Title :
An Active Noise Cancellation System for fMRI
Author :
Cho, Kuan-Hung ; Chiueh, Tzi-Dar ; Lin, Ching-Po ; Chen, Casper K. ; Chen, Jyh-Horng
Author_Institution :
Nat. Taiwan Univ., Taipei
Abstract :
MRI acoustic noise could be high up to 120 dB while acquiring images with high speed echo planar imaging (EPI). It reaches the hearing limit of human and also impedes the research of functional MRI. In this research, an active noise cancellation (ANC) system was implemented using a filtered-x recursive least-square (FXRLS) filter and combined with passive noise cancellation to reduce the noise from EPI. Further, the visual fMRI experiments were performed with and without the ANC system. Our results showed extra 9.4 dB reduction was obtained by active noise cancellation at the main frequency of EPI noise. Besides, the fMRI results showed 140% activated pixel numbers increased.
Keywords :
biomedical MRI; image denoising; least squares approximations; medical image processing; active noise cancellation; echo planar imaging; fMRI; filtered-x recursive least-square filter; Acoustic imaging; Acoustic noise; Active noise reduction; Auditory system; Frequency; Humans; Impedance; Magnetic resonance imaging; Noise cancellation; Passive filters;
Conference_Titel :
Noninvasive Functional Source Imaging of the Brain and Heart and the International Conference on Functional Biomedical Imaging, 2007. NFSI-ICFBI 2007. Joint Meeting of the 6th International Symposium on
Conference_Location :
Hangzhou
Print_ISBN :
978-1-4244-0949-5
Electronic_ISBN :
978-1-4244-0949-5
DOI :
10.1109/NFSI-ICFBI.2007.4387747
