Optimization of Echo Time for BOLD Dynamic Susceptibility Contrast MRI

Motivation: Achieving accurate quantification of absolute CBV and CBF in BOLD-DSC depends on maximizing the hypoxia-induced signal changes and accurately determining the arterial input function. Goal(s): The choice of echo time affects both baseline signal-to-noise ratio and hypoxia-induced changes1,2, our study aimed to investigate the effects of different TEs on the quantification of CBV and CBF. Approach: We systematically varied TE within the range of 11.57 ms to 20 ms , measured hypoxia-induced signal changes in arterial, venous, and somatosensory tissue voxels, and quantified perfusion metrics. Results: We discovered that a shorter TE, which produces sufficient signal changes without causing arterial peak saturation, is preferable. Impact: Shorter TE leads to less hypoxia-induced signal changes, while longer TE decreases baseline SNR and increase the risk of arterial signal saturation. This signal saturation leads to the underestimation of AIF, and consequently, overestimation of perfusion quantification.