Question

The purpose of the initial 180 RF pulse in inversion recovery imaging is to create a ___________ environment before the 90 RF pulse

A) Homogeneous
B) Saturated
C) Reversed
D) Excited

Answer 1

The initial 180 RF pulse in inversion recovery imaging creates a reversed magnetization environment, enabling enhanced tissue contrast in MRI by flipping the spins before the subsequent 90 RF pulse.

Step-by-step explanation:

The purpose of the initial 180 RF pulse in inversion recovery imaging is to create a reversed environment before the 90 RF pulse. What this means is that the initial 180-degree Radio Frequency (RF) pulse is used to invert the net magnetization of the spins in the tissue, effectively flipping it to be opposite to the direction of the main magnetic field. After a specific time period, known as the inversion time (TI), a 90-degree RF pulse is then applied, which places the net magnetization into the transverse plane where it can be detected. This technique is particularly useful for enhancing the contrast of different tissues in magnetic resonance imaging (MRI), especially for detecting pathological changes such as those seen in multiple sclerosis or stroke.