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Welcome to the Pubget Medical Subject Headings (MESH) browser. Click on a topic or subtopic below to explore related papers. In the gold box is the most recent paper about the current MESH term, and below are 20 related papers.
Phantoms, Imaging (0):
Recent article
Phantoms, Imaging
Medical Physics (38)7 2011
Abstract
Our compute unified device architecture (CUDA) codes provide the exceedingly fast forward projection and backprojection that outperform those using the shading languages, cell broadband engine architecture and previous CUDA implementations. The reconstruction times in the FDK and the EM algorithms w...
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PMID: 21859004
PDF is available here.
PDF is available here.
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Medical Physics (38)7 2011
Abstract
Our approach involves the construction of a 3D digital healthy heart template from the delineation of the patient's left ventricle in the SPECT image. This patient-specific template of the heart, filled with uniform activity, is then analytically projected and reconstructed using the same algorithm...
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PMID: 21859020
PDF is available here.
PDF is available here.
Medical Physics (38)7 2011
Abstract
The differential phase contrast CT is emerging as a new technology to improve the contrast sensitivity of the conventional CT. Via system analysis, modeling, and computer simulation, the authors study the noise power spectrum (NPS)--an imaging performance indicator-of the differentia...
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PMID: 21859039
PDF is available here.
PDF is available here.
Medical Physics (38)7 2011
Abstract
We validate the algorithm using a physical phantom and obtain volumes that are comparable to those from physically determined means. The algorithm segments volumes with an error of within 13% as determined using a physical phantom.
Our original work in fetal cardiac segmentation comp...
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PMID: 21859035
PDF is available here.
PDF is available here.
Medical Physics (38)7 2011
Abstract
Integration of positron emission tomography (PET) and magnetic resonance (MR) in a merged device requires shielding of the PET detector electronics. The authors demonstrate that a multiple shell setup exhibits advantages over a single shell shielding enclosure.
A sphe...
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PMID: 21858996
PDF is available here.
PDF is available here.
Ultrasonic Imaging (33)3 2011
Abstract
We described a 5 MHz center frequency PZT-P[VDF-TrFE] dual-layer transducer that used two perpendicular 1-D arrays for 3-D rectilinear imaging. This design substantially reduces the channel count as well as fabrication complexity, which makes 3-D imaging more realizable. Higher frequencies (>5 MHz)...
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PMID: 21842584
PDF is available here.
PDF is available here.
Ultrasonic Imaging (33)3 2011
Abstract
The progression of atherosclerotic disease is a complex process believed to be a function of the localized mechanical properties and hemodynamic loading associated with the arterial wall. It is hypothesized that measurements of cardiovascular stiffness and wall-shear rate (WSR) may provide important...
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PMID: 21842581
PDF is available here.
PDF is available here.
Ultrasonic Imaging (33)3 2011
Abstract
Our group has proposed the concept of subharmonic aided pressure estimation (SHAPE) utilizing microbubble-based ultrasound contrast agent signals for the noninvasive estimation of hydrostatic blood pressures. An experimental system for in vitro SHAPE was constructed based on two single-element transd...
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PMID: 21842580
PDF is available here.
PDF is available here.
Abstract
Magnetic resonance elastography (MRE) uses accumulated phases that are acquired at multiple, uniformly spaced relative phase offsets, to estimate harmonic motion information. Heavily wrapped phase occurs when the motion is large and unwrapping procedures are necessary to estimate the displacements re...
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PMID: 21666289
PDF is available here.
PDF is available here.
Abstract
We first formulated the simultaneous dual-isotope MPS reconstruction problem as a joint estimation problem. A cross-tracer prior that couples voxel values on both images was then proposed. We developed an iterative algorithm to reconstruct the MPS images that converges to the maximum a posteriori so...
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PMID: 20952334
PDF is available here.
PDF is available here.
Abstract
The setup presented in this work allows routine acquisition of high-quality images with high SNR and isotropic resolutions up to 10 μm within an acceptable measurement time. CONCLUSION: This study demonstrates that MR microscopy can be applied at low cost on animal MR imaging systems, which are in...
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PMID: 21331647
PDF is available here.
PDF is available here.
Medical Physics (38)6 2011
Abstract
The goal of this work was to investigate the effects of MRI surface coils on attenuation-corrected PET emission data. The authors studied the cases where either an MRI or a CT scan would be used to provide PET attenuation correction (AC). Combined MR/PET scanners that use the MRI for PET AC (MR-AC) f...
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PMID: 21815368
PDF is available here.
PDF is available here.
Medical Physics (38)6 2011
Nonrigid PET motion compensation in the lower abdomen using simultaneous tagged-MRI and PET imaging.
