What is a common characteristic of tissues that have undergone high flip angles in MRI?

Tissues that have undergone high flip angles in MRI tend to exhibit a low signal-to-noise ratio. When a high flip angle is used, a greater portion of the magnetization vector is tipped into the transverse plane, leading to a more significant saturation effect and less net available magnetization for detecting signal. This saturation can cause a decrease in the signal strength that reaches the receiver, resulting in a lower signal-to-noise ratio.

In contrast, the other factors mentioned aren't directly related to the effect of high flip angles. Increased signal duration pertains more to the time it takes for the signal to decay and not directly to the impact of high flip angles. High relaxation time generally refers to how quickly protons can return to equilibrium, which doesn't change just by altering the flip angle. Increased imaging speed could be influenced by other factors but is not inherently a result of high flip angles.