Real time blood flow imaging by spiral scan phase velocity mapping.
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.
Magnetic Resonance Unit, Royal Brompton National Heart and Lung Hospital, London, England.
P D
PD
Gatehouse
D N
DN
Firmin
S
S
Collins
D B
DB
Longmore
D000465:Algorithms; D001011:Aorta / Q000502:physiology; D016477:Artifacts; D001775:Blood Circulation / Q000502:physiology*; D001783:Blood Flow Velocity; D002302:Cardiac Output / Q000502:physiology; D003198:Computer Simulation; D003300:Copper; D019327:Copper Sulfate; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008955:Models, Cardiovascular; D008961:Models, Structural; D005082:Physical Exertion / Q000502:physiology; D010938:Plant Oils; D011651:Pulmonary Artery / Q000502:physiology; D012039:Regional Blood Flow; D012212:Rheology; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors; D014636:Valsalva Maneuver
D010938:Plant Oils; D003300:Copper; D019327:Copper Sulfate