Abstract
Blood flow in large vessels can be noninvasively evaluated with phase-contrast (PC) MRI by encoding the spin velocity to the image phase. Conventional phase-difference processing of the flow-encoded image data yields velocity images. Complex-difference processing is an alternative to phase-difference methods, and has the advantage of eliminating signal from stationary spins. In this study, two acquisitions with differential flow encoding are subtracted to yield a single projection that contains signal from only those spins moving in the direction of the flow-encoding gradients. The increase in acquisition efficiency allows real-time flow imaging with a temporal window as short as two acquisition lengths (60 ms). Validation of the complex-difference method by comparison with conventional gated-segmented PC-MRI in a flow phantom yielded a correlation of r > 0.99. Peak arterial flow rates in the popliteal artery and desending aorta measured in vivo with the complex-difference method were 0.92 ± 0.06 of the values measured with conventional PC imaging. Real-time in vivo volumetric flow imaging of transient flow events is also presented.
Original language | English (US) |
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Pages (from-to) | 1248-1255 |
Number of pages | 8 |
Journal | Magnetic Resonance in Medicine |
Volume | 50 |
Issue number | 6 |
DOIs | |
State | Published - Dec 2003 |
Externally published | Yes |
Keywords
- Complex-difference
- Flow
- MRI
- Phase-contrast
- Real-time
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Radiological and Ultrasound Technology