Characterization of the electromagnetic near-field absorption in layered biological tissue in the frequency range from 30 MHz to 6,000 MHz.

abstract：:The imaging performance of a high-resolution preclinical micro-positron emission tomography (micro-PET) system employing liquid xenon (LXe) as the gamma-ray detection medium was simulated. The arrangement comprises a ring of detectors consisting of trapezoidal LXe time projection ionization chambers and two arrays of ...

journal_title：Physics in medicine and biology

authors： Miceli A,Glister J,Andreyev A,Bryman D,Kurchaninov L,Lu P,Muennich A,Retiere F,Sossi V

更新日期：2012-03-21 00:00:00

abstract：:Four-dimensional computed tomography (4D-CT) requires breathing information from the patient, and for this, several systems are available. Testing of these systems, under realistic conditions, requires a phantom with a moving target and an expandable outer contour. An anthropomorphic phantom was developed to simulate ...

journal_title：Physics in medicine and biology

authors： Vásquez AC,Runz A,Echner G,Sroka-Perez G,Karger CP

更新日期：2012-05-07 00:00:00

abstract：:To replace the conventional pinhole (normal cone-beam) collimator, a novel skew-slit collimator was previously proposed and a Novikov-type algorithm developed to reconstruct images using the skew-slit geometry. The goal of this paper is to develop a reconstruction algorithm that has better noise control than the Novik...

journal_title：Physics in medicine and biology

authors： Tang Q,Zeng GL,Huang Q

更新日期：2006-12-07 00:00:00

abstract：:This work modified the commonly used Monte Carlo tool package GATE by developing a new 'multiPatchPET' system so that GATE users can easily simulate PET systems with irregular geometries. The motivation was to design a brain PET scanner with high sensitivity. It is known that compact PET scanners with a large solid co...

journal_title：Physics in medicine and biology

authors： Chen G,Weng F,Hong X,Tao W,Zhao Z,Peng Q,Huang Q

更新日期：2018-09-06 00:00:00

abstract：:Monte Carlo simulation techniques are applied to track the annihilation photons from positron decay, and store the photon histories. Reasonably realistic models of the isotope distribution in the brain and heart during typical PET studies, as well as the traditional phantoms used for measuring PET scanner performance ...

journal_title：Physics in medicine and biology

authors： Thompson CJ,Moreno-Cantu J,Picard Y

更新日期：1992-03-01 00:00:00

abstract：:The origin of the differences in the refractive index observed between normal and tumor tissues using terahertz spectroscopy has been described quantitatively. To estimate water content differences in tissues, we prepared fresh and paraffin-embedded samples from rats. An approximately 5% increase of water content in t...

journal_title：Physics in medicine and biology

authors： Yamaguchi S,Fukushi Y,Kubota O,Itsuji T,Ouchi T,Yamamoto S

更新日期：2016-09-21 00:00:00

abstract：:Positron emission tomography (PET) has become an important modality in medical and molecular imaging. However, in most PET applications, the resolution is still mainly limited by the physical crystal sizes or the detector's intrinsic spatial resolution. To achieve images with better spatial resolution in a central reg...

journal_title：Physics in medicine and biology

authors： Li Y,Matej S,Karp JS,Metzler SD

更新日期：2015-01-21 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：:The phosphor GdO2S:Tb is widely used in camera-based electronic portal imaging devices (EPIDs). There is considerable interest in the application of EPIDs to dosimetry and the verification of intensity modulated radiation therapy produced by dynamic multileaf collimation (DMLC). This paper presents direct measurement ...

journal_title：Physics in medicine and biology

authors： Glendinning AG,Hunt SG,Bonnett DE

更新日期：2001-02-01 00:00:00

abstract：:In magnetic drug targeting a chemotherapeutic agent is bound to coated magnetic nanoparticles, which are administered to the blood vessel system and subsequently focused by an external applied magnetic field. The optimization of intra-arterial magnetic drug targeting (MDT) requires detailed knowledge about the biodist...

journal_title：Physics in medicine and biology

authors： Richter H,Wiekhorst F,Schwarz K,Lyer S,Tietze R,Alexiou Ch,Trahms L

更新日期：2009-09-21 00:00:00

abstract：:Many of the inadequacies of the system presently used for surveying environments containing penetrating radiation stem from the impossibility of defining a radiation parameter which is additive, measurable and closely related to peak dose equivalent in the body. Many of the present conceptual difficulties would be eli...

journal_title：Physics in medicine and biology

authors： Harvey JR

更新日期：1975-11-01 00:00:00

abstract：:Assessment of image quality for digital x-ray mammography systems used in European screening programs relies mainly on contrast-detail CDMAM phantom scoring and requires the acquisition and analysis of many images in order to reduce variability in threshold detectability. Part II of this study proposes an alternative ...

journal_title：Physics in medicine and biology

authors： Monnin P,Marshall NW,Bosmans H,Bochud FO,Verdun FR

更新日期：2011-07-21 00:00:00

abstract：:We present a new version of STIR (Software for Tomographic Image Reconstruction), an open source object-oriented library implemented in C++ for 3D positron emission tomography reconstruction. This library has been designed such that it can be used for many algorithms and scanner geometries, while being portable to var...

journal_title：Physics in medicine and biology

authors： Thielemans K,Tsoumpas C,Mustafovic S,Beisel T,Aguiar P,Dikaios N,Jacobson MW

