Question

The MRI device is of interest:

1. Determine the relative position (x_n,y_m) from the centre for ¹H, given f_n = 78,5 MHz, G_x = 10^-4 T/m, t_p = 5 μs and u_m = 21,3 m/T.
2. Answer the following:
   1. What is displayed in an MRI image?
   2. How is a location from a set of signals in the body determined?
   3. Of the three imagining axes, which are actively controlled and which are passively sensed?

Answer 1

A) the brain , spinal cord and nerves as well as muscles , ligaments , and tendons are clearly seen in MRI than with regular x rays and CT scans. This is the reason why MRI used for shoulder and knee injuries.

B) MRI Sequences - T1 weighted sequence,T2 weighted sequence,PD weighted sequence,Gradient & spin echo sequence,Fat suppression,MRI contrast,Diffusion weighted image,In/out-of-phase

C) Active sensors have its own source of light or illumination. In particular, it actively sends a wave and measures that backscatter reflected back to it. But passive sensors measure reflected sunlight emitted from the sun. When the sun shines, passive sensors measure this energy.