Table 2.

Biological correlation of perfusion-related parameters

BV and BF (often coupled)	Permeability	Biological interpretation
↑↑↑	↓ or ↔ or ↑	New vessel formation (increased perfusion and blood volume) with varying degrees of maturation
↓ or ↔ or ↑	↑↑↑	Poor perfusion with increased permeability (immature vessels), which usually represent a reaction to hypoxia
↑	↔ or ↓	Mature vasculature
↑	↔ or ↑	Inflammation +/− early fibrosis
↓	↓	Mature fibrotic areas (usually showing a progressive enhancement)
↓↓	↓↓	Poor vascularized areas
BF↓ relating to BV	----	Blood flow-blood volume mismatch, which usually represents hypoxia
+/− 0	+/− 0	Necrotic areas

Note—Data from literature reviews and personal experience and adapted from references 30,31, and 45

BV = blood volume, BF = blood flow