Cerebral blood flow measurement by dynamic contrast MRI using singular value decomposition with an adaptive threshold

Singular value decomposition (SVD) is a promising deconvolution technique f or use in dynamic contrast agent magnetic resonance perfusion imaging. Comp uter simulations, however, show that the selection of the threshold for SVD affects the accuracy of the cerebral blood flow measurements and may disto rt the shape of the vascular residue function. In this report, a pixel-by-p ixel thresholding method is proposed based on the signal-to-noise ratio of the concentration time curve at maximum concentration (SNRC). Monte Carlo s imulations were used to determine the optimal threshold for different SNRC. This technique was used to analyze data from six healthy volunteers, resul ting in a mean gray to white matter cerebral blood flow ratio of 2.67 +/- 0 .07. This value is in excellent agreement with values published in the lite rature. Magn Reson Med 42:167-172, 1999, (C) 1999 Wiley Liss, Inc.