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 incorporated to provide physiological guidance for the reconstruction, harnessing the temporal information of the dynamic data. Dynamic reconstruction is formulated in a state-space representation, where a compartmental model describes the kinetic processes in a continuous-time system equation, and the imaging data are expressed in a discrete measurement equation. Tracer activity concentrations are treated as the state variables, and are estimated from the dynamic data. Sampled-data H(∞) filtering is adopted for robust estimation. H(∞) filtering makes no assumptions on the system and measurement statistics, and guarantees bounded estimation error for finite-energy disturbances, leading to robust performance for dynamic data with low SNR and/or errors. This alternative reconstruction approach could help us to deal with unpredictable situations in imaging (e.g. data corruption from failed detector blocks) or inaccurate noise models. Experiments on synthetic phantom and patient PET data are performed to demonstrate feasibility of the SSIR framework, and to explore its potential advantages over frame-by-frame statistical reconstruction approaches.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Tong S,Alessio AM,Kinahan PE,Liu H,Shi Pdoi
10.1088/0031-9155/56/8/010subject
Has Abstractpub_date
2011-04-21 00:00:00pages
2481-98issue
8eissn
0031-9155issn
1361-6560pii
S0031-9155(11)71043-0journal_volume
56pub_type
杂志文章abstract::In clinical computed tomography (CT) images, cortical bone features with sub-millimeter (sub-mm) thickness are substantially blurred, such that their thickness is overestimated and their intensity appears underestimated. Therefore, any inquiry of the geometry or the density of such bones based on these images is sever...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/57/23/8099
更新日期:2012-12-07 00:00:00
abstract::For plane-parallel chambers used in electron dosimetry, modern dosimetry protocols recommend a cross-calibration against a calibrated cylindrical chamber. The rationale for this is the unacceptably large (up to 3-4%) chamber-to-chamber variations of the perturbation factors (pwall)Co, which have been reported for plan...
journal_title:Physics in medicine and biology
pub_type: 杂志文章,多中心研究
doi:10.1088/0031-9155/52/23/026
更新日期:2007-12-07 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
pub_type: 杂志文章
doi:10.1088/0031-9155/50/3/n01
更新日期:2005-02-07 00:00:00
abstract::In this paper, we investigate an off-line strategy to incorporate inter-fraction organ motion in IMRT treatment planning. It was suggested that inverse planning could be based on a probability distribution of patient geometries instead of a single snap shot. However, this concept is connected to two intrinsic problems...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/49/17/013
更新日期:2004-09-07 00:00:00
abstract::As the use of radiofrequency (RF) electromagnetic (EM) fields has increased along with increased use of wireless communication, the possible related health risks have also been widely discussed. One safety aspect is the interaction of medical implants and RF devices like mobile phones. In the literature, effects on ac...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/52/5/001
更新日期:2007-03-07 00:00:00
abstract::The purpose of this research is to develop a 4DCBCT-based dose assessment method for calculating actual delivered dose for patients with significant respiratory motion or anatomical changes during the course of SBRT. To address the limitation of 4DCT-based dose assessment, we propose to calculate the delivered dose us...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/61/2/554
更新日期:2016-01-21 00:00:00
abstract::Percutaneous coronary interventions are associated with increased radiation exposure compared to most radiological examinations. This prospective study aimed at (1) measuring entrance doses for all in-room personnel, (2) performing an assessment of patient effective dose and intracoronary doses, (3) investigating the ...
journal_title:Physics in medicine and biology
pub_type: 临床试验,杂志文章
doi:10.1088/0031-9155/48/18/307
更新日期:2003-09-21 00:00:00
abstract::Intracoronary thermography is a technique that measures lumen wall temperatures for vulnerable plaque detection. In this paper the influence of vulnerable plaque composition on lumen wall temperatures was studied numerically. Concerning the vulnerable plaque heat generation, the location of the heat source and its hea...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/51/22/010
更新日期:2006-11-21 00:00:00
abstract::Inverse planning techniques are known to produce intensity-modulated beams (IMBs) that are highly modulated. They are characterized by the fact that they contain high-frequency modulations that are absent in the profiles that are easier to deliver. For the purpose of this study these clinically unwanted fluctuations a...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/49/17/003
更新日期:2004-09-07 00:00:00
abstract::This study presents a new approach to accurately account for the medium-dependent effect in model-based dose calculations for kilovoltage (kV) x-rays. This approach is based on the hypothesis that the correction factors needed to convert dose from model-based dose calculations to absorbed dose-to-medium depend on both...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/56/13/011
更新日期:2011-07-07 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
pub_type: 杂志文章
doi:10.1088/0031-9155/43/2/009
更新日期:1998-02-01 00:00:00
abstract::In critical organ in vivo x-ray dosimetry, the relative contaminating electron contribution to the total dose and total detector response outside the field will be different to the corresponding contributions at the central axis detector calibration position, mainly due to the effects of shielding in the linear accele...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/51/24/013
更新日期:2006-12-21 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
pub_type: 杂志文章
doi:10.1088/0031-9155/49/10/004
更新日期:2004-05-21 00:00:00
