Abstract:
:This paper presents a Fourier rebinning algorithm for three-dimensional image reconstruction in PET that incorporates the concept of spectral transfer function. It suggests the need for discarding low-frequency components in the rebinning. It also includes the correction for rebinning efficiency which was evaluated by simulations as a function of oblique angle of projections. The performance was optimized by high-pass filters and axial smoothing. The algorithm yields satisfactory images with negligible axial cross-talk for a maximum oblique angle up to 26.6 degrees. The statistical noise was evaluated in terms of 'noise equivalent number of oblique angles', and reasonable results were obtained in view of the theoretical expectation. Ring artefacts due to noise are negligibly small.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Tanaka E,Amo Ydoi
10.1088/0031-9155/43/4/004subject
Has Abstractpub_date
1998-04-01 00:00:00pages
739-46issue
4eissn
0031-9155issn
1361-6560journal_volume
43pub_type
杂志文章abstract::Dose calculations of pencil beam scanning treatment plans rely on the accuracy of proton spot profiles; not only the primary component but also the broad tail components. Four films are placed at several locations in air and multiple depths in Solidwater® for six selected energies. The films used for the primary compo...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/58/17/6193
更新日期:2013-09-07 00:00:00
abstract::The combined build-up and attenuation factor, B exp (-mu r), of point isotropic photon sources in a water medium has been calculated using the Monte Carlo method, for energies (20-1500 keV) and distances (1-10 cm) relevant in brachytherapy. For the transport of photons and electrons, up-to-date and self-consistent tot...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/36/6/005
更新日期:1991-06-01 00:00:00
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journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/52/11/020
更新日期:2007-06-07 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
pub_type: 杂志文章
doi:10.1088/0031-9155/52/19/004
更新日期:2007-10-07 00:00:00
abstract::Values of W (the mean energy required to create an ion pair when a charged particle is stopped in a gas) are needed in radiation dosimetry to convert ionisation chamber current readings to absorbed dose. For neutron dosimetry the most important W values are those for protons, and this paper describes absolute measurem...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/30/11/003
更新日期:1985-11-01 00:00:00
abstract::Managing uncertainty is a major challenge in radiation therapy treatment planning, including uncertainty induced by intrafraction motion, which is particularly important for tumours in the thorax and abdomen. Common methods to account for motion are to introduce a margin or to convolve the static dose distribution wit...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/51/10/014
更新日期:2006-05-21 00:00:00
abstract::To generate large thermal lesions in ultrasound thermal therapy, cooling intermissions are usually introduced during the treatment to prevent near-field heating, which leads to a long treatment time. A possible strategy to shorten the total treatment time is to eliminate the cooling intermissions. In this study, the t...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/48/9/307
更新日期:2003-05-07 00:00:00
abstract::Segmentation is often required for the analysis of dynamic positron emission tomography (PET) images. However, noise and low spatial resolution make it a difficult task and several supervised and unsupervised methods have been proposed in the literature to perform the segmentation based on semi-automatic clustering of...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/58/19/6931
更新日期:2013-10-07 00:00:00
abstract::Amorphous silicon (aSi:H) flat panel detectors are prevalent in radiotherapy for megavoltage imaging tasks. Any clinical and dosimetrical application requires a well-defined dose response of the system to achieve meaningful results. Due to radiation damages, panels deteriorate and the linearity of pixel response to do...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/58/18/6429
更新日期:2013-09-21 00:00:00
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journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/61/12/4412
更新日期:2016-06-21 00:00:00
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journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/aa5dae
更新日期:2017-05-07 00:00:00
abstract::In positron emission tomography (PET), there is an increasing interest in studying not only the regional mean tracer concentration, but its variation arising from local differences in physiology, the tissue heterogeneity. However, in reconstructed images this physiological variation is shadowed by a large reconstructi...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/58/14/4849
更新日期:2013-07-21 00:00:00
abstract::Effective detective quantum efficiency (eDQE) describes the resolution and noise properties of an imaging system along with scatter and primary transmission, all measured under clinically appropriate conditions. Effective dose efficiency (eDE) is the eDQE normalised to mean glandular dose and has been proposed as a us...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/aaa307
更新日期:2018-01-16 00:00:00
abstract::Accurate scatter compensation in SPECT can be performed by modelling the scatter response function during the reconstruction process. This method is called reconstruction-based scatter compensation (RBSC). It has been shown that RBSC has a number of advantages over other methods of compensating for scatter, but using ...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/43/4/014
