title: Improved localization of a 'hot spot' in the lungs for an array of four HPGe detectors--the isotopic ratio effect.
abstract: Considerable errors in the determination of radioactivity in lungs are caused by the usual assumption of homogeneous distribution, while actually the radioactive contamination can be distributed, and even in the form of a 'hot spot'. Modern lung counter systems use several HPGe detectors, and the ratio of the different count rates of the detectors can be used to locate a 'hot spot' and apply correction algorithms for activity calculation. In the present work it is shown that the variability of the isotopic composition of the uranium source has a major effect on the process of localization of the 'hot spot' in the lungs. A way to eliminate this effect is proposed by separate normalization of the count rates of each energy peak.
authors.affiliation: Nuclear Research Center Negev, P.O.B. 9001, Beer-Sheva, 84190, Israel. opelled@bezeqint.net
authors.forename: O
authors.initials: O
authors.lastname: Pelled
authors.forename: U
authors.initials: U
authors.lastname: German
authors.forename: A
authors.initials: A
authors.lastname: Abraham
authors.forename: S
authors.initials: S
authors.lastname: Tsroya
authors.forename: Z B
authors.initials: ZB
authors.lastname: Alfassi
mesh_terms: D000465:Algorithms; D001681:Biological Assay / Q000379:methods*; D003198:Computer Simulation; D004781:Environmental Exposure / Q000032:analysis*; D006801:Humans; D038622:Internationality; D008168:Lung / Q000378:metabolism*; D008954:Models, Biological; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods*; D011835:Radiation Protection / Q000379:methods; D011868:Radioisotopes / Q000032:analysis* / Q000493:pharmacokinetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers
chemical_list: D011868:Radioisotopes