Venous versus arterial blood samples for plasma input pharmacokinetic analysis of different radiotracer PET studies

Objectives Full quantitative analysis of dynamic PET studies often requires a metabolite corrected arterial plasma input function. A whole blood input function can be obtained either by online arterial sampling or from an image derived input function (IDIF). Next, data from several manual arterial blood samples are used to correct for changing plasma to blood (P/B) activity concentration (AC) ratios and parent fractions (PF). Use of venous blood samples is more patient friendly especially in case of an IDIF. The purpose of this study was to validate the use of venous blood samples to generate a metabolite corrected plasma IDIF.

Methods During several PET studies with different tracers (see table) both arterial and venous manual blood samples were taken at different time points (n= 3 to 7 per study). Both sets of samples were used to measure blood and plasma ACs, P/B ratios and, if necessary, PFs. Venous data were compared with arterial data using linear regression analysis.

Results During several PET studies with different tracers (see table) both arterial and venous manual blood samples were taken at different time points (n= 3 to 7 per study). Both sets of samples were used to measure blood and plasma ACs, P/B ratios and, if necessary, PFs. Venous data were compared with arterial data using linear regression analysis.

Conclusions Manual arterial samples cannot be replaced by venous sampling without proper validation. Use of venous sampling to correct IDIFs for P/B ratios and PFs may be valid for some tracers

• Download figure
• Open in new tab
• Download powerpoint