更新日期：2012-02-21 00:00:00

abstract：:A method to measure the detector-to-object distance from the images obtained with stationary high-spatial-resolution gamma-ray cameras for in vivo studies has been developed. It exploits the shift of the imaged object in the image plane, obtained at a certain tilt of the parallel-hole collimator. A linear dependence o...

journal_title：Physics in medicine and biology

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

更新日期：2006-05-07 00:00:00

abstract：:Persistence of the video signal between TV frames, an effect also known as image lag, can lead to anomalously good contrast-detail test results for fluoroscopy systems. In this practical paper, a simple method is described which quantifies lag in fluoroscopy systems and corrects for its effect on threshold contrast. A...

journal_title：Physics in medicine and biology

authors： Marshall NW,Kotre CJ

更新日期：2002-03-21 00:00:00

abstract：:It has been reported that the dose effects of metallic guidewires are significant in intravascular brachytherapy (IVBT) using a beta source. The purpose of this work is to investigate the dependence of these dose effects on guidewire position. The EGS4 Monte Carlo codes were used to perform the dose calculations for t...

journal_title：Physics in medicine and biology

authors： Shih R,Hsu WL,Li XA

更新日期：2002-05-21 00:00:00

abstract：:The purpose of this work is to provide an evaluation of the mean glandular dose (MGD) for breast computed tomography (CT) with synchrotron radiation in an axial scanning configuration with a partial or total organ volume irradiation, for the in vivo program of breast CT ongoing at the ELETTRA facility (Trieste, Italy)...

journal_title：Physics in medicine and biology

authors： Mettivier G,Fedon C,Di Lillo F,Longo R,Sarno A,Tromba G,Russo P

更新日期：2016-01-21 00:00:00

abstract：:The process of organ motion correction in scintigraphy is analysed in the frequency domain. The sequence of the chi- and gamma- coordinates registered during scintigraphic recording is converted to a frequency spectrum by a discrete Fourier transform. In the frequency domain motion correction is performed by linear fi...

journal_title：Physics in medicine and biology

authors： Schmidlin P

更新日期：1975-05-01 00:00:00

abstract：:There are a number of gel dosimeter calibration methods in contemporary usage. The present study is a detailed Monte Carlo investigation into the accuracy of several calibration techniques. Results show that for most arrangements the dose to gel accurately reflects the dose to water, with the most accurate method invo...

journal_title：Physics in medicine and biology

authors： Taylor ML,Franich RD,Johnston PN,Millar RM,Trapp JV

更新日期：2007-07-07 00:00:00

abstract：:Ultrasound in the low megahertz frequency range is used by physiotherapists to treat a variety of conditions. The treatments reduce swelling, reduce pain and increase movement at joints. Ultrasound is now also beginning to be used to treat malignant tumours. The tumours are heated to temperatures between 42 degrees an...

journal_title：Physics in medicine and biology

authors： Quan KM,Shiran M,Watmough DJ

更新日期：1989-11-01 00:00:00

abstract：:Magnetic particle imaging is a new approach to visualizing magnetic nanoparticles. It is capable of 3D real-time in vivo imaging of particles injected into the blood stream and is a candidate for medical imaging applications. To date, only one particle type has been imaged at a time, however, the ability to separate s...

journal_title：Physics in medicine and biology

authors： Rahmer J,Halkola A,Gleich B,Schmale I,Borgert J

更新日期：2015-03-07 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：:We have developed and tested an MR-compatible gamma probe to simultaneously obtain anatomical information and functional information during surgery. The probe consists of a probe head, an optical fibre bundle and a photo-multiplier tube (PMT). The NaI(T1) scintillator contained in the probe head is connected to a 7 m ...

journal_title：Physics in medicine and biology

authors： Yamamoto S,Kuroda K,Senda M

更新日期：2004-08-07 00:00:00

abstract：:Automatic cell cycle analysis (DNA histograms) is usually performed with flow cytometry. In cases when only few cells are available, the DNA content has to be measured with a fluorescence microscope combined with sensitive camera systems (SIT, MCP, cooled CCDs) and a frame grabber for image analysis. The fluorescent c...

journal_title：Physics in medicine and biology

authors： Böcker W,Gantenberg HW,Müller WU,Streffer C

更新日期：1996-03-01 00:00:00

abstract：:In stereotactic radiosurgery, a seven-irradiation film was used to define any discrepancy between the beam and target centres. A mathematical model based on the linac alignment and target set-up was developed to diagnose the discrepancies of the seven-irradiation film between the beam and simulation target centres. Fr...

journal_title：Physics in medicine and biology

authors： Tsai JS

更新日期：1996-09-01 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：:Breast cancer is one of the leading causes of female cancer deaths. Early diagnosis with prophylactic may improve the patients' prognosis. So far ultrasound (US) imaging is a popular method in breast cancer diagnosis. However, its accuracy is bounded to traditional handcrafted feature methods and expertise. A novel me...

journal_title：Physics in medicine and biology

authors： Xie J,Song X,Zhang W,Dong Q,Wang Y,Li F,Wan C

更新日期：2020-10-29 00:00:00

abstract：:The signal properties of polycrystalline mercuric iodide (HgI2) film detectors, under irradiation conditions relevant to mammographic, radiographic, fluoroscopic and radiotherapy x-ray imaging, are reported. Each film detector consists of an approximately 230 to approximately 460 microm thick layer of HgI2 (fabricated...

journal_title：Physics in medicine and biology

authors： Su Z,Antonuk LE,El-Mohri Y,Hu L,Du H,Sawant A,Li Y,Wang Y,Yamamoto J,Zhao Q

更新日期：2005-06-21 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：: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