BOLD imaging: a potential predictive biomarker of renal functional outcome following revascularization in atheromatous renovascular disease.

BACKGROUND Stenting of the stenosed renal artery is commonly employed in atheromatous renovascular disease (ARVD) in order to revascularize the affected kidney. However, it is still far from clear which patient subgroups should be revascularized as stenting carries small but significant risks. We have previously demonstrated that the ratio of magnetic resonance-measured renal volume to isotopic single kidney glomerular filtration rate (isoSK-GFR) is higher in kidneys which show functional improvement after revascularization. Blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) does not require contrast administration and is sensitive to changes in tissue concentration of deoxyhaemoglobin. METHODS In this study, we test the hypothesis that baseline BOLD R2* map signal and R2*:isoSK-GFR ratio will provide an additional independent predictive biomarker of response to revascularization. RESULTS Studies were performed in 28 subjects (16 ARVD and 12 controls). All subjects had R2* mapping and isoSK-GFR measured at baseline and at 4-month follow-up. MRI data were collected on a 3 T whole-body MRI scanner using a coronal dual-echo, 2D gradient-echo breath-hold acquisition. Parenchymal regions of interest (ROIs) were drawn on a representative slice through the middle of the kidney. Parametric maps of R2* were generated and mean values of R2* were calculated for every ROI. The ratio of R2*:isoSK-GFR at baseline was significantly greater in kidneys where renal function improved (5.91 ± 6.51) versus stable (1.78 ± 1.11), deteriorated (2.15 ± 1.79) or controls (1.5 ± 0.91), P = 0.003. R2*:isoSK-GFR ratio that was greater than 95% confidence interval of the control kidneys was 66.7% sensitive, but 85.7% specific in predicting a positive renal functional outcome. CONCLUSIONS These pilot data show that BOLD R2* imaging, presumably by detecting intra-renal deoxyhaemoglobin in still viable 'hibernating' parenchyma, coupled with isoSK-GFR may provide an effective predictive biomarker for positive renal functional response to revascularization. R2* imaging is non-invasive, quick to perform and could provide further insight into reversible parenchymal changes in ARVD kidneys.

[1]  Michael Sabel,et al.  Comparison of 18F-FET PET and 5-ALA fluorescence in cerebral gliomas , 2011, European Journal of Nuclear Medicine and Molecular Imaging.

[2]  C. Moonen,et al.  Renal hemodynamics and oxygenation in transient renal artery occluded rats evaluated with iron-oxide particles and oxygenation-sensitive imaging. , 2010, Zeitschrift fur medizinische Physik.

[3]  D. Buckley,et al.  Effects of renal volume and single-kidney glomerular filtration rate on renal functional outcome in atherosclerotic renal artery stenosis. , 2010, Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association.

[4]  L. Lerman,et al.  Preserved Oxygenation Despite Reduced Blood Flow in Poststenotic Kidneys in Human Atherosclerotic Renal Artery Stenosis , 2010, Hypertension.

[5]  M. Klein.  Revascularization versus Medical Therapy for Renal-Artery Stenosis , 2010 .

[6]  Sean B. Fain,et al.  Blood oxygen level-dependent and perfusion magnetic resonance imaging: detecting differences in oxygen bioavailability and blood flow in transplanted kidneys. , 2010, Magnetic resonance imaging.

[7]  Jeffrey H Maki,et al.  Renovascular imaging in the NSF Era , 2009, Journal of magnetic resonance imaging : JMRI.

[8]  L. Lerman,et al.  Comparison of 1.5 and 3 T BOLD MR to Study Oxygenation of Kidney Cortex and Medulla in Human Renovascular Disease , 2009, Investigative radiology.

[9]  L. Lerman,et al.  Increased hypoxia and reduced renal tubular response to furosemide detected by BOLD magnetic resonance imaging in swine renovascular hypertension. , 2009, American journal of physiology. Renal physiology.

[10]  I. Bricault,et al.  Evaluation of intrarenal oxygenation by blood oxygen level-dependent magnetic resonance imaging in living kidney donors and their recipients: preliminary results. , 2009, Transplantation proceedings.

[11]  J. Olin,et al.  Diagnosis and management of atherosclerotic renal artery stenosis: improving patient selection and outcomes , 2009, Nature Clinical Practice Cardiovascular Medicine.

[12]  S. Riederer,et al.  The use of magnetic resonance to evaluate tissue oxygenation in renal artery stenosis. , 2008, Journal of the American Society of Nephrology : JASN.

[13]  N. Morioka,et al.  Renal artery stenosis in cardio-and cerebrovascular disease: renal duplex ultrasonography as an initial screening examination. , 2007, Circulation journal : official journal of the Japanese Circulation Society.

[14]  B. Krumme,et al.  Doppler sonography in renal artery stenosis--does the Resistive Index predict the success of intervention? , 2007, Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association.

[15]  Sean B Fain,et al.  BOLD-MRI assessment of intrarenal oxygenation and oxidative stress in patients with chronic kidney allograft dysfunction. , 2007, American journal of physiology. Renal physiology.

[16]  R. D'Agostino,et al.  Stent revascularization for the prevention of cardiovascular and renal events among patients with renal artery stenosis and systolic hypertension: rationale and design of the CORAL trial. , 2006, American heart journal.

[17]  D. Buckley,et al.  MR-derived renal morphology and renal function in patients with atherosclerotic renovascular disease. , 2006, Kidney international.

[18]  R. Foley,et al.  Atherosclerotic renovascular disease in United States patients aged 67 years or older: risk factors, revascularization, and prognosis. , 2005, Kidney international.

[19]  Hans Stødkilde-Jørgensen,et al.  Validation of quantitative BOLD MRI measurements in kidney: application to unilateral ureteral obstruction. , 2005, Kidney international.

[20]  Stephen J Riederer,et al.  Blood oxygen level-dependent measurement of acute intra-renal ischemia. , 2004, Kidney international.

[21]  M. Rehling,et al.  99mTc-DTPA gamma-camera renography: Normal values and rapid determination of single-kidney glomerular filtration rate , 2004, European Journal of Nuclear Medicine.

[22]  J. V. van Engelshoven,et al.  The benefit of STent placement and blood pressure and lipid-lowering for the prevention of progression of renal dysfunction caused by Atherosclerotic ostial stenosis of the Renal artery. The STAR-study: rationale and study design. , 2003, Journal of nephrology.

[23]  R R Edelman,et al.  Breath‐hold R2* mapping with a multiple gradient‐recalled echo sequence: Application to the evaluation of intrarenal oxygenation , 1997, Journal of magnetic resonance imaging : JMRI.

[24]  R R Edelman,et al.  Noninvasive evaluation of intrarenal oxygenation with BOLD MRI. , 1996, Circulation.

[25]  M. Brezis,et al.  Determinants of intrarenal oxygenation. I. Effects of diuretics. , 1994, The American journal of physiology.

[26]  L. Smith,et al.  Renal artery stenosis: prevalence and associated risk factors in patients undergoing routine cardiac catheterization. , 1992, Journal of the American Society of Nephrology : JASN.