FBP-Net for direct reconstruction of dynamic PET images.

abstract：:A method of computing theoretical X-ray spectra in the range 30-150 kV is presented. The theoretical spectra are compared with constant potential, high resolution spectra from a tungsten target measured with a Ge(Li) detector, for a range of target angles, tube voltage and filtrations. Above 100 kV the spectra were al...

journal_title：Physics in medicine and biology

authors： Birch R,Marshall M

更新日期：1979-05-01 00:00:00

abstract：:Single monochromator charge-coupled device (CCD) array spectroradiometers have the advantage of ease of use and speed compared with double grating instruments. Their inherently inferior stray-light rejection, however, can critically affect their accuracy in phototherapy and research-related dosimetry applications. Thi...

journal_title：Physics in medicine and biology

authors： Coleman A,Sarkany R,Walker S

更新日期：2008-09-21 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：: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：: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：: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：:Although physical metrics can objectively characterize computed tomography (CT) image quality, quantitative approaches to predict human observer performance are more accurate and clinically relevant. This study compared a modified channelized Hotelling model observer (CHO) with human observers in a shape discriminatio...

journal_title：Physics in medicine and biology

authors： Zhang Y,Leng S,Yu L,Carter RE,McCollough CH

更新日期：2014-07-07 00:00:00

abstract：:We have developed and tested a GSO (gadolinium oxyorthosilicate) position-sensitive gamma detector which can be used with positron and single-photon radionuclides for imaging breast cancer or sentinel lymph node detection. Because GSO has a relatively good energy resolution for annihilation gammas as well as low energ...

journal_title：Physics in medicine and biology

authors： Yamamoto S,Matsumoto K,Senda M

更新日期：2006-01-21 00:00:00

abstract：:In this paper the propagation of a UWB pulse into a layered model of the human body is studied to characterize absorption and reflection of the UWB signal due to the different body tissues. Several time behaviours for the incident UWB pulse are considered and compared with reference to the feasibility of breath and he...

journal_title：Physics in medicine and biology

authors： Cavagnaro M,Pittella E,Pisa S

更新日期：2013-12-21 00:00:00

abstract：:A calibration of the Fricke dosimeter is a measurement of epsilon G(Fe3+). Although G(Fe3+) is expected to be approximately energy independent for all low-LET radiation, existing data are not adequate to rule out the possibility of changes of a few per cent with beam quality. When a high-precision Fricke dosimeter, wh...

journal_title：Physics in medicine and biology

authors： Klassen NV,Shortt KR,Seuntjens J,Ross CK

更新日期：1999-07-01 00:00:00

abstract：:By the end of 2002, 33 398 patients worldwide had been treated with proton radiotherapy, 10 829 for eye diseases. The dose prediction algorithms used today for ocular proton therapy treatment planning rely on parameterizations of measured proton dose distributions, i.e., broad-beam and pencil-beam techniques, whose pr...

journal_title：Physics in medicine and biology

authors： Newhauser W,Koch N,Hummel S,Ziegler M,Titt U

更新日期：2005-11-21 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：:A hybrid proportional-integral-in-time and cost-minimizing-in-space feedback control system for electromagnetic, deep regional hyperthermia is proposed. The unique features of this controller are that (1) it uses temperature, not specific absorption rate, as the criterion for selecting the relative phases and amplitud...

journal_title：Physics in medicine and biology

authors： Kowalski ME,Jin JM

更新日期：2003-03-07 00:00:00

abstract：:A Geiger-mode avalanche photodiode (Si-PM) is a promising photodetector for PET, especially for use in a magnetic resonance imaging (MRI) system, because it has high gain and is less sensitive to a static magnetic field. We developed a Si-PM-based depth-of-interaction (DOI) PET system for small animals. Hamamatsu 4 × ...

journal_title：Physics in medicine and biology

authors： Yamamoto S,Imaizumi M,Watabe T,Watabe H,Kanai Y,Shimosegawa E,Hatazawa J

更新日期：2010-10-07 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：:Optical computed tomography (optical-CT) of 3D radiation dosimeters is a promising avenue for delivering an economic and reliable quality control of radiotherapy treatments such as intensity modulated radiotherapy, brachytherapy and stereotactic radiosurgery. The main problems in transferring 3D dosimeters to clinical...

journal_title：Physics in medicine and biology

authors： Krstajić N,Doran SJ

更新日期：2007-06-07 00:00:00

abstract：:It is well known that the experimental dosimetry of brachytherapy sources presents a challenge. Depending on the particular-dosimeter used, measurements can suffer from poor spatial resolution (ion chambers), lack of 3D information (film) or errors due to the presence of the dosimeter itself distorting the radiation f...

journal_title：Physics in medicine and biology

authors： McJury M,Tapper PD,Cosgrove VP,Murphy PS,Griffin S,Leach MO,Webb S,Oldham M

