## Abstract A real‐time, 20‐Hz, one‐dimensional MR velocity imaging technique is described. A two‐dimensional RF pulse excites a 3‐cm diameter column. Velocity maps are formed from the phase difference between successive flow encoded and compensated acquisitions. A three‐point subtraction variation
Real time blood flow imaging by spiral scan phase velocity mapping
✍ Scribed by P. D. Gatehouse; D. N. Firmin; S. Collins; D. B. Longmore
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 901 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0740-3194
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✦ Synopsis
Abstract
The work describes the development of a novel sequence that uses rapid spiral k‐space sampling, combined with phase velocity mapping, for real time flow velocity imaging. The performance of the technique is assessed on phantoms for both through‐plane and in‐plane flows. The flow measurements compared well with those measured using a bucket and stopwatch. One advantage of the technique is that flow related signal loss is minimal due to the early acquisition of the center of k‐space data. Flow artifacts were observed for in‐plane flow and these were understood with the aid of computer simulations. In vivo studies involved cine velocity mapping in normal volunteers; aortic blood flow waveforms acquired by spiral scanning in two cardiac cycles compared well with data from a conventional gradient‐echo sequence. Potential applications of the method are demonstrated by studying the response of aortic flow to physical exercise and the real time monitoring of aortic flow during a valsalver maneuver.
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