Xiaodong Zhong1,2, Patrick Helm3, Frederick H. Epstein1,3
1Biomedical Engineering, University of Virginia, Charlottesville, VA, USA; 2MR R&D Collaborations, Siemens Medical Solutions, Atlanta, GA, USA; 3Radiology, University of Virginia, Charlottesville, VA, USA
Various DENSE sequences have encoded displacement using a strategy analogous to the simple multi-point method for velocity-encoded phase contrast (PC) imaging. We developed general n-dimension balanced multi-point encoding for DENSE. Using these methods, phase noise variance decreased experimentally by 73.7%, 65.6%, and 61.9% compared to simple methods, which closely matched the theoretical decreases of 75%, 66.7%, and 62.5% for 1D, 2D and 3D encoding, respectively. Phase noise covariances decreased by 99.2% and 99.3% for balanced 2D and 3D encoding, consistent with the zero-covariance prediction. The direction bias inherent to the simple methods was decreased to almost zero using balanced methods.