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Proceedings Paper

Coherent scatter x-ray imaging of plastic/water phantoms
Author(s): Mohammad Nisar; Paul C. Johns
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Paper Abstract

Conventional medical x-ray imaging, based on the transmission of primary photons, works well to distinguish between hard and soft tissues. Up to 90% of the photons that reach the image receptor, however, are coherently or incoherently scattered, and so there is growing interest in utilizing scattered x rays for diagnosis. The semi-analytical model developed by our group predicts better contrast and signal-to-noise ratio for scatter imaging than for primary for some diagnostic examinations such as distinguishing white versus gray brain matter, and for mammography. Low-angle scattered photons can only be distinguished from primary on the basis of direction and consequently a well-collimated x-ray system is required. A hexagonal array of seven 1.5 mm diameter pinholes is designed and tested to record the diffraction pattern of plastic and water phantoms. These materials are amorphous solids and result in rotationally-symmetric diffraction patterns which are characteristic of the materials. The intensities of the diffraction patterns are numerically integrated over concentric rings and the scatter images are made by assigning the ring sums as the pixel values. For these measurements the tube is operated with technique factors ranging from 70 kV 2500 mAs to 120 kV 500 mAs. The scatter patterns are recorded on a storage phosphor image plate. Test images are made of 1 cm thick targets in air and in a water tank. The ultimate goal is to make scatter images of different kinds of tissues for better diagnostic information.

Paper Details

Date Published: 9 December 2004
PDF: 9 pages
Proc. SPIE 5578, Photonics North 2004: Photonic Applications in Astronomy, Biomedicine, Imaging, Materials Processing, and Education, (9 December 2004); doi: 10.1117/12.567128
Show Author Affiliations
Mohammad Nisar, Carleton Univ. (Canada)
Paul C. Johns, Carleton Univ. (Canada)
Univ. of Ottawa (Canada)


Published in SPIE Proceedings Vol. 5578:
Photonics North 2004: Photonic Applications in Astronomy, Biomedicine, Imaging, Materials Processing, and Education
Marc Nantel; Glen Herriot; Graham H. McKinnon; Leonard MacEachern; Robert A. Weersink; Rejean Munger; Andrew Ridsdale, Editor(s)

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