Figure 2. Signal intensity-time curve for DCE-MRI.

Signal intensity-time curve for DCE-MRI showing early (PE₁) and late (PE₂) percent enhancement measurements. S₀, S₁, and S₂ represent the signal intensity of images obtained at t₀ (before contrast injection), t₁ (2.5 minutes after contrast injection), and t₂ (7.5 minutes after contrast injection), respectively. Three curves display different patterns of signal increase and washout: 1) the blue curve shows a slow gradual increase in enhancement, more characteristic of normal tissue; 2) the green curve shows an early enhancement with little washout, essentially a plateau in signal intensity; 3) the red curve shows a pattern of early enhancement with a fast washout, which is more characteristic of highly vascularized tissues.