Abstract
We propose a novel approach for PET respiratory motion correction using tagged-MRI and simultaneous PET-MRI acquisitions.
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PMID: 21815376
PDF is available here.
PDF is available here.
Medical Physics (38)6 2011
Abstract
Electron spin-echo (ESE) oxygen imaging is a new and evolving electron paramagnetic resonance (EPR) imaging (EPRI) modality that is useful for physiological in vivo applications, such as EPR oxygen imaging (EPROI), with potential application to imaging of multicentimeter objects as large as human tum...
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PMID: 21815379
PDF is available here.
PDF is available here.
Medical Physics (38)6 2011
Abstract
A dual modality SPECT-CT prototype system dedicated to uncompressed breast imaging (mammotomography) has been developed. The computed tomography subsystem incorporates an ultrathick K-edge filtration technique producing a quasi-monochromatic x-ray cone beam that optimizes the dose efficiency of the s...
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PMID: 21815398
PDF is available here.
PDF is available here.
MMW Fortschritte der Medizin (153)21 2011
Abstract
Abstract
Skin dose is often the quantity of interest for radiological protection, as the skin is the organ that receives maximum dose during kilovoltage X-ray irradiations. The purpose of this study was to simulate the energy response and the depth dose water equivalence of the MOSkin radiation detector (Cent...
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PMID: 21559885
PDF is available here.
PDF is available here.
Abstract
We made original phantom based on the counts of clinical study imaging.
On 89Sr bremsstrahlung merged SPECT image, focal accumulations were recognized in the parts of 99mTc-H-MDP merged SPECT accumulation. Focal accumulations were much clearer on 89Sr bremsstrahlung merged SPECT imag...
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PMID: 21736040
PDF is available here.
PDF is available here.
Abstract
The echogenicity of whole blood is known to vary during the flow cycle under pulsatile flow both in vitro and in vivo. However, the fundamental underlying mechanisms remain uncertain. The combined effects of flow acceleration and the shear rate were recently used to explain the cyclic variations of s...
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PMID: 21134805
PDF is available here.
PDF is available here.
Abstract
We explore the addition of a laser sensor and associated algorithms in order to provide a rapid and accurate estimate of the breast surface location. We demonstrate that the laser is capable of estimating surfaces with improved accuracy compared to microwave measurements. The impact of accurate surf...
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PMID: 21147590
PDF is available here.
PDF is available here.
Abstract
The ultimate goal of quantitative ultrasound (QUS) imaging methods based on backscatter coefficient (BSC) estimates is to obtain system-independent structural information about samples. In the current study, three BSC estimation methods were compared and evaluated using the same backscattered pressur...
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PMID: 21568393
PDF is available here.
PDF is available here.
Abstract
The problem of high-resolution image volume reconstruction from reduced frequency acquisition sequences has drawn significant attention from the scientific community because of its practical importance in medical diagnosis. To address this issue, several reconstruction strategies have been recently p...
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PMID: 20729163
PDF is available here.
PDF is available here.
Medical Physics (38)5 2011
Abstract
The use of magnetic resonance (MR) radiofrequency (RF) surface coils is a prerequisite for high-quality positron emission tomography (PET)/MR imaging. In lack of in-gantry transmission (TX) sources, the exact position of the RF coils is unknown in PET/MR, and may, therefore, lead to...
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PMID: 21776816
PDF is available here.
PDF is available here.
Medical Physics (38)5 2011
Abstract
To propose a method to calculate the tissue phantom ratio (TPR) using the depth dose and to compare the proposed method with two other methods.
An analytical dose model from Bjärngard was used to describe the depth dose and the TPR. The parameters of the model were d...
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PMID: 21776770
PDF is available here.
PDF is available here.
Medical Physics (38)5 2011
Abstract
The standardized uptake value (SUV) is a quantitative measure of FDG tumor uptake frequently used as a tool to monitor therapeutic response. This study aims to (i) assess the reproducibility and uncertainty of SUV max and SUV mean, due to purely statistical, i.e., nonbiological, effe...
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PMID: 21776800
PDF is available here.
PDF is available here.
Medical Physics (38)5 2011
Abstract
We have to overcome the difficulty of unmatched protocols between FKS and routine CT exams. In this paper, we propose to match the low contrast detectability (LCD), a critical image quality metric impacting diagnostic quality, before measuring CTDI(VOL). The kVp pair, flux ratio, and optimal monochr...
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PMID: 21776796
PDF is available here.
PDF is available here.
Medical Physics (38)5 2011
Abstract
We have developed an algorithm for reconstructing volumetric images and extracting 3D tumor motion information from a single x-ray projection [Li et al., Med. Phys. 37, 2822-2826 (2010)]. We have demonstrated its feasibility using a digital respiratory phantom with regular breathing patterns. In thi...
