EP0114968A1
Expired / Lapsed
EP
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Method of measuring radioactivity
Assignee: Hitachi Ltd
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Filing: 1983-11-24
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Granted: —
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Expires: 2003-11-24
Abstract
Abstract The present invention relates to a method of measuring radioactivity which is suitable for discriminating between surface and internal contaminations of a body. The radioactivity of a subject is measured to obtain a y-ray energy spectrum of radioactivity signals obtained thereby, and a discrimination between surface and internal contamination of the subject is performed on the basis of the ratio between a photoelectric effect component and a Compton-scattered component of the y-ray energy spectrum. According to the present invention, surface and internal contaminations can be clearly identified.
Inventors
- 👤 Masaaki Fuji
- 👤 Yuichi Izumi
- 👤 Hiroshi Kitaguchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 19:13
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/161; G01T1/163; G01T1/167
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
58 words
A method of measuring the radioactivity wherein the radioactivity of a subject is measured to obtain a y-ray energy spectrum of radioactivity signals obtained thereby, and a discrimination between surface and internal contamination of said subject is performed on the basis of the ratio between a photoelectric effect component and a Compton-scattered component of said y-ray energy spectrum.
Claim 2
Independent Claim
58 words
A method of measuring the radioactivity wherein the radioactivity of a subject is measured to obtain a y-ray energy spectrum of radioactivity signals obtained thereby, and a discrimination between surface and internal contamination of said subject is performed on the basis of the ratio between a photoelectric effect component and a Compton-scattered component of said y-ray energy spectrum.
Claim 3
Dependent Claim
34 words
A method of measuring the radioactivity according to Claim 1, wherein the radioactive nuclides of a source of contamination are identified on the basis of the photoelectric peak energy of said y-ray energy spectrum.
Claim 4
Dependent Claim
30 words
A method of measuring the radioactivity according to in Claim 1, wherein said Compton-scattered component is determined on the higher-energy side of the Compton edge of said y-ray energy spectrum.
Claim 5
Dependent Claim
30 words
A method of measuring the radioactivity according to in Claim 2, wherein said Compton-scattered component is determined on the higher-energy side of the Compton edge of said y-ray energy spectrum.
Claim 6
Independent Claim
76 words
A method of measuring the radioactivity wherein the radioactivity of a subject is measured to obtain a y-ray energy spectrum of radioactivity signals obtained thereby, and a discrimination between surface and internal contamination of said subject is performed on the basis of the ratio between a photoelectric effect component and a Compton-scattered component of said y-ray energy spectrum so that the internal exposure dose of said subject can be determined in the case of internal contamination.
Claim 7
Independent Claim
76 words
A method of measuring the radioactivity wherein the radioactivity of a subject is measured to obtain a y-ray energy spectrum of radioactivity signals obtained thereby, and a discrimination between surface and internal contamination of said subject is performed on the basis of the ratio between a photoelectric effect component and a Compton-scattered component of said y-ray energy spectrum so that the internal exposure dose of said subject can be determined in the case of internal contamination.
Claim 8
Dependent Claim
34 words
A method of measuring the radioactivity according to Claim 5, wherein the radioactive nuclides of a source of contamination are identified on the basis of the photoelectric peak energy of said y-ray energy spectrum.
Claim 9
Dependent Claim
29 words
A method of measuring the radioactivity according to Claim 5, wherein said Compton-scattered component is determined on the higher-energy side of the Compton edge of said y-ray energy spectrum.
Claim 10
Dependent Claim
29 words
A method of measuring the radioactivity according to Claim 6, wherein said Compton-scattered component is determined on the higher-energy side of the Compton edge of said y-ray energy spectrum.
Claim 11
Dependent Claim
43 words
A method of measuring the radioactivity according to Claim 5, wherein the radioactivity is again measured in the longitudinal direction of said subject when internal contamination has been identified to determine said internal exposure dose on the basis of the radioactivity signals measured.
Claim 12
Dependent Claim
62 words
A method of measuring the radioactivity according to Claim 9, wherein said internal exposure dose is determined on the basis of both the radioactive nuclides, determined in a manner which corresponds to the photoelectric peak energies of the y-ray energy spectrum of said re-measured radioactivity signals, and the intake of said radioactive nuclides by said subject, obtained from said re-measured radioactivity signals.
Claim 13
Dependent Claim
82 words
A method of measuring the radioactivity according to Claim 10, wherein the elapsed time since said radioactive nuclides were taken in is determined from the distribution of said radioactive nuclides in said subject, obtained on the basis of the position of the measurements and said radioactive nuclides both detected simultaneously with said radioactivity measurement, so that the intake of said radioactive nuclides is determined from both the retained radioactivity in said subject, obtained from said re-measured radioactivity signals, and said elapsed time.
References Cited (Backward Citations)
US3876882A
Cited
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