Which parameter must be minimized to achieve quick T1 recovery in a GRE sequence?

To achieve quick T1 recovery in a Gradient Echo (GRE) sequence, minimizing the repetition time (TR) is crucial. The TR is the time interval between successive pulse sequences applied to the same slice. A shorter TR allows for a quicker return to the equilibrium state between excitations, facilitating faster T1 recovery.

In magnetic resonance imaging, T1 recovery refers to the return of the longitudinal magnetization to its equilibrium state after excitation. When the TR is decreased, the time allowed for T1 recovery is also reduced, thereby facilitating shorter intervals between excitations and making it more efficient for imaging sequences that are sensitive to T1 effects.

This principle is significant in applications where high temporal resolution is necessary, as in dynamic imaging techniques or when scanning tissues with varying T1 properties. A short TR maximizes the efficiency of the imaging process, making it a vital factor in optimizing a GRE sequence for rapid acquisition times while balancing image quality.

The other parameters mentioned, such as short TE, high flip angle, and long TE, influence the imaging process in various ways but do not directly minimize the time needed for T1 recovery in the same manner as TR does.