Multimodality Imaging of Tumor Angiogenesis: Perfusion Modeling for Tumor Angiogenesis

When a tracer, such as Gd-doped or iodinated extracellular contrast, is introduced into the blood stream of a patient its transport through the vascular system, heart and lungs and eventual excretion via the kidneys is a well-established process [1,2]. At the level of the imaging voxel (for example, in the centre of a breast tumor) we can only speculate as to the precise nature of the tracer kinetics. We can, however, form a hypothesis. The tracer kinetic model helps us to formulate such a hypothesis, provides us with the opportunity to predict the behavior of the system and subsequently test our predictions [3]. With time, like most hypotheses, our models become more complex attempting to describe the system with greater realism.