User Tools

Site Tools


cest_eval

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision Both sides next revision
cest_eval [2016/02/14 15:35]
cest_eval [2020/06/15 11:53]
127.0.0.1 external edit
Line 1: Line 1:
 +====== CEST data evaluation tool======
 +{{ :cest_eval.png?direct&200|}}
 +This tool allows you to evaluate CEST MRI data and create CEST images and ROI evaluations from basic contrasts as well as sophisticated multi-Lorentzian fits
 +
 +Dowload zipped Matlab implementations [[https://github.com/cest-sources/CEST_EVAL/archive/master.zip|here]] or find the package on [[https://github.com/cest-sources/CEST_EVAL/]]
 +
 +====== Tutorial ======
 +These routines allow you to
 +  * import raw data 
 +  * Calculate B0 maps from Z-spectra
 +  * B0 correct Z-spectra
 +  * investigate CEST spectra for pixels and ROIs
 +  * calculate contrasts (MTRasym, MTRRex, Lorentzian difference, AREX)
 +  * fit multi-Lorentzian fits to Z-spectra
 +
 +MTRRex,AREX: **Zaiss et al. NMR Biomed., 27: 240–252. [[http://onlinelibrary.wiley.com/doi/10.1002/nbm.3054/|doi: 10.1002/nbm.3054]]**. 
 +
 +Fitting: **Windschuh et al. (2015), NMR Biomed., 28(5):529-37.  [[http://onlinelibrary.wiley.com/doi/10.1002/nbm.3283/abstract|doi: 10.1002/nbm.3283]]**. 
 +
 +WASABI B1/B0 mapping and correction: **Schuenke et al. (2016), MRM [[http://onlinelibrary.wiley.com/doi/10.1002/mrm.26133/abstract|doi: 10.1002/mrm.26133]]**. 
 +
 +===== 1/2 Basic Z-spectra evaluation =====
 +{{youtube>4aA1D2A60Og?500x360|Tutorial: 10 minutes for basic CEST evaluation}}
 +
 +===== 2/2 Lorentzian fitting for isolated CEST evaluation =====
 +{{youtube>NxCXS5_X3yk?500x360|Tutorial: 10 minutes for basic CEST evaluation}}
 +
 +There are 4 important inputs:
 +  * **M0_stack(x,y,z)** the thermal M0 magnetization, or the normalization image w/o saturation
 +  * **Mz_stack(x,y,z,w)** the stack of saturated images at frequency w
 +  * **dB0_stack_int(x,y,z)** the internal dB0 map in ppm calculated by the minimum of Mz_stack
 +  * **dB0_stack_ext(x,y,z)** an external dB0 map in ppm
 +
 +further we need the frequency offset axis, or the omega-axis (w-axis) of the Z-spectrum. It is saved in the parameter struct P under the sequence parameters P.SEQ
 +  * **P.SEQ.w**
 +
 +To calculate the internal B0 map the function MINFIND_SPLINE_3D is called
 +after that the **B0-correction** and **normalization** can be performed
 +and the final stack is  
 +  * **Z_corrExt**  - the B0-corrected and normalized stack of Z-spectra
 +
 +
 +====== Alternatives ======
 +find the //CEST data processing tool// of the John Hopkins group here 
 +[[http://godzilla.kennedykrieger.org/CEST/]]
 +
 +
 +{{ :logo_dkfz.png?direct&180|powered by DKFZ}}
  
cest_eval.txt · Last modified: 2021/10/11 13:22 (external edit)