QMRITools`
QMRITools`
DixonReconstruct
DixonReconstruct[real,imag,echo]
reconstruxt Dixon data with initital guess b0 = 0 and T2star = 0.
DixonReconstruct[real,imag,echo,b0]
reconstructs Dixon data with intitial guess T2star = 0.
DixonReconstruct[real,imag,echo,b0,t2]
reconstructs Dixon data. real is the real data in radials. imag is the imaginary data in radians. B0 can be estimated from two phase images using Unwrap. T2 can be estimated from multiple echos using T2fit. Output is {{watF,fatF},{watSig,fatSig},{inphase,outphase},{B0,T2star},itterations}. The fractions are between 0 and 1, the B0 field map is in Hz and the T2start map is in ms.
is based on DOI: 10.1002/mrm.20624 and 10.1002/mrm.21737 (10.1002/nbm.3766).
Details and Options
- The following options can be given:
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DixonPrecessions -1 DixonPrecessions is an options for DixonReconstruct. Defines the rotation of the signal {-1,1} default is -1. DixonFieldStrength 3 DixonFieldStrength is an options for DixonReconstruct. Defines the fieldstrengths in Tesla on which the data was acquired. DixonNucleus "1H" DixonNucleus is an option for DixonReconstruct. Defines the nucleus for which the reconstruction is performed. DixonFrequencies {{0}, {3.8, 3.4, 3.13, 2.67, 2.46, 1.92, 0.57, -0.6}} DixonFrequencies is an options for DixonReconstruct. Defines the frequencies in ppm of the fat peaks being used. DixonAmplitudes {{1}, {0.089, 0.598, 0.047, 0.077, 0.052, 0.011, 0.035, 0.066}} DixonAmplitudes is an options for DixonReconstruct. Defines the relative amplitudes of the fat peaks being used. DixonIterations 15 DixonIterations is an options for DixonReconstruct. Defines the maximum itterations the fit can use. DixonTollerance 0.001 DixonTollerance is an options for DixonReconstruct. Defines at which change per itteration of b0 and R2star the ittarative methods stops. Default value is 0.1. DixonMaskThreshhold 0.01 DixonMaskThreshhold is an options for DixonReconstruct. Defines at which threshhold the dixon reconstruction considers a voxel to be background noise. Defualt values is 0.05. DixonFilterInput True DixonFilterInput is an options for DixonReconstruct. If True the input b0 and T2star values are smoothed using a gaussian kernel. DixonFilterOutput True DixonFilterOutput is an options for DixonReconstruct. If True the out b0 and T2star values are smoothed Median filter and lowpassfiltering after which the water and fat maps are recomputed. DixonFilterDimensions "3D" DixonFilterDimensions is an options for DixonReconstruct. Defines if the filtering is done in 2D or 3D. DixonFilterSize 1 DixonFilterSize is an options for DixonReconstruct. Defines the number of voxel with which the input b0 and T2star values are smoothed. DixonBipolar False DixonBipolar is an option for DixonReconstruct. If set to true it assumes alternating readout directions. DixonClipFraction False DixonClipFraction is an option for DixonReconstruct. If set true the fat fraction is clipped between 0 and 1.