Feasibility of using limited‐population‐based arterial input function for pharmacokinetic modeling of osteosarcoma dynamic contrast‐enhanced MRI data

Abstract

For clinical dynamic contrast‐enhanced (DCE) MRI studies, it is often not possible to obtain reliable arterial input function (AIF) in each measurement. Thus, it is important to find a representative AIF for pharmacokinetic modeling of DCE‐MRI data when individual AIF (Ind‐AIF) measurements are not available. A total of 16 patients with osteosarcomas in the lower extremity (knee region) underwent multislice DCE‐MRI. Reliable Ind‐AIFs were obtained in five patients with a contrast injection rate of 2 cc/s and another five patients with a 1 cc/s injection rate. Average AIF (Avg‐AIF) for each injection rate was constructed from the corresponding five Ind‐AIFs. For each injection rate there are no statistically significant differences between pharmacokinetic parameters of the five patients derived with Ind‐AIFs and Avg‐AIF. There are no statistically significant changes in pharmacokinetic parameters of the 16 patients when the two Avg‐AIFs were applied in kinetic modeling. The results suggest that it is feasible, as well as practical, to use a limited‐population‐based Avg‐AIF for pharmacokinetic modeling of osteosarcoma DCE‐MRI data. Further validation with a larger population and multiple regions is desirable. Magn Reson Med 59:1183–1189, 2008.