RF,Duane S,Shipley DR,Thomas RA

更新日期：2002-02-07 00:00:00

abstract：:Electrical properties (EP), namely conductivity and permittivity, can provide endogenous contrast for tissue characterization. Using electrical property tomography (EPT), maps of EP can be generated from conventional MRI data. This report investigates the feasibility and accuracy of EPT at 21.1 T for multiple RF coils...

journal_title：Physics in medicine and biology

authors： Amouzandeh G,Mentink-Vigier F,Helsper S,Bagdasarian FA,Rosenberg JT,Grant SC

更新日期：2020-02-28 00:00:00

abstract：:The whole prostatic volume (PV) is an important indicator for benign prostate hyperplasia. Correlating the PV with other clinical parameters in a population-based prospective cohort study (SHIP-2) requires valid prostate segmentation in a large number of whole-body MRI scans. The axial proton density fast spin echo fa...

journal_title：Physics in medicine and biology

authors： Habes M,Schiller T,Rosenberg C,Burchardt M,Hoffmann W

更新日期：2013-09-07 00:00:00

abstract：:We describe an improved algorithm for localising equivalent sources of biomagnetic fields in the human brain. The algorithm is an improvement over the sphere model in that it considers two distinct surfaces: an ellipsoid, to model the region of the skull on which the sensors are placed, and a sphere as the medium in w...

journal_title：Physics in medicine and biology

authors： Pistella F,Barone P,Narici L,Ocello N,Pizzella V,Romani GL

更新日期：1987-01-01 00:00:00

abstract：:As a part of an ongoing effort to develop computerized planning tools for cryosurgery, an experimental study has been conducted to verify a recently developed numerical technique for bioheat transfer simulations. Experiments were performed on gelatin solution as a phantom material, using proprietary liquid-nitrogen cr...

journal_title：Physics in medicine and biology

authors： Rossi MR,Rabin Y

更新日期：2007-08-07 00:00:00

abstract：:Experimental radiobiological investigations of fast neutron beams involve irradiation of thin cell layers. The irradiation of cells is done either in free air or with a material such as graphite, TE plastic or bone-equivalent plastic covering the cells. This paper discusses the computed dose distributions in LET at sh...

journal_title：Physics in medicine and biology

authors： Bhatia DP,Nagarajan PS

更新日期：1979-09-01 00:00:00

abstract：:Physical properties of a position-sensitive camera for the analysis of biodistributions of gamma- and beta-emitting radiopharmaceuticals in small animals have been studied, in order to achieve optimal operating conditions. The camera consisted of a highly segmented yttrium-aluminate perovskite (YAP) scintillator, coup...

journal_title：Physics in medicine and biology

authors： Uzunov N,Bello M,Boccaccio P,Moschini G,Baldazzi G,Bollini D,de Notaristefani F,Mazzi U,Riondato M

更新日期：2005-02-07 00:00:00

abstract：:Indocyanine green (ICG) is a near-infrared dye that has the potential to be used as a tracer for the minimally invasive measurement of cerebral blood flow (CBF). In order to examine the technique, the arterial and cerebral concentrations of ICG were measured in newborn piglets during the bolus passage of ICG at normoc...

journal_title：Physics in medicine and biology

authors： Springett R,Sakata Y,Delpy DT

更新日期：2001-08-01 00:00:00

abstract：:Our goal was to develop a method for generating high-resolution three-dimensional pulmonary compliance images in rodents from computed tomography (CT) images acquired at a series of constant pressures in ventilated animals. One rat and one mouse were used to demonstrate this technique. A pre-clinical GE flat panel CT ...

journal_title：Physics in medicine and biology

authors： Guerrero T,Castillo R,Sanders K,Price R,Komaki R,Cody D

更新日期：2006-03-07 00:00:00

abstract：:Infrared measurements have been used to profile or image biological tissue, including human skin. Usually, analysis of such measurements has assumed that infrared absorption is due to water and collagen. Such an assumption may be reasonable for soft tissue, but introduction of exogenous agents into skin or the measure...

journal_title：Physics in medicine and biology

authors： Viator JA,Choi B,Peavy GM,Kimel S,Nelson JS

更新日期：2003-01-21 00:00:00

abstract：:The Akaike information criterion and the associated Akaike weights (AW) rank pharmacokinetic models on the basis of goodness-of-fit and number of parameters. The usefulness of this information for improving the haemodynamic parameter estimates from DCE-MRI was investigated through two examples. In each of these, the e...

journal_title：Physics in medicine and biology

authors： Luypaert R,Ingrisch M,Sourbron S,de Mey J

更新日期：2012-06-07 00:00:00

abstract：:A three-dimensional (3D) point-kernel multiple scatter model for point spread function (PSF) determination in parallel-beam single-photon emission computed tomography (SPECT), based on a dose gamma-ray buildup factor, is proposed. This model embraces nonuniform attenuation in a voxelized object of imaging (patient bod...

journal_title：Physics in medicine and biology

authors： Marinkovic P,Ilic R,Spaic R

更新日期：2007-10-07 00:00:00