Biomedical subjects

Esam M A Hussein

Publications and source records attributed to Esam M A Hussein.

3 recordsLinked to original sources

PubMed2006

Flaw detection by spatially coded backscatter radiography.

Backscatter imaging is useful for inspecting structures that are accessible only from one side. However, indications provided by scattered radiation are typically weak, convoluted and difficult to interpret. This paper explores the use of the coded aperture technique to detect flaws using gamma-ray backscatter imaging. The viability of this approach is demonstrated with indications obtained from Monte Carlo simulations of radiation scattering measurements. The results show that, with a 2 mm wide beam of 137Cs photons, flaws as small as 1.5 mm in width can be detected using this technique. Indications of changes in flaw size, location, multiplicity and density were also observable. In addition, it is possible to quantify, from the decoded indications, the flaw location and its size.

Journal Article↗

PubMed2004

Use of isotopic gamma sources for identifying anti-personnel landmines.

Density is one of the indicators that can be utilized to distinguish an explosive material from an innocuous anomaly. Compton scattering of photons can be used to provide such density indication. Although X-rays have been employed for this purpose, isotopic gamma-rays offer some advantage for use in a portable device, because of their small size and self-powered nature. Radioisotopes were considered in the 1970's by the US Army. This work re-examines the utility of these sources for the detection of shallowly buried anti-personnel landmines. Monte Carlo studies indicated that the most effective configuration for identifying and locating a buried landmine should employ a collimated (241)Am source, along with a set of well-collimated detectors. Experimental measurements verified the feasibility of the proposed method and demonstrated the detectablility of mockups of landmines as small as 45 mm in diameter buried near the soil surface, or mockups larger than 80 mm in diameter buried at a depth of 80 mm, in light soil. In heavy soil, targets 80 mm in diameter were detectable at a depth of 30 mm. The use of the low-energy (60 keV) (241)Am source makes it possible to design a light-weight hand-held device that can augment other methods of detecting plastic landmines.

Americium↗

PubMed2003

A three-dimensional x-ray scattering system for multi-parameter imaging of the human head.

This work examines the suitability of a non-rotating one-side 3D x-ray scatter system for imaging the human head. The system simultaneously produces images of the x-ray attenuation coefficients at two photon energies, as well as an image of the electron density. The system relies on measuring the scattered radiation at two directions orthogonal to an incident beam that scans the object from one side, in addition to the traditionally recorded transmitted radiation. Algorithms for this multi-parameter imaging process are presented, and their numerical viability is demonstrated, using both idealized detector responses and those independently estimated from Monte Carlo simulations. The absorbed radiation dose is also calculated, and was shown to be about one quarter of that of conventional CT systems, for 5 mm spatial-resolution images. The introduced system can therefore be useful in radiotherapy planning, and in post-treatment imaging.

Algorithms↗