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Farg HM, El-Diasty T, Ali-El-Dein B, Refaie A, Abou El-Ghar M. Functional MRI evaluation of blood oxygen dependent (BOLD) in renal allograft dysfunction: a prospective study. Acta Radiol 2023:2841851231217052. [PMID: 38146146 DOI: 10.1177/02841851231217052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
BACKGROUND Blood oxygen level dependent-magnetic resonance imaging (BOLD-MRI) is a non-invasive functional imaging technique that can be used to assess renal allograft dysfunction. PURPOSE To evaluate the diagnostic performance of BOLD-MRI using a 3-T scanner in discriminating causes of renal allograft dysfunction in the post-transplant period. MATERIAL AND METHODS This prospective study was conducted on 112 live donor-renal allograft recipients: 53 with normal graft function, as controls; 18 with biopsy-proven acute rejection (AR); and 41 with biopsy-proven acute tubular necrosis (ATN). Multiple fast-field echo sequences were performed to obtain T2*-weighted images. Cortical R2* (CR2*) level, medullary R2* (MR2*) level, and medullary over cortical R2* ratio (MCR) were measured in all participants. RESULTS The mean MR2* level was significantly lower in the AR group (20.8 ± 2.8/s) compared to the normal group (24 ± 2.4/s, P <0.001) and ATN group (27.4 ± 1.7/s, P <0.001). The MCR was higher in ATN group (1.47 ± 0.18) compared to the AR group (1.18 ± 0.17) and normal functioning group (1.34 ± 0.2). Both MR2* (area under the curve [AUC] = 0.837, P <0.001) and MCR (AUC = 0.727, P = 0.003) can accurately discriminate ATN from AR, however CR2* (AUC = 0.590, P = 0.237) showed no significant difference between both groups. CONCLUSION In early post-transplant renal dysfunction, BOLD-MRI is a valuable non-invasive diagnostic technique that can differentiate between AR and ATN by measuring changes in intra-renal tissue oxygenation.
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Affiliation(s)
- Hashim Mohamed Farg
- Radiology Department, Urology and Nephrology Center, Mansoura University, Egypt
| | - Tarek El-Diasty
- Radiology Department, Urology and Nephrology Center, Mansoura University, Egypt
| | - Bedeir Ali-El-Dein
- Urology Department, Urology and Nephrology Center, Mansoura University, Egypt
| | - Ayman Refaie
- Nephrology Department, Urology and Nephrology Center, Mansoura University, Egypt
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2
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Solomon R. Hydration to Prevent Contrast-Associated Acute Kidney Injury in Patients Undergoing Cardiac Angiography. Interv Cardiol Clin 2023; 12:515-524. [PMID: 37673495 DOI: 10.1016/j.iccl.2023.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Administration of fluid (oral and intravenous) is the cornerstone of prevention of contrast-associated acute kidney injury in the cardiac environment. Intravenous saline is the preferred fluid. The amount, timing, and duration of therapy are discussed. A key determinant of the benefit may be the rate of urine output stimulated by the therapy. Approaches using hemodynamic-guided rates of fluid administration and novel techniques to generate large urine outputs while maintaining fluid balance are highlighted.
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Affiliation(s)
- Richard Solomon
- Larner College of Medicine, University of Vermont, Burlington, VT 05401, USA.
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3
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Prasad PV, Li LP, Hack B, Leloudas N, Sprague SM. Quantitative Blood Oxygenation Level Dependent Magnetic Resonance Imaging for Estimating Intra-renal Oxygen Availability Demonstrates Kidneys Are Hypoxemic in Human CKD. Kidney Int Rep 2023; 8:1057-1067. [PMID: 37180507 PMCID: PMC10166744 DOI: 10.1016/j.ekir.2023.02.1092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/08/2023] [Accepted: 02/27/2023] [Indexed: 03/09/2023] Open
Abstract
Introduction Kidney blood oxygenation level dependent (BOLD) magnetic resonance imaging (MRI) has shown great promise in evaluating relative oxygen availability. This method is quite efficacious in evaluating acute responses to physiological and pharmacologic maneuvers. Its outcome parameter, R2∗ is defined as the apparent spin-spin relaxation rate measured in the presence of magnetic susceptibility differences and it is measured using gradient echo MRI. Although associations between R2∗ and renal function decline have been described, it remains uncertain to what extent R2∗ is a true reflection of tissue oxygenation. This is primarily because of not taking into account the confounding factors, especially fractional blood volume (fBV) in tissue. Methods This case-control study included 7 healthy controls and 6 patients with diabetes and chronic kidney disease (CKD). Using data before and after administration of ferumoxytol, a blood pool MRI contrast media, the fBVs in kidney cortex and medulla were measured. Results This pilot study independently measured fBV in kidney cortex (0.23 ± 0.03 vs. 0.17 ± 0.03) and medulla (0.36 ± 0.08 vs. 0.25 ± 0.03) in a small number of healthy controls (n = 7) versus CKD (n = 6). These were then combined with BOLD MRI measurements to estimate oxygen saturation of hemoglobin (StO2) (0.87 ± 0.03 vs. 0.72 ± 0.10 in cortex; 0.82 ± 0.05 vs. 0.72 ± 0.06 in medulla) and partial pressure of oxygen in blood (bloodPO2) (55.4 ± 6.5 vs. 38.4 ± 7.6 mm Hg in cortex; 48.4 ± 6.2 vs. 38.1 ± 4.5 mm Hg in medulla) in control versus CKD. The results for the first time demonstrate that cortex is normoxemic in controls and moderately hypoxemic in CKD. In the medulla, it is mildly hypoxemic in controls and moderately hypoxemic in CKD. Whereas fBV, StO2, and bloodPO2 were strongly associated with estimated glomerular filtration rate (eGFR), R2∗ was not. Conclusion Our results support the feasibility of quantitatively assessing oxygen availability using noninvasive quantitative BOLD MRI that could be translated to the clinic.
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Affiliation(s)
- Pottumarthi V. Prasad
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA
- Pritzker School of Medicine, University of Chicago, Chicago, Illinois, USA
| | - Lu-Ping Li
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA
- Pritzker School of Medicine, University of Chicago, Chicago, Illinois, USA
| | - Bradley Hack
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA
| | - Nondas Leloudas
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA
| | - Stuart M. Sprague
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois, USA
- Pritzker School of Medicine, University of Chicago, Chicago, Illinois, USA
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4
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Sørensen SS, Gullaksen S, Vernstrøm L, Ringgaard S, Laustsen C, Funck KL, Laugesen E, Poulsen PL. Evaluation of renal oxygenation by BOLD-MRI in high-risk patients with type 2 diabetes and matched controls. Nephrol Dial Transplant 2023; 38:691-699. [PMID: 35612982 DOI: 10.1093/ndt/gfac186] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Diabetic kidney disease (DKD) accounts for ∼50% of end-stage kidney disease. Renal hypoxia is suggested as a main driver in the pathophysiology underlying chronic DKD. Blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) has made noninvasive investigations of renal oxygenation in humans possible. Whether diabetes per se contributes to measurable changes in renal oxygenation by BOLD-MRI remains to be elucidated. We investigated whether renal oxygenation measured with BOLD-MRI differs between people with type 2 diabetes (T2DM) with normal to moderate chronic kidney disease (CKD) (Stages 1-3A) and matched controls. The repeatability of the BOLD-MRI method was also assessed. METHODS In this matched cross-sectional study, 20 people with T2DM (age 69.2 ± 4.7 years, duration of diabetes 10.5 ± 6.7 years, male 55.6%) and 20 matched nondiabetic controls (mean age 68.8 ± 5.4 years, male 55.%) underwent BOLD-MRI analysed with the 12-layer concentric object method (TLCO). To investigate the repeatability, seven in the T2DM group and nine in the control group were scanned twice. RESULTS A significant reduction in renal oxygenation from the cortex to medulla was found in both groups (P < .01) but no intergroup difference was detected [0.71/s (95% confidence interval -0.28-1.7), P = .16]. The median intraindividual coefficient of variation (CV) varied from 1.2% to 7.0%. CONCLUSION T2DM patients with normal to moderate CKD do not seem to have lower renal oxygenation when measured with BOLD-MRI and TLCO. BOLD-MRI has a low intraindividual CV and seems like a reliable method for investigation of renal oxygenation in T2DM.
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Affiliation(s)
- Steffen S Sørensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | - Søren Gullaksen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | - Liv Vernstrøm
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | | | | | - Kristian L Funck
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | - Esben Laugesen
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | - Per L Poulsen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Steno Diabetes Center, Aarhus University Hospital, Aarhus, Denmark
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5
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Copur S, Yavuz F, Sag AA, Tuttle KR, Kanbay M. Future of kidney imaging: Functional magnetic resonance imaging and kidney disease progression. Eur J Clin Invest 2022; 52:e13765. [PMID: 35267195 DOI: 10.1111/eci.13765] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/01/2022] [Accepted: 03/05/2022] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Chronic kidney disease (CKD) which is a common cause of death has an increasing trend, but there is no established approach for predicting CKD progression yet. Functional magnetic resonance imaging (fMRI) studies such as blood oxygenation level-dependent MRI (BOLD-MRI), diffusion-weighted MRI (DWI-MRI), diffusion-tensor MRI (DTI-MRI) and arterial spin labelling MRI (ASL-MRI) are rising methods for the assessment of kidney functions in native and transplanted kidneys as well as the estimation of CKD progression. METHODS Systematic literature review was performed through the Embase (Elsevier), Cochrane Central Register of Controlled Trials (Wiley), PubMed/Medline and Web of Science databases, and studies investigating the role of fMRI methods assessing kidney functions in native and transplanted kidneys, as well as the value of fMRI methods to predict CKD progression, were included. Working mechanisms, advantages and limitations of the fMRI modalities were reviewed, and three studies investigating the role of fMRI studies in kidney functions were analysed. RESULTS AND CONCLUSION BOLD-MRI signal was found to be inversely correlated with annual eGFR change, and DWI/ADC (apparent diffusion coefficient map) values were shown to be correlated with annual eGFR decline. fMRI methods which are currently used for other systems can be utilized to provide more detailed information about kidney functions, and doctors should be ready to interpret kidney MRIs.
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Affiliation(s)
- Sidar Copur
- Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Furkan Yavuz
- Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Alan A Sag
- Department of Radiology, Division of Vascular and Interventional Radiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Kathherine R Tuttle
- Division of Nephrology, University of Washington, Seattle, Washington, USA.,Providence Medical Research Center, Providence Health Care, Washington, District of Columbia, USA
| | - Mehmet Kanbay
- Department of Medicine, Division of Nephrology, Koc University School of Medicine, Istanbul, Turkey
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6
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Mani LY, Seif M, Nikles F, Tshering Vogel DW, Diserens G, Martirosian P, Burnier M, Vogt B, Vermathen P. Hip Position Acutely Affects Oxygenation and Perfusion of Kidney Grafts as Measured by Functional Magnetic Resonance Imaging Methods-The Bent Knee Study. Front Med (Lausanne) 2021; 8:697055. [PMID: 34447762 PMCID: PMC8384256 DOI: 10.3389/fmed.2021.697055] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 07/12/2021] [Indexed: 12/16/2022] Open
Abstract
Background: Kidney perfusion and oxygenation are two important determinants of kidney graft function. In kidney transplantation, repeated graft hypoperfusion may occur during hip flexion, for example in the sitting position, due to the progressive development of fibrotic tissue around iliac arteries. The aim of this study was to assess the changes in oxygenation and perfusion of kidney grafts during hip flexion and extension using a new functional magnetic resonance imaging (fMRI) protocol. Methods: Nineteen kidney graft recipients prospectively underwent MRI on a 3T scanner including diffusion-weighted, blood oxygenation level dependent (BOLD), and arterial spin labeling sequences in hip positions 0° and >90° before and after intravenous administration of 20 mg furosemide. Results: Unexpectedly, graft perfusion values were significantly higher in flexed compared to neutral hip position. Main diffusion-derived parameters were not affected by hip position. BOLD-derived cortico-medullary R2* ratio was significantly modified during hip flexion suggesting an intrarenal redistribution of the oxygenation in favor of the medulla and to the detriment of the cortex. Furthermore, the increase in medullary oxygenation induced by furosemide was significantly blunted during hip flexion (p < 0.001). Conclusion: Hip flexion has an acute impact on perfusion and tissue oxygenation in kidney grafts. Whether these position-dependent changes affect the long-term function and outcome of kidney transplants needs further investigation.
