Photon-counting spectral computed tomography using silicon strip detectors: a feasibility study.

abstract：:In this response we underscore that the instrumentation described in the original publication (Liu et al 2012 Phys. Med. Biol. 57 843-65) was based on pulse-sampling technique, while the comment by Zhang et al is based on the assumption that a time-correlated single photon counting (TCSPC) instrumentation was used. Th...

journal_title：Physics in medicine and biology

authors： Ma D,Liu J,Qi J,Marcu L

更新日期：2017-02-21 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：:Dose calculations were performed for a tissue phantom irradiated by uniform circular beams of negative pions with an assumed gaussian momentum distribution. The mean momentum of the pions was varied from 104.4 to 171.5 MeV/c (mean range 5-20 cm in unit-density tissue) and the momentum spread from 0 to 5% of the mean. ...

journal_title：Physics in medicine and biology

authors： Hamm RN,Wright HA,Turner JE

更新日期：1979-05-01 00:00:00

abstract：:Radiation therapy is an image-guided process whose success critically depends on the imaging modality used for treatment planning and the level of integration of the available imaging information. In this work, we establish a dose optimization framework for incorporating metabolic information from functional imaging m...

journal_title：Physics in medicine and biology

authors： Xing L,Cotrutz C,Hunjan S,Boyer AL,Adalsteinsson E,Spielman D

更新日期：2002-10-21 00:00:00

abstract：:Subharmonic contrast imaging promises to improve ultrasound-imaging quality by taking advantage of an increased contrast to tissue signal. However, acoustic pressures beyond the subharmonic generation threshold using common ultrasound pulses may induce significant contrast microbubble destruction. In this work, a chir...

journal_title：Physics in medicine and biology

authors： Zhang D,Gong Y,Gong X,Liu Z,Tan K,Zheng H

更新日期：2007-09-21 00:00:00

abstract：:The purpose of this work was to characterize expert variation in segmentation of intracranial structures pertinent to radiation therapy, and to assess a registration-driven atlas-based segmentation algorithm in that context. Eight experts were recruited to segment the brainstem, optic chiasm, optic nerves, and eyes, o...

journal_title：Physics in medicine and biology

authors： Deeley MA,Chen A,Datteri R,Noble JH,Cmelak AJ,Donnelly EF,Malcolm AW,Moretti L,Jaboin J,Niermann K,Yang ES,Yu DS,Yei F,Koyama T,Ding GX,Dawant BM

更新日期：2011-07-21 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：:A clinical trial named PROMETHEUS is currently ongoing for inoperable hepatocellular carcinoma (HCC) at the Heidelberg Ion Beam Therapy Center (HIT, Germany). In this framework, 4D PET-CT datasets are acquired shortly after the therapeutic treatment to compare the irradiation induced PET image with a Monte Carlo PET p...

journal_title：Physics in medicine and biology

authors： Gianoli C,Kurz C,Riboldi M,Bauer J,Fontana G,Baroni G,Debus J,Parodi K

更新日期：2016-06-07 00:00:00

abstract：:Scattered doses, e.g. neutron doses in proton therapy, are of concern in radiation therapy. Although measured data are the gold standard, Monte Carlo simulations allow a more realistic consideration of patient anatomy via whole-body phantoms. When calculating neutron doses with Monte Carlo techniques, the dose can be ...

journal_title：Physics in medicine and biology

authors： Jarlskog CZ,Paganetti H

更新日期：2008-09-07 00:00:00

abstract：:Our study aimed to quantitatively evaluate blood flow in the left ventricle (LV) of apical hypertrophic cardiomyopathy (APH) by combining wall thickness obtained from cardiac magnetic resonance imaging (MRI) and myocardial perfusion from single-photon emission computed tomography (SPECT). In this study, we considered ...

journal_title：Physics in medicine and biology

authors： Fukami T,Sato H,Wu J,Lwin TT,Yuasa T,Kawano S,Iida K,Akatsuka T,Hontani H,Takeda T,Tamura M,Yokota H

