| 摘要 |
Referenceless techniques for flow imaging are described that exploit a refocusing property of balanced steady state free precession (“SSFP”) magnetic resonance imaging (“MRI”), and achieve up to approximately a 50% reduction in total scan time. With the echo time set to one half of the sequence repetition time (TE=TR/2), non-flow-related image phase tends to vary smoothly across the field-of-view, and can be estimated from static tissue regions to produce a phase reference for nearby voxels containing flowing blood. These approaches produce accurate in vivo one-dimensional velocity estimates in half the scan time compared with conventional balanced SSFP phase-contrast methods. The feasibility of referenceless time-resolved 3D flow imaging (called “7D” flow) is demonstrated for a carotid bifurcation application from just three acquisitions. Related systems are also described. Other attributes such as blood acceleration can also be imaged with such techniques. |
