For T1 weighting in a GRE sequence, what parameters should be used?

For T1 weighting in a Gradient Echo (GRE) sequence, the appropriate parameters focus on optimizing contrast based on tissue relaxation times. A large flip angle is essential because it saturates longitudinal magnetization, enhancing the T1 contrast of tissues. By using a short TE (Echo Time), the imaging focuses on capturing signals when T1 weighted tissues have had sufficient time to relax, which further accentuates the differences in tissue characteristics based on their T1 relaxation times.

Additionally, employing a short TR (Repetition Time) allows for more efficient sampling of the signal before it has the opportunity to relax significantly, thus retaining a strong signal related to T1 properties. This combination of parameters effectively highlights T1 contrast, making the tissues with shorter T1 relaxation times appear brighter and more discernible compared to those with longer T1s.

The other combinations of parameters would not effectively enhance T1 weighting. For instance, using a long TE or long TR would result in diminished signal strength and contrast, making it unsuitable for T1 weighted imaging.