In vivo and ex vivo virtual biopsy of the liver with near-infrared, reflectance confocal microscopy

Abstract

The assessment of liver architecture is an essential part of the understanding of its physiology and pathology. Current fluorescence confocal microscopy methods face numerous drawbacks, such as cytotoxicity, quenching effect, potential negative ino-and chrono-tropic effects and leaking of fluorescent agents through the sinusoid fenestrations. The recently developed, near-infrared reflectance confocal microscopy allows highresolution optical sectioning through intact tissues, without employing fluorescent stains, while contrast between structures is provided by the natural refractivity of the tissue. The aim of this study is to assess the utility of near-infrared reflectance confocal microscopy in the evaluation of the hepatic microscopic architecture in vivo and ex vivo. Rat livers were noninvasively examined in vivo and ex vivo with near-infrared reflectance confocal microscopy. Two experimental contrast agents were subsequently used to enhance particular structures. Parenchymal and vascular structures are readily identified, as well as some intracellular details. Differences between in vivo and ex vivo states were also observed. The use of contrast agents also highlights certain morphologic structures. In conclusion, near-infrared reflectance confocal microscopy stands as a useful adjunct technique to the study of hepatic parenchyma offering details equivalent to, if not surpassing traditional light microscopy.

In vivo confocal laser laparoscopy allows real time subsurface microscopy in animal models of liver disease

“…Dynamic imaging cannot be achieved in biopsy specimens after fixation. It has been found challenging even in rodent liver slices, since microarchitectural changes have been described to occur in a matter of minutes after resection [24].…”

Near‐Infrared Light Emission from a GaN/Si Nanoheterostructure Array

“…[3][4][5] Currently, most NIR light emitting diodes (LEDs) are made from polymer or other organic materials, [6][7][8] narrow-bandgap III-V semiconductors, [ 9 ] and their rare-earth or transitional metal doped counterparts. [10][11][12] The electroluminescence (EL) of these NIR LEDs are generally attributed to either the carrier band-to-band transition of the semiconductor(s) making up the heterojunctions, [ 9 ] or the carrier transition between the energy levels of the doped metal ions.…”

Virtual biopsy of the joint tissues using near‐infrared, reflectance confocal microscopy. A pilot study

“…Our studies demonstrate that the use of acetic acid highlights nuclei and certain matrix fibers (Campo-Ruiz et al, 2005b). This phenomenon of nuclei enhancement has only been described for epithelial and glandular cells (Campo-Ruiz et al, 2002, 2005aDrezek et al, 2000;Rajadhyaksha et al, 2000). In theory, acetic acid disrupts the bond between histones and DNA, making it clump and thus become more refractile.…”