Ionizing Radiation Imaging System and Method With Decreased Radiation Dose

Abstract

A system and method for imaging a volume having a detector including a first atomic species with an absorption edge at a first wavelength. The system also includes a source having a second atomic species for emitting an ionizing energy. The second atomic species has a characteristic emission peak that substantially matches the absorption edge of the detector. A filter may be provided for blocking ionizing energy from the source in regions other than a region proximate the characteristic emission peak. Effective imaging with a lower radiation dose may be achieved with the system and method.

1 . A method of producing a system for imaging a volume, the method comprising: 
 identifying a first wavelength corresponding to a characteristic emission peak of a source atomic species or a second wavelength corresponding to an absorption edge of a detector atomic species;    selecting a corresponding detector atomic species or corresponding source species, respectively, based on the result of said identifying step to substantially match a characteristic emission peak of a source atomic species with an absorption edge of a detector atomic species;    including the source atomic species in a source element, the source element for delivering an ionizing radiation to the volume; and    including the detector atomic species in a detector element, the detector element configured to detect the ionizing radiation that passes through the volume.    
   
   
       2 . A method according to  claim 1 , wherein the ionizing radiation that passes through the volume includes radiation at the characteristic emission peak and the system for imaging a volume is configured to utilize the radiation at the characteristic emission peak in producing an image of at least a portion of the volume.  
   
   
       3 . A method according to  claim 1 , wherein said identifying step includes identifying an absorption wavelength corresponding to an absorption edge of the detector atomic species, and said selecting step includes, in response to said identifying of the absorption wavelength and using the absorption wavelength as a guide, selecting a source atomic species to substantially match an emission wavelength corresponding to a characteristic emission peak of a source atomic species to the absorption wavelength.  
   
   
       4 . A method according to  claim 1 , wherein said identifying step includes identifying an emission wavelength corresponding to a characteristic emission peak of the source atomic species, and said selecting step includes, in response to said identifying of the emission wavelength and using the emission wavelength as a guide, selecting a detector atomic species to substantially match an absorption wavelength corresponding to an absorption edge of the detector atomic species to the emission wavelength.  
   
   
       5 . A method according to  claim 1 , wherein the source atomic species and detector atomic species are substantially matched so that a wavelength corresponding to the characteristic emission peak corresponds to a relative absorption of the detector atomic species that is not less than about fifty percent below the relative absorption at the peak of the absorption edge.  
   
   
       6 . A method according to  claim 1 , wherein the source atomic species and detector atomic species are substantially matched so that a wavelength corresponding to the characteristic emission peak corresponds to a relative absorption of the detector atomic species that is not less than about twenty percent below the relative absorption at the peak of the absorption edge.  
   
   
       7 . A method according to  claim 1 , further comprising limiting the ionizing radiation for delivery to the volume to a narrow imaging band of wavelengths including the emission wavelength and including a wavelength at or below the absorption edge, wherein the narrow imaging band includes only wavelengths necessary to achieve a predetermined desired quality of the image.  
   
   
       8 . A method according to  claim 7 , wherein the narrow imaging band is limited to wavelengths from about 0.04 angstroms below said first wavelength to about 0.005 angstroms above said first wavelength.  
   
   
       9 . A method according to  claim 1 , wherein said detector atomic species includes a species selected from the group consisting of erbium, dysprosium, europium, samarium, neodymium, gadolinium, lanthanum, and any combinations thereof.  
   
   
       10 . A method according to  claim 1 , wherein said source atomic species includes a species selected from the group consisting of rhenium, tungsten, molybdenum, niobium, tantalum, hafnium, iridium, osmium, and any combinations thereof.  
   
   
       11 . An imaging system produced by a method according to  claim 1 .  
   