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PMID: 21776815
PDF is available here.
PDF is available here.
Medical Physics (38)5 2011
Abstract
We showed that the PSD system used in this study, which was capable of stem effect removal, can perform accurate dosimetry during 192Ir HDR brachytherapy treatment in a water phantom. The system presented here shows some clear advantages over previously proposed dosimetry systems for HDR brachythera...
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PMID: 21776789
PDF is available here.
PDF is available here.
Medical Physics (38)5 2011
Abstract
The focus of this article is to develop signal and imaging processing methods to derive an accurate estimation of local tissue elasticity using the crawling wave (CrW) sonoelastography method. The task is to reduce noise and to improve the contrast of the elasticity map....
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PMID: 21776792
PDF is available here.
PDF is available here.
Medical Physics (38)5 2011
Abstract
To introduce a correction for speed of sound (SOS) aberrations in three dimensional (3D) ultrasound (US) imaging systems for small but systematic positioning errors in image guided radiotherapy (IGRT) applications. US waves travel at different speeds in different human tissues. Conve...
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PMID: 21776803
PDF is available here.
PDF is available here.
Abstract
Though appropriate image acquisition parameters allow an effective dose below 1 mSv for CT coronary angiography (CTCA) performed with the latest dual-source CT scanners, a single-source 64-detector CT procedure results in a significant radiation dose due to its technical limitations. Therefore, estim...
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PMID: 21525109
PDF is available here.
PDF is available here.
Abstract
In a large radiological center, the ultrasound (US) quality assurance (QA) program involves several professionals. Although the operator and the parameters utilized can contribute to the results, the selected QA parameters should still reflect the quality of the US scanner, not the measuring process....
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PMID: 21508202
PDF is available here.
PDF is available here.
Abstract
Although CT urography (CTU) is widely used for the evaluation of the entire urinary tract, the most important drawback is the radiation exposure.
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PMID: 21508198
PDF is available here.
PDF is available here.
Abstract
The results show that the proposed method allows measurement and correction of the geometric distortions in EPI with high accuracy, and reduction of residual blurring. In addition, this method prevents errors in the shift map induced by PSF-ghost artifacts. CONCLUSION: More precise mapping and corre...
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PMID: 21509590
PDF is available here.
PDF is available here.
Abstract
The aim of this study was to illustrate the influence of digital filters on the signal-to-noise ratio (SNR) and modulation transfer function (MTF) of digital images. The article will address image pre-processing that may be beneficial for the production of clinically useful digital radiographs with l...
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PMID: 21493878
PDF is available here.
PDF is available here.
Abstract
The aim of this study was to assess the influence of inclination of the object on the reliability and reproducibility of linear measurements of anatomic structures of the mandible on images obtained using cone-beam CT (CBCT).
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PMID: 21493881
PDF is available here.
PDF is available here.
Abstract
These results suggested that this may provide an effective way to minimize thermal losses from perfusion during focused ultrasound exposures....
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PMID: 21476689
PDF is available here.
PDF is available here.
Abstract
The mean accuracy on the phantom was 1.28±0.53 mm, and 90% of the measured distances were ≤1.90 mm. The mean accuracy in swine was 4.18±1.76 mm, and 90% of the measured distances were ≤5.73 mm. Conclusion: This 3D navigation system demonstrates good ex vivo accuracy and is sufficiently acc...
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PMID: 21521064
PDF is available here.
PDF is available here.
Abstract
Abstract
Compressed sensing (CS) has the potential to reduce magnetic resonance (MR) data acquisition time. In order for CS-based imaging schemes to be effective, the signal of interest should be sparse or compressible in a known representation, and the measurement scheme should have good mathematical propert...
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PMID: 20937579
PDF is available here.
PDF is available here.
Abstract
We also exploit techniques from robust statistics to make the methods resistant to large local decorrelations. We further introduce Kalman filtering for calculating the strain field from the displacement field given by the AM methods. Simulation and phantom experiments show that both methods generat...
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PMID: 21075717
PDF is available here.
PDF is available here.
Abstract
We examined the application of an iterative penalized maximum likelihood (PML) reconstruction method for improved detectability of microcalcifications (MCs) in digital breast tomosynthesis (DBT). Localized receiver operating characteristic (LROC) psychophysical studies with human observers and 2-D im...
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PMID: 21041158
PDF is available here.
PDF is available here.
Abstract
We evaluated if cementation influenced the measured BMD (g/cm(2)), the scan reproducibility with the new knee-specific software, and the consequences of leg rotation around a vertical axis. Secondly, in a clinical study, we assessed the clinical reproducibility in repetitive scans performed with the...
