Abstract
In this work a method for considerably improving the signal-to-noise ratio (SNR) in T(1) maps based on the variable flip angle approach is proposed, employing spoiled fast low angle shot (FLASH) echo-planar imaging (EPI) hybrid sequences with two echoes per excitation. In phantom measurements it could be verified that the SNR improvement in the underlying images translated into an SNR increase in the T(1) maps exceeding theoretical predictions. Even a hybrid sequence with an 18% shorter measurement time than a standard FLASH readout with identical spatial coverage and resolution yielded an SNR gain of 23% in the resulting T(1) maps. Hybrid sequences with either identical measurement time (9:05 min) or bandwidth (9:30 min) yielded gains of 60% and 67%, respectively. These results could be confirmed by measurements on four healthy volunteers. The image quality of T(1) maps based on hybrid sequences was excellent and the SNR improvement was clearly visible. The measured SNR gains in T(1) maps were between 20% (shortest sequence, white matter) and 66% (sequence with identical bandwidth, gray matter). The resulting T(1) values were comparable, with a slight tendency toward higher values in the hybrid sequences. In summary, without prolonging experiment durations the method proposed yields SNR gains that are commonly achieved by acquiring two averages.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