更新日期：1999-10-01 00:00:00

abstract：:In order (i) to evaluate the dose uncertainty of the mouthpiece in daily use during intensity-modulated radiotherapy of patients with head and neck cancer, and (ii) to present a system for in vivo dosimetry of the oral mucosa, we equipped the mouthpiece with alanine dosimeter probes for in vivo dosimetry. The aim was ...

journal_title：Physics in medicine and biology

authors： Wagner D,Anton M,Vorwerk H

更新日期：2011-03-07 00:00:00

abstract：:The goal of this study was to determine the quantitative accuracy of our OSEM-APDI reconstruction method based on SPECT/CT imaging for Tc-99m, In-111, I-123, and I-131 isotopes. Phantom studies were performed on a SPECT/low-dose multislice CT system (Infinia-Hawkeye-4 slice, GE Healthcare) using clinical acquisition p...

journal_title：Physics in medicine and biology

authors： Shcherbinin S,Celler A,Belhocine T,Vanderwerf R,Driedger A

更新日期：2008-09-07 00:00:00

abstract：:This work applies a previously developed analytical algorithm to the reconstruction problem in a rotating multi-segment slant-hole (RMSSH) SPECT system. The RMSSH collimator has greater detection efficiency than the parallel-hole collimator with comparable spatial resolution at the expense of limited common volume-of-...

journal_title：Physics in medicine and biology

authors： Huang Q,Xu J,Tsui BM,Gullberg GT

更新日期：2009-07-07 00:00:00

abstract：:Identification of prostate gold fiducial markers in magnetic resonance imaging (MRI) images is challenging when CT images are not available, due to misclassifications from intra-prostatic calcifications. It is also a time consuming task and automated identification methods have been suggested as an improvement for bot...

journal_title：Physics in medicine and biology

authors： Gustafsson CJ,Swärd J,Adalbjörnsson SI,Jakobsson A,Olsson LE

更新日期：2020-11-12 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：:This note describes a simple phantom which can be used to check the long term stability and accuracy of relative attenuation measurements made by near infra-red (NIR) spectrometers. The phantom has been calibrated, and the results of the calibration are shown to agree with theoretical predictions of the relative atten...

journal_title：Physics in medicine and biology

authors： Firbank M,Delpy DT

更新日期：1994-09-01 00:00:00

abstract：:This paper presents a new algorithm for constrained intensity-modulated radiotherapy (IMRT) planning, made tractable by a dimensionality reduction using a set of plans obtained by fast, unconstrained optimizations. The main result is to reduce planning time by an order of magnitude, producing viable five field prostat...

journal_title：Physics in medicine and biology

authors： Lu R,Radke RJ,Yang J,Happersett L,Yorke E,Jackson A

更新日期：2008-12-07 00:00:00

abstract：:Values of the relative permittivity and conductivity of the rabbit retina and lens have been measured between 10 MHz and 10 GHz over the temperature range 20 to -20 degrees C. As the temperature was lowered from 20 degrees C the dielectric parameters changed smoothly until -9 degrees C where freezing occurred. At this...

journal_title：Physics in medicine and biology

authors： Gabriel C,Grant EH

更新日期：1985-09-01 00:00:00

abstract：:The dosimetrical characteristics of a new miniature multileaf collimator (ModuLeaf MLC, MRC Systems GmbH, Heidelberg, Germany) attached to the accessory holder of a Siemens accelerator with 6 MV x-rays (PRIMUS, Siemens OCS, Concord, California, USA) have been investigated. In particular, those parameters which are imp...

journal_title：Physics in medicine and biology

authors： Hartmann GH,Föhlisch F

更新日期：2002-06-21 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：:In the field of regenerative medicine, there has been a growing interest in studying the combination of bone scaffolds and cells that can maximize newly formed bone. In-line phase-contrast x-ray tomography was used to image porous bone scaffolds (Skelite(©)), seeded with bone forming cells. This technique allows the q...

journal_title：Physics in medicine and biology

authors： Weber L,Langer M,Tavella S,Ruggiu A,Peyrin F

更新日期：2016-05-07 00:00:00

abstract：:Fully three-dimensional positron emission tomography is considered and a reconstruction algorithm derived. The reconstruction problem is formulated mathematically as a three-dimensional convolution integral of a point spread function with an unknown positron activity distribution and is solved by Fourier transform met...

journal_title：Physics in medicine and biology

authors： Colsher JG

更新日期：1980-01-01 00:00:00

abstract：:The development of new biological imaging technologies offers the opportunity to further individualize radiotherapy. Biologically conformal radiation therapy (BCRT) implies the use of the spatial distribution of one or more radiobiological parameters to guide the IMRT dose prescription. Our aim was to implement BCRT i...

journal_title：Physics in medicine and biology

authors： Vanderstraeten B,De Gersem W,Duthoy W,De Neve W,Thierens H

更新日期：2006-08-21 00:00:00