Affiliation:
1. Department of Radiology Northwestern University Feinberg School of Medicine Chicago Illinois USA
2. Department of Biomedical Engineering, McCormick School of Engineering Northwestern University Evanston Illinois USA
3. Department of Biomedical Engineering Lehigh University Bethlehem Pennsylvania USA
4. Department of Pediatrics Northwestern University Feinberg School of Medicine Chicago Illinois USA
5. Division of Cardiology Ann & Robert H. Lurie Children's Hospital Chicago Illinois USA
6. Department of Medical Imaging Ann & Robert H. Lurie Children's Hospital Chicago Illinois USA
Abstract
AbstractPurposeTo develop a highly‐accelerated, real‐time phase contrast (rtPC) MRI pulse sequence with 40 fps frame rate (25 ms effective temporal resolution).MethodsHighly‐accelerated golden‐angle radial sparse parallel (GRASP) with over regularization may result in temporal blurring, which in turn causes underestimation of peak velocity. Thus, we amplified GRASP performance by synergistically combining view‐sharing (VS) and k‐space weighted image contrast (KWIC) filtering. In 17 pediatric patients with congenital heart disease (CHD), the conventional GRASP and the proposed GRASP amplified by VS and KWIC (or GRASP + VS + KWIC) reconstruction for rtPC MRI were compared with respect to clinical standard PC MRI in measuring hemodynamic parameters (peak velocity, forward volume, backward volume, regurgitant fraction) at four locations (aortic valve, pulmonary valve, left and right pulmonary arteries).ResultsThe proposed reconstruction method (GRASP + VS + KWIC) achieved better effective spatial resolution (i.e., image sharpness) compared with conventional GRASP, ultimately reducing the underestimation of peak velocity from 17.4% to 6.4%. The hemodynamic metrics (peak velocity, volumes) were not significantly (p > 0.99) different between GRASP + VS + KWIC and clinical PC, whereas peak velocity was significantly (p < 0.007) lower for conventional GRASP. RtPC with GRASP + VS + KWIC also showed the ability to assess beat‐to‐beat variation and detect the highest peak among peaks.ConclusionThe synergistic combination of GRASP, VS, and KWIC achieves 25 ms effective temporal resolution (40 fps frame rate), while minimizing the underestimation of peak velocity compared with conventional GRASP.
Funder
American Heart Association
National Institutes of Health
Radiological Society of North America
Subject
Radiology, Nuclear Medicine and imaging