Abstract
A T2-relaxation-under-spin-tagging technique was recently developed to estimate cerebral blood oxygenation, providing potentials for noninvasive assessment of the brain's oxygen consumption. A limitation of the current sequence is the need for long repetition time, as shorter repetition time causes an over-estimation in blood R2. This study proposes a post-saturation T2-relaxation-under-spin-tagging by placing a non-selective 90° pulse after the signal acquisition to reset magnetization in the whole brain. This scheme was found to eliminate estimation bias at a slight cost of precision. To improve the precision, echo time of the sequence was optimized and it was found that a modest echo time shortening of 3.4 ms can reduce the estimation error by 49%. We recommend the use of postsaturation T2-relaxation-under-spin-tagging sequence with a repetition time of 3000 ms and a echo time of 3.6 ms, which allows the determination of global venous oxygenation with scan duration of 1 min 12 s and an estimation precision of ±1% (in units of oxygen saturation percentage).
Original language | English (US) |
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Pages (from-to) | 198-204 |
Number of pages | 7 |
Journal | Magnetic resonance in medicine |
Volume | 68 |
Issue number | 1 |
DOIs | |
State | Published - Jul 2012 |
Keywords
- Arterial spin labeling
- Brain
- Magnetization saturation
- Noninvasive measurement
- Oxygen saturation
- Oxygenation
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging