Results 171 to 180 of about 50,958 (240)
Some of the next articles are maybe not open access.
Uranium pinhole collimators for I-131 SPECT imaging
IEEE Transactions on Nuclear Science, 1999Pinhole apertures made of depleted uranium were evaluated for high-resolution SPECT brain tumor imaging of therapeutic doses (30-100 mCi) of intratumorally administered I-131 radiolabeled monoclonal antibodies. High resolution is required for imaging residual tumor tissue, although for therapeutic doses, high collimator sensitivity is less important ...
C.R. Tenney +3 more
openaire +1 more source
CZT gamma camera with pinhole collimator: Spectral measurements
2008 IEEE Nuclear Science Symposium Conference Record, 2008To date, CZT has been investigated for a variety of nuclear imaging applications using mostly parallel hole collimators. The image quality realized has evolved to make these configurations competitive with the mature conventional configurations using scintillators such as NaI. However the full potential of CZT detectors is still evolving.
Ira Blevis +5 more
openaire +1 more source
Resolution- versus sensitivity-effective diameter in pinhole collimation: experimental verification
Physics in Medicine and Biology, 2005To account for photon penetration, the formulae used to calculate the geometric resolution of a pinhole collimator use an effective diameter d(e) rather than the physical diameter of the aperture. The expressions commonly used for d(e), however, were originally derived to include penetration in sensitivity calculations.
S D, Metzler, R, Accorsi
openaire +2 more sources
Analytical derivation of the point spread function for pinhole collimators
Physics in Medicine and Biology, 2006The point spread function (PSF) of a pinhole collimator plays an important role in determining the resolution and characterizing the sensitivity of the accepted photons from a given point in the image space. The focus of this paper is to derive an analytical expression for the PSF of two different types of focusing pinhole collimators that are based on
Girish, Bal, Paul D, Acton
openaire +2 more sources
Thyroid Tomography Using a Seven Pinhole Collimator
1986In this paper we discuss a new application of the seven pinhole (7-P) collimator: tomographic imaging of the thyroid. The collimator has been re-optimized for this purpose by diminishing the distance from the aperture plate to the crystal and by choosing a smaller diameter for the pinholes.
John W. van Giessen +4 more
openaire +1 more source
High-resolution SPECT using multipinhole collimation
IEEE Transactions on Nuclear Science, 2003The authors present a novel SPECT imaging technique for small animal research based on multipinhole collimation. This new method is an extension of single-pinhole tomography and combines high resolution with increased system sensitivity. This paper describes the multipinhole imaging system and its preliminary characterization on simulated and measured ...
N.U. Schramm +5 more
openaire +1 more source
Smearing effects in `pinhole' collimation with one-dimensional detection
Journal of Applied Crystallography, 1988Owing to the recent availability of intense X-ray sources, small-angle X-ray scattering experiments can now be performed with pseudo-pinhole collimation. However, smearing effects are still present in 'pinhole' data collected with one-dimensional detectors, owing to both the finite size of the beam and particularly the finite width of the detector ...
R. A. Register, S. L. Cooper
openaire +1 more source
XFCT imaging system with pinhole collimation and attenuation correction
2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop (NSS/MIC/RTSD), 2016The study of gold nanoparticles (GNPs) has been more attractive because of its application for cancer detection and therapy. X-ray fluorescence computed tomography (XFCT), which is sensitive to high Z elements such as gold, is a promising approach to determine the distribution of GNPs in vivo.
Siyuan Zhang, Liang Li, Zhiqiang Chen
openaire +1 more source
IEEE Nuclear Science Symposium Conference Record, 2005, 2006
A rotating-slit system is proposed for small animal imaging. The spatial resolution and noise propagation properties of the rotating-slit system are evaluated and compared with a pinhole system using iterative methods. Our results show that the two systems achieve comparable resolutions, and the rotating-slit system has better noise performance than ...
B. Zhang, L. Zeng
openaire +1 more source
A rotating-slit system is proposed for small animal imaging. The spatial resolution and noise propagation properties of the rotating-slit system are evaluated and compared with a pinhole system using iterative methods. Our results show that the two systems achieve comparable resolutions, and the rotating-slit system has better noise performance than ...
B. Zhang, L. Zeng
openaire +1 more source
An Investigation to Design High Performance Multi-Pinhole Collimator
2006 IEEE Nuclear Science Symposium Conference Record, 2006The aim of this study is to design a detector module employing multi-pinhole collimator which could be utilized in various SPECT systems. Monte Carlo simulations using Geant4 application for tomographic emission (GATE) were performed to estimate the performance of various multi-pinhole collimators and compared to that of low energy high resolution ...
Byung Jun Min +7 more
openaire +1 more source