Abstract：As an important short half-life radionuclide,the 18F is widely used in nuclear medicine for positron emission tomography(PET).It disintegrates to 18O by β+ emission(96.86%)and electron capture(3.14%).Since the very high detection efficiency of β+ decay branch in the liquid scintillation counter,the radioactive solution of 18F has been standardized by TDCR-LS method.The results indicate that the detection efficiency of β+ emission in Ultima GoldTM AB cocktail is close to 1 and the uncertainty of 18F by TDCR-LS method is equal to 0.6%(k=2).
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2011, Vol. 32 
