Abstract
The effects of the k-space data undersampling and the discontinuities associated with the keyhole approach in functional magnetic resonance imaging (fMRI) have been addressed. Undersampling of high k-space data increases the high spatial-frequency noise by a factor of m( 1/2 ), where m is the number of images sharing the high k-space data. However, the effects of the noise can be effectively removed using clustered-pixel statistical analysis. The amplitude and phase discontinuities may result in an increase in the low spatial-frequency noise level, which has no impact on specificity and only a minimal impact on sensitivity. Although dramatically reducing acquisition time and preserving the spatial resolution of functional magnetic resonance imaging, the keyhole technique may have a limited capability in detecting highly focal activations.
Original language | English (US) |
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Pages (from-to) | 109-119 |
Number of pages | 11 |
Journal | Magnetic Resonance Imaging |
Volume | 17 |
Issue number | 1 |
DOIs | |
State | Published - Feb 1999 |
Keywords
- Algorithms
- Functional MRI
- Functional imaging
- Keyhole
ASJC Scopus subject areas
- Biophysics
- Radiology Nuclear Medicine and imaging
- Biomedical Engineering