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PMID: 21474349
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
In this study, newly formulated XR-RV3 GafChromic film was calibrated with National Institute of Standards and Technology (NIST) traceability for measurement of patient skin dose during fluoroscopically guided interventional procedures.
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PMID: 21626925
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
Pressure ulcers are areas of soft tissue breakdown induced by a sustained mechanical stress that damages the skin and underlying tissues. They represent a considerable burden to the society in terms of health care and cost. Yet, techniques for prevention and detection of pressure ulcers still remain...
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PMID: 21626927
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
The authors examine the nonstationary noise behavior of a cone-beam CT system with FDK reconstruction.
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PMID: 21626945
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
To develop an alternating focused ultrasound system (AFUS) for preclinical studies of thermal and acoustic responses of tumors in small animal models. This work was motivated by the need of noninvasively creating relatively small spheroidal thermal lesions in small targets (e.g., a murine tumor) with...
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PMID: 21626921
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
Recently, the attenuating behavior of soft tissue has been addressed in magnetic resonance elastography by the inclusion of a damping mechanism in the methods used to reconstruct the resulting mechanical property image. To date, this mechanism has been based on a viscoelastic model for material behav...
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PMID: 21626932
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
In image-guided radiotherapy, an artifact typically seen in axial slices of x-ray cone-beam computed tomography (CBCT) reconstructions is a dark region or "black hole" situated below the scan isocenter. The authors trace the cause of the artifact to scattered radiation produced by radiotherapy patien...
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PMID: 21626939
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
To present and evaluate a new image reconstruction method for dynamic CT based on a nonconvex prior image constrained compressed sensing (NCPICCS) algorithm. The authors systematically compared the undersampling potential, functional information recovery, and solution convergence speed of four compre...
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PMID: 21626949
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
This study was performed to investigate the accuracies of the synthesized monochromatic images and effective atomic number maps obtained with the new GE Discovery CT750 HD CT scanner.
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PMID: 21626956
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
Current commercial treatment planning systems are not able to accurately predict output factors and calculate monitor units for proton fields. Patient-specific field output factors are thus determined by either measurements or empirical modeling based on commissioning data. The objective of this stud...
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PMID: 21626965
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
The PEM Flex Solo II (Naviscan, Inc., San Diego, CA) is currently the only commercially available positron emission mammography (PEM) scanner. This scanner does not apply corrections for count rate effects, attenuation, or scatter during image reconstruction, potentially affecting the quantitative ac...
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PMID: 21626946
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
The dosimetric accuracy of the recently released Acuros XB advanced dose calculation algorithm (Varian Medical Systems, Palo Alto, CA) is investigated for single radiation fields incident on homogeneous and heterogeneous geometries, and a comparison is made to the analytical anisotropic algorithm (AA...
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PMID: 21626955
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
Scatter and beam hardening are prominent artifacts in x-ray CT. Currently, there is no precorrection method that inherently accounts for tube voltage modulation and shaped prefiltration.
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PMID: 21626957
PDF is available here.
PDF is available here.
Medical Physics (38)4 2011
Abstract
To present a conceptually new method for metal artifact reduction (MAR) that can be used on patients with multiple objects within the scan plane that are also of small sized along the longitudinal (scanning) direction, such as dental fillings.
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PMID: 21626962
PDF is available here.
PDF is available here.
Ultrasonic Imaging (33)2 2011
Abstract
The data-transfer and computation requirements are compared between software-based beamforming using a phased array (PA) and a synthetic transmit aperture (STA). The advantages of a software-based architecture are reduced system complexity and lower hardware cost. Although this architecture can be im...
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PMID: 21710826
PDF is available here.
PDF is available here.
Ultrasonic Imaging (33)2 2011
Abstract
We demonstrate a novel imaging technique, named short-lag spatial coherence (SLSC) imaging, which uses short distance (or lag) values of the coherence function of backscattered ultrasound to create images. Simulations using Field II are used to demonstrate the detection of lesions of varying sizes an...
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PMID: 21710827
PDF is available here.
PDF is available here.
Ultrasonic Imaging (33)2 2011
Abstract
A new GPU-based scan-conversion algorithm implemented using OpenGL is described. The compute performance of this new algorithm running on a modem GPU is compared to the performance of three common scan-conversion algorithms (nearest-neighbor, linear interpolation and bilinear interpolation) implement...
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PMID: 21710829
PDF is available here.
PDF is available here.
Abstract
A methodology has been developed for a dosimetry inter-comparison of intensity modulated radiation therapy (IMRT) delivery in Australasia. The inter-comparison is part of site credentialing for those sites participating in the prostate fractionated irradiation trial (PROFIT) for intermediate-risk pro...
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PMID: 21424814
PDF is available here.
PDF is available here.