abstract::Approximately 70% of acute coronary artery disease is caused by unstable (vulnerable) plaques with an inflammation of the overlying cap and high lipid content. A rupturing of the inflamed cap of the plaque results in propagation of the thrombus into the lumen, blockage of the artery and acute ischaemic syndrome or sud...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/51/4/014
更新日期:2006-02-21 00:00:00
abstract::The concepts of radiance and fluence are fundamental to the description of a radiation field. The International Commission on Radiological Units and Measurements (ICRU) has defined fluence in terms of the number of the radiation particles crossing a small sampling sphere. A second definition has been proposed in which...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/39/6/011
更新日期:1994-06-01 00:00:00
abstract::The biological mechanisms of platelet destruction must be correctly identified before platelet survival curves can be interpreted. This report develops a theory of platelet destruction which is compared with experiments performed on platelets labelled with the radioactive isotope 51Cr. Platelet destruction rate is a c...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/28/12/001
更新日期:1983-12-01 00:00:00
abstract::Magnetic Particle Imaging (MPI) is a promising medical imaging technique for visualizing the three-dimensional distribution of tracer materials, specifically iron oxide nanoparticles (IONP). The optimization of magnetic nanoparticles (MNP) plays an essential role to improve the image resolution and sensitivity of imag...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/1361-6560/abcd19
更新日期:2020-11-23 00:00:00
abstract::The feasibility is demonstrated of a numerical method to calculate dose deposition by broad high-energy electron beams in homogeneous matter or in heterogeneous matter in which the heterogeneities are arranged in slabs perpendicular to the beam axis. The method is based only on the basic physical interaction processes...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/34/10/003
更新日期:1989-10-01 00:00:00
abstract::In external beam radiation therapy, radioactive beams offer the best clinical solution to simultaneously treat and in vivo monitor the dose delivery and tumor response using PET or PET-CT imaging. However, difficulties mainly linked to the low production efficiency have so far limited their use. This study is devoted ...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/56/6/005
更新日期:2011-03-21 00:00:00
abstract::The purpose of this study was to apply a novel method of multiscale echo texture analysis for distinguishing benign (hemangiomas) from malignant (hepatocellular carcinomas (HCCs) and metastases) focal liver lesions in B-mode ultrasound images. In this method, regions of interest (ROIs) extracted from within the lesion...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/48/22/008
更新日期:2003-11-21 00:00:00
abstract::Magnetoencephalography (MEG) source analysis has largely relied on spherical conductor models of the head to simplify forward calculations of the brain's magnetic field. Multiple- (or overlapping, local) sphere models, where an optimal sphere is selected for each sensor, are considered an improvement over single-spher...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/56/17/010
更新日期:2011-09-07 00:00:00
abstract::Near-infrared fluorescence optical imaging has the unique opportunity of differentiating diseased lesions from normal lesions based upon environmentally indicated changes in the lifetime of a fluorescent imaging agent. In this paper, we demonstrate three-dimensional lifetime tomography using the gradient-based penalty...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/52/14/009
更新日期:2007-07-21 00:00:00
abstract::Earlier work on the dielectric properties of cryoprotectant agents is extended using a modified measuring cell and method of data reduction yielding results more efficiently over a temperature range from -75 to +25 degrees C at frequencies from 27 MHz to 3 GHz. Dimethyl sulphoxide and butanediol are investigated at lo...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/43/10/011
更新日期:1998-10-01 00:00:00
abstract::Recent acute shortage of medical radioisotopes prompted investigations into alternative methods of production and the use of a cyclotron and ¹⁰⁰Mo(p,2n)(99m)Tc reaction has been considered. In this context, the production yields of (99m)Tc and various other radioactive and stable isotopes which will be created in the ...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/56/17/002
更新日期:2011-09-07 00:00:00
abstract::Monitoring the spatio-temporal characteristics of microcirculation is crucial for studying the functional activities of biotissue and the mechanism of disease. However, conventional methods used to measure blood flow suffer from limited spatial resolution or the injection of exogenous substances or the need of scannin...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/49/7/020
更新日期:2004-04-07 00:00:00
abstract::For the first time the absolute photon mass energy-absorption coefficient of air in the energy range of 10 to 60 keV has been measured with relative standard uncertainties below 1%, considerably smaller than those of up to 2% assumed for calculated data. For monochromatized synchrotron radiation from the electron stor...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/57/24/8231
更新日期:2012-12-21 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
pub_type: 杂志文章
doi:10.1088/0031-9155/58/24/8689
更新日期:2013-12-21 00:00:00
abstract::Two detectors for fast two-dimensional (2D) and quasi-three-dimensional (quasi-3D) verification of the dose delivered by radiotherapy beams have been developed at University and Istituto Nazionale di Fisica Nucleare (INFN) of Torino. The Magic Cube is a stack of strip-segmented ionization chambers interleaved with wat...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/49/16/017
更新日期:2004-08-21 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
abstract::Measurements of patient entrance surface dose rate provide valuable data for interpreting results from dose-area product studies on fluoroscopic x-ray equipment. Methods for measurement of entrance surface dose rate with backscatter and incident dose rate without backscatter have been investigated. Entrance surface do...
journal_title:Physics in medicine and biology
pub_type: 杂志文章
doi:10.1088/0031-9155/40/5/008
更新日期:1995-05-01 00:00:00