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Optical Medical Imaging

Working Group 8.31

Characterization of renal haemodynamics and oxygenation by near-infrared spectroscopy

Project renalMROXY

  Validation of quantitative magnetic resonance oximetry for diagnostics of
  acute and chronic kidney diseases

Funding
   Federal Ministry of Education and Research (grant 03VP00083)
   01/2016 – 12/2018

Partners

  • Prof. Thoralf Niendorf, Max Delbrueck Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin
  • Dr. Erdmann Seeliger, Institute of Vegetative Physiology, Center for Cardiovascular Research, Charité University Medicine Berlin 
Relative changes of total hemoglobin concentration (left) and blood oxygen saturation (right) in small animal kidneys due to a three minute arterial (red lines) or venous occlusion (blue lines). Data were obtained by near-infrared spectroscopy.

Renal tissue hypoperfusion and hypoxia are considered to be key elements of acute kidney injury (AKI). To improve the understanding of the pathophysiology of AKI and its possible progression to chronic kidney disease basic investigations of renal hemodynamics and oxygenation in animal models are of high importance.

The project renalMROXY of the partners Max Delbrueck Center for Molecular Medicine, Charité and PTB aims at the development of quantitative Magnetic Resonance Imaging (MRI) as a tool for diagnosis and therapy of acute and chronic kidney diseases. The project partners will develop a small animal imager which combines parametric MRI with quantitative methods of integrative physiology (PHYSIOL) and quantitative near-infrared spectroscopy (NIRS). This imager will be applied for various interventions on small animal kidney models to better understand the linking between MRI parameters and the true perfusion and oxygenation parameters accessible by the PHYSIOL and NIRS methodologies.

The NIRS technology for the multi-modality small animal imager relies on a recently developed method that permits recording of oxy- and deoxyhemoglobin concentrations in renal tissue of small animals (s. Fig. above). This technique has been combined with the invasive probe methodology developed by the integrative kidney physiology group at the Charité Center for Cardiovascular Research which comprises ultrasound transit time difference measurements and laser-Doppler fluxmetry to assess tissue perfusion, and invasive probes to measure local tissue oxygenation. First studies on small animals have shown that the combined approach yields a quantitative and comprehensive characterization of renal hemodynamics and oxygenation.

Publications

D. Grosenick, K. Cantow, K. Arakelyan, H. Wabnitz, B. Flemming, A. Skalweit, M. Ladwig, R. Macdonald, T. Niendorf, and E. Seeliger, “Detailing renal hemodynamics and oxygenation in rats by a combined near-infrared spectroscopy and invasive probe approach,” Biomed. Opt. Express 6(2), 309–323 (2015) [doi:Opens external link in new window10.1364/BOE.6.000309].

T. Niendorf, A. Pohlmann, K. Arakelyan, B. Flemming, K. Cantow, J. Hentschel, D. Grosenick, M. Ladwig, H. Reimann, S. Klix, S. Waiczies, and E. Seeliger, “How bold is blood oxygenation level-dependent (BOLD) magnetic resonance imaging of the kidney? Opportunities, challenges and future directions,” Acta Physiol. (Oxf). 213(1), 19–38 (2015) [doi:Opens external link in new window10.1111/apha.12393].