Total body potassium determination using a whole-body counter.

A scanning bed whole-body counter with two NaI(Tl) scintillation detectors was used for total body potassium determination with 40K for clinical application. For the calibration an in vivo dilution technique with 42K was used. The present counting method effectively minimised effects of redistribution and body build. For routine use the (W/H)1/2 calibration curve is suggested instead of the more complicated individual 42K calibration.