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biac:analysis:topup_correction
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| Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
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biac:analysis:topup_correction [2021/08/24 18:22] cmp12 |
biac:analysis:topup_correction [2021/08/24 18:26] cmp12 |
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| You need to calculate readout time in seconds of the PEPOLAR images ( the physical time it takes to get the acquisition matrix of a single slice ) and get the polarity direction ( phase encode direction ). | You need to calculate readout time in seconds of the PEPOLAR images ( the physical time it takes to get the acquisition matrix of a single slice ) and get the polarity direction ( phase encode direction ). | ||
| + | |||
| the readout time in seconds for the parameter file will be: | the readout time in seconds for the parameter file will be: | ||
| - | < | ||
| **For singleband images :** | **For singleband images :** | ||
| + | < | ||
| readout = (echospacing * (acquisitionmatrix[0] * (percentsampling/ | readout = (echospacing * (acquisitionmatrix[0] * (percentsampling/ | ||
| echospacing in the BXH header is in microseconds | echospacing in the BXH header is in microseconds | ||
| + | </ | ||
| **For mutli-band images the readout calculation is more complex: | **For mutli-band images the readout calculation is more complex: | ||
| + | < | ||
| readout = ( ( ceil ((1/ | readout = ( ( ceil ((1/ | ||
| Line 26: | Line 29: | ||
| Round_factor = 4 if partial fourier ( PFF is in scanoptions ), 2 if full fourier. | Round_factor = 4 if partial fourier ( PFF is in scanoptions ), 2 if full fourier. | ||
| Asset_R_factor = the reciprocal of the first value of dcm tag (0043,1083) | Asset_R_factor = the reciprocal of the first value of dcm tag (0043,1083) | ||
| - | |||
| </ | </ | ||
| Line 111: | Line 113: | ||
| ==== Create your acq_params.txt file === | ==== Create your acq_params.txt file === | ||
| - | the readout time in seconds for the parameter file will be: | + | calculate your readout time from above |
| - | < | + | |
| - | + | ||
| - | echospacing in BXH header is in microseconds | + | |
| - | </ | + | |
| the regular B0s will get the " | the regular B0s will get the " | ||
| Line 206: | Line 204: | ||
| If you are running dwidenoise, do it BEFORE dwipreproc. | If you are running dwidenoise, do it BEFORE dwipreproc. | ||
| - | ==== Calculate your readout time ==== | + | ==== Calculate your readout time as mentioned above ==== |
| - | < | + | |
| - | + | ||
| - | echospacing in BXH header is in microseconds | + | |
| - | </ | + | |
| ==== Prepare your input datasets ==== | ==== Prepare your input datasets ==== | ||
biac/analysis/topup_correction.txt · Last modified: 2023/02/23 18:43 (external edit)
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