3D X-Ray and FTIR imaging for routine histopathology in chronic kidney disease – 3DXIR-Pathology

We propose the development of a new diagnostic strategy by image-guided biopsy using transmission X-Ray microscopy (TXM) and three-dimensional (3D) infrared (IR) imaging for combining the morphological and molecular/biochemical features of a pathological tissue. The application example for proof-of-concept is chronic kidney disease (CKD), a pathology leading to loss of glomerular filtration functionality due to inflammation, fibrosis, metabolic dysfunctions, oxidative stress…etc., which are heterogeneous in the tissue volume and organ. CKD is a major medical issue in Taiwan, which has one of the highest incidence and prevalence rates of end-stage renal diseases in the world. For diagnosis, successful kidney biopsy could provide sufficient information about the origin and stage of the disease. However, the spatially localized characters of the disease requires effective imaging techniques to precisely target the biopsy that has otherwise a high risk of false negative results. Furthermore, 3D imaging should be also used in the biopsy specimen as a volumetric histology analysis.
Adequate imaging techniques do not currently exist. Specifically, immunohistochemistry is a 2-dimensional (2D) technique with limited effectiveness in detecting the complex 3D organization of the kidney. We propose a new strategy to solve this problem, based on combining high-resolution TXM with a novel development of the IR imaging technique for 3D analysis of tissues. We will combine the morphological information by TXM on the kidney filtration loss (microvascular/glomeruli network) and the IR information on structural (collagens distribution in fibrotic tissue), biochemical (oxidative stress), and metabolic (glycogen, glucose, lactic acid…) parameters of the vascular microenvironment. IR imaging in 3D will be required to take into account the morphological complexity of kidney organ. At the pre-clinical stage, animal studies will establish the basis for a diagnostic method based on TXM imaging of live specimens during the pathology evolution, followed by histological analysis using 3D IR imaging.
Our partnership is a unique position for the implementation of this project. The Taiwan members developed in the recent years synchrotron-radiation TXM with unprecedented performances and used it to image the complete microvasculature of organs in small animals. The objective now is to develop a benchtop X-Ray microscope for routine analysis of tissue specimen, in vivo for small animal models and ex vivo for human kidney biopsies. The French partners bring advanced expertize in IR imaging. Specifically, they used it for histological analysis based on characteristic IR molecular absorptions and advanced data treatments to obtain 2D imaging of chemical distributions. The next step, in collaboration with the industrial partner Bruker-Optics, is to develop the first automated 3D IR imaging system equipped with a tunable laser. This instrument will reveal the distribution of molecules in large tissue samples in delays compatible with clinical histology.
The instrumentation development will be complemented by medical analysis performed by one of the Taiwan partners. This will use CKD animal models to test the multimodal 3D imaging strategy at the organ level. Finally, an initial clinical phase will test the multimodal approach on human biopsy samples (from a hospital tissue bank), with validation based on other techniques (anatomo-pathology, immunohistochemistry, urine tests).
In addition to the medical and social impact, our project could lead to important industrial developments in the biomedical technology domain. Indeed, we will produce a prototype of integrated TXM/IR 3D imaging for routine clinical use that can be then used by industry to develop large-scale production. The consortium includes all the required expertize for this project, including unique know-how on the specific imaging techniques. Furthermore, it already has a solid record of successful collaboration.