AJDRAJNR - American Journal of Neuroradiology

This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Harrington, G.S.
Right arrow Articles by Farias, S. T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Harrington, G.S.
Right arrow Articles by Farias, S. T.

American Journal of Neuroradiology 27:938-944, April 2006
© 2006 American Society of Neuroradiology

FUNCTIONAL

Intrasubject Reproducibility of Functional MR Imaging Activation in Language Tasks

G.S. Harringtona, M.H. Buonocorea and S. Tomaszewski Fariasb

a Department of Radiology, University of California at Davis, Davis, Calif
b Department of Neurology, University of California at Davis, Davis, Calif

Address correspondence to Greg Harrington, PhD, 1101 E Marshall St., Sanger Hall B3-020, Richmond, VA 23298

BACKGROUND AND PURPOSE: The purpose of this study was to examine the reproducibility of functional MR imaging (fMRI) activation (volume and laterality) within both inferior frontal and temporoparietal regions of interest for both receptive and expressive language tasks.

METHODS: Ten healthy volunteers participated in fMRI experiments for 6 language tasks: verb generation, confrontation naming, semantic decision making, visual sentence comprehension, auditory sentence comprehension, and story listening. Each subject was scanned during 2 separate sessions separated by a minimum of 4 weeks. Laterality of activation was defined by laterality indices (LIs), which were calculated by 2 methods: one method based on the measured volume of activation and the other method based on the F statistic of the activation. Reproducibility was calculated by using concurrence ratios for the volume of activation (Roverlap, Rvolume) and test-retest correlation for LIs.

RESULTS: All tasks generated reproducible LIs within at least one of the regions of interest, but verb generation produced the highest test-retest correlations (r = 0.99) within both regions of interest. Verb generation was associated with the highest average concurrence ratios within the inferior frontal region of interest (Roverlap = 45.2; Rvolume = 70.9). In general, the concurrence ratios were lower within the temporoparietal region of interest compared with the inferior frontal region of interest. LIs calculated with F statistics were more reproducible than the LIs calculated by activation volume.

CONCLUSION: fMRI is able to provide reproducible LIs in both inferior frontal and temporoparietal regions for assessing hemispheric dominance in language processing. The volume of activation, especially within the temporoparietal regions, is less reproducible than the laterality of activation, so the former should be used with caution.






Copyright © 2008 by the American Society of Neuroradiology. Print ISSN: 0195-6108 Online ISSN: 1936-959X