Thresholding Artefacts in sSVD and oSVD Deconvolution
Gyldensted L, Mouridsen K, stergaard L
Aarhus University Hospital
Deconvolution methods are widely used in perfusion-weighted MRI for obtaining CBF, CBV and MTT, but are sensitive to thresholding. Typically a single threshold depending on SNR is determined for the whole brain. We have found optimized thresholds for different SNRs for sSVD and oSVD and compared the two methods. We found that over-regularization in sSVD increases the delay-sensitivity, causing MTT overestimation in the posterior vascular territory. oSVD we have found to be less sensitive to over-regularization. However we report a general overestimation of MTT values in oSVD compared to sSVD.