QUANTIFICATION IN FUNCTIONAL MAGNETIC-RESONANCE-IMAGING - FUZZY CLUSTERING VS. CORRELATION-ANALYSIS

The potential of functional MRI (fMRI) data analysis using the paradig m independent fuzzy cluster analysis (FCA) applied in the time domain compared to frequently used paradigm based correlation analysis (CA) w as studied with simulated and in vivo fMRI data, The performance of FC A and CA was investigated in a typical contrast-to-noise range for fMR I, ranging from 1.33 to 3.33, Using simulated fMRI data the methods we re quantitatively compared in terms of generation of true positives, f alse positives, and the corresponding signal enhancement, Even without prior knowledge about the stimulation paradigm and the actual hemodyn amic response function the performance of FCA was comparable to that o f CA where extensive prior knowledge has to be added, Furthermore, dis crimination of nonanticipated hemodynamic responses by FCA, such as di fferent levels of activation and delayed response, are demonstrated in simulated and in vivo fMRI data, We demonstrate that using CA one can not differentiate between these responses at least without extensive p rior knowledge, i.e., FCA yields a more particular description of fMRI data, This may be worthwhile for analysis and optimization of data qu ality in fMRI as well as in the final data analysis. (C) 1998 Elsevier Science Inc.