title: Comparison of TCA and ICA techniques in fMRI data processing.
abstract: OBJECTIVE
  To make a quantitative comparison of temporal cluster analysis (TCA) and independent component analysis (ICA) techniques in detecting brain activation by using simulated data and in vivo event-related functional MRI (fMRI) experiments.
  
  
  METHODS
  A single-slice MRI image was replicated 150 times to simulate an fMRI time series. An event-related brain activation pattern with five different levels of intensity and Gaussian noise was superimposed on these images. Maximum contrast-to-noise ratio (CNR) of the signal change ranged from 1.0 to 2.0 by 0.25 increments. In vivo visual stimulation fMRI experiments were performed on a 1.9 T magnet. Six human volunteers participated in this study. All imaging data were analyzed using both TCA and ICA methods.
  
  
  RESULTS
  Both simulated and in vivo data have shown that no statistically significant difference exists in the activation areas detected by both ICA and TCA techniques when CNR of fMRI signal is larger than 1.75.
  
  
  CONCLUSIONS
  TCA and ICA techniques are comparable in generating functional brain maps in event-related fMRI experiments. Although ICA has richer features in exploring the spatial and temporal information of the functional images, the TCA method has advantages in its computational efficiency, repeatability, and readiness to average data from group subjects
authors.affiliation: Research Imaging Center, University of Texas Health Science Center, San Antonio, Texas 78229, USA.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhao
authors.forename: David
authors.initials: D
authors.lastname: Glahn
authors.forename: Li Hai
authors.initials: LH
authors.lastname: Tan
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Jinhu
authors.initials: J
authors.lastname: Xiong
authors.forename: Jia-Hong
authors.initials: JH
authors.lastname: Gao
mesh_terms: D001931:Brain Mapping; D016000:Cluster Analysis; D003627:Data Interpretation, Statistical; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010775:Photic Stimulation; D012815:Signal Processing, Computer-Assisted; D014793:Visual Cortex / Q000502:physiology