Which combination of flip angle and TR produces a T2 weighted gradient echo?

To achieve a T2-weighted gradient echo image, it's important to understand the impact of flip angles and repetition times (TR) on the contrast of the resulting image. T2-weighted images highlight differences in T2 relaxation times, which are influenced by the flip angle and TR.

A combination of a short TR and a small flip angle is effective in creating T2-weighted images via gradient echo sequences. Typically, a flip angle of less than 90 degrees, along with a relatively short TR, helps to minimize T1 weighting and accentuates T2 effects, allowing for better visualization of fluid-containing structures and pathology.

The correct answer specifies a TR of 450 ms alongside a flip angle of 30 degrees. This combination strikes a balance that reduces T1 effects, making the image more sensitive to T2 contrast. The shorter TR limits T1 relaxation effect, while the small flip angle enables efficient sampling with a focus on T2 decay. This approach ensures that tissue with longer T2 times (like fluid) appears bright, while tissues with shorter T2 times appear darker, creating the desired contrast for T2-weighted imaging.

In summary, a TR of 450 ms and a flip angle of 30 degrees provide the necessary