Results 211 to 220 of about 369,043 (263)

Compensators for intensity-modulated beams

Medical Dosimetry, 2002
This study describes the importance of attenuator scatter in the construction of compensators. The attenuator used in this study was Lipowitz metal, commonly referred to as cerrobend. Linear attenuation coefficients of cerrobend were measured in air for different thickness of cerrobend sheets and different field sizes for a 6-MV photon beam.
D M, Dimitriadis, B G, Fallone
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Intensity-modulated moiré topography

Applied Optics, 1999
Moiré topography has the advantage of requiring only a single image to obtain a three-dimensional measurement, but it cannot discern the fringe order. Because there is an ambiguity problem when calculating the depth range by use of fringe intensity or phase unwrapping, it is impossible to obtain an absolute phase and an absolute depth range.
C, Lu, S, Inokuchi
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Intensity‐modulated radiation therapy

Journal of Surgical Oncology, 2008
AbstractIntensity‐modulated radiation therapy (IMRT) has found widespread use in the treatment of head and neck cancers. This technology allows for conformal dose distributions around a tumor target while a rapid dose fall‐off spares surrounding critical structures.
N Y, Lee, S A, Terezakis
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Intensity modulated moire and its intensity-phase analysis

Proceedings. Fourteenth International Conference on Pattern Recognition (Cat. No.98EX170), 2002
Moire topography has the advantage that it just requires a single image, but it cannot discern the fringe order. So, it is difficult to discern the connection among fringes in the case where the fringe orders are not continuous. In our work, an intensity modulated moire is presented. By modulating the transmission of projection and observation grating,
Cunwei Lu, Akashi Yamaguchi, Seiji Inokuchi   +2 more
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Acoustooptic modulator intensity servo

Applied Optics, 1979
A device has been constructed that combines optical isolation and amplitude noise reduction by the use of a servo controlled acoustooptic intensity modulator. The isolation can, in principle, be perfect while the noise reduction can be significant up to about 100 kHz and as large as 80 dB at low frequency.
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Achromatic Intensity Modulator

Spatial Light Modulators and Applications, 1993
The limits of polarization rotation as a means of intensity modulation can be significantly improved using a system employing chiral smectic liquid crystals.
J. E. Stockley, G. D. Sharp, D. Doroski, K. M. Johnson   +3 more
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Modulation of the intensity of formalized attributes

1988
A ‘mechanism’ to commit modifiers for the specification of at tributes is presented in this paper. Such a mechanism consists in a proce dure of Approximate Reasoning.
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Intensity-Modulated Radiotherapy

2012
Intensity-modulated radiotherapy (IMRT) is a radiation delivery technique that allows “dose sculpting” to improve target coverage while sparing normal tissues. In an IMRT plan, the number of photons delivered (or “fluence”) varies within a field. Such variability can be used to avoid normal structures with lower radiation tolerance than the cancer and ...
Bridget F. Koontz, Devon Godfrey, W. Robert Lee   +2 more
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Reshapable physical modulator for intensity modulated radiation therapy

Medical Physics, 2002
A new method of generating beam intensity modulation filters for intensity modulated radiation therapy (IMRT) is presented. The modulator was based on a reshapable material, which is not compressible but can be deformed under pressure. A two‐dimensional (2D) piston array was used to repeatedly shape the attenuating material.
Tong, Xu, Polad M, Shikhaliev, Muthana, Al-Ghazi, Sabee, Molloi   +3 more
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Treatment planning considerations of reshapeable automatic intensity modulator for intensity modulated radiation therapy

Medical Physics, 2004
As compared with multi-leaf collimator based intensity modulated radiation therapy (IMRT) techniques, physical modulators have the major advantage of temporally invariant intensity map delivery which makes it more flexible with monitor unit rate, simpler resolution of interrupted treatment and easier implementation and use with respiratory gating ...
Tong, Xu, Muthana S, Al-Ghazi, Sabee, Molloi   +2 more
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