Advanced

AJNR - American Journal of Neuroradiology

This Article Abstract Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Miki, A. Articles by Liu, G. T. Search for Related Content PubMed PubMed Citation Articles by Miki, A. Articles by Liu, G. T.

Reproducibility of Visual Activation in Functional MR Imaging and Effects of Postprocessing

Atsushi Miki^,a, Jonathan Raz^a, Theo G. M. van Erp^a, Chia-Shang J. Liu^a, John C. Haselgrove^a and Grant T. Liu^a

^a From the Department of Neurology (Division of Neuro-ophthalmology), Hospital of the University of Pennsylvania (A.M., G.T.L.); the Division of Biostatistics (J.R.) and the Department of Psychology (T.G.M.v.E.), University of Pennsylvania; the University of Pennsylvania School of Medicine (C-S.J.L.); and the Department of Radiology, Children's Hospital of Philadelphia (J.C.H.).

View larger version (39K): [in a new window]   FIG 1. A and B, Z maps of the first (A) and second (B) studies in a volunteer show high reproducibility (type 2 comparison). A height threshold of uncorrected P < .001 was selected for this figure. Supra-threshold clusters of voxels were identified using a corrected spatial extent threshold of P < .05.

View larger version (37K): [in a new window]   FIG 2. A and B, Z maps of the first (A) and second (B) studies in a volunteer show lower reproducibility (type 2 comparison). This subject had much less visual activation in the second study.

View larger version (36K): [in a new window]   FIG 3. A and B, Box plots of Rsize for seven subjects (A) and plots for each subject (B) show the effects of the type of comparison and threshold value on reproducibility. Black bars in A represent the Rsize values of the upper quartile (75th percentile) to the lower quartile (25th percentile). The median (50th percentile) values for each threshold are represented by the white lines in the bars. The minimum and maximum values are connected to the black bar with whiskers (the dotted lines extending from the bar). The brackets at both ends represent the maximum and minimum values. Where the maximum or minimum value exceeds the upper or lower quartile, respectively, by 1.5 times the difference of the values of the upper and lower quartiles, the extreme point is shown separately from the bar without the whiskers. The points in B represent the Rsize values of each individual in each type of comparison, with dotted lines connecting each individual's set of values across the types of comparison

View larger version (36K): [in a new window]   FIG 4. A and B, Box plots of Roverlap for seven subjects (A) and plots for each subject (B)