- Workshop presentation
- Open Access
Rapid phase contrast MRI with minimum time gradient waveform design using convex optimization
© Middione et al.; licensee BioMed Central Ltd. 2014
- Published: 16 January 2014
- Spatiotemporal Resolution
- Shaped Gradient
- Waveform Design
- Sequence Efficiency
- Breath Hold Duration
Phase contrast MRI (PC-MRI) sequences conventionally use triangular and trapezoidal gradient waveforms to construct flow compensated and flow encoded (FCFE)  or Bipolar  velocity encoding gradients. This approach does not make optimal use of the available gradient hardware for all time points, but convex optimization (CVX) can be used to design minimum-duration, arbitrarily shaped gradient waveforms subject to gradient hardware and pulse sequence constraints (e.g. target gradient moments and imaging parameters) . Our objective was to quantitatively evaluate CVX PC-MRI measurement accuracy and sequence efficiency.
The Bland-Altman results indicate excellent agreement between CVX and FCFE (very low measurement bias and narrow 95%-CIs). Calculations show that ECVX can be increased by as much as 44%. Improvements in ECVX can be used to improve spatiotemporal resolution for a fixed breath hold duration or to reduce breath hold duration for an otherwise fixed protocol.
This work was enabled by research support from Siemens Medical Solutions and the Department of Radiological Sciences to DBE.
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