Abstract
A method to tailor the view order to the reconstruction cycle is introduced for real-time MRI. It is well known that view sharing and oversampling central k-space views can improve the temporal resolution of gradient-echo pulse sequences. By ordering phase-encodes to synchronize k- space acquisition with the reconstruction cycle, apparent temporal resolution can match the frame rate with as few as one-fourth of the phase-encodes sampled per reconstruction. Spatial resolution is maintained by periodically updating high spatial frequencies. In addition to apparent temporal resolution, three other criteria for real-time imaging are identified and evaluated: display latency, dispersion, and frame-to-frame consistency. Latency is minimized by ordering views in a reverse-centric manner within each reconstruction interval, sampling high-energy views immediately prior to beginning reconstruction. Dispersion is kept low and consistent by synchronizing acquisition and reconstruction, thus avoiding poorly timed reconstruction instances. Real-time implementation demonstrates pulsatile time-of-flight blood signal enhancement in humans.
Original language | English (US) |
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Pages (from-to) | 69-81 |
Number of pages | 13 |
Journal | Magnetic Resonance in Medicine |
Volume | 42 |
Issue number | 1 |
DOIs | |
State | Published - 1999 |
Keywords
- Dynamic imaging
- Real-time MRI
- Temporal resolution
- View order
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging