X-Ray Phase-Contrast Tomography of Renal Ischemia-Reperfusion Damage

Abstract

PurposeThe aim of the study was to investigate microstructural changes occurring in unilateral renal ischemia-reperfusion injury in a murine animal model using synchrotron radiation.Material and MethodsThe effects of renal ischemia-reperfusion were investigated in a murine animal model of unilateral ischemia. Kidney samples were harvested on day 18. Grating-Based Phase-Contrast Imaging (GB-PCI) of the paraffin-embedded kidney samples was performed at a Synchrotron Radiation Facility (beam energy of 19 keV). To obtain phase information, a two-grating Talbot interferometer was used applying the phase stepping technique. The imaging system provided an effective pixel size of 7.5 µm. The resulting attenuation and differential phase projections were tomographically reconstructed using filtered back-projection. Semi-automated segmentation and volumetry and correlation to histopathology were performed.ResultsGB-PCI provided good discrimination of the cortex, outer and inner medulla in non-ischemic control kidneys. Post-ischemic kidneys showed a reduced compartmental differentiation, particularly of the outer stripe of the outer medulla, which could not be differentiated from the inner stripe. Compared to the contralateral kidney, after ischemia a volume loss was detected, while the inner medulla mainly retained its volume (ratio 0.94). Post-ischemic kidneys exhibited severe tissue damage as evidenced by tubular atrophy and dilatation, moderate inflammatory infiltration, loss of brush borders and tubular protein cylinders.ConclusionIn conclusion GB-PCI with synchrotron radiation allows for non-destructive microstructural assessment of parenchymal kidney disease and vessel architecture. If translation to lab-based approaches generates sufficient density resolution, and with a time-optimized image analysis protocol, GB-PCI may ultimately serve as a non-invasive, non-enhanced alternative for imaging of pathological changes of the kidney.

Three-dimensional non-destructive soft-tissue visualization with X-ray staining micro-tomography

“…4 ), with the additional benefit of providing non-distorted and fast 3D information. The staining method presented here yielded micro-CT images of a mouse kidney and a mouse cerebellum at a level of detail that is only available from other multiple sectioning techniques or highly sophisticated large-scale-facility-based X-ray methods 26 27 . Probably the biggest advantage over other lab-based techniques is the relatively fast (few hours) data acquisition, and the non-destructive and non-distorted 3D imaging visualisation.…”

Synchrotron Phase Tomography: An Emerging Imaging Method for Microvessel Detection in Engineered Bone of Craniofacial Districts

“…Differently from the conventional (attenuation-based) microCT in which the contrast is due to attenuation differences within the sample, in PhC-microCT the contrast originates from the phase shift of the X-ray beam passing through the matter (Snigirev et al, 1995 ; Bravin et al, 2013 ). This phase shift in non-mineralized biological tissues can be up to three orders of magnitude larger than attenuation (Momose et al, 1996 ; Lewis et al, 2003 ), explaining the highly increased contrast that has been observed with PhC-microCT imaging in investigating esophagus (Lewis et al, 2003 ), brain (Connor et al, 2009 ; Pinzer et al, 2012 ; Marinescu et al, 2013 ), liver (Lewis et al, 2003 ; Herzen et al, 2014 ), kidney (Velroyen et al, 2014 ), lung (Lewis et al, 2003 ), cartilage (Coan et al, 2010 ; Marenzana et al, 2012 ; Horng et al, 2014 ) and breast tissues (Arfelli et al, 2000 ; Stampanoni et al, 2011 ).…”

High‐resolution 3D imaging of microvascular architecture in human glioma tissues using X‐ray phase‐contrast computed tomography as a potential adjunct to histopathology

“…[12][13][14] Particularly in the imaging blood vessels, microvascular architectures in various organs (such as liver, heart and kidney) have been clearly presented via PCCT without contrast agents at micrometer or even submicrometer level. [15][16][17] High-resolution 3D visualization of the microvascular networks obtained by PCCT provides new possibilities for analyzing and characterizing 3D anatomical features of the vessels, especially for differentiating between healthy and diseased vessels. 18,19 Currently, most studies focused on demonstrating the high significance of the PCCT in analysis of brain vascular networks in small animals.…”