fmri_cnr

Description

FMRI_CNR Temporal contrast-to-noise ratio (tCNR) for fMRI data. Calculates the functional CNR per unit time (fCNR), defined as the ratio of the mean absolute scan-to-scan signal change (delta-S) to the temporal standard deviation of the signal per voxel: fCNR = mean|delta-St| / sigma_t

Usage

CNR = fmri_cnr(v)

Inputs

• V: fMRI data, vectorized (228453 x T) or volume (91 x 109 x 91 x T)

Outputs

• CNR: Voxelwise tCNR map, vectorized (228453 x 1). Voxels with zero temporal variance (e.g. outside the brain mask) are set to 0.

Examples

CNR = fmri_cnr(data);
fmri_showslices(CNR, 1, 2, [0 5])

References

• Welvaert, M. & Rosseel, Y. (2013). On the definition of signal-to-noise ratio and contrast-to-noise ratio for fMRI data. PLoS ONE, 8(11).

See Also

• fmri_snri

• fmri_snrt