Blood Oxygen Level–Dependent (BOLD) MRI in Renovascular Hypertension

• Published in: Current hypertension reports Vol. 13; no. 5; pp. 370 - 377
• Main Authors: Gloviczki, Monika L., Lerman, Lilach O., Textor, Stephen C.
• Format: Journal Article
• Language: English
• Published: New York Current Science Inc 01-10-2011; Springer Nature B.V
• Subjects: Cardiology; Family Medicine; General Practice; Glomerular Filtration Rate; Humans; Hypertension; Hypertension, Renovascular - blood; Hypertension, Renovascular - diagnosis; Hypertension, Renovascular - pathology; Hypoxia - blood; Hypoxia - diagnosis; Hypoxia - pathology; Internal Medicine; Kidney - blood supply; Magnetic Resonance Imaging - instrumentation; Medicine; Medicine & Public Health; Metabolic Diseases; Nephrology; Oxidative Stress; Oxygen - blood; Oxygen Consumption; Primary Care Medicine; Renal Artery Obstruction - blood; Renal Artery Obstruction - diagnosis; Renal Artery Obstruction - pathology; Thrombosis - blood; Thrombosis - diagnosis; Thrombosis - pathology; BOLD MRI; Oxidative stress; Oxygen; Magnetic resonance imaging; Ischemic nephropathy; Renovascular hypertension; Hypoxia; Renal artery stenosis; Kidney
• ISSN: 1522-6417; 1534-3111
• DOI: 10.1007/s11906-011-0218-7

Establishing whether large vessel occlusive disease threatens tissue oxygenation and viability in the post-stenotic kidney is difficult for clinicians. Development of blood oxygen level–dependent (BOLD) MRI methods can allow functional evaluation of regional differences in deoxyhemoglobin levels within the kidney without requiring contrast. The complex renal circulation normally provides a gradient of oxygenation from a highly vascular cortex to much reduced levels in the deep sections of medulla, dependent upon adjustments in renal afferent arterioles, oxygen consumption related to solute transport, and arteriovenous shunting related to the juxtaposition of descending and ascending vasa recta. Studies with BOLD imaging have identified adaptation to substantial reductions in renal blood flow, volume, and glomerular filtration rate in post-stenotic kidneys that preserves medullary and cortical oxygenation during medical therapy. However, extreme vascular compromise overwhelms these adaptive changes and leads to cortical hypoxia and microvascular injury.