====== Standard CEST protocols ======

We want to hint that there is a more detailed and growing site for standard protocols based on pulseq here
[[https://github.com/kherz/pulseq-cest|https://github.com/kherz/pulseq-cest]]

We recommend to follow this site in the future for standardization of protocols.


below you find the old information, which will at some point be removed for the sake of pulseq-cest.

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B1 definitions here are the flip angle equivalent (pure FA), thus the average B1 of a **single** saturation pulse.
This also means that the flip angle of each saturation pulse is directly given by FA = B1·γ·t_p

t_p  = duration of a single saturation pulse,
t_sat = total time of the saturation pulse train 


----

===== 3T APT =====

====APTw_1 : APT-weighted, low DC, t_sat=1.8s (//GLINT//) ====
  * pulse shape = Gaussian
  * B1 = 2.22 µT
  * n = 20
  * t_p = 50 ms
  * t_d = 40 ms  
  * => DC = 0.55 and t_sat = n*(t_p+t_d) = 1.8 s
  * T_rec = 2.4/12 s (saturated/M0)

total acquisition time (depends on the readout) : approximately 3min24s for snapshot-GRE


====APTw_2  : APT-weighted, low DC, t_sat=0.8s (//HDAPTTRIO//) ====

  * pulse shape = RECT
  * B1 = 2 µT
  * n = 5
  * t_p = 100 ms
  * t_d = 72 ms  
  * => DC = 0.58 and t_sat = n*(t_p+t_d) = 860 ms
  * T_rec = 2 s
  * measurements= 17

Δω [ppm] = -300, 4, -3.75, -3.75, -3.5, -3.5, -3.25, -3.25, -3, 3, 3.25, 3.25, 3.5, 3.5 3.75, 3.75, 4

====APTw_3 : APT-weighted, high DC, t_sat=0.8s (//HDAPT//) ====

  * pulse shape = RECT
  * B1 = 2 µT
  * n = 8
  * t_p = 100 ms
  * t_d = 5 ms  
  * => DC = 0.95 and t_sat = n*(t_p+t_d) = 840 ms
  * T_rec = 2 s
  * measurements= 17

Δω [ppm] = -300, 4, -3.75, -3.75, -3.5, -3.5, -3.25, -3.25, -3, 3, 3.25, 3.25, 3.5, 3.5 3.75, 3.75, 4




----


===== 3T Multi-Pool (MP)  -  low power -  selective amide and NOE protocols =====


==== MP_1 : low DC (//GLINT//) ====

  * pulse shape = Gaussian
  * B1 = 0.6 µT (first scan),  B1 = 0.9 µT (second scan)
  * n = 80
  * t_p = 20.48 ms
  * t_d = 20 ms  
  * => DC = 0.5 and t_sat = n*(t_p+t_d) = 3.2 s
  * T_rec = 0 ms
  * measurements = 54

Δω [ppm] = [ -300, -100, -50, -40, -30, -20, -10, -9.5, -9,-8.5,-8,-7.5,-7,-6.5,-6,-5.5,-5,-4.5,-4,-3.5,-3,-2.5,-2,-1.5,-1,-0.5,-0.25,0,0.25,0.5,1,1.5,2,2.5,3,3.5,4,4.5,5,5.5,6,6.5,7,7.5, 8,8.5,9,9.5,10,20,30,40,50,100 ]

total acquisition time (depends on the readout) : approximately 5min20s for snapshot-GRE

==== MP_2 : high DC (//HD//) ====

  * pulse shape = Gaussian
  * B1 = 0.6 µT (first scan),  B1 = 0.9 µT (second scan)
  * n = 148
  * t_p = 20 ms
  * t_d = 5 ms
  * => DC = 0.8 and t_sat = n*(t_p+t_d) = 3.7 s
  * T_rec = 0/12 s (saturated/M0)
  * measurements = 57

Δω [ppm] = 250, 200, 150, 110, 80, 60, 45, 35, 28, 22, 17, 13, 10, 7.5, 6, 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1.2, 0.9, 0.7, 0.5, 0.3, 0, −0.3, −0.5, −0.7, −0.9, −1.2, −1.5, −2, −2.5, −3, −3.5, −4, −4.5, −5, −6, −7.5, −10, −13, −17, −22, −28, −35, −45, −60, −80, −110, −150, −200, −250

total acquisition time (depends on the readout) : approximately 7min34s per B1 for snapshot-GRE


===== 7T Multi-Pool (MP)  -  low power -  selective amide and NOE protocols =====

==== MP_1 (//GUFI TH2//) ====

  * pulse shape = Gaussian
  * B1 = 0.6 µT (first scan),  B1 = 0.9 µT (second scan)
  * n = 120
  * t_p = 15ms
  * t_d = 10 ms
  * => DC = 0.6 and t_sat = n*(t_p+t_d) = 3.0 s
  * T_rec = 0/12 s (saturated/M0)
  * measurements = 56

Δω [ppm] = [-300
-100
-50
-20
-12
-9
-7.25
-6.25
-5.5
-4.7
-4
-3.3
-2.7
-2
-1.7
-1.5
-1.1
-0.9
-0.6
-0.4
0
0.4
0.6
0.95
1.1
1.25
1.4
1.55
1.7
1.85
2
2.15
2.3
2.45
2.6
2.75
2.9
3.05
3.2
3.35
3.5
3.65
3.8
3.95
4.1
4.25
4.4
4.7
5.25
6.25
8
12
20
50
100
-300
]


total acquisition time (depends on the readout) : approximately 6:40s per B1 for snapshot-GRE