Optical Coherence Tomography of Human Kidney

To determine histopathological status of living human kidneys in real time and a noninvasive fashion would be a significant advancement in renal disease diagnosis. Recently we reported that optical coherence tomography has the requisite high spatial resolution to noninvasively determine histopathological changes in rodent kidneys with microm scale resolution. We established whether optical coherence tomography could 1) effectively penetrate the connective tissue capsule surrounding human kidneys, 2) provide a global survey of the human renal surface and 3) determine histopathological changes in human renal microstructure.Using a high speed optical coherence tomography system equipped with a frequency swept laser light source (1.3 microm wavelength) we obtained cross-sectional images of 4 ex vivo human kidneys. All scanned sections underwent subsequent conventional light microscopic histological analysis, allowing direct comparisons.Optical coherence tomography enabled characterization of the tubules, glomeruli and cortical vessels with a penetration depth of up to 2 mm and 10 microm spatial resolution. We surveyed and imaged an entire human kidney within minutes in a noninvasive fashion. Acquired optical coherence tomography images documented histopathological changes in the tubules, glomeruli and interstitium that closely matched the conventional histological observations.Optical coherence tomography resolution and low cost, and the versatility of the probes required for imaging acquisition make this optical technology a promising modality to diagnose renal pathology.