Biodistribution and estimation of radiation-absorbed doses in humans for 13N-ammonia PET/CT / 中国医学影像技术

ABSTRACT

Objective To evaluate the biodistribution and radiation-absorbed doses of main organs in healthy people with 13 N-ammonia.Methods Five healthy volunteers underwent whole-body PET and CT scans after injection of 666-814 MBq of 13 N-ammonia.The serial dynamic emission images of each healthy volunteer were acquired.ROI were drawn manually based on the transverse CT images and transferred to the corresponding PET slices.Radiation-absorbed doses were calculated using the medical internal radiation dosimetry (MIRD) method.Results The highest concentrations of 13 N-ammonia were found in the heart,liver and kidneys,followed by pancreas,brain,spleen and stomach.The organ of highest absorbed dose was heart with (7.14±3.63) × 10-3 mGy/MBq.The whole-body absorbed dose was (2.11±0.44) × 10 3 mGy/MBq.The whole-body effective dose was (6.58± 1.23) × 10-3 mSv/MBq.Conclusion As one of the most important myocardial perfusion tracers,the whole-body 13 N-NH3 · H2 O PET appears to be safe for humans.