Simulation for double editing pulse MegaPress sequence
bsjeong opened this issue · 2 comments
Hi,
With editing "run_simMegPressShaped.m" file, I'd like to simulate basis set for MegaPress sequence using double editing pulse.
My questions are
-
Dual band RF were applied at -1.9 and -4.7 ppm.
In this case, do I add 4.7 as well as 1.9 for "editOnFreq"? Otherwise, 4.7 can be neglected? -
In edit OFF pulse sequence, the dual band RF pulse is shifted about -3.01 ppm.
What is the correct value for "editOffFreq"? 4.91 (=1.9 + 3.01) or 7.71 (=4.7+3.01) -
In event block, refocusing pulses with 180 degree were applied at - 4.7 ppm.
If so, refPhCyc1 & 2 are [0, 180] & [0,180] in contrast to [0,90] in default value in the example script.
I believe editPhCyc1 & 2 are [0 90] & [0 90] same as in the example script. -
If exponential line broadening is 3 Hz, is the linewidth of the output spectrum 3 Hz?
Thanks in advance,
Bumseok
Dear Jamie,
Thank you so much for your reply.
I got your answer regarding to my question 3 and 4.
It is hard to follow your answer 1 and 2 as, I believe, I'm a very beginner in terms of MR sequence stuff.
I'm worried that the following question doesn't make any sense at all.
- How to create a dual band version of gaussian editing pulse?
It seems "rf_dualBand.m" may be the code for it, but I need your help.
Just I guess few parameters for it.
tp (pulse duration, ms) = 19.712 ;
df (frequency of 2nd gaussian band, Hz) = ? ; (2.8ppm = -1.9 + 4.7)
n = 400; (just follow to it in single band pulse)
bw = ? ;
ph = ? ; (610.28)
shft = ? ; (3.01ppm)
- if I understand my event blocks in my dual band pulse, the RF pulse have two bands may be symmetrically placed off resonance and exact frequencies of band may be 299 and -209, respectively.
in editing on sequence,
The 1st refocusing pulse (180 degree of flip, 7ms long) have 299/-286.74 ~ 0/-466.74 (Freq/Phase)
The 1st editing pulse(19.712ms long) is placed between -172/610.28 ~ 0/610.28
The 2nd refocusing pulse (180 degree, 0.6ms long) have -209/112.57 ~ 0/-67.43
The 2nd editing pulse(19.712ms long) is placed between -172/610.28 ~ 0/610.28
The 3rd (180 degree of flip, 7ms long) have -159/ 290.34 ~ 0/110.34
In editing OFF sequence, both frequency and phase of editing pulse is change from -172 to 172. 610.28 to -610.28, respectively.
The 1st editing pulse(19.712ms long) is placed between 172/-610.28 ~ 0/-610.28
The 2nd editing pulse(19.712ms long) is placed between 172/-610.28 ~ 0/-610.28
Warm regards,
Bumseok