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Regional impact of field strength on voxel-based morphometry results
| Content Provider | Scilit |
|---|---|
| Author | Tardif, Christine L. Collins, D. Louis Pike, G. Bruce |
| Copyright Year | 2009 |
| Description | Journal: Human brain mapping The objective of this study was to characterize the sensitivity of voxel-based morphometry (VBM) results to choice field strength. We chose to investigate the two most widespread acquisition sequences for VBM, FLASH and MP-RAGE, at 1.5 and 3 T. We first evaluated image quality of the four acquisition protocols in terms of SNR and image uniformity. We then performed a VBM study on eight subjects scanned twice using the four protocols to evaluate differences in grey matter (GM) density and corresponding scan-rescan variability, and a power analysis for each protocol in the context a longitudinal and cross-sectional VBM study. As expected, the SNR increased significantly at 3 T for both FLASH and MP-RAGE. Image non-uniformity increased as well, in particular for MP-RAGE. The differences in CNR and contrast non-uniformity cause regional biases between protocols in the VBM results, in particular between sequences at 3 T. The power analysis results show an overall decrease in the number of subjects required in a longitudinal study to detect a difference in GM density at 3 T for MP-RAGE, but an increase for FLASH. The number of subjects required in a cross-sectional VBM study is higher at 3 T for both sequences. Our results show that each protocol has a distinct regional sensitivity pattern to morphometric change, which goes against the classical view of VBM as an unbiased whole brain analysis technique, complicates the combination of data within a VBM study and the direct comparison of VBM studies based on different protocols |
| Ending Page | 957 |
| Starting Page | 943 |
| ISSN | 00221295 |
| e-ISSN | 10970193 |
| DOI | 10.1002/hbm.20908 |
| Journal | Human brain mapping |
| Issue Number | 7 |
| Volume Number | 31 |
| Language | English |
| Publisher | Wiley-Blackwell |
| Publisher Date | 2009-10-27 |
| Access Restriction | Open |
| Subject Keyword | Journal: Human brain mapping Magnetic Resonance Imaging Voxel‐based Morphometry Field Strength Comparison |
| Content Type | Text |
| Resource Type | Article |
| Subject | Physiology |
