Pharmacokinetic models in clinical practice: What model to use for DCE-MRI of the breast?

Pharmacokinetic modeling is increasingly used in DCE-MRI high risk breast cancer screening. Several models are available. The most common models are the standard and extended Tofts, the shutter-speed, and the Brix model. Each model and the meaning of its parameters is explained. It was investigated which models can be used in a clinical setting by simulating a range of sampling rates and noise levels representing different MRI acquisition schemes. In addition, an investigation was performed on the errors introduced in the estimates of the pharmacokinetic parameters when using a physiologically less complex model, i.e. the standard Tofts model, to fit curves generated with more complex models. It was found that the standard Tofts model is the only model that performs within an error margin of 20% on parameter estimates over a range of sampling rates and noise levels. This still holds when small complex physiological effects are present.