Final answer:
The predominant factor in determining T2 contrast is the difference in T2 relaxation times between tissues, influenced by tissue type and conditions like inflammation.
Step-by-step explanation:
The predominant factor in determining T2 contrast in magnetic resonance imaging (MRI) is the difference in T2 relaxation times between different types of tissues. Relaxation time is the period it takes for protons to return to their equilibrium state after the external magnetic field is turned off.
Factors such as tissue type and the presence of conditions like inflammation can significantly influence relaxation mechanisms, thereby affecting the contrast seen in T2-weighted images.