Research Projects

Rapid Time-Resolved 3D Phase-Contrast Pediatric Cardiovascular MRI

Michael Lustig, Shreyas Vasanawala1 and Martin Uecker

American Heart Association 12BGIA9660006

Magnetic resonance imaging provides essential information used in the care of children with heart defects: heart function (chamber sizes and pumping efficiencies), blood flow (in various vessels and across heart valves), and anatomy. However, as MRI exams take longer than an hour and require children to remain motionless, anesthesia is often required, which is risky in these fragile patients. This project will develop and validate a rapid comprehensive MRI technique for evaluation of congenital heart defects. In particular we aim to develop velocity encoding strategies with high velocity-to-noise ratio and large velocity dynamic range, subsampling strategies for 3D time resolved phase-contrast, Reconstructions from subsampled data that exploit spatio-temporal sparsity of 4D flow, fast and clinically feasible implementation and clinical validation.

Figure 1
Figure 1: Accelerated 4D flow scan in a 6 year old with partial anomalous pulmonary venous re- turn (arrow) to obtain high spatio-temporal resolution. Right image shows right coronary artery, highlighting potential for anatomic assessment of small fast- moving structures as well as flow and function.

Figure 2
Figure 2: The case for accelerated 4D flow: A child with a repaired atrioventricular canal was found to have an abnormal- ity of the coronary sinus on an echocardiogram, but the nature of the abnormality was incompletely under- stood. In addition, the abnormality could not be well seen on conventional cardiac MRI. In contrast, 4D flow showed a regurgitant jet through a cleft in the mitral valve into a coronary sinus that was surgically com- mitted to drain into the left atrium by an atrial patch. This enabled surgical planning and the intraoperative findings confirmed the accuracy of the 4D flow diag- nosis.


1Stanford University

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