更新日期：2007-07-21 00:00:00

abstract：:In this work we present a new 3D numerical model for heat transfer in the human eye, which takes into account the aqueous humour flow in the anterior chamber. We show that consideration of this phenomenon in the calculations alters the temperature distribution on the corneal and lens surfaces, without, however, notice...

journal_title：Physics in medicine and biology

authors： Karampatzakis A,Samaras T

更新日期：2010-10-07 00:00:00

abstract：:The use of thermographic techniques has increased as infrared detector technology has evolved and improved. For laser-tissue interactions, thermal cameras have been used to monitor the thermal response of tissue to pulsed and continuous wave irradiation. It is important to note that the temperature indicated by the th...

journal_title：Physics in medicine and biology

authors： Choi B,Pearce JA,Welch AJ

更新日期：2000-02-01 00:00:00

abstract：:The prompt-gamma neutron activation facility at Brookhaven National Laboratory was upgraded to improve both the precision and accuracy of its in vivo determinations of total body nitrogen. The upgrade, guided by Monte Carlo simulations, involved elongating and modifying the source collimator and its shielding, reposit...

journal_title：Physics in medicine and biology

authors： Dilmanian FA,Lidofsky LJ,Stamatelatos I,Kamen Y,Yasumura S,Vartsky D,Pierson RN Jr,Weber DA,Moore RI,Ma R

更新日期：1998-02-01 00:00:00

abstract：:It is difficult to test near-infrared spectrophotometry instruments in vivo. Therefore we constructed a liquid phantom which mimics the neonatal head. It consists of a spherical 3.5 mm thick layer of silicone rubber simulating skin and bone and a 0.5 mm thick clear layer of polypropylene imitating cerebrospinal fluid....

journal_title：Physics in medicine and biology

authors： Wolf M,Keel M,Dietz V,von Siebenthal K,Bucher HU,Baenziger O

更新日期：1999-07-01 00:00:00

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：:Simultaneous near-infrared spectroscopy (NIRS) and magnetic resonance imaging (MRI) were used to investigate the correlation between tumour vascular oxygenation and tissue oxygen tension dynamics in rat breast 13762NF tumours with respect to hyperoxic gas breathing. NIRS directly detected global variations in the oxyg...

journal_title：Physics in medicine and biology

authors： Xia M,Kodibagkar V,Liu H,Mason RP

更新日期：2006-01-07 00:00:00

abstract：:Magnetoencephalography (MEG) is a non-invasive functional imaging modality based on the measurement of the external magnetic field produced by neural current sources within the brain. The reconstruction of the underlying sources is a severely ill-posed inverse problem typically tackled using either low-dimensional par...

journal_title：Physics in medicine and biology

authors： Jerbi K,Mosher JC,Baillet S,Leahy RM

更新日期：2002-02-21 00:00:00

abstract：:In this paper we present a novel method of reducing the dosimetric effects of the finite leaf width of a multileaf collimator (MLC) in conformal and intensity modulated radiotherapy (IMRT). This is achieved by decomposing the required high-resolution fluence distribution into two orthogonal components, which are deliv...

journal_title：Physics in medicine and biology

authors： Evans PM,Partridge M

更新日期：2000-03-01 00:00:00

abstract：:By analyzing the radiobiological model, and the equations derived from the model, it is shown that the main results of the article 'The influence of dose heterogeneity on tumor control probability in fractionated radiation therapy' by Wiklund et al (2011 Phys. Med. Biol. 56 7585-600) are valid only under the condition...

journal_title：Physics in medicine and biology

authors： Grusell E

更新日期：2013-09-21 00:00:00

abstract：:The classical Sievert integral method is a valuable tool for dose rate calculations around brachytherapy sources, combining simplicity with reasonable computational times. However, its accuracy in predicting dose rate anisotropy around 192Ir brachytherapy sources has been repeatedly put into question. In this work, we...

