Overcoming tissue scattering in wide-field deep imaging by extended detection and computational reconstruction

Compared to the golden technique of point-scanning multiphoton microscopy, line-scanning temporal focusing microscopy (LTFM) is competitive in high imaging speed while maintaining tight axial confinement. However, considering its wide-field detection mode, LTFM suffers from shallow penetration depth as a result of crosstalk induced by tissue scattering. In contrast to the spatial filtering based on confocal slit detection, we propose the extended detection LTFM (ED-LTFM), the first technique to extract signals from scattered photons and thus effectively extend the imaging depth. By recording a succession of line-shape excited signals in 2D and reconstructing signals under Hessian regularization, we can push the depth limitation in scattering tissue imaging. We valid the concept with numerical simulations, and demonstrate the performance of enhanced imaging depth in in vivo imaging of mouse brains.