Choose the correct option from ae and explain why this is yo
     Choose the correct option from (a)-(e) and explain why this is your choice. The maximum MR signal is obtained by using:  90 degree RF pulse, short TE, and short TR;  45 degree RF pulse, short TE, and short TR;  90 degree RF pulse, short TE, and long TR;  90 degree RF pulse, long TE, and short TR;  45 degree RF pulse, long TE, and short TR.   
  
  Solution
ans) option c
The maximum signal is obtained when the flip angle is 90°. (Remember, sin(0°) = 0, sin(90°) = 1.0) The signal unaffected by any gradient is known as a Free Induction Decay (FID). The time constant that determines the rate of decay is called T2. An FID has no positional information.

