审稿意见中审稿人提的The authors have to pay attention to the final inversion of the contrast as the mapping is not stable Do the authors consider a kind of regularization when moving from R to chi的问题该怎么修改与回答？

修改建议：

The authors should address the issue of the final inversion of the contrast, which can lead to unstable mapping. Have the authors considered implementing a regularization method when transitioning from R to \chi?

回答：

We thank the reviewer for their comment. We acknowledge the potential instability of the contrast inversion and recognize the importance of addressing this issue. To mitigate this problem, we plan to explore different regularization methods, such as Tikhonov regularization and Bayesian regularization, to improve the stability of the mapping from R to \chi. We will update the manuscript accordingly