Jing Yu1,2, Michael Schr, 23,
Harsh Agarwal, 2,4, Matthias Stuber2,5
1Department of Biomedical Engineering,
Johns Hopkins University, Baltimore, MD, United States; 2Russell
H. Morgan Department of Radiology and Radiological Science, Johns Hopkins
University, Baltimore, MD, United States; 3Philips Healthcare,
Cleveland, OH, United States; 4Department of Electrical and
Computer Engineering, John Hopkins University, Baltimore, MD, United States; 5Department
of Radiology, University Hospital Center and University of Lausanne (CHUV),
Lausanne, VD, Switzerland
One
of the challenges in coronary MRA is insufficient SNR. To improve the
blood-pool SNR in prospective respiratory navigator gated whole-heart
coronary MRA, radiofrequency excitations of the gradient echo readout train
are suspended in real-time, when the respiratory position is outside the
predefined gating window. Phase encoding is adapted to deposit the increased
signal in central k-space and to minimize signal variation of adjacent
k-space profiles. Consistent with the numerical simulation, in vivo
experiments demonstrated 35% improvement in blood-pool SNR, without
compromising scan time or spatial resolution. The SNR advantage affords great
potential towards better depiction of the coronary arteries.