# Depth-Variant Deconvolution Applied to Widefield Microscopy for Rapid Large-Volume Tissue Imaging

## TL;DR

This paper introduces a new imaging method that combines tissue clearing and deconvolution to enable detailed 3D imaging of thick tissues using widefield microscopy.

## Contribution

The novel contribution is a depth-variant deconvolution approach that enables subnuclear resolution in large-volume tissues using widefield microscopy.

## Key findings

- The method achieved subnuclear axial resolution in tissues up to 500 μm deep.
- It enabled 3D visualization of blood vessels and amyloid deposits in brain slices comparable to confocal microscopy.
- The approach allowed rapid 3D imaging of human kidney biopsies in under five minutes.

## Abstract

Innovations in 3D tissue imaging have revolutionized research, but limitations stemming from lengthy protocols and equipment accessibility persist. Classical widefield microscopy is fast and accessible but often excluded from 3D imaging workflows due to its lack of optical sectioning. Here we combine tissue clearing with a depth-variant deconvolution approach customized for large-volume widefield imaging to achieve subnuclear axial resolution in tissues to a depth of 500 μm. We illustrate the utility of this method in a mouse model of ileitis and to gain a 3D perspective in thick brain slices from a mouse model of cerebral amyloid angiopathy, where we resolved large and small blood vessels, including those with amyloid deposits, attaining resolution that compared favorably to tile-scanning confocal microscopy. Finally, we sought to leverage our approach to allow for richer pathological evaluation of human kidney biopsies. Our approach produced hundreds of consecutive z-planes in five minutes of imaging for 3D visualization of winding arterioles feeding into glomeruli. This 3D perspective afforded straightforward identification of atrophic tubes in fresh kidney biopsies prepared in 2 hours to simulate the time-constrained evaluation of donor kidneys for transplant suitability. Having achieved subnuclear z-resolution in sections hundreds of microns thick, widefield microscopy coupled to robust deconvolution now emerges as an accessible and viable method to gain 3D insight in research or clinical pathological evaluations.