更新日期:1998-04-01 00:00:00
abstract::This paper analyzes the radio frequencies (RF) exposure in the head tissues of children using a cellular handset or RF sources (a dipole and a generic handset) at 900, 1800, 2100 and 2400 MHz. Based on magnetic resonance imaging, child head models have been developed. The maximum specific absorption rate (SAR) over 10...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/53/13/019
更新日期:2008-07-07 00:00:00
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journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/ab990e
更新日期:2020-07-06 00:00:00
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journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/aad9b5
更新日期:2018-09-06 00:00:00
abstract::Complex intra-fractional motion and deformation of the liver significantly impacts the accuracy of delivered dose in radiotherapy. It limits margin reduction, dose escalation and normal tissue sparing. A critical component of motion management is to accurately reconstruct tumor motion. In this study, we developed a si...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/ab4c0d
更新日期:2019-11-21 00:00:00
abstract::The performance of a light sharing and recirculation mechanism that allows the extraction of depth of interaction (DOI) are investigated in this paper, with a particular focus on timing. In parallel, a method to optimize the coincidence time resolution (CTR) of PET detectors by use of the DOI information is proposed a...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/ab2cb0
更新日期:2019-08-07 00:00:00
abstract::Proton computed tomography (pCT) promises to reduce or even eliminate range uncertainties inherent in the conversion of Hounsfield units into relative stopping power (RSP) for proton therapy treatment planning. This is of particular interest for proton irradiation studies in animal models due to the high precision req...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/ab8afc
更新日期:2020-08-13 00:00:00
abstract::Depth-dose distributions were calculated for thermal and epithermal neutron fluence and capture gamma ray dose rates using a two-dimensional neutron-coupled gamma-ray transport code (DOT 3.5) for gadolinium neutron capture therapy. The results show that (i) a capture gamma-ray dose rate of 10 Gy h-1 was obtained with ...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/37/1/010
更新日期:1992-01-01 00:00:00
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journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/52/12/015
更新日期:2007-06-21 00:00:00
abstract::The treatment of lung cancer with radiation therapy is hindered by respiratory motion. Real-time adjustments to compensate for this motion are hampered by mechanical system latencies and imaging-rate restrictions. To better understand tumour motion behaviour for adaptive image-guided radiation therapy of lung cancer, ...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/55/12/005
更新日期:2010-06-21 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
pub_type: 杂志文章
doi:10.1088/0031-9155/58/17/5899
更新日期:2013-09-07 00:00:00
abstract::A significant timer error has been found on a linear accelerator used for intraoperative radiation therapy. Since typical treatment doses range up to 20 Gy, calibrations that do not account for this effect can incur a large dosimetry error. The effect is dose rate dependent, but energy independent. For a dose rate of ...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/43/10/031
更新日期:1998-10-01 00:00:00
abstract::The widely applied single-interaction analytic expression characterizing the energy resolution component of the angular resolution precision for an electronically collimated point source is extended to include multiple-interaction Compton scatter sequences as well as sequences terminated by photoelectric absorption. T...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/43/10/021
更新日期:1998-10-01 00:00:00
abstract::In this study, we explore the potential of compressed sensing (CS) accelerated broadband 3D phase-encoded turbo spin-echo (3D-PE-TSE) for the purpose of geometrically undistorted imaging in the presence of field inhomogeneities. To achieve this goal 3D-PE-SE and 3D-PE-TSE sequences with broadband rf pulses and dedicat...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/60/2/615
更新日期:2015-01-21 00:00:00
abstract::Ultrasound may provide a quantitative technique for the characterization of cartilage changes typical of early osteoarthrosis. In this study, specific changes in bovine articular cartilage were induced using collagenase and chondroitinase ABC, enzymes that selectively degrade collagen fibril network and digest proteog...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/44/11/303
更新日期:1999-11-01 00:00:00
abstract::The implementation of two algorithms for calculating dose distributions for radiation therapy treatment planning of intermediate energy proton beams is described. A pencil kernel algorithm and a depth penetration algorithm have been incorporated into a commercial three dimensional treatment planning system (Helax-TMS,...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/45/1/302
更新日期:2000-01-01 00:00:00
abstract::The effect of the physical state (phase) of the absorbing medium and the energy straggling of the alpha particles on the calculation of the radiation dose due to the daughter products of radon deposited in the lung have been studied in detail. The stopping power data for alpha particles in water and water vapour have ...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/32/8/004
更新日期:1987-08-01 00:00:00