journal_title：Physics in medicine and biology

authors： Karaiskos P,Angelopoulos A,Baras P,Rozaki-Mavrouli H,Sandilos P,Vlachos L,Sakelliou L

更新日期：2000-02-01 00:00:00

abstract：:An inflatable endorectal balloon (ERB) is often used during stereotactic body radiation therapy (SBRT) for treatment of prostate cancer in order to reduce both intrafraction motion of the target and risk of rectal toxicity. However, the ERB can exert significant force on the prostate, and this work assessed the impact...

journal_title：Physics in medicine and biology

authors： Jones BL,Gan G,Kavanagh B,Miften M

更新日期：2013-11-21 00:00:00

abstract：:Quality control (QC) data of radiotherapy linear accelerators, collected by Helsinki University Central Hospital between the years 2000 and 2004, were analysed. The goal was to provide information for the evaluation and elaboration of QC of accelerator outputs and to propose a method for QC data analysis. Short- and l...

journal_title：Physics in medicine and biology

authors： Kapanen M,Tenhunen M,Hämäläinen T,Sipilä P,Parkkinen R,Järvinen H

更新日期：2006-07-21 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：: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：:Monte Carlo simulation was used to calculate correction factors for output factor (OF), percentage depth-dose (PDD), and off-axis ratio (OAR) measurements with the CyberKnife M6 System. These include the first such data for the InCise MLC. Simulated detectors include diodes, air-filled microchambers, a synthetic micro...

journal_title：Physics in medicine and biology

authors： Francescon P,Kilby W,Noll JM,Masi L,Satariano N,Russo S

更新日期：2017-02-07 00:00:00

abstract：:The development of alpha-emitting radiopharmaceuticals using 211At requires quantitative determination of the time-dependent nature of the 211At biodistribution. However, imaging-based methods for acquiring this information with 211At have not found wide-spread use because of its low abundance of decay emissions suita...

journal_title：Physics in medicine and biology

authors： Crawford JR,Robertson AKH,Yang H,Rodríguez-Rodríguez C,Esquinas PL,Kunz P,Blinder S,Sossi V,Schaffer P,Ruth TJ

更新日期：2018-02-21 00:00:00

abstract：:Radiographic imaging of large patients is compromised by x-ray scatter. Optimization of digital x-ray imaging systems used for projection radiography requires the use of the best possible antiscatter grid. The performance of antiscatter grids used in conjunction with digital x-ray imaging systems can be characterized ...

journal_title：Physics in medicine and biology

authors： Fetterly KA,Schueler BA

更新日期：2007-08-21 00:00:00

abstract：:Analytic solutions to the time-dependent multiregion bioheat equation are evaluated numerically for cartesian and spherical models. Principle and alternate branch contributions to the solutions are examined. The calculations include a parametric investigation and analyses of temperature behaviour in idealised upper th...

journal_title：Physics in medicine and biology

authors： Durkee JW Jr,Antich PP,Lee CE

更新日期：1990-07-01 00:00:00

abstract：:We report a simulation study on diffuse reflective optical computed tomography, in which continuous-wave sources and detectors are placed on the plane surface of a semi-infinite body. We adopted a simple Tikhonov regularization in the inverse problem and demonstrated the feasibility of three-dimensional reconstruction...

journal_title：Physics in medicine and biology

authors： Endoh R,Suzuki A,Fujii M,Nakayama K

更新日期：2004-05-21 00:00:00

abstract：:The Jacobian of the deformation field of elastic registration between images taken during radiotherapy is a measure of inter-fraction local deformation. The histogram of the Jacobian values (Jac) within an organ was introduced (JVH-Jacobian-volume-histogram) and first applied in quantifying parotid shrinkage. MVCTs of...

journal_title：Physics in medicine and biology

authors： Fiorino C,Maggiulli E,Broggi S,Liberini S,Cattaneo GM,Dell'oca I,Faggiano E,Di Muzio N,Calandrino R,Rizzo G

更新日期：2011-06-07 00:00:00