title: A comparison of region-of-interest measures for extracting whole brain data using survival analysis in alcoholism as an example.
abstract: BACKGROUND
  Aggregation of functional magnetic resonance imaging (fMRI) data in regions-of-interest (ROIs) is required for complex statistical analyses not implemented in standard fMRI software. Different data-aggregation measures assess various aspects of neural activation, including spatial extent and intensity.
  
  
  METHODS
  In this study, conducted within the framework of the PREDICT study, we compared different aggregation measures for voxel-wise fMRI activations to be used as prognostic factors for relapse in 49 abstinent alcohol-dependent individuals in an outpatient setting using a cue-reactivity task. We compared the importance of the data-aggregation measures as prognostic factors for treatment outcomes by calculating the proportion of explained variation.
  Relapse risk was associated with cue-induced brain activation during abstinence in the ventral striatum (VS) and in the orbitofrontal cortex (OFC). While various ROI measures proved appropriate for using fMRI cue-reactivity to predict relapse, on the descriptive level the most "important" prognostic factor was a measure defined as the sum of t-values exceeding an individually defined threshold. Data collected in the VS was superior to that from other regions.
  
  
  CONCLUSIONS
  In conclusion, it seems that fMRI cue-reactivity, especially in the VS, can be used as prognostic factor for relapse in abstinent alcohol-dependent patients. Our findings suggest that data-aggregation measures that take both spatial extent and intensity of cue-induced brain activation into account make better biomarkers for predicting relapse than measures that consider an activation's spatial extent or intensity alone.
authors.affiliation: Department of Biostatistics, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, 68159 Mannheim, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Reinhard
authors.affiliation: Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, 68159 Mannheim, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Leménager
authors.affiliation: Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, 68159 Mannheim, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Fauth-Bühler
authors.affiliation: Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, 68159 Mannheim, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Hermann
authors.affiliation: Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, 68159 Mannheim, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Hoffmann
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin Berlin, Charité Mitte, 10117 Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Heinz
authors.affiliation: Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, 68159 Mannheim, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Kiefer
authors.affiliation: Section of Systems Neuroscience, Department of Psychiatry and Psychotherapy, Technische Universität Dresden, 01187 Dresden, Germany.
authors.forename: M N
authors.initials: MN
authors.lastname: Smolka
authors.affiliation: Department of Biostatistics, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, 68159 Mannheim, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Wellek
authors.affiliation: Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, 68159 Mannheim, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Mann
authors.affiliation: Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, 68159 Mannheim, Germany. Electronic address: s.vollstaedt-klein@zi-mannheim.de.
authors.forename: S
authors.initials: S
authors.lastname: Vollstädt-Klein
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000175:diagnosis* / Q000503:physiopathology* / Q000628:therapy; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D003463:Cues; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010045:Outpatients; D011379:Prognosis; D012008:Recurrence; D012306:Risk; D012815:Signal Processing, Computer-Assisted; D016019:Survival Analysis; D016896:Treatment Outcome; D014796:Visual Perception / Q000502:physiology
keywords: Addiction; Prognostic factor; Region of interest; Relapse; Survival analysis; fMRI