Analysis of inhalation rCBF data.

Relative to other approaches that have been recommended, fitting all head data, solving for a time shift, and including an air passage artifact term in the model significantly improved the estimate of gray matter blood flow by the inhalation technique. A robust algorithm, which incorporates these features, has been developed. Formulas which facilitate implementation of this algorithm are reported. An artifact from large scalp arteries was not significant and does not need to be included in the model.