US 6,563,906 B2 · X-ray compton scattering density measurement at a point within an object

Abstract

The present invention pertains to a non-rotating method for non-intrusively determining the density of a point embedded within an object, without necessarily obtaining a full image for the entire object. The method consists of passing a X-ray beam through a point within an object and measuring Compton scatterings from the point from a first and second energy bands within the energy spectrum of the X-ray beam, along a first and second angles from the X-ray beam. Using the kinetics of Compton scattering at a specific angle, four equations are formulated with four measurements and four unknowns; the radiation attenuation factor along the object between the X-ray source and the point, the radiation attenuation factor between the point and each of the detectors and the density of the object at the point. The four equations are solved simultaneously to determined the four unknowns. There is also provided a matrix inversion process to facilitate the solution of the equations.

Claims21

Dependent claims

A method for determining the density at a point within a body, comprising the steps of:

providing a X-ray source;
providing a first and second radiation detectors;
using said X-ray source, passing a X-ray beam through a point within a body;
said X-ray beam having an energy spectrum;
selecting a first and second source energy bands within said energy spectrum;
using said first and second radiation detectors, obtaining measurements of Compton scattering from said point within said body from said first and second source energy bands, along a first and second angles from said X-ray beam;
using said measurements of Compton scattering from said point within said body from said first and second source energy bands, along said first and second angles from said X-ray beam, mathematically determining a density of said point within said body.

4 more elements

A method for determining the density at a point within a body, comprising the steps of:

providing a X-ray source;
providing a first and second radiation detectors;
using said X-ray source, passing a X-ray beam through a point within a body;
said X-ray beam having a first source energy spectrum;
selecting a first and second source energy bands within said source energy spectrum of said X-ray beam;
using said first radiation detector, obtaining measurement of Compton scattering from said point within said body along a first angle and within a first detected energy spectrum related to said source energy spectrum and said first angle;
selecting a first and second detected energy bands within said first detected energy spectrum;
said first and second detected energy bands being related to said first and second source energy bands respectively and said first angle;
using said second radiation detector, obtaining measurement of Compton scattering from said point within said body along a second angle and within a second detected energy spectrum related to said source energy spectrum and said second angle;
selecting a third and fourth detected energy bands within said second detected energy spectrum;
said third and fourth energy bands being related to said first and second source energy bands respectively and said second angle;
extracting, from said measurement of Compton scattering from said point within said body along a first angle and within a first detected energy spectrum, measurements of Compton scattering from said point within said body along said first angle and within said first and second detected energy bands;
extracting, from said measurement of Compton scattering from said point within said body along a second angle and within a second detected energy spectrum, measurements of Compton scattering from said point within said body along said second angle and within said third and fourth detected energy bands;
and
using said measurements of Compton scattering from said point within said body along said first angle, within said first and second detected energy bands;
said measurements of Compton scattering from said point within said body along said second angle, within said third and fourth detected energy bands;
mathematically determining an attenuation factor of said X-ray beam between said X-ray source and said point;
an attenuation factor of Compton scattering between said point and said first detector;
an attenuation factor of Compton scattering between said point and said second detector, and a density of said point within said body;
such that a density of said point within said body is determinable by exposing said body to a single X-ray beam.

17 more elements

Dependencies are inferred from the claim text.

X-ray compton scattering density measurement at a point within an object

Life of this patent

X-ray compton scattering density measurement at a point within an object

Life of this patent

Abstract

Claims21