Internal dosimetry in F-18 FDG PET examinations based on long-time-measured organ activities using total-body PET/CT: does it make any difference from a short-time measurement?

EJNMMI Physics

Table 1 Average residence time and standard deviation calculated using spline method and multi-exponential methods

Organ	Spline method	Multi-exponential method 12 frames	Multi-exponential method 12 frames (only physical decay after 60 min)	Multi-exponential method 3 frames	Multi-exponential method 3 frames (only physical decay after 70 min)	Multi-exponential with 18 min of data
Brain	0.391±0.066	0.377±0.073*	0.358±0.071**	0.380±0.067*	0.354±0.065***	0.370±0.073**
Heart	0.041±0.022	0.044±0.021	0.039±0.019	0.040±0.023	0.036±0.018	0.044±0.038
Liver	0.117±0.025	0.099±0.015***	0.136±0.021***	0.086±0.013***	0.135±0.021***	0.101±0.023*
Lungs	0.058±0.030	0.062±0.038	0.071±0.038***	0.049±0.022	0.072±0.032**	0.057±0.030
Kidneys	0.033±0.009	0.032±0.011	0.041±0.012***	0.025±0.008***	0.040±0.013***	0.028±0.033*