Results 181 to 190 of about 50,958 (240)
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Tomographic Scintigraphy Using a Pinhole Collimator and a Rotating Gamma Camera
Nuklearmedizin, 1990When a pinhole collimator is to be used for tomographic studies the standard SPECT software has to be modified so as to avoid serious image distortion outside the axis of rotation. The MTF measured at the axis of rotation shows that the better resolution of the pinhole collimator as compared with that of a parallel-hole collimator improves the ...
L E, Olsson, L, Ahlgren
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Design and evaluation of two multi-pinhole collimators for brain SPECT
Annals of Nuclear Medicine, 2017SPECT is a powerful tool for diagnosing or staging brain diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD) but is limited by its inferior resolution and sensitivity. At the same time, pinhole SPECT provides superior resolution and detection efficiency trade-off as compared to the conventional parallel-hole collimator for imaging ...
Ling, Chen +2 more
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Efficient Model of the Collimator Blurring in Pinhole SPECT
2006 IEEE Nuclear Science Symposium Conference Record, 2006We propose a new method for collimator blurring correction in pinhole SPECT, that uses the spherical symmetry of the blob basis functions. We study its performance and compare with the other correction methods, namely multi-ray methods. We also investigate some limitations of the multi-ray methods.
Andriy Andreyev +2 more
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Multi-pinhole collimator optimization for high resolution SPECT imaging
1997 IEEE Nuclear Science Symposium Conference Record, 2002Recent studies show Tl-201 and Tc-99m MIBI to have high sensitivity for detecting and differentiating tumor from benign lesions in the breast. A study was conducted to optimize the design of a multi-pinhole collimator for high spatial resolution SPECT imaging of the breast to detect small tumors (0.5/spl times/0.5 cm).
M. Ivanovic, D.A. Weber, S. Loncaric
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Is Field Size Enlargement with Divergent and Pinhole Collimators Acceptable?
Radiology, 1970Abstract In all but a few of 100 patients, the divergent collimator has allowed both lungs to be encompassed in one view. Phantom studies demonstrate mild-to-moderate image distortion. There is a 50% loss of sensitivity but no loss in resolution when the divergent collimator is compared with its “1000” parallel-hole counterpart designed for the same ...
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Enhanced PET resolution by combining pinhole collimation and coincidence detection
Physics in Medicine and Biology, 2015Spatial resolution of clinical PET scanners is limited by detector design and photon non-colinearity. Although dedicated small animal PET scanners using specialized high-resolution detectors have been developed, enhancing the spatial resolution of clinical PET scanners is of interest as a more available alternative.
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Pitfalls in the Lateral Imaging of the Thyroid with Pinhole Collimators
Nuklearmedizin, 1981Imaging of the thyroid gland with pinhole collimators in the lateral projection is associated with the problem of count rate contribution from the contralateral lobe. In a series of experiments conducted using a thyroid-simulating phantom, the contribution of this nature was calculated.
A N, Jain, P, Ramanathan, R D, Ganatra
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Two-level multi-pinhole collimator for SPECT imaging using a small-field-of-view gamma camera
Journal of the Korean Physical Society, 2017J. Bae +7 more
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