Quantifying Tumor Vascular Heterogeneity with Dynamic Contrast-Enhanced Magnetic Resonance Imaging: A Review
Figure 1
In the literature, several models are available for DCE-MRI pharmacokinetic analysis. The Tofts’ model ((a), also known as Kety’s or Larsson’s model) [22] models the gadolinium concentration dynamic change in a tissue voxel as the result of convolution between an exponential kernel and a measured or assumed arterial input function (AIF). A plasma term with volume fraction is added in the extended Toft’s model (b) [23] by the assumption that the influence of the intravascular compartment is nonnegligible. The Brix’s model (c) [24] takes the gadolinium concentration in blood plasma as another unknown variable and solves it with the tissue dynamic curve from a set of ordinary differential equations. In the adjusted Brix’s model (d) [25], an oversimplified assumption in the original Brix’s model is corrected, leading to a more realistic description of the plasma signal. In the reference region model (e) [26], two dynamic curves are simultaneously measured from the target voxel and a nearby reference region with known and values. The need for an AIF is eliminated by jointly solving two pharmacokinetic equations for target voxel and reference region.
