title: Blood oxygen level-dependent (BOLD) MRI analysis in atherosclerotic renal artery stenosis.
abstract: OBJECTIVE
  Blood oxygen level-dependent MRI (BOLD MRI) is a noninvasive technique for evaluating kidney tissue oxygenation that requires no contrast exposure, with the potential to allow functional assessment in patients with atherosclerotic renal artery stenosis. Normal cortical-to-medulla oxygenation gradients are preserved in many patients treated for several years with medical antihypertensive therapy without restoring renal blood flow. The current review is of particular interest as new methods have been applied to the analyses of BOLD MRI, opening the perspective of its wider utilization in clinical practice.
  
  
  RESULTS
  Recent findings show that more severe vascular compromise ultimately overwhelms renal adaptive changes, leading to overt cortical hypoxia and expansion of medullary hypoxic zones. 'Fractional kidney hypoxia' method of analysis, developed as an alternative method of BOLD MRI analysis, avoids the assumption of discrete cortical and medullary values and decreases the bias related to operator selection of regions of interests.
  
  
  CONCLUSIONS
  We believe that thoughtful application and analysis of BOLD MRI can provide critical insights into changes in renal function prior to the onset of irreversible renal injury and may identify patients most likely to gain from measures to reverse or repair disorders of tissue oxygenation.
authors.affiliation: Gonda Vascular Center, Mayo Clinic, Rochester, Minnesota 55905, USA. gloviczki.monika@gmail.com
authors.forename: Monika L
authors.initials: ML
authors.lastname: Gloviczki
authors.forename: Ahmed
authors.initials: A
authors.lastname: Saad
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Textor
mesh_terms: D000818:Animals; D050197:Atherosclerosis / Q000175:diagnosis* / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D012078:Renal Artery Obstruction / Q000175:diagnosis* / Q000473:pathology*; D012079:Renal Circulation / Q000502:physiology
chemical_list: D010100:Oxygen
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