   
       12 . A method of imaging a volume, the method comprising: 
 selecting a detector atomic species or a source atomic species;    if said selecting step includes selecting a detector atomic species: 
 identifying an absorption wavelength corresponding to an absorption edge of the detector atomic species; and  
 in response to said identifying of the absorption wavelength and using the absorption wavelength as a guide, selecting a source atomic species to substantially match an emission wavelength corresponding to a characteristic emission peak of a source atomic species to the absorption wavelength;  
   if said selecting step includes selecting a source atomic species: 
 identifying an emission wavelength corresponding to a characteristic emission peak of the source atomic species; and  
 in response to said identifying of the emission wavelength and using the emission wavelength as a guide, selecting a detector atomic species to substantially match an absorption wavelength corresponding to an absorption edge of the detector atomic species to the emission wavelength;  
   including the source atomic species in a source element, the source element for delivering an ionizing radiation to the volume;    including the detector atomic species in a detector element, the detector element configured to detect the ionizing radiation that passes through the volume;    delivering an ionizing radiation from the source element to the volume;    using the detector element to detect the ionizing radiation that passes through the volume; and    producing an image based on the ionizing radiation detected by the detector element.    
   
   
       13 . A method according to  claim 12 , wherein the ionizing radiation that passes through the volume includes radiation at the characteristic emission peak and the image is based on detected ionizing radiation at a wavelength corresponding to the characteristic emission peak.  
   
   
       14 . A method according to  claim 12 , wherein the method includes: 
 selecting a detector atomic species;    identifying an absorption wavelength corresponding to an absorption edge of the detector atomic species; and    in response to said identifying of the absorption wavelength and using the absorption wavelength as a guide, selecting a source atomic species to substantially match an emission wavelength corresponding to a characteristic emission peak of a source atomic species to the absorption wavelength.    
   
   
       15 . A method according to  claim 12 , wherein the method includes: 
 selecting a source atomic species;    identifying an emission wavelength corresponding to a characteristic emission peak of the source atomic species; and    in response to said identifying of the emission wavelength and using the emission wavelength as a guide, selecting a detector atomic species to substantially match an absorption wavelength corresponding to an absorption edge of the detector atomic species to the emission wavelength;    
   
   
       16 . A method according to  claim 12 , wherein the source atomic species and detector atomic species are substantially matched so that the emission wavelength corresponds to a relative absorption of the detector atomic species that is not less than about fifty percent below the relative absorption at the peak of said absorption edge.  
   
   
       17 . A method according to  claim 12 , wherein the source atomic species and detector atomic species are substantially matched so that the emission wavelength corresponds to a relative absorption of the detector atomic species that is not less than about twenty percent below the relative absorption at the peak of said absorption edge.  
   
   
       18 . A method according to  claim 12 , further comprising limiting the ionizing radiation for delivery to the volume to a narrow imaging band of wavelengths including the emission wavelength and including a wavelength at or below the absorption edge, wherein the narrow imaging band includes only wavelengths necessary to achieve a predetermined desired quality of the image.  
   
   
       19 . A method according to  claim 18 , wherein the narrow imaging band is limited to wavelengths from about 0.04 angstroms below said first wavelength to about 0.005 angstroms above said first wavelength.  
   
   
       20 . A method of producing a system for imaging a volume, the method comprising: 
 selecting a detector atomic species or a source atomic species;    if said selecting step includes selecting a detector atomic species: 
 identifying an absorption wavelength corresponding to an absorption edge of the detector atomic species; and  
 in response to said identifying of the absorption wavelength and using the absorption wavelength as a guide, selecting a source atomic species to substantially match an emission wavelength corresponding to a characteristic emission peak of a source atomic species to the absorption wavelength;  
   if said selecting step includes selecting a source atomic species: 
 identifying an emission wavelength corresponding to a characteristic emission peak of the source atomic species; and  
 in response to said identifying of the emission wavelength and using the emission wavelength as a guide, selecting a detector atomic species to substantially match an absorption wavelength corresponding to an absorption edge of the detector atomic species to the emission wavelength;  
   including the source atomic species in a source element, the source element for delivering an ionizing radiation to the volume; and    including the detector atomic species in a detector element, the detector element configured to detect the ionizing radiation that passes through the volume.