Niendorf T.,Berlin Ultrahigh Field Facility Buff Max Delbru Ck Center For Molecular Medicine Berlin Germany |
Pohlmann A.,Berlin Ultrahigh Field Facility Buff Max Delbru Ck Center For Molecular Medicine Berlin Germany |
Arakelyan K.,Berlin Ultrahigh Field Facility Buff Max Delbru Ck Center For Molecular Medicine Berlin Germany |
Flemming B.,Institute of Physiology and Center for Cardiovascular Research Charite University tsmedizin Berlin Berlin Germany |
And 8 more authors.
Renal tissue hypoperfusion and hypoxia are key elements in the pathophysiology of acute kidney injury and its progression to chronic kidney disease. Yet, in vivo assessment of renal haemodynamics and tissue oxygenation remains a challenge. Many of the established approaches are invasive, hence not applicable in humans. Blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) offers an alternative. BOLD-MRI is non-invasive and indicative of renal tissue oxygenation. Nonetheless, recent (pre-) clinical studies revived the question as to how bold renal BOLD-MRI really is. This review aimed to deliver some answers. It is designed to inspire the renal physiology, nephrology and imaging communities to foster explorations into the assessment of renal oxygenation and haemodynamics by exploiting the powers of MRI. For this purpose, the specifics of renal oxygenation and perfusion are outlined. The fundamentals of BOLD-MRI are summarized. The link between tissue oxygenation and the oxygenation-sensitive MR biomarker T* 2 is outlined. The merits and limitations of renal BOLD-MRI in animal and human studies are surveyed together with their clinical implications. Explorations into detailing the relation between renal T* 2 and renal tissue partial pressure of oxygen (pO2) are discussed with a focus on factors confounding the T* 2 vs. tissue pO2 relation. Multi-modality in vivo approaches suitable for detailing the role of the confounding factors that govern T* 2 are considered. A schematic approach describing the link between renal perfusion, oxygenation, tissue compartments and renal T* 2 is proposed. Future directions of MRI assessment of renal oxygenation and perfusion are explored. © 2014 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd. Source