Jieying Luo1, Nii Okai Addy1, R Reeve Ingle1, Brian A Hargreaves2, Bob S Hu1,3, Dwight G Nishimura1, Taehoon Shin4. 1. Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA. 2. Department of Radiology, Stanford University, Stanford, California, USA. 3. Palo Alto Medical Foundation, Palo Alto, California, USA. 4. Diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, Maryland, USA.
Abstract
PURPOSE: To develop a magnetization preparation sequence for simultaneous outer volume suppression (OVS) and T2 weighting in whole-heart coronary magnetic resonance angiography. METHODS: A combined OVS and T2 preparation sequence (OVS-T2 Prep) was designed with a nonselective adiabatic 90° tipdown pulse, two adiabatic 180° refocusing pulses, and a 2D spiral -90° tipup pulse. The OVS-T2 Prep preserves the magnetization inside an elliptic cylinder with T2 weighting, while saturating the magnetization outside the cylinder. Its performance was tested on phantoms and on 13 normal subjects with coronary magnetic resonance angiography using 3D cones trajectories. RESULTS: Phantom studies showed expected T2 -dependent signal amplitude in the spatial passband and suppressed signal in the spatial stopband. In vivo studies with full-field-of-view cones yielded a passband-to-stopband signal ratio of 3.18 ± 0.77 and blood-myocardium contrast-to-noise ratio enhancement by a factor of 1.43 ± 0.20 (P < 0.001). In vivo studies with reduced-field-of-view cones showed that OVS-T2 Prep well suppressed the aliasing artifacts, as supported by significantly reduced signal in the regions with no tissues compared to the images acquired without preparation (P < 0.0001). CONCLUSION: OVS-T2 Prep is a compact sequence that can accelerate coronary magnetic resonance angiography by suppressing signals from tissues surrounding the heart while simultaneously enhancing the blood-myocardium contrast.
PURPOSE: To develop a magnetization preparation sequence for simultaneous outer volume suppression (OVS) and T2 weighting in whole-heart coronary magnetic resonance angiography. METHODS: A combined OVS and T2 preparation sequence (OVS-T2 Prep) was designed with a nonselective adiabatic 90° tipdown pulse, two adiabatic 180° refocusing pulses, and a 2D spiral -90° tipup pulse. The OVS-T2 Prep preserves the magnetization inside an elliptic cylinder with T2 weighting, while saturating the magnetization outside the cylinder. Its performance was tested on phantoms and on 13 normal subjects with coronary magnetic resonance angiography using 3D cones trajectories. RESULTS: Phantom studies showed expected T2 -dependent signal amplitude in the spatial passband and suppressed signal in the spatial stopband. In vivo studies with full-field-of-view cones yielded a passband-to-stopband signal ratio of 3.18 ± 0.77 and blood-myocardium contrast-to-noise ratio enhancement by a factor of 1.43 ± 0.20 (P < 0.001). In vivo studies with reduced-field-of-view cones showed that OVS-T2 Prep well suppressed the aliasing artifacts, as supported by significantly reduced signal in the regions with no tissues compared to the images acquired without preparation (P < 0.0001). CONCLUSION:OVS-T2 Prep is a compact sequence that can accelerate coronary magnetic resonance angiography by suppressing signals from tissues surrounding the heart while simultaneously enhancing the blood-myocardium contrast.
Authors: Nii Okai Addy; R Reeve Ingle; Jieying Luo; Corey A Baron; Phillip C Yang; Bob S Hu; Dwight G Nishimura Journal: Magn Reson Med Date: 2016-05-13 Impact factor: 4.668
Authors: David Y Zeng; Corey A Baron; Mario O Malavé; Adam B Kerr; Phillip C Yang; Bob S Hu; Dwight G Nishimura Journal: Magn Reson Med Date: 2019-11-05 Impact factor: 4.668
Authors: Yang Yang; Li Zhao; Xiao Chen; Peter W Shaw; Jorge A Gonzalez; Frederick H Epstein; Craig H Meyer; Christopher M Kramer; Michael Salerno Journal: Magn Reson Med Date: 2017-03-20 Impact factor: 4.668