NeuroImage
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Comparative Study
Quantitative comparison of functional magnetic resonance imaging with positron emission tomography using a force-related paradigm.
The intention of our study was to compare functional magnetic resonance imaging (fMRI) with positron emission tomography (PET). We used the same force-related motor paradigm for both techniques, which allows for quantification of stimulus intensity. Regional cerebral blood flow (rCBF) was determined with PET in six male subjects (age 30 +/- 3) using the slow bolus injection technique and oxygen-15-labeled water. ⋯ The maximum increase in fMRI signal was 5.0% +/- 0.9 at 60% of the maximum voluntary contraction while the corresponding increase in rCBF was 13.7% +/- 1.2. The ratio of percentage rCBF change to percentage fMRI signal change was very similar across all force levels. The high degree of correspondence between PET and fMRI data provides good cross-validation for the two techniques.