Enhancement of respiratory navigator-gated three-dimensional spoiled gradient-recalled echo sequence with variable flip angle scheme
Year: 2013
Type: article
Abstract: PURPOSE: To develop and demonstrate the feasibility of a new technique for respiratory-gated, fat-suppressed, three-dimensional spoiled gradient-recalled echo (3D-SPGR) with navigator gating for more accurate and robust motion detection. METHODS: A navigator-gated 3D-SPGR technique was modified to include a wait period immediately prior to the navigator sequence for magnetization recovery. Furthermore, a variable flip angle scheme was realized by a combination of ramp-up, ramp-down, and attenuation strategies for optimizing point spread functions. Phantom and human experiments were conducted with our technique on 1.5T scanners. RESULTS: Using the method, T1-weighted 3D images with improved signal homogeneity were acquired with a maximum flip angle of 30° in phantom and human tests. Also, compared with the conventional navigator-gated 3D-SPGR, accurate respiratory motion detection of free-breathing subjects was provided, leading to reduced motion artifacts. CONCLUSION: The combination of wait insertion and the variable flip angle method improved both motion detection accuracy and image homogeneity in a navigator-gated 3D-SPGR study.
Source: Magnetic Resonance in Medicine
DOI: 10.1002/mrm.24902
Institutions: GE HealthCare (Japan), Stanford University
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W1927753009