Kang D, Sung YW, Shioiri S. Estimation of physiological sources of nonlinearity in blood oxygenation level-dependent contrast signals.
Magn Reson Imaging 2017;
46:121-129. [PMID:
29122668 DOI:
10.1016/j.mri.2017.10.017]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 10/13/2017] [Accepted: 10/31/2017] [Indexed: 11/25/2022]
Abstract
Blood oxygenation level-dependent (BOLD) contrast appears through a variation in the transverse relaxation rate of magnetic resonance signals induced by neurovascular coupling and is known to have nonlinear characteristics along echo time (TE) due to the intra-vasculature. However, the physiological causes of this nonlinearity are unclear. We attempted to estimate the physiological information related to the nonlinearity of BOLD signals by using a two-compartment model. For this purpose, we used a multi-echo gradient-echo echo-planar imaging sequence and developed a computational method to estimate the physiological information from the TE-dependent BOLD signals. The results showed that the average chemical exchange time in the intra-vasculature varied during stimulation, which might be the essential source of the nonlinearity.
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