Reduction of transient signal oscillations in true-FISP using a linear flip angle series magnetization preparation

• Published in: Magnetic resonance in medicine Vol. 49; no. 1; pp. 151 - 157
• Main Authors: Deshpande, Vibhas S., Chung, Yiu-Cho, Zhang, Qiang, Shea, Steven M., Li, Debiao
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01.01.2003; Williams & Wilkins
• Subjects: Adult; Aged; Arteries - anatomy & histology; Biological and medical sciences; Cardiovascular system; Computer Simulation; coronary arteries; Coronary Vessels - anatomy & histology; Electroencephalography; fast imaging; Female; Humans; image artifacts; Investigative techniques, diagnostic techniques (general aspects); magnetic resonance imaging (MRI); Magnetic Resonance Imaging - methods; Male; Medical sciences; Middle Aged; MR angiography; Phantoms, Imaging; Radiodiagnosis. Nmr imagery. Nmr spectrometry; steady-state free precession (SSFP); Human; Visualization; Healthy subject; Volunteer; Coronary artery; steady-state free precession (SSFP); Nuclear magnetic resonance imaging; Steady state; image artifacts; magnetic resonance imaging (MRI); Precession; coronary arteries; Angle; Simulation; Fluorescence in situ hybridization; MR angiography; Medical imagery; Technique; NMR angiography; Test object; fast imaging
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.10337

An electrocardiogram (ECG)‐triggered, magnetization‐prepared, segmented, 3D true fast imaging with steady‐state precession (true‐FISP) sequence with fat saturation was recently proposed for coronary artery imaging. A magnetization preparation scheme consisting of an α/2 radiofrequency (RF) pulse followed by 20 constant flip angle dummy RF cycles was used to reduce signal oscillations in the approach to steady state. However, if large resonance offsets on the order of 70–100 Hz are present, significant magnetization oscillations will still occur during data acquisition, which will result in image ghosting and blurring. The goal of this work was to validate that a linear flip angle (LFA) series can be used during magnetization preparation to reduce these image artifacts. Computer simulations, phantom studies, and coronary artery imaging in healthy volunteers were performed to compare this magnetization preparation scheme with that of an α/2 pulse followed by constant flip angle dummy RF cycles. The results demonstrated substantial reduction in the apparent image artifacts when using linearly increasing flip angles during magnetization preparation. Magn Reson Med 49:151–157, 2003. © 2003 Wiley‐Liss, Inc.