HIGH-RESOLUTION MEASUREMENT OF CEREBRAL BLOOD-FLOW USING INTRAVASCULAR TRACER BOLUS PASSAGES .2. EXPERIMENTAL COMPARISON AND PRELIMINARY-RESULTS

This report evaluates several methods to map relative cerebral blood f low (rCBF) by applying both parametric and nonparametric techniques to deconvolve high resolution dynamic MRI measurements of paramagnetic b olus passages with noninvasively determined arterial inputs, We found a nonparametric (singular value decomposition (SVD)) deconvolution tec hnique produced the most robust results, giving mean gray:white flow r atio of 2.7 +/- 0.5 (SEM) in six normal volunteers, in excellent agree ment with recent PET literature values for age-matched subjects. Simil ar results were obtained by using a model-dependent approach that assu mes an exponential residue function, but not for a Gaussian-shaped res idue function or for either Fourier or regularization-based model-inde pendent approaches, Pilot studies of our CBF mapping techniques in pat ients with tumor, stroke, and migraine aura demonstrated that these te chniques can be readily used on data routinely acquired by using curre nt echo planar imaging technology, By using these techniques, the auth ors visualized important regional hemodynamic changes not detectable w ith rCBV mapping algorithms.