Magnetic lensing for beta emission imaging

Patent metadata

Field	Value
Publication number	US-10162029-B2
Application number	US-201815980777-A
Country	US
Kind code	B2
Filing date	May 16, 2018
Priority date	Jul 11, 2016
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

In beta emission imaging, magnetic lensing allows a lower resolution detector to detect the spatial distribution of emissions at a higher resolution. The sample is placed in a magnetic field with field lines at a given density, and the detector is placed away from the sample where the magnet field lines diverge, resulting in a lesser density. Since the beta emissions travel along the field lines, the divergence of the field lines from the sample to the detector result in lensing or magnification. Using positron attenuation tomography to detect annihilation in the detector allows for correction due to self-absorption by the sample. The correction and lensing are used together or may be used independently.

First claim

I claim:

1. A method for magnetic lensing in beta emission imaging, the method comprising:
generating beta emissions from a sample positioned in magnetic field lines having a first density;
detecting the beta emissions at a location spaced from the sample where the magnetic field lines have a second density, less than the first density; and
forming an image of the detected beta emissions of the sample,
wherein the beta emissions comprise positrons, and wherein detecting comprises detecting annihilation events of the positrons interacting with a stopper at the location with a detector ring for positron emission tomography, the stopper being within the detector ring.

2. The method of claim 1 wherein generating comprises generating the beta emissions with the sample positioned in a bore of a cylindrical magnet.

3. The method of claim 1 wherein detecting comprises detecting with a beta detector positioned where the magnetic field lines have diverged from the first density to the second density, the beta detector intercepting the magnetic field lines at the second density.

4. The method of claim 1 wherein detecting comprises detecting a spatial distribution of counts of the positrons.

5. The method of claim 1 further comprising:
estimating positron attenuations of the positrons in the spatial distribution; and
correcting the counts as a function of the positron attenuations.

6. The method of claim 1 wherein detecting where the magnetic field lines have the second density comprises detecting a magnified version of the beta emissions at the first density due to divergence of the magnetic field lines from the first density to the second density.

7. A method for magnetic lensing in beta emission imaging, the method comprising:
generating beta emissions from a sample positioned in magnetic field lines having a first density;
detecting the beta emissions at a location spaced from the sample where the magnetic field lines have a second density, less than the first density; and
forming an image of the detected beta emissions of the sample,
wherein detecting where the magnetic field lines have the second density comprises detecting a magnified version of the beta emissions at the first density due to divergence of the magnetic field lines from the first density to the second density.

Assignees

• Siemens Medical Solutions Usa Inc

Inventors

• Watson Charles C

Classifications

• G01T1/2985

  In depth localisation, e.g. using positron emitters; Tomographic imaging (longitudinal and transverse section imaging; apparatus for radiation diagnosis sequentially in different planes, steroscopic radiation diagnosis); (using external radiation sources A61B6/02) · CPC title

• A61B6/037

  Emission tomography · CPC title

• G01R33/481 Primary

  MR combined with positron emission tomography [PET] or single photon emission computed tomography [SPECT] · CPC title

• G01N33/4833

  of solid biological material, e.g. tissue samples, cell cultures (tissue in vivo A61B5/00; cell suspensions G01N33/48735) · CPC title