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Affiliation(s)
- Laila-Yasmin Mani
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Maryam Seif
- Departments of Biomedical Research and Radiology, University of Bern, Bern, Switzerland.,Spinal Cord Injury Center, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Florence Nikles
- Departments of Biomedical Research and Radiology, University of Bern, Bern, Switzerland
| | - Dechen W Tshering Vogel
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Gaëlle Diserens
- Departments of Biomedical Research and Radiology, University of Bern, Bern, Switzerland
| | - Petros Martirosian
- Section on Experimental Radiology, University of Tübingen, Tübingen, Germany
| | - Michel Burnier
- Service of Nephrology and Hypertension, Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland
| | - Bruno Vogt
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Peter Vermathen
- Departments of Biomedical Research and Radiology, University of Bern, Bern, Switzerland
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7
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Nishino T, Takahashi K, Ono S, Mimaki M. Effects of low-dose oxygen administration on renal blood oxygenation level-dependent MRI in children with glomerulonephritis. MAGMA 2021; 34:823-31. [PMID: 34275036 DOI: 10.1007/s10334-021-00945-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/07/2021] [Accepted: 07/12/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Children are often sedated for renal blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) and may require low-dose oxygen administration. It is unclear whether low-dose oxygen administration affects results of BOLD MRI. We investigated the effect of low-dose oxygen administration on renal BOLD MRI and its variation by the presence or absence of renal disease. MATERIALS AND METHODS We retrospectively examined children undergoing MRI for renal disease between 2013 and 2020. Patients were divided into glomerulonephritis and non-glomerulonephritis groups; spin relaxation time (T2*) was determined using a 3.0 T MRI system. RESULTS The study included 10 children (5 patients in each group); patient characteristics between the groups did not differ significantly. In the entire cohort, oxygen administration reduced mean spin relaxation rate (R2*) value in the medulla (p < 0.04). The mean R2* value decreased with oxygen administration in the non-glomerulonephritis group, whereas this was not observed in the glomerulonephritis group. The responses to oxygen administration of the two groups differed significantly in the cortex (p < 0.05) and medulla (p < 0.02). DISCUSSION Low-dose oxygen administration affects the results of BOLD MRI. We suggest that understanding the fluctuations due to oxygen administration is useful in monitoring the disease activity of glomerulonephritis.
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8
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Laursen JC, Søndergaard-Heinrich N, de Melo JML, Haddock B, Rasmussen IKB, Safavimanesh F, Hansen CS, Størling J, Larsson HBW, Groop PH, Frimodt-Møller M, Andersen UB, Rossing P. Acute effects of dapagliflozin on renal oxygenation and perfusion in type 1 diabetes with albuminuria: A randomised, double-blind, placebo-controlled crossover trial. EClinicalMedicine 2021; 37:100895. [PMID: 34386735 PMCID: PMC8343250 DOI: 10.1016/j.eclinm.2021.100895] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Inhibitors of the sodium-glucose cotransporter 2 (SGLT2) slow the progression of diabetic kidney disease, possibly by reducing the proximal tubule transport workload with subsequent improvement of renal oxygenation. We aimed to test this hypothesis in individuals with type 1 diabetes and albuminuria. METHODS A randomised, double-blind, placebo-controlled, crossover trial with a single 50 mg dose of the SGLT2 inhibitor dapagliflozin and placebo in random order, separated by a two-week washout period. Magnetic resonance imaging (MRI) was used to assess renal R2* (a low value corresponds to a high tissue oxygenation), renal perfusion (arterial spin labelling) and renal artery flow (phase contrast imaging) at baseline, three- and six hours from tablet ingestion. Exploratory outcomes, including baroreflex sensitivity, peripheral blood oxygen saturation, peripheral blood mononuclear cell mitochondrial oxygen consumption rate, and biomarkers of inflammation were evaluated at baseline and 12 h from medication. The study is registered in the EU Clinical Trials Register (EudraCT 2019-004,557-92), on ClinicalTrials.gov (NCT04193566), and is completed. FINDINGS Between February 3, 2020 and October 23, 2020, 31 individuals were screened, and 19 eligible individuals were randomised. Three dropped out before receiving any of the interventions and one dropped out after receiving only placebo. We included 15 individuals (33% female) in the per-protocol analysis with a mean age of 58 (SD 14) years, median urinary albumin creatinine ratio of 46 [IQR 21-58] mg/g and an eGFR of 73 (32) ml/min/1·73m2. The mean changes in renal cortical R2* from baseline to six hours were for dapagliflozin -1·1 (SD 0·7) s-1 and for placebo +1·3 (0·7) s-1, resulting in a difference between interventions of -2·3 s-1 [95% CI -4·0 to -0·6]; p = 0·012. No between-intervention differences were found in any other MRI outcomes, physiological parameters or exploratory outcomes. There were no adverse events. INTERPRETATION A single dose of 50 mg dapagliflozin acutely improved renal cortical R2* without changing renal perfusion or blood flow. This suggests improved renal cortical oxygenation due to a reduced tubular transport workload in the proximal tubules. Such improved oxygenation may in part explain the long-term beneficial renal effects seen with SGLT2 inhibitors, but it remains to be determined whether the observed effects can be achieved with lower doses, with chronic treatment and if they occur in type 2 diabetes as well.
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Affiliation(s)
| | | | | | - Bryan Haddock
- Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Copenhagen University Hospital, Denmark
| | | | | | | | | | - Henrik Bo Wiberg Larsson
- Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Copenhagen University Hospital, Denmark
| | - Per-Henrik Groop
- Folkhälsan Research Center, Helsinki, Finland
- Department of Nephrology, University of Helsinki and Helsinki University Hospital, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Finland
- Department of Medicine, Central Clinical School, Monash University, Melbourne, Australia
| | | | - Ulrik Bjørn Andersen
- Steno Diabetes Center Copenhagen, Denmark
- University of Copenhagen, Denmark
- Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Copenhagen University Hospital, Denmark
- Folkhälsan Research Center, Helsinki, Finland
- Department of Nephrology, University of Helsinki and Helsinki University Hospital, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Finland
- Department of Medicine, Central Clinical School, Monash University, Melbourne, Australia
| | - Peter Rossing
- Steno Diabetes Center Copenhagen, Denmark
- University of Copenhagen, Denmark
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9
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Darawshi S, Yaseen H, Gorelik Y, Faor C, Szalat A, Abassi Z, Heyman SN, Khamaisi M. Biomarker evidence for distal tubular damage but cortical sparing in hospitalized diabetic patients with acute kidney injury (AKI) while on SGLT2 inhibitors. Ren Fail 2021; 42:836-844. [PMID: 32787602 PMCID: PMC7472507 DOI: 10.1080/0886022x.2020.1801466] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Background Inhibitors of sodium-glucose co-transporter-2 (SGLT2i) were found to improve renal outcome in diabetic patients in large prospective randomized trials. Yet, SGLT2i may acutely reduce kidney function through volume depletion, altered glomerular hemodynamics or intensified medullary hypoxia leading to acute tubular injury (ATI). The aim or this study was to prospectively assess the pathophysiology of acute kidney injury (AKI) in patients hospitalized while on SGLT2i, differing ATI from pre-renal causes using renal biomarkers. Methods Serum and urine Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Kidney Ischemia Molecule (KIM)-1, markers of distal and proximal tubular injury, respectively, were determined in 46 diabetic patients who were on SGLT2i upon hospitalization with an acute illness. Results Serum and urine NGAL, but not KIM-1, were significantly increased in 21 of the patients who presented with AKI upon admission, as compared with 25 patients that maintained kidney function. Both serum and urinary NGAL correlated with the degree of impaired renal function, which in many cases was likely the result of additional acute renal perturbations, such as sepsis. Conclusions Increased urinary and serum NGAL indicates that ATI, principally affecting distal tubular segments, may develop in some of the patients hospitalized with an acute illness and AKI while on SGLT2i. It is suggested that intensified medullary hypoxia by SGLT2i might be detrimental in this injury. By contrast, concomitantly unaltered KIM-1 might reflect improved cortical oxygenation by SGLT2i, and may explain an overall reduced risk of AKI with SGLT1i in large series. The independent potential of SGLT2i to inflict medullary hypoxic damage should be explored further.
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Affiliation(s)
- Said Darawshi
- Department of Medicine D, Ruth & Bruce Rappaport Faculty of Medicine, Rambam Health Care Campus, Technion-IIT, Haifa, Israel.,Clinical Research Institute, Rambam Health Care Campus, Haifa, Israel
| | - Hiba Yaseen
- Clinical Research Institute, Rambam Health Care Campus, Haifa, Israel
| | - Yuri Gorelik
- Department of Medicine D, Ruth & Bruce Rappaport Faculty of Medicine, Rambam Health Care Campus, Technion-IIT, Haifa, Israel.,Clinical Research Institute, Rambam Health Care Campus, Haifa, Israel
| | - Caroline Faor
- Department of Medicine D, Ruth & Bruce Rappaport Faculty of Medicine, Rambam Health Care Campus, Technion-IIT, Haifa, Israel.,Clinical Research Institute, Rambam Health Care Campus, Haifa, Israel
| | - Auryan Szalat
- Department of Medicine, Hadassah Hebrew University Hospital, Jerusalem, Israel
| | - Zaid Abassi
- Department of Physiology, Ruth & Bruce Rappaport Faculty of Medicine, Technion-IIT, Haifa, Israel.,Department of Laboratory Medicine, Rambam Health Care Campus, Haifa, Israel
| | - Samuel N Heyman
- Department of Medicine, Hadassah Hebrew University Hospital, Jerusalem, Israel
| | - Mogher Khamaisi
- Department of Medicine D, Ruth & Bruce Rappaport Faculty of Medicine, Rambam Health Care Campus, Technion-IIT, Haifa, Israel.,Clinical Research Institute, Rambam Health Care Campus, Haifa, Israel
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10
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Mora-Gutiérrez JM, Fernández-Seara MA, Echeverria-Chasco R, Garcia-Fernandez N. Perspectives on the Role of Magnetic Resonance Imaging (MRI) for Noninvasive Evaluation of Diabetic Kidney Disease. J Clin Med 2021; 10:2461. [PMID: 34199385 DOI: 10.3390/jcm10112461] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 01/09/2023] Open
Abstract
Renal magnetic resonance imaging (MRI) techniques are currently in vogue, as they provide in vivo information on renal volume, function, metabolism, perfusion, oxygenation, and microstructural alterations, without the need for exogenous contrast media. New imaging biomarkers can be identified using these tools, which represent a major advance in the understanding and study of the different pathologies affecting the kidney. Diabetic kidney disease (DKD) is one of the most important diseases worldwide due to its high prevalence and impact on public health. However, its multifactorial etiology poses a challenge for both basic and clinical research. Therefore, the use of novel renal MRI techniques is an attractive step forward in the comprehension of DKD, both in its pathogenesis and in its detection and surveillance in the clinical practice. This review article outlines the most promising MRI techniques in the study of DKD, with the purpose of stimulating their clinical translation as possible tools for the diagnosis, follow-up, and monitoring of the clinical impacts of new DKD treatments.
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11
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Zheng Z, Wang Y, Yan T, Jia J, Li D, Wei L, Shang W, Shi H. Detection of renal hypoxia configuration in patients with lupus nephritis: a primary study using blood oxygen level-dependent MR imaging. Abdom Radiol (NY) 2021; 46:2032-44. [PMID: 33079255 DOI: 10.1007/s00261-020-02794-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 09/15/2020] [Accepted: 09/27/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Renal microstructure and function are closely associated with oxygenation homeostasis. Analyzing renal blood oxygen level‒dependent (BOLD) magnetic resonance imaging (MRI) examination results will provide information on the biological status of the kidneys. The current study was performed to explore the hypoxia mode of the entire renal parenchyma in patients with lupus nephritis (LN). METHODS A total of 23 adult patients with LN and 18 healthy volunteers were recruited. R2* values were acquired using BOLD MRI analysis. The narrow rectangular region of interest was used to explore the hypoxia configuration in entire depths of renal parenchyma. Acquired sequential R2* data were fitted using four categories of mathematic functions. The tendency of R2* data in both patients with LN and healthy volunteers was also compared using repeated-measures analysis of variance. RESULTS R2* data from the superficial cortex to deep medulla displayed two patterns called a sharp uptrend style and a flat uptrend style. After sequential R2* data were fitted individually with the use of four mathematic formulas, the multiple-compartment Gaussian function showed the highest goodness of fit. Compared with two categories of R2* value styles, the R2* tendency of entire parenchyma in patients with LN was different from that in healthy volunteers. CONCLUSIONS Deep renal medullary oxygenation was not always overtly lower than oxygenation in the superficial renal cortical zone. The manifestation of renal parenchyma oxygenation could be described using a Gaussian function model. Deoxygenation tolerance was damaged in patients with LN.
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Textor SC, Abumoawad A, Saad A, Ferguson C, Dietz A. Stem Cell Therapy for Microvascular Injury Associated with Ischemic Nephropathy. Cells 2021; 10:cells10040765. [PMID: 33807289 PMCID: PMC8066553 DOI: 10.3390/cells10040765] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 03/22/2021] [Accepted: 03/26/2021] [Indexed: 12/15/2022] Open
Abstract
Ischemic nephropathy reflects progressive loss of kidney function due to large vessel atherosclerotic occlusive disease. Recent studies indicate that this process is characterized by microvascular rarefaction, increased tissue hypoxia and activation of inflammatory processes of tissue injury. This review summarizes the rationale and application of functional MR imaging to evaluate tissue oxygenation in human subjects that defines the limits of renal adaptation to reduction in blood flow, development of increasingly severe tissue hypoxia and recruitment of inflammatory injury pathways in ischemic nephropathy. Human mesenchymal stromal/stem cells (MSC) are capable of modifying angiogenic pathways and immune responses, but the potency of these effects vary between individuals and various clinical characteristics including age and chronic kidney disease and levels of hypoxia. We summarize recently completed first-in-human studies applying intrarenal infusion of autologous adipose-derived MSC in human subjects with ischemic nephropathy that demonstrate a rise in blood flow and reduction in tissue hypoxia consistent with partial repair of microvascular injury, even without restoring main renal arterial blood flow. Inflammatory biomarkers in the renal vein of post-stenotic kidneys fell after MSC infusion. These changes were associated with modest but significant dose-related increments in kidney function. These data provide support a role for autologous MSC in repair of microvascular injury associated with tissue hypoxia.
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Affiliation(s)
- Stephen C. Textor
- Mayo Clinic, Division of Nephrology and Hypertension, Rochester, MN 55905, USA;
- Correspondence:
| | - Abdu Abumoawad
- Department of Medicine University of Missouri, Kansas, MO 64108, USA;
| | - Ahmed Saad
- Department of Medicine Creighton University School of Medicine, Omaha, NE 68124, USA;
| | | | - Allan Dietz
- Mayo Clinic, Human Cell Therapy Laboratory, Rochester, MN 55905, USA;
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Reavey JJ, Walker C, Nicol M, Murray AA, Critchley HOD, Kershaw LE, Maybin JA. Markers of human endometrial hypoxia can be detected in vivo and ex vivo during physiological menstruation. Hum Reprod 2021; 36:941-950. [PMID: 33496337 PMCID: PMC7970728 DOI: 10.1093/humrep/deaa379] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 12/17/2020] [Indexed: 12/23/2022] Open
Abstract
STUDY QUESTION Can markers of human endometrial hypoxia be detected at menstruation in vivo? SUMMARY ANSWER Our in vivo data support the presence of hypoxia in menstrual endometrium of women during physiological menstruation. WHAT IS KNOWN ALREADY Current evidence from animal models and human in vitro studies suggests endometrial hypoxia is present at menstruation and drives endometrial repair post menses. However, detection of human endometrial hypoxia in vivo remains elusive. STUDY DESIGN, SIZE, DURATION We performed a prospective case study of 16 women with normal menstrual bleeding. PARTICIPANTS/MATERIALS, SETTING, METHODS Reproductively aged female participants with a regular menstrual cycle underwent objective measurement of their menstrual blood loss using the alkaline haematin method to confirm a loss of <80 ml per cycle. Exclusion criteria were exogenous hormone use, an intrauterine device, endometriosis or fibroids >3 cm. Participants attended for two MRI scans; during days 1-3 of menstruation and the early/mid-secretory phase of their cycle. The MRI protocol included dynamic contrast-enhanced MRI and T2* quantification. At each visit, an endometrial sample was also collected and hypoxia-regulated repair factor mRNA levels (ADM, VEGFA, CXCR4) were quantified by RT-qPCR. MAIN RESULTS AND THE ROLE OF CHANCE Women had reduced T2* during menstrual scans versus non-menstrual scans (P = 0.005), consistent with menstrual hypoxia. Plasma flow (Fp) was increased at menstruation compared to the non-menstrual phase (P = 0.0005). Laboratory findings revealed increased ADM, VEGF-A and CXCR4 at menstruation on examination of paired endometrial biopsies from the menstrual and non-menstrual phase (P = 0.008; P = 0.03; P = 0.009). There was a significant correlation between T2* and these ex vivo hypoxic markers (P < 0.05). LIMITATIONS, REASONS FOR CAUTION This study examined the in vivo detection of endometrial hypoxic markers at specific timepoints in the menstrual cycle in women with a menstrual blood loss <80 ml/cycle and without significant uterine structural abnormalities. Further research is required to determine the presence of endometrial hypoxia in those experiencing abnormal uterine bleeding with and without fibroids/adenomyosis. WIDER IMPLICATIONS OF THE FINDINGS Heavy menstrual bleeding (HMB) is a common, debilitating condition. Understanding menstrual physiology may improve therapeutics. To our knowledge, this is the first in vivo data supporting the presence of menstrual hypoxia in the endometrium of women with normal menstrual bleeding. If aberrant in those with HMB, these non-invasive tests may aid diagnosis and facilitate personalized treatments for HMB. STUDY FUNDING/COMPETING INTEREST(S) This work was funded by Wellbeing of Women grant RG1820, Wellcome Trust Fellowship 209589/Z/17/Z and undertaken in the MRC Centre for Reproductive Health, funded by grants G1002033 and MR/N022556/1. H.O.D.C. has clinical research support for laboratory consumables and staff from Bayer AG and provides consultancy advice (but with no personal remuneration) for Bayer AG, PregLem SA, Gedeon Richter, Vifor Pharma UK Ltd, AbbVie Inc; Myovant Sciences GmbH. H.O.D.C. receives royalties from UpToDate for articles on abnormal uterine bleeding. TRIAL REGISTRATION NUMBER N/A.
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Affiliation(s)
- J J Reavey
- MRC Centre for Reproductive Health, The Queen’s Medical Research Institute, Edinburgh, UK
| | - C Walker
- MRC Centre for Reproductive Health, The Queen’s Medical Research Institute, Edinburgh, UK
| | - M Nicol
- MRC Centre for Reproductive Health, The Queen’s Medical Research Institute, Edinburgh, UK
| | - A A Murray
- MRC Centre for Reproductive Health, The Queen’s Medical Research Institute, Edinburgh, UK
| | - H O D Critchley
- MRC Centre for Reproductive Health, The Queen’s Medical Research Institute, Edinburgh, UK
| | - L E Kershaw
- Edinburgh Imaging, The Queen’s Medical Research Institute, Edinburgh, UK
- Centre for Inflammation Research, The Queen’s Medical Research Institute, Edinburgh, UK
| | - J A Maybin
- MRC Centre for Reproductive Health, The Queen’s Medical Research Institute, Edinburgh, UK
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Abstract
Over the past 20 years, there has been an increased appreciation of the long-term sequelae of acute kidney injury (AKI) and the potential development of chronic kidney disease (CKD). Several pathophysiologic features have been proposed to mediate AKI to CKD progression including maladaptive alterations in tubular, interstitial, inflammatory, and vascular cells. These alterations likely interact to culminate in the progression to CKD. In this article we focus primarily on evidence of vascular rarefaction secondary to AKI, and the potential mechanisms by which rarefaction occurs in relation to other alterations in tubular and interstitial compartments. We further focus on the potential that rarefaction contributes to renal hypoxia. Consideration of the role of hypoxia in AKI to CKD transition focuses on experimental evidence of persistent renal hypoxia after AKI and experimental maneuvers to evaluate the influence of hypoxia, per se, in progressive disease. Finally, consideration of methods to evaluate hypoxia in patients is provided with the suggestion that noninvasive measurement of renal hypoxia may provide insight into progression in post-AKI patients.
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Affiliation(s)
- Md Mahbub Ullah
- Department of Anatomy, Cell Biology and Physiology, Indiana University, Indianapolis, IN
| | - David P Basile
- Department of Medicine, Division of Nephrology, Indiana University, Indianapolis, IN.
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Abstract
A gradually developing reduction in renal blood flow from atherosclerotic renovascular disease results in loss of kidney volume and a decrease in glomerular filtration rate that eventually becomes irreversible. Whether this process fundamentally reflects tissue hypoxia has been difficult to establish. Studies of human renovascular disease have indicated that reductions in blood flow of up to 30% to 40% can be tolerated with preservation of normal oxygenation and structural integrity. These observations are consistent with remarkable stability of poststenotic kidney function during sustained medical antihypertensive drug therapy in moderate renovascular disease. With more severe and sustained reductions, however, cortical oxygenation decreases and the magnitude of medullary hypoxia expands. These changes are associated with increasing renal venous levels of inflammatory cytokines, angiogenic markers, and infiltration of inflammatory cells, including tissue macrophages and T cells. Although restoring large-vessel blood flow can improve oxygenation, some of these processes reflect microvascular rarefication, remain activated, and do not depend on hemodynamic factors alone. Elucidation of tissue injury pathways associated with hypoxia opens the possibility of adjunctive therapeutic measures beyond renal revascularization. These include cell-based regeneration, mitochondrial protection, and/or angiogenic cytokine therapy to restore or preserve renal function in ischemic nephropathy.
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Affiliation(s)
- Stephen C Textor
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN.
| | - Lilach O Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN
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16
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Sugahara M, Tanaka T, Nangaku M. Hypoxia-Inducible Factor and Oxygen Biology in the Kidney. ACTA ACUST UNITED AC 2020; 1:1021-1031. [DOI: 10.34067/kid.0001302020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/21/2020] [Indexed: 12/19/2022]
Abstract
Kidney tissue hypoxia is detected in various kidney diseases and is considered to play an important role in the pathophysiology of both AKI and CKD. Because of the characteristic vascular architecture and high energy demand to drive tubular solute transport, the renal medulla is especially prone to hypoxia. Injured kidneys often present capillary rarefaction, inflammation, and fibrosis, which contribute to sustained kidney hypoxia, forming a vicious cycle promoting progressive CKD. Hypoxia-inducible factor (HIF), a transcription factor responsible for cellular adaptation to hypoxia, is generally considered to protect against AKI. On the contrary, consequences of sustained HIF activation in CKD may be either protective, neutral, or detrimental. The kidney outcomes seem to be affected by various factors, such as cell types in which HIF is activated/inhibited, disease models, balance between two HIF isoforms, and time and methods of intervention. This suggests multifaceted functions of HIF and highlights the importance of understanding its role within each specific context. Prolyl-hydroxylase domain (PHD) inhibitors, which act as HIF stabilizers, have been developed to treat anemia of CKD. Although many preclinical studies demonstrated renoprotective effects of PHD inhibitors in CKD models, there may be some situations in which they lead to deleterious effects. Further studies are needed to identify patients who would gain additional benefits from PHD inhibitors and those who may need to avoid them.
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Abstract
The literature (in English) was accessed to review the evidence that administration of fluids is protective of contrast-associated acute kidney injury (CA-AKI). The evidence was evaluated with the intent of understanding mechanisms of protection. Prospective randomized trials comparing oral versus intravenous fluid, sodium chloride versus no intravenous fluid, sodium bicarbonate versus sodium chloride, and forced matched hydration versus intravenous sodium chloride provided the data. In general, the more fluid administered, the lower the incidence of CA-AKI. However, understanding the mechanism of this beneficial effect suggests that it is the urine output that most directly affects the incidence of CA-AKI.
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Affiliation(s)
- Richard Solomon
- Division of Nephrology, Larner College of Medicine, University of Vermont, University of Vermont Medical Center, UHC 2309, 1 South Prospect Street, Burlington, VT 05401, USA.
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18
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Bane O, Mendichovszky IA, Milani B, Dekkers IA, Deux JF, Eckerbom P, Grenier N, Hall ME, Inoue T, Laustsen C, Lerman LO, Liu C, Morrell G, Pedersen M, Pruijm M, Sadowski EA, Seeliger E, Sharma K, Thoeny H, Vermathen P, Wang ZJ, Serafin Z, Zhang JL, Francis ST, Sourbron S, Pohlmann A, Fain SB, Prasad PV. Consensus-based technical recommendations for clinical translation of renal BOLD MRI. MAGMA 2020; 33:199-215. [PMID: 31768797 PMCID: PMC7021747 DOI: 10.1007/s10334-019-00802-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 10/18/2019] [Accepted: 10/22/2019] [Indexed: 01/08/2023]
Abstract
Harmonization of acquisition and analysis protocols is an important step in the validation of BOLD MRI as a renal biomarker. This harmonization initiative provides technical recommendations based on a consensus report with the aim to move towards standardized protocols that facilitate clinical translation and comparison of data across sites. We used a recently published systematic review paper, which included a detailed summary of renal BOLD MRI technical parameters and areas of investigation in its supplementary material, as the starting point in developing the survey questionnaires for seeking consensus. Survey data were collected via the Delphi consensus process from 24 researchers on renal BOLD MRI exam preparation, data acquisition, data analysis, and interpretation. Consensus was defined as ≥ 75% unanimity in response. Among 31 survey questions, 14 achieved consensus resolution, 12 showed clear respondent preference (65-74% agreement), and 5 showed equal (50/50%) split in opinion among respondents. Recommendations for subject preparation, data acquisition, processing and reporting are given based on the survey results and review of the literature. These technical recommendations are aimed towards increased inter-site harmonization, a first step towards standardization of renal BOLD MRI protocols across sites. We expect this to be an iterative process updated dynamically based on progress in the field.
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Affiliation(s)
- Octavia Bane
- BioMedical Engineering and Imaging Institute and Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Iosif A Mendichovszky
- Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, UK
| | - Bastien Milani
- Center for BioMedical Imaging, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Ilona A Dekkers
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jean-Francois Deux
- Department of Radiology, Groupe Hospitalier Henri Mondor, Créteil, France
| | - Per Eckerbom
- Department of Radiology, Institution for Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Nicolas Grenier
- Department of Radiology, Université de Bordeaux, CHU de Bordeaux, Bordeaux, France
| | - Michael E Hall
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Tsutomu Inoue
- Department of Nephrology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Christoffer Laustsen
- The MR Research Center Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Lilach O Lerman
- Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Chunlei Liu
- Electrical Engineering and Computer Science, and Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, USA
| | - Glen Morrell
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Michael Pedersen
- Department of Clinical Medicine-Comparative Medicine Lab, Aarhus University Hospital, Aarhus, Denmark
| | - Menno Pruijm
- Nephrology and Hypertension Service, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Elizabeth A Sadowski
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Erdmann Seeliger
- Institute of Physiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Kanishka Sharma
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Harriet Thoeny
- Department of Radiology, Hôpital Cantonal Fribourgois, University of Fribourg, Fribourg, Switzerland
| | - Peter Vermathen
- Departments for BioMedical Research and Radiology, Inselspital, Universitaetspital Bern, Bern, Switzerland
| | - Zhen J Wang
- Department of Radiology and Biomedical Imaging, University of California San Francisco Medical Center, San Francisco, CA, USA
| | - Zbigniew Serafin
- Department of Radiology, Nicolaus Copernicus University, Collegium Medicum, Bydgoszcz, Poland
| | - Jeff L Zhang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Susan T Francis
- Sir Peter Mansfield Centre, University of Notthingham, Notthingham, UK
| | - Steven Sourbron
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Andreas Pohlmann
- Berlin Ultrahigh Field Facility, Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sean B Fain
- Departments of Biomedical Engineering, Radiology, and Medical Physics, University of Wisconsin, Madison, WI, USA
| | - Pottumarthi V Prasad
- Department of Radiology, Center for Advanced Imaging, NorthShore University Health System, Evanston, IL, USA.
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19
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Li LP, Milani B, Pruijm M, Kohn O, Sprague S, Hack B, Prasad P. Renal BOLD MRI in patients with chronic kidney disease: comparison of the semi-automated twelve layer concentric objects (TLCO) and manual ROI methods. Magn Reson Mater Phy 2019; 33:113-120. [DOI: 10.1007/s10334-019-00808-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 11/18/2019] [Accepted: 11/21/2019] [Indexed: 12/25/2022]
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20
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Bane O, Mendichovszky IA, Milani B, Dekkers IA, Deux JF, Eckerbom P, Grenier N, Hall ME, Inoue T, Laustsen C, Lerman LO, Liu C, Morrell G, Pedersen M, Pruijm M, Sadowski EA, Seeliger E, Sharma K, Thoeny H, Vermathen P, Wang ZJ, Serafin Z, Zhang JL, Francis ST, Sourbron S, Pohlmann A, Fain SB, Prasad PV. Consensus-based technical recommendations for clinical translation of renal BOLD MRI. MAGMA 2019. [PMID: 31768797 DOI: 10.1007/s10334‐019‐00802‐x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Harmonization of acquisition and analysis protocols is an important step in the validation of BOLD MRI as a renal biomarker. This harmonization initiative provides technical recommendations based on a consensus report with the aim to move towards standardized protocols that facilitate clinical translation and comparison of data across sites. We used a recently published systematic review paper, which included a detailed summary of renal BOLD MRI technical parameters and areas of investigation in its supplementary material, as the starting point in developing the survey questionnaires for seeking consensus. Survey data were collected via the Delphi consensus process from 24 researchers on renal BOLD MRI exam preparation, data acquisition, data analysis, and interpretation. Consensus was defined as ≥ 75% unanimity in response. Among 31 survey questions, 14 achieved consensus resolution, 12 showed clear respondent preference (65-74% agreement), and 5 showed equal (50/50%) split in opinion among respondents. Recommendations for subject preparation, data acquisition, processing and reporting are given based on the survey results and review of the literature. These technical recommendations are aimed towards increased inter-site harmonization, a first step towards standardization of renal BOLD MRI protocols across sites. We expect this to be an iterative process updated dynamically based on progress in the field.
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Affiliation(s)
- Octavia Bane
- BioMedical Engineering and Imaging Institute and Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Iosif A Mendichovszky
- Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, UK
| | - Bastien Milani
- Center for BioMedical Imaging, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Ilona A Dekkers
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jean-Francois Deux
- Department of Radiology, Groupe Hospitalier Henri Mondor, Créteil, France
| | - Per Eckerbom
- Department of Radiology, Institution for Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Nicolas Grenier
- Department of Radiology, Université de Bordeaux, CHU de Bordeaux, Bordeaux, France
| | - Michael E Hall
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Tsutomu Inoue
- Department of Nephrology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Christoffer Laustsen
- The MR Research Center Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Lilach O Lerman
- Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Chunlei Liu
- Electrical Engineering and Computer Science, and Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, USA
| | - Glen Morrell
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Michael Pedersen
- Department of Clinical Medicine-Comparative Medicine Lab, Aarhus University Hospital, Aarhus, Denmark
| | - Menno Pruijm
- Nephrology and Hypertension Service, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Elizabeth A Sadowski
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Erdmann Seeliger
- Institute of Physiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Kanishka Sharma
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Harriet Thoeny
- Department of Radiology, Hôpital Cantonal Fribourgois, University of Fribourg, Fribourg, Switzerland
| | - Peter Vermathen
- Departments for BioMedical Research and Radiology, Inselspital, Universitaetspital Bern, Bern, Switzerland
| | - Zhen J Wang
- Department of Radiology and Biomedical Imaging, University of California San Francisco Medical Center, San Francisco, CA, USA
| | - Zbigniew Serafin
- Department of Radiology, Nicolaus Copernicus University, Collegium Medicum, Bydgoszcz, Poland
| | - Jeff L Zhang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Susan T Francis
- Sir Peter Mansfield Centre, University of Notthingham, Notthingham, UK
| | - Steven Sourbron
- Imaging Biomarkers Group, Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Andreas Pohlmann
- Berlin Ultrahigh Field Facility, Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sean B Fain
- Departments of Biomedical Engineering, Radiology, and Medical Physics, University of Wisconsin, Madison, WI, USA
| | - Pottumarthi V Prasad
- Department of Radiology, Center for Advanced Imaging, NorthShore University Health System, Evanston, IL, USA.
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Li H, Cao W, Zhang X, Sun B, Jiang S, Li J, Liu C, Yin W, Wu Y, Liu T, Yao D, Luo C. BOLD-fMRI reveals the association between renal oxygenation and functional connectivity in the aging brain. Neuroimage 2019; 186:510-517. [DOI: 10.1016/j.neuroimage.2018.11.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 11/19/2018] [Accepted: 11/20/2018] [Indexed: 01/23/2023] Open
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Lal H, Mohamed E, Soni N, Yadav P, Jain M, Bhadauria D, Kaul A, Prasad N, Gupta A, Sharma RK. Role of Blood Oxygen Level-dependent MRI in Differentiation of Acute Renal Allograft Dysfunction. Indian J Nephrol 2019; 28:441-447. [PMID: 30647498 PMCID: PMC6309386 DOI: 10.4103/ijn.ijn_43_18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Early graft dysfunction after renal transplantation manifests as acute rejection (AR) or acute tubular necrosis (ATN). Blood oxygen level-dependent (BOLD) magnetic resonance (MR) imaging is a noninvasive method of assessing tissue oxygenation, which may be useful for predicting acute allograft dysfunction. This was a prospective study involving 40 patients scheduled for renal transplantation from August 2012 to August 2014. In addition, 15 healthy donors were also enrolled in this study. All recipients underwent BOLD MR imaging (MRI) and R2* mapping 10–20 days after transplant, and additionally within 48 h of biopsy if there was any evidence of graft dysfunction. The healthy donors underwent BOLD MRI 1–2 days before surgery. The biopsies were grouped into AR, ATN, and no evidence of AR or ATN. The mean medullary R2*, cortical R2*, corticomedullary gradient, and medullary: cortical R2* ratio were compared between groups using one-way analysis of variance. Spearman's correlation and multinomial linear regression were applied to determine the influence factors of R2* value. Overall, nine patients had graft dysfunction. Six were reported as AR, two as ATN, and one as no evidence of ATN or rejection. The mean medullary and cortical R2* were significantly higher in ATN group compared with AR and normal group, whereas the mean medullary and cortical R2* of AR group were significantly lower than normal group. The corticomedullary gradient of AR group was significantly lower compared with ATN and normal group. Medullary R2*:cortical R2* ratio was significantly lower in AR group compared with normal group. No significant difference was noted between the 15 donors and patients with normal graft function. R2* values on BOLD MRI are significantly decreased in AR allografts and increased in an early stage of ATN allografts, suggesting that BOLD MRI can become a valuable tool for discriminating between AR and ATN.
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Affiliation(s)
- Hira Lal
- Department of Radiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Ezaz Mohamed
- Department of Radiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Neelam Soni
- Department of Radiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Priyank Yadav
- Department of Urology and Renal Transplantation, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Manoj Jain
- Department of Pathology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Dharmendra Bhadauria
- Department of Nephrology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Anupma Kaul
- Department of Nephrology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Narayan Prasad
- Department of Nephrology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Amit Gupta
- Department of Nephrology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - R K Sharma
- Department of Nephrology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
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23
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Wengler K, Wang J, Serrano Sosa M, Gumus S, He A, Hussain S, Huang C, Tae Bae K, He X. Mapping hepatic blood oxygenation by quantitative BOLD (qBOLD) MRI. Magn Reson Med 2019; 81:3272-3282. [PMID: 30652357 DOI: 10.1002/mrm.27642] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 11/21/2018] [Accepted: 12/02/2018] [Indexed: 12/11/2022]
Abstract
PURPOSE Abnormalities in hepatic oxygen delivery and oxygen consumption may serve as a significant indicator of hepatic cellular dysfunction and may predict treatment response. However, conventional and oxygen-enhanced hepatic BOLD MRI can only provide semiquantitative assessment of hepatic oxygenation. METHODS A hepatic quantitative BOLD (qBOLD) model was proposed for noninvasive mapping of hepatic venous blood oxygen saturation (Yv ) and deoxygenated blood volume (DBV) in human subjects. The validity and the estimation bias of the proposed model were evaluated by Monte Carlo simulations. Eight healthy subjects were scanned after written consent with institutional review board approval. RESULTS Monte Carlo simulations demonstrated that the proposed single-compartment hepatic qBOLD model leads to significant deviation of the predicted T2 * decay profile from the simulated signal due to high hepatic blood volume fraction. Small relative estimation bias for hepatic Yv and significant overestimation for hepatic DBV were observed, which can be corrected by applying the calibration curves established from simulations. After correction, the mean hepatic Yv in human subjects was 56.8 ± 6.8%, and the mean hepatic DBV was 0.190 ± 0.035, consistent with measurements from other invasive approaches. Except in regions with significant vascular contamination, the maps for hepatic Yv and DBV were relatively homogenous. CONCLUSIONS With estimation bias correction, the hepatic qBOLD approach enables noninvasive mapping of hepatic blood volume and oxygenation in human subjects. The established protocol may be used to quantitatively assess hepatic tissue hypoxia in multiple liver diseases.
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Affiliation(s)
- Kenneth Wengler
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, New York
| | - Jinhong Wang
- Department of Medical Imaging, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
| | - Mario Serrano Sosa
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, New York
| | - Serter Gumus
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Andrea He
- College of Letters and Science, University of Berkeley, Berkeley, California
| | - Shahid Hussain
- Department of Radiology, Stony Brook University, Stony Brook, New York, New York
| | - Chuan Huang
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, New York.,Department of Radiology, Stony Brook University, Stony Brook, New York, New York.,Department of Psychiatry, Stony Brook University, Stony Brook, New York, New York
| | - Kyong Tae Bae
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Xiang He
- Department of Radiology, Stony Brook University, Stony Brook, New York, New York
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Sugiyama K, Inoue T, Kozawa E, Ishikawa M, Shimada A, Kobayashi N, Tanaka J, Okada H. Reduced oxygenation but not fibrosis defined by functional magnetic resonance imaging predicts the long-term progression of chronic kidney disease. Nephrol Dial Transplant 2018; 35:964-970. [DOI: 10.1093/ndt/gfy324] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 09/12/2018] [Indexed: 12/14/2022] Open
Abstract
Abstract
Background
Although chronic hypoxia and fibrosis may be a key to the progression of chronic kidney disease (CKD), a noninvasive means of measuring these variables is not yet available. Here, using blood oxygen level–dependent (BOLD) and diffusion-weighted (DW) magnetic resonance imaging (MRI), we assessed changes in renal tissue oxygenation and fibrosis, respectively, and evaluated their correlation with prognosis for renal function.
Methods
The study was conducted under a single-center, longitudinal, retrospective observational design. We examined the prognostic significance of T2* values of BOLD-MRI and apparent diffusion coefficient (ADC) values on DW-MRI and other clinical parameters. The rate of decline in estimated glomerular filtration rate (eGFR) was calculated by linear regression analysis using changes in eGFR during the observation period.
Results
A total of 91 patients were enrolled, with a mean age of 55.8 ± 15.6 years. Among patients, 51 (56.0%) were males and 38 (41.8%) had diabetes mellitus. The mean eGFR was 49.2 ± 28.9 mL/min/1.73 m2 and the mean observation period was 5.13 years. ADC values of DW-MRI but not T2* values of BOLD-MRI were well correlated with eGFR at the initial time point. The mean annual rate of decline in eGFR during the 5-year observation period was −1.92 ± 3.00 mL/min/1.73 m2. On multiple linear regression analysis, the rate of decline in eGFR was significantly correlated with eGFR at the start point, period average amount of proteinuria and T2* values, but not with ADC values (t = 2.980, P = 0.004).
Conclusions
Reduced oxygenation as determined by low T2* values on BOLD-MRI is a clinically useful marker of CKD progression.
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Affiliation(s)
- Kei Sugiyama
- Department of Nephrology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Tsutomu Inoue
- Department of Nephrology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Eito Kozawa
- Department of Radiology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Masahiro Ishikawa
- School of Clinical Engineering, Faculty of Health and Medical Care, Saitama Medical University, Saitama, Japan
| | - Akira Shimada
- Department of Endocrinology and Diabetes, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Naoki Kobayashi
- School of Clinical Engineering, Faculty of Health and Medical Care, Saitama Medical University, Saitama, Japan
| | - Junji Tanaka
- Department of Radiology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Hirokazu Okada
- Department of Nephrology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
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25
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Pruijm M, Mendichovszky IA, Liss P, Van der Niepen P, Textor SC, Lerman LO, Krediet CTP, Caroli A, Burnier M, Prasad PV. Renal blood oxygenation level-dependent magnetic resonance imaging to measure renal tissue oxygenation: a statement paper and systematic review. Nephrol Dial Transplant 2018; 33:ii22-ii28. [PMID: 30137579 PMCID: PMC6106642 DOI: 10.1093/ndt/gfy243] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 06/27/2018] [Indexed: 11/14/2022] Open
Abstract
Tissue hypoxia plays a key role in the development and progression of many kidney diseases. Blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) is the most promising imaging technique to monitor renal tissue oxygenation in humans. BOLD-MRI measures renal tissue deoxyhaemoglobin levels voxel by voxel. Increases in its outcome measure R2* (transverse relaxation rate expressed as per second) correspond to higher deoxyhaemoglobin concentrations and suggest lower oxygenation, whereas decreases in R2* indicate higher oxygenation. BOLD-MRI has been validated against micropuncture techniques in animals. Its reproducibility has been demonstrated in humans, provided that physiological and technical conditions are standardized. BOLD-MRI has shown that patients suffering from chronic kidney disease (CKD) or kidneys with severe renal artery stenosis have lower tissue oxygenation than controls. Additionally, CKD patients with the lowest cortical oxygenation have the worst renal outcome. Finally, BOLD-MRI has been used to assess the influence of drugs on renal tissue oxygenation, and may offer the possibility to identify drugs with nephroprotective or nephrotoxic effects at an early stage. Unfortunately, different methods are used to prepare patients, acquire MRI data and analyse the BOLD images. International efforts such as the European Cooperation in Science and Technology (COST) action 'Magnetic Resonance Imaging Biomarkers for Chronic Kidney Disease' (PARENCHIMA) are aiming to harmonize this process, to facilitate the introduction of this technique in clinical practice in the near future. This article represents an extensive overview of the studies performed in this field, summarizes the strengths and weaknesses of the technique, provides recommendations about patient preparation, image acquisition and analysis, and suggests clinical applications and future developments.
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Affiliation(s)
- Menno Pruijm
- Service of Nephrology and Hypertension, Department of Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Iosif A Mendichovszky
- Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke’s Hospital, Cambridge, UK
| | - Per Liss
- Department of Surgical Sciences, Section of Radiology, Uppsala University, Uppsala, Sweden
| | - Patricia Van der Niepen
- Department of Nephrology and Hypertension, Universitair Ziekenhuis Brussel (VUB), Brussels, Belgium
| | - Stephen C Textor
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Lilach O Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - C T Paul Krediet
- Department of Internal Medicine, Division of Nephrology, Academic Medical Center at the University of Amsterdam, Amsterdam, The Netherlands
| | - Anna Caroli
- Medical Imaging Unit, Bioengineering Department, IRCCS Istituto di Ricerche Farmacologiche Mario Negri, Bergamo, Italy
| | - Michel Burnier
- Service of Nephrology and Hypertension, Department of Medicine, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
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26
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Milani B, Ansaloni A, Sousa-Guimaraes S, Vakilzadeh N, Piskunowicz M, Vogt B, Stuber M, Burnier M, Pruijm M. Reduction of cortical oxygenation in chronic kidney disease: evidence obtained with a new analysis method of blood oxygenation level-dependent magnetic resonance imaging. Nephrol Dial Transplant 2018; 32:2097-2105. [PMID: 27798200 DOI: 10.1093/ndt/gfw362] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 08/18/2016] [Indexed: 11/12/2022] Open
Abstract
Background Determinations of renal oxygenation by blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) in chronic kidney disease (CKD) patients have given heterogeneous results, possibly due to the lack of a reproducible method to analyse BOLD-MRI. It therefore remains uncertain whether patients with CKD have a reduced renal tissue oxygenation. We developed a new method to analyse BOLD-MRI signals and applied it to CKD patients and controls. Methods MRI was performed under standardized conditions before and 15 min after IV furosemide in 104 CKD patients, 61 hypertensives and 42 controls. MR images were analysed with the new twelve-layer concentric objects method (TLCO) that divides renal parenchyma in 12 layers of equal thickness. The mean R2* value of each layer was reported, along with the change in R2* between successive layers, as measured by the slope steepness of the relevant curve. Results Inter-observer variability was 2.3 ± 0.9%, 1.9 ± 0.8% and 3.0 ± 2.3% in, respectively, controls, moderate and severe CKD. The mean R2* of the outer (more cortical) layers was significantly higher in CKD, suggesting lower cortical oxygenation as compared with controls. In CKD patients, the response to furosemide was blunted in the inner (more medullary) layers, and the R2* slope was flatter. In multivariable regression analysis, the R2* slope correlated positively with estimated glomerular filtration rate (eGFR) in patients with an eGFR <90 mL/min/1.73 m2 (P < 0.001). Conclusions Using the new TLCO method, we confirm the hypothesis that renal cortical oxygenation is reduced in CKD in humans, and that the level of cortical oxygenation correlates with CKD severity.
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Affiliation(s)
- Bastien Milani
- Service of Nephrology and Hypertension, CHUV, Lausanne, Switzerland.,Center for Biomedical Imaging, University Hospital Lausanne, Lausanne, Switzerland
| | | | | | - Nima Vakilzadeh
- Service of Nephrology and Hypertension, CHUV, Lausanne, Switzerland
| | | | - Bruno Vogt
- Service of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Matthias Stuber
- Center for Biomedical Imaging, University Hospital Lausanne, Lausanne, Switzerland.,Department of Radiology, CHUV, Lausanne, Switzerland
| | - Michel Burnier
- Service of Nephrology and Hypertension, CHUV, Lausanne, Switzerland
| | - Menno Pruijm
- Service of Nephrology and Hypertension, CHUV, Lausanne, Switzerland
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28
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Abstract
Magnetic resonance (MR) imaging, a non-invasive modality that provides anatomic and physiologic information, is increasingly used for diagnosis of pathophysiologic conditions and for understanding renal physiology in humans. Although functional MR imaging methods were pioneered to investigate the brain, they also offer powerful techniques for investigation of other organ systems such as the kidneys. However, imaging the kidneys provides unique challenges due to potential complications from contrast agents. Therefore, development of non-contrast techniques to study kidney anatomy and physiology is important. Blood oxygen level-dependent (BOLD) MR is a non-contrast imaging technique that provides functional information related to renal tissue oxygenation in various pathophysiologic conditions. Here we discuss technical considerations, clinical uses and future directions for use of BOLD MR as well as complementary MR techniques to better understand renal pathophysiology. Our intent is to summarize kidney BOLD MR applications for the clinician rather than focusing on the complex physical challenges that functional MR imaging encompasses; however, we briefly discuss some of those issues.
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Affiliation(s)
- Michael E Hall
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA.,Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA
| | - Jennifer H Jordan
- Department of Internal Medicine, Section on Cardiovascular Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Luis A Juncos
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA.,Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA
| | - W Gregory Hundley
- Department of Internal Medicine, Section on Cardiovascular Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - John E Hall
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA
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29
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Cox EF, Buchanan CE, Bradley CR, Prestwich B, Mahmoud H, Taal M, Selby NM, Francis ST. Multiparametric Renal Magnetic Resonance Imaging: Validation, Interventions, and Alterations in Chronic Kidney Disease. Front Physiol 2017; 8:696. [PMID: 28959212 PMCID: PMC5603702 DOI: 10.3389/fphys.2017.00696] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 08/30/2017] [Indexed: 12/15/2022] Open
Abstract
Background: This paper outlines a multiparametric renal MRI acquisition and analysis protocol to allow non-invasive assessment of hemodynamics (renal artery blood flow and perfusion), oxygenation (BOLD T2*), and microstructure (diffusion, T1 mapping). Methods: We use our multiparametric renal MRI protocol to provide (1) a comprehensive set of MRI parameters [renal artery and vein blood flow, perfusion, T1, T2*, diffusion (ADC, D, D*, fp), and total kidney volume] in a large cohort of healthy participants (127 participants with mean age of 41 ± 19 years) and show the MR field strength (1.5 T vs. 3 T) dependence of T1 and T2* relaxation times; (2) the repeatability of multiparametric MRI measures in 11 healthy participants; (3) changes in MRI measures in response to hypercapnic and hyperoxic modulations in six healthy participants; and (4) pilot data showing the application of the multiparametric protocol in 11 patients with Chronic Kidney Disease (CKD). Results: Baseline measures were in-line with literature values, and as expected, T1-values were longer at 3 T compared with 1.5 T, with increased T1 corticomedullary differentiation at 3 T. Conversely, T2* was longer at 1.5 T. Inter-scan coefficients of variation (CoVs) of T1 mapping and ADC were very good at <2.9%. Intra class correlations (ICCs) were high for cortex perfusion (0.801), cortex and medulla T1 (0.848 and 0.997 using SE-EPI), and renal artery flow (0.844). In response to hypercapnia, a decrease in cortex T2* was observed, whilst no significant effect of hyperoxia on T2* was found. In CKD patients, renal artery and vein blood flow, and renal perfusion was lower than for healthy participants. Renal cortex and medulla T1 was significantly higher in CKD patients compared to healthy participants, with corticomedullary T1 differentiation reduced in CKD patients compared to healthy participants. No significant difference was found in renal T2*. Conclusions: Multiparametric MRI is a powerful technique for the assessment of changes in structure, hemodynamics, and oxygenation in a single scan session. This protocol provides the potential to assess the pathophysiological mechanisms in various etiologies of renal disease, and to assess the efficacy of drug treatments.
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Affiliation(s)
- Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Charlotte E Buchanan
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Christopher R Bradley
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Benjamin Prestwich
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
| | - Huda Mahmoud
- Centre for Kidney Research and Innovation, Royal Derby Hospital, University of NottinghamDerby, United Kingdom
| | - Maarten Taal
- Centre for Kidney Research and Innovation, Royal Derby Hospital, University of NottinghamDerby, United Kingdom
| | - Nicholas M Selby
- Centre for Kidney Research and Innovation, Royal Derby Hospital, University of NottinghamDerby, United Kingdom
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, University of NottinghamNottingham, United Kingdom
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30
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Leung G, Kirpalani A, Szeto SG, Deeb M, Foltz W, Simmons CA, Yuen DA. Could MRI Be Used To Image Kidney Fibrosis? A Review of Recent Advances and Remaining Barriers. Clin J Am Soc Nephrol 2017; 12:1019-1028. [PMID: 28298435 PMCID: PMC5460707 DOI: 10.2215/cjn.07900716] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 12/19/2016] [Indexed: 12/18/2022]
Abstract
A key contributor to the progression of nearly all forms of CKD is fibrosis, a largely irreversible process that drives further kidney injury. Despite its importance, clinicians currently have no means of noninvasively assessing renal scar, and thus have historically relied on percutaneous renal biopsy to assess fibrotic burden. Although helpful in the initial diagnostic assessment, renal biopsy remains an imperfect test for fibrosis measurement, limited not only by its invasiveness, but also, because of the small amounts of tissue analyzed, its susceptibility to sampling bias. These concerns have limited not only the prognostic utility of biopsy analysis and its ability to guide therapeutic decisions, but also the clinical translation of experimental antifibrotic agents. Recent advances in imaging technology have raised the exciting possibility of magnetic resonance imaging (MRI)-based renal scar analysis, by capitalizing on the differing physical features of fibrotic and nonfibrotic tissue. In this review, we describe two key fibrosis-induced pathologic changes (capillary loss and kidney stiffening) that can be imaged by MRI techniques, and the potential for these new MRI-based technologies to noninvasively image renal scar.
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Affiliation(s)
- General Leung
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael’s Hospital
- Department of Medical Imaging, St. Michael’s Hospital
- Department of Medical Imaging
| | - Anish Kirpalani
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael’s Hospital
- Department of Medical Imaging, St. Michael’s Hospital
- Department of Medical Imaging
| | - Stephen G. Szeto
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael’s Hospital
| | - Maya Deeb
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael’s Hospital
| | | | - Craig A. Simmons
- Department of Mechanical and Industrial Engineering and Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Darren A. Yuen
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael’s Hospital
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Djamali A, Wilson NA, Sadowski EA, Zha W, Niles D, Hafez O, Dorn JR, Mehner TR, Grimm PC, Hoffmann FM, Zhong W, Fain SB, Reese SR. Nox2 and Cyclosporine-Induced Renal Hypoxia. Transplantation 2016; 100:1198-210. [PMID: 26950727 DOI: 10.1097/TP.0000000000001137] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND We hypothesized that nicotinamide adenosine diphosphate oxidase 2 (Nox2) plays an important role in cyclosporine A (CsA)-induced chronic hypoxia. METHODS We tested this hypothesis in Fisher 344 rats, C57BL/6 J wild type and Nox2-/- mice, and in liver transplant recipients with chronic CsA nephrotoxicity. We used noninvasive molecular imaging (blood oxygen level-dependent magnetic resonance imaging and dynamic contrast-enhanced magnetic resonance imaging) and molecular diagnostic tools to assess intrarenal oxygenation and perfusion, and the molecular phenotype of CsA nephrotoxicity. RESULTS We observed that chemical and genetic inhibition of Nox2 in rats and mice resulted in the prevention of CsA-induced hypoxia independent of regional perfusion (blood oxygen level-dependent magnetic resonance imaging and dynamic contrast-enhanced magnetic resonance imaging, pimonidazole, HIF-1α). Nicotinamide adenosine diphosphate oxidase 2 knockout was also associated with decreased oxidative stress (Nox2, HIF-1α, hydrogen peroxide, hydroxynonenal), and fibrogenesis (α-smooth muscle actin, picrosirius red, trichrome, vimentin). The molecular signature of chronic CsA nephrotoxicity using transcriptomic analyses demonstrated significant changes in 40 genes involved in injury repair, metabolism, and oxidative stress in Nox2-/- mice. Immunohistochemical analyses of kidney biopsies from liver transplant recipients with chronic CsA nephrotoxicity showed significantly greater Nox2, α-smooth muscle actin and picrosirius levels compared with controls. CONCLUSIONS These studies suggest that Nox2 is a modulator of CsA-induced hypoxia upstream of HIF-1α and define the molecular characteristics that could be used for the diagnosis and monitoring of chronic calcineurin inhibitor nephrotoxicity.
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Pruijm M, Milani B, Burnier M. Blood Oxygenation Level-Dependent MRI to Assess Renal Oxygenation in Renal Diseases: Progresses and Challenges. Front Physiol 2017; 7:667. [PMID: 28105019 PMCID: PMC5214762 DOI: 10.3389/fphys.2016.00667] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 12/19/2016] [Indexed: 11/13/2022] Open
Abstract
BOLD-MRI (blood oxygenation-level dependent magnetic resonance imaging) allows non-invasive measurement of renal tissue oxygenation in humans, without the need for contrast products. BOLD-MRI uses the fact that magnetic properties of hemoglobin depend of its oxygenated state:: the higher local deoxyhemoglobin, the higher the so called apparent relaxation rate R2* (sec-1), and the lower local tissue oxygen content. Several factors other than deoxyhemoglobin (such as hydration status, dietary sodium intake, and susceptibility effects) influence the BOLD signal, and need to be taken into account when interpreting results. The last 5 years have witnessed important improvements in the standardization of these factors, and the appearance of new, highly reproducible analysis techniques of BOLD-images, that are reviewed in this article. Using these new BOLD-MRI analysis techniques, it has recently been shown that persons suffering from chronic kidney diseases (CKD) have lower cortical oxygenation than normotensive controls, thus confirming the chronic hypoxia hypothesis. The acute alterations in R2* after the administration of furosemide are smaller in CKD, and represent an estimate of the oxygen-dependent tubular transport of sodium. BOLD-MRI-alone or in combination with other functional MRI methods- can be used to monitor the renal effects of drugs, and is increasingly used in the preclinical setting. The near future will tell whether or not BOLD-MRI represents a new tool to predict renal function decline an adverse renal outcome.
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Affiliation(s)
- Menno Pruijm
- Service of Nephrology and Hypertension, Department of Medicine, Centre Hospitalier Universitaire Vaudois Lausanne, Switzerland
| | - Bastien Milani
- Service of Nephrology and Hypertension, Department of Medicine, Centre Hospitalier Universitaire Vaudois Lausanne, Switzerland
| | - Michel Burnier
- Service of Nephrology and Hypertension, Department of Medicine, Centre Hospitalier Universitaire Vaudois Lausanne, Switzerland
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Li J, Li Y, Xu B, Jia G, Guo T, Wang D, Xu K, Deng J, Han Y. Short-term rosuvastatin therapy prevents contrast-induced acute kidney injury in female patients with diabetes and chronic kidney disease: a subgroup analysis of the TRACK-D study. J Thorac Dis 2016; 8:1000-6. [PMID: 27162677 DOI: 10.21037/jtd.2016.03.26] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Female patients are at higher risk of contrast-induced acute kidney injury (CIAKI) compared to males. In the multicenter, prospective, TRACK-D study, short-term rosuvastatin has proven effectively reduce CIAKI in patients with type 2 diabetes mellitus and stage 2-3 chronic kidney disease (CKD). This study aimed to explore the efficacy of rosuvastatin in the female TRACK-D population. METHODS This study was a gender-based analysis of 2,998 patients (1,044 females) enrolled in the TRACK-D study and were randomized to short-term (2 days before and 3 days after procedure) rosuvastatin therapy or standard of care. The primary outcome was the incidence of CIAKI and the secondary outcome was a composite of death, dialysis/hemofiltration or worsening heart failure at 30 days. RESULTS CIAKI incidence was comparable between male and female patients in the overall study population (2.5% vs. 3.4%, P=0.165) and in the rosuvastatin group (2.4% vs. 2.1%, P=0.72), while it was higher in females than in males in the control group (3.1% vs. 5.3%, P=0.04). Female gender was an independent risk factor of CIAKI [odds ratio (OR) =1.65; 95% confidence interval (CI), 1.03-2.63; P=0.036]. Rosuvastatin treatment vs. control lowered CIAKI rate in females [2.1% vs. 5.3%; relative risk (RR) =0.39; 95% CI, 0.19-0.77; number needed to treat (NNT) =31], particularly among those with CKD stage 2 (1.2% vs. 4.1%, P=0.011). Secondary outcome incidence was similar for females in the rosuvastatin and control groups (3.7% vs. 4.9%, P=0.37). CONCLUSIONS Compared to males, untreated females with diabetes mellitus and CKD had a higher risk of CIAKI, which can be reduced by short-term rosuvastatin treatment.
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Affiliation(s)
- Jing Li
- 1 Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang 110016, China ; 2 Nanjing Drum Tower Hospital Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing 210029, China ; 3 Dongguan Kanghua Hospital, Dongguan 523080, China ; 4 First Affiliated Hospital of Kunming Medical University, Kunming 650031, China ; 5 Shijiazhuang Peace Hospital, Shijiazhuang 050081, China
| | - Yi Li
- 1 Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang 110016, China ; 2 Nanjing Drum Tower Hospital Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing 210029, China ; 3 Dongguan Kanghua Hospital, Dongguan 523080, China ; 4 First Affiliated Hospital of Kunming Medical University, Kunming 650031, China ; 5 Shijiazhuang Peace Hospital, Shijiazhuang 050081, China
| | - Biao Xu
- 1 Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang 110016, China ; 2 Nanjing Drum Tower Hospital Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing 210029, China ; 3 Dongguan Kanghua Hospital, Dongguan 523080, China ; 4 First Affiliated Hospital of Kunming Medical University, Kunming 650031, China ; 5 Shijiazhuang Peace Hospital, Shijiazhuang 050081, China
| | - Guoliang Jia
- 1 Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang 110016, China ; 2 Nanjing Drum Tower Hospital Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing 210029, China ; 3 Dongguan Kanghua Hospital, Dongguan 523080, China ; 4 First Affiliated Hospital of Kunming Medical University, Kunming 650031, China ; 5 Shijiazhuang Peace Hospital, Shijiazhuang 050081, China
| | - Tao Guo
- 1 Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang 110016, China ; 2 Nanjing Drum Tower Hospital Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing 210029, China ; 3 Dongguan Kanghua Hospital, Dongguan 523080, China ; 4 First Affiliated Hospital of Kunming Medical University, Kunming 650031, China ; 5 Shijiazhuang Peace Hospital, Shijiazhuang 050081, China
| | - Dongmei Wang
- 1 Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang 110016, China ; 2 Nanjing Drum Tower Hospital Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing 210029, China ; 3 Dongguan Kanghua Hospital, Dongguan 523080, China ; 4 First Affiliated Hospital of Kunming Medical University, Kunming 650031, China ; 5 Shijiazhuang Peace Hospital, Shijiazhuang 050081, China
| | - Kai Xu
- 1 Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang 110016, China ; 2 Nanjing Drum Tower Hospital Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing 210029, China ; 3 Dongguan Kanghua Hospital, Dongguan 523080, China ; 4 First Affiliated Hospital of Kunming Medical University, Kunming 650031, China ; 5 Shijiazhuang Peace Hospital, Shijiazhuang 050081, China
| | - Jie Deng
- 1 Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang 110016, China ; 2 Nanjing Drum Tower Hospital Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing 210029, China ; 3 Dongguan Kanghua Hospital, Dongguan 523080, China ; 4 First Affiliated Hospital of Kunming Medical University, Kunming 650031, China ; 5 Shijiazhuang Peace Hospital, Shijiazhuang 050081, China
| | - Yaling Han
- 1 Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang 110016, China ; 2 Nanjing Drum Tower Hospital Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing 210029, China ; 3 Dongguan Kanghua Hospital, Dongguan 523080, China ; 4 First Affiliated Hospital of Kunming Medical University, Kunming 650031, China ; 5 Shijiazhuang Peace Hospital, Shijiazhuang 050081, China
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Kalis IM, Pilutti D, Krafft AJ, Hennig J, Bock M. Prospective MR image alignment between breath-holds: Application to renal BOLD MRI. Magn Reson Med 2016; 77:1573-1582. [PMID: 27099024 DOI: 10.1002/mrm.26247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 03/02/2016] [Accepted: 03/25/2016] [Indexed: 11/10/2022]
Abstract
PURPOSE To present an image registration method for renal blood oxygen level-dependent (BOLD) measurements that enables semiautomatic assessment of parenchymal and medullary R2* changes under a functional challenge. METHODS In a series of breath-hold acquisitions, three-dimensional data were acquired initially for prospective image registration of subsequent BOLD measurements. An algorithm for kidney alignment for BOLD renal imaging (KALIBRI) was implemented to detect the positions of the left and right kidney so that the kidneys were acquired in the subsequent BOLD measurement at consistent anatomical locations. Residual in-plane distortions were corrected retrospectively so that semiautomatic dynamic R2* measurements of the renal cortex and medulla become feasible. KALIBRI was tested in six healthy volunteers during a series of BOLD experiments, which included a 600- to 1000-mL water challenge. RESULTS Prospective image registration and BOLD imaging of each kidney was achieved within a total measurement time of about 17 s, enabling its execution within a single breath-hold. KALIBRI improved the registration by up to 35% as found with mutual information measures. In four volunteers, a medullary R2* decrease of up to 40% was observed after water ingestion. CONCLUSION KALIBRI improves the quality of two-dimensional time-resolved renal BOLD MRI by aligning local renal anatomy, which allows for consistent R2* measurements over many breath-holds. Magn Reson Med 77:1573-1582, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Inge M Kalis
- Department of Radiology-Medical Physics, University Medical Center Freiburg, Freiburg, Germany
| | - David Pilutti
- Department of Radiology-Medical Physics, University Medical Center Freiburg, Freiburg, Germany
| | - Axel J Krafft
- Department of Radiology-Medical Physics, University Medical Center Freiburg, Freiburg, Germany.,German Cancer Consortium, Heidelberg, Germany.,German Cancer Research Center, Heidelberg, Germany
| | - Jürgen Hennig
- Department of Radiology-Medical Physics, University Medical Center Freiburg, Freiburg, Germany
| | - Michael Bock
- Department of Radiology-Medical Physics, University Medical Center Freiburg, Freiburg, Germany
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Abstract
Interest in functional renal magnetic resonance imaging (MRI) has significantly increased in recent years. This review article provides an overview of the most important functional imaging techniques and their potential clinical applications for assessment of native and transplanted kidneys, with special emphasis on the clarification of renal tumors.
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Ding J, Xing W, Wu D, Chen J, Pan L, Sun J, Xing S, Dai Y. Evaluation of Renal Oxygenation Level Changes after Water Loading Using Susceptibility-Weighted Imaging and T2* Mapping. Korean J Radiol 2015; 16:827-34. [PMID: 26175582 PMCID: PMC4499547 DOI: 10.3348/kjr.2015.16.4.827] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 04/08/2015] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE To assess the feasibility of susceptibility-weighted imaging (SWI) while monitoring changes in renal oxygenation level after water loading. MATERIALS AND METHODS Thirty-two volunteers (age, 28.0 ± 2.2 years) were enrolled in this study. SWI and multi-echo gradient echo sequence-based T2(*) mapping were used to cover the kidney before and after water loading. Cortical and medullary parameters were measured using small regions of interest, and their relative changes due to water loading were calculated based on baseline and post-water loading data. An intraclass correlation coefficient analysis was used to assess inter-observer reliability of each parameter. A receiver operating characteristic curve analysis was conducted to compare the performance of the two methods for detecting renal oxygenation changes due to water loading. RESULTS Both medullary phase and medullary T2(*) values increased after water loading (p < 0.001), although poor correlations were found between the phase changes and the T2(*) changes (p > 0.05). Interobserver reliability was excellent for the T2(*) values, good for SWI cortical phase values, and moderate for the SWI medullary phase values. The area under receiver operating characteristic curve of the SWI medullary phase values was 0.85 and was not different from the medullary T2(*) value (0.84). CONCLUSION Susceptibility-weighted imaging enabled monitoring changes in the oxygenation level in the medulla after water loading, and may allow comparable feasibility to detect renal oxygenation level changes due to water loading compared with that of T2(*) mapping.
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Affiliation(s)
- Jiule Ding
- Department of Radiology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu 213003, China
| | - Wei Xing
- Department of Radiology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu 213003, China
| | - Dongmei Wu
- Shanghai Key Laboratory of Magnetic Resonance Imaging, East China Normal University, Shanghai 200241, China
| | - Jie Chen
- Department of Radiology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu 213003, China
| | - Liang Pan
- Department of Radiology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu 213003, China
| | - Jun Sun
- Department of Radiology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu 213003, China
| | - Shijun Xing
- Department of Radiology, Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu 213003, China
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Piskunowicz M, Hofmann L, Zuercher E, Bassi I, Milani B, Stuber M, Narkiewicz K, Vogt B, Burnier M, Pruijm M. A new technique with high reproducibility to estimate renal oxygenation using BOLD-MRI in chronic kidney disease. Magn Reson Imaging 2015; 33:253-61. [PMID: 25523609 DOI: 10.1016/j.mri.2014.12.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 10/31/2014] [Accepted: 12/10/2014] [Indexed: 12/21/2022]
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Pohlmann A, Arakelyan K, Hentschel J, Cantow K, Flemming B, Ladwig M, Waiczies S, Seeliger E, Niendorf T. Detailing the relation between renal T2* and renal tissue pO2 using an integrated approach of parametric magnetic resonance imaging and invasive physiological measurements. Invest Radiol 2014; 49:547-60. [PMID: 24651661 DOI: 10.1097/RLI.0000000000000054] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES This study was designed to detail the relation between renal T2* and renal tissue pO2 using an integrated approach that combines parametric magnetic resonance imaging (MRI) and quantitative physiological measurements (MR-PHYSIOL). MATERIALS AND METHODS Experiments were performed in 21 male Wistar rats. In vivo modulation of renal hemodynamics and oxygenation was achieved by brief periods of aortic occlusion, hypoxia, and hyperoxia. Renal perfusion pressure (RPP), renal blood flow (RBF), local cortical and medullary tissue pO2, and blood flux were simultaneously recorded together with T2*, T2 mapping, and magnetic resonance-based kidney size measurements (MR-PHYSIOL). Magnetic resonance imaging was carried out on a 9.4-T small-animal magnetic resonance system. Relative changes in the invasive quantitative parameters were correlated with relative changes in the parameters derived from MRI using Spearman analysis and Pearson analysis. RESULTS Changes in T2* qualitatively reflected tissue pO2 changes induced by the interventions. T2* versus pO2 Spearman rank correlations were significant for all interventions, yet quantitative translation of T2*/pO2 correlations obtained for one intervention to another intervention proved not appropriate. The closest T2*/pO2 correlation was found for hypoxia and recovery. The interlayer comparison revealed closest T2*/pO2 correlations for the outer medulla and showed that extrapolation of results obtained for one renal layer to other renal layers must be made with due caution. For T2* to RBF relation, significant Spearman correlations were deduced for all renal layers and for all interventions. T2*/RBF correlations for the cortex and outer medulla were even superior to those between T2* and tissue pO2. The closest T2*/RBF correlation occurred during hypoxia and recovery. Close correlations were observed between T2* and kidney size during hypoxia and recovery and for occlusion and recovery. In both cases, kidney size correlated well with renal vascular conductance, as did renal vascular conductance with T2*. Our findings indicate that changes in T2* qualitatively mirror changes in renal tissue pO2 but are also associated with confounding factors including vascular volume fraction and tubular volume fraction. CONCLUSIONS Our results demonstrate that MR-PHYSIOL is instrumental to detail the link between renal tissue pO2 and T2* in vivo. Unravelling the link between regional renal T2* and tissue pO2, including the role of the T2* confounding parameters vascular and tubular volume fraction and oxy-hemoglobin dissociation curve, requires further research. These explorations are essential before the quantitative capabilities of parametric MRI can be translated from experimental research to improved clinical understanding of hemodynamics/oxygenation in kidney disorders.
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Niendorf T, Pohlmann A, Arakelyan K, Flemming B, Cantow K, Hentschel J, Grosenick D, Ladwig M, Reimann H, Klix S, Waiczies S, Seeliger E. How bold is blood oxygenation level-dependent (BOLD) magnetic resonance imaging of the kidney? Opportunities, challenges and future directions. Acta Physiol (Oxf) 2015; 213:19-38. [PMID: 25204811 DOI: 10.1111/apha.12393] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 07/04/2014] [Accepted: 09/04/2014] [Indexed: 12/11/2022]
Abstract
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 T2∗ 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 T2∗ and renal tissue partial pressure of oxygen (pO2 ) are discussed with a focus on factors confounding the T2∗ vs. tissue pO2 relation. Multi-modality in vivo approaches suitable for detailing the role of the confounding factors that govern T2∗ are considered. A schematic approach describing the link between renal perfusion, oxygenation, tissue compartments and renal T2∗ is proposed. Future directions of MRI assessment of renal oxygenation and perfusion are explored.
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Affiliation(s)
- T. Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - A. Pohlmann
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - K. Arakelyan
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
- Institute of Physiology and Center for Cardiovascular Research (CCR); Charité - Universitätsmedizin Berlin; Berlin Germany
| | - B. Flemming
- Institute of Physiology and Center for Cardiovascular Research (CCR); Charité - Universitätsmedizin Berlin; Berlin Germany
| | - K. Cantow
- Institute of Physiology and Center for Cardiovascular Research (CCR); Charité - Universitätsmedizin Berlin; Berlin Germany
| | - J. Hentschel
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - D. Grosenick
- Physikalisch-Technische Bundesanstalt (PTB); Berlin Germany
| | - M. Ladwig
- Institute of Physiology and Center for Cardiovascular Research (CCR); Charité - Universitätsmedizin Berlin; Berlin Germany
| | - H. Reimann
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - S. Klix
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - S. Waiczies
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin Germany
| | - E. Seeliger
- Institute of Physiology and Center for Cardiovascular Research (CCR); Charité - Universitätsmedizin Berlin; Berlin Germany
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Zheng Z, Shi H, Ma H, Li F, Zhang J, Zhang Y. Renal Oxygenation Characteristics in Healthy Native Kidneys: Assessment with Blood Oxygen Level-Dependent Magnetic Resonance Imaging. Nephron Clin Pract 2014; 128:47-54. [PMID: 25471091 DOI: 10.1159/000366448] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 08/04/2014] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE To explore the characteristics of blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) in healthy native kidneys. METHODS Seventy-nine patients without chronic kidney disease underwent BOLD-MRI with T2* spoiled gradient recalled echo sequences. BOLD images were analyzed using R2*map software to produce an R2* pseudo-color map. Cortical and medullary R2* values were analyzed in both kidneys and in both sexes. Different regional R2* values in the cortex and medulla were also analyzed. Physiological indices including age, height, weight, body mass index, body surface area, and estimated glomerular filtration rate (eGFR) were recorded. Correlations between R2* value and physiological indices were determined. RESULTS Renal cortical R2* values were lower than values in the medulla (p < 0.001). Female and male cortical R2* values were also lower than the corresponding values in the medulla (p < 0.001). Renal medullary R2* values in the lower renal pole were lower than values in the middle and upper poles (p = 0.001). Age was positively correlated with R2* values in the medulla (r = 0.32, p = 0.004). eGFR was negatively correlated with both cortical R2* values (r = -0.26, p = 0.02) and medullary R2* values (r = -0.29, p = 0.009). CONCLUSIONS BOLD-MRI can directly visualize renal oxygenation. There was variation in the oxygenation of different regions of the kidney. Renal cortical and medullary oxygenation in healthy kidneys decreased with patient age. eGFR also decreased with patient age.
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Affiliation(s)
- Zhenfeng Zheng
- Department of Nephrology, General Hospital of Tianjin Medical University, Tianjin, PR China
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Abstract
Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) has recently emerged as an important noninvasive technique to assess intrarenal oxygenation under physiologic and pathophysiologic conditions. Although this tool represents a major addition to our armamentarium of methodologies to investigate the role of hypoxia in the pathogenesis of acute kidney injury and progressive chronic kidney disease, numerous technical limitations confound interpretation of data derived from this approach. BOLD MRI has been utilized to assess intrarenal oxygenation in numerous experimental models of kidney disease and in human subjects with diabetic and nondiabetic chronic kidney disease, acute kidney injury, renal allograft rejection, contrast-associated nephropathy, and obstructive uropathy. However, confidence in conclusions based on data derived from BOLD MRI measurements will require continuing advances and technical refinements in the use of this technique.
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Affiliation(s)
- Joel Neugarten
- Renal Division, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Ladan Golestaneh
- Renal Division, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA
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Abstract
We studied the effect of oxygen inhalation during resting state functional MRI scanning in healthy control individuals. We hypothesized that resting state networks would be modified under hyperoxic conditions. Thirty-four normal volunteers were recruited for this study. All participants were scanned twice: once while breathing atmospheric air and once under hyperoxic conditions in a randomized order. Hyperoxic conditions were produced by administering 100% O2. Blood oxygen level-dependent T2* scans were obtained for each of the scans. Resting state networks were extracted using independent component analysis. A paired t-test showed that the resting state networks scans (default mode network, attention network and executive network) acquired under hyperoxic conditions had significantly higher Z-scores than scans performed under atmospheric air. Spectral analysis of the time-course signal in these networks also showed a difference in the total power of low frequencies between the two conditions. These results were reversed in the visual network. Clinical or research applications of oxygen-enhanced MRI need to take into account the modularly effects that hyperoxia exerts on the networks resting state functional MRI.
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Pruijm M, Hofmann L, Piskunowicz M, Muller ME, Zweiacker C, Bassi I, Vogt B, Stuber M, Burnier M. Determinants of renal tissue oxygenation as measured with BOLD-MRI in chronic kidney disease and hypertension in humans. PLoS One 2014; 9:e95895. [PMID: 24760031 PMCID: PMC3997480 DOI: 10.1371/journal.pone.0095895] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Accepted: 04/01/2014] [Indexed: 11/19/2022] Open
Abstract
Experimentally renal tissue hypoxia appears to play an important role in the pathogenesis of chronic kidney disease (CKD) and arterial hypertension (AHT). In this study we measured renal tissue oxygenation and its determinants in humans using blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) under standardized hydration conditions. Four coronal slices were selected, and a multi gradient echo sequence was used to acquire T2* weighted images. The mean cortical and medullary R2* values ( = 1/T2*) were calculated before and after administration of IV furosemide, a low R2* indicating a high tissue oxygenation. We studied 195 subjects (95 CKD, 58 treated AHT, and 42 healthy controls). Mean cortical R2 and medullary R2* were not significantly different between the groups at baseline. In stimulated conditions (furosemide injection), the decrease in R2* was significantly blunted in patients with CKD and AHT. In multivariate linear regression analyses, neither cortical nor medullary R2* were associated with eGFR or blood pressure, but cortical R2* correlated positively with male gender, blood glucose and uric acid levels. In conclusion, our data show that kidney oxygenation is tightly regulated in CKD and hypertensive patients at rest. However, the metabolic response to acute changes in sodium transport is altered in CKD and in AHT, despite preserved renal function in the latter group. This suggests the presence of early renal metabolic alterations in hypertension. The correlations between cortical R2* values, male gender, glycemia and uric acid levels suggest that these factors interfere with the regulation of renal tissue oxygenation.
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Affiliation(s)
- Menno Pruijm
- Department of Nephrology, University Hospital, Lausanne, Switzerland
| | - Lucie Hofmann
- Department of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | | | - Marie-Eve Muller
- Department of Nephrology, University Hospital, Lausanne, Switzerland
| | - Carole Zweiacker
- Department of Nephrology, University Hospital, Lausanne, Switzerland
| | - Isabelle Bassi
- Department of Nephrology, University Hospital, Lausanne, Switzerland
| | - Bruno Vogt
- Department of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Matthias Stuber
- Department of Radiology, University Hospital, Lausanne, Switzerland
| | - Michel Burnier
- Department of Nephrology, University Hospital, Lausanne, Switzerland
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Vivier PH, Storey P, Chandarana H, Yamamoto A, Tantillo K, Khan U, Zhang JL, Sigmund EE, Rusinek H, Babb JS, Bubenheim M, Lee VS. Renal blood oxygenation level-dependent imaging: contribution of R2 to R2* values. Invest Radiol 2013; 48:501-8. [PMID: 23385400 DOI: 10.1097/RLI.0b013e3182823591] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The aim of this study was to assess the impact of oral water and intravenous furosemide challenges on blood oxygenation level-dependent magnetic resonance imaging measurements in the kidney and to examine the contribution of R2 (=1/T2) to changes in R2* (=1/T2*). MATERIALS AND METHODS This Health Insurance Portability and Accountability Act-compliant study had institutional review board approval, and written informed consent was obtained from all subjects. Nine healthy volunteers were imaged at 3 T on 2 visits. During each visit, a baseline fasting magnetic resonance acquisition was followed by a diuretic challenge: oral water load for the first visit and furosemide for the second. R2* and R2 values in the renal cortex and medulla were measured using multiple gradient echo and multiple spin echo sequences, respectively, and R2' values were computed as R2' = R2* - R2. Timed urinary output was also measured. RESULTS Averaged across all subjects, the R2* response to furosemide was greater than to water and greater in the medulla than the cortex. The mean R2 responses exhibited the same trends but were uniformly smaller than the mean R2* responses. The peak changes in R2* and R2 appeared, on average, 10 to 14 minutes before peak urinary output. The median percentage contribution of R2 to R2* changes was 16% in the medulla after both challenges. In the cortex, the median contribution was 48% after water load and 58% after furosemide challenge. CONCLUSIONS The contributions of R2 to R2* changes after water load and furosemide challenge are not negligible, especially in the renal cortex. In routine clinical practice, R2* could be used alone as a rough surrogate for R2' in the medulla. However, in the cortex, both R2 and R2* should be measured to obtain accurate values of R2'.
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Neyra JA, Shah S, Mooney R, Jacobsen G, Yee J, Novak JE. Contrast-induced acute kidney injury following coronary angiography: a cohort study of hospitalized patients with or without chronic kidney disease. Nephrol Dial Transplant 2013; 28:1463-71. [PMID: 23585585 DOI: 10.1093/ndt/gft082] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Contrast-induced acute kidney injury (CIAKI) has been linked to unfavorable consequences. In routine clinical practice, small increases in serum creatinine (SCr) following coronary angiography tend to be underestimated, especially in patients without chronic kidney disease (CKD). METHODS We conducted a retrospective observational cohort study to analyze in-hospital and long-term outcomes of CIAKI following coronary angiography in patients with or without CKD (eGFR ≥ 60 mL/min/1.73 m(2)) from January 2008 through December 2009. CIAKI was defined as SCr either ≥ 25% or ≥ 0.5 mg/dL from baseline within 72 h after contrast exposure. Multivariable logistic regression for in-hospital mortality and Cox proportional hazards calculations for long-term mortality and requirement for dialysis were performed. RESULTS A total of 1160 patients were included in the study. CIAKI occurred in 19% of CKD patients and in 18% of non-CKD patients. In CKD and non-CKD patients, CIAKI was more frequent in patients requiring mechanical ventilation or inotropes or in those given furosemide, and it was associated with adverse in-hospital (prolonged hospitalization, acute dialysis and mortality) and long-term (increased creatinine, initiation of dialysis and mortality) outcomes. In multivariable analysis, CKD patients had greater in-hospital mortality if they developed CIAKI (adjusted OR 8, 95% CI 1.9-34.5, P = 0.005), and non-CKD patients had greater long-term mortality if they developed CIAKI (adjusted HR 2.2, 95% CI 1.2-4.1, P = 0.016). CONCLUSIONS CIAKI following coronary angiography was associated with adverse in-hospital and long-term outcomes in both CKD and non-CKD patients.
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Affiliation(s)
- Javier A Neyra
- Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Pohlmann A, Cantow K, Hentschel J, Arakelyan K, Ladwig M, Flemming B, Hoff U, Persson PB, Seeliger E, Niendorf T. Linking non-invasive parametric MRI with invasive physiological measurements (MR-PHYSIOL): towards a hybrid and integrated approach for investigation of acute kidney injury in rats. Acta Physiol (Oxf) 2013; 207:673-89. [PMID: 23336404 DOI: 10.1111/apha.12065] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 12/17/2012] [Accepted: 01/16/2013] [Indexed: 01/11/2023]
Abstract
Acute kidney injury of various origins shares a common link in the pathophysiological chain of events: imbalance between renal medullary oxygen delivery and oxygen demand. For in vivo assessment of kidney haemodynamics and oxygenation in animals, quantitative but invasive physiological methods are established. A very limited number of studies attempted to link these invasive methods with parametric Magnetic Resonance Imaging (MRI) of the kidney. Moreover, the validity of parametric MRI (pMRI) as a surrogate marker for renal tissue perfusion and renal oxygenation has not been systematically examined yet. For this reason, we set out to combine invasive techniques and non-invasive MRI in an integrated hybrid setup (MR-PHYSIOL) with the ultimate goal to calibrate, monitor and interpret parametric MR and physiological parameters by means of standardized interventions. Here we present a first report on the current status of this multi-modality approach. For this purpose, we first highlight key characteristics of renal perfusion and oxygenation. Second, concepts for in vivo characterization of renal perfusion and oxygenation are surveyed together with the capabilities of MRI for probing blood oxygenation-dependent tissue stages. Practical concerns evoked by the use of strong magnetic fields in MRI and interferences between MRI and invasive physiological probes are discussed. Technical solutions that balance the needs of in vivo physiological measurements together with the constraints dictated by small bore MR scanners are presented. An early implementation of the integrated MR-PHYSIOL approach is demonstrated including brief interventions of hypoxia and hyperoxia.
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Affiliation(s)
- A. Pohlmann
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin; Germany
| | - K. Cantow
- Institute of Physiology; Charité - Universitätsmedizin Berlin; Campus Mitte, and Center for Cardiovascular Research; Berlin; Germany
| | - J. Hentschel
- Berlin Ultrahigh Field Facility (B.U.F.F.); Max Delbrück Center for Molecular Medicine; Berlin; Germany
| | | | - M. Ladwig
- Institute of Physiology; Charité - Universitätsmedizin Berlin; Campus Mitte, and Center for Cardiovascular Research; Berlin; Germany
| | - B. Flemming
- Institute of Physiology; Charité - Universitätsmedizin Berlin; Campus Mitte, and Center for Cardiovascular Research; Berlin; Germany
| | - U. Hoff
- Nephrology and Intensive Care Medicine; Charité - Universitätsmedizin Berlin; Campus Virchow-Klinikum, and Center for Cardiovascular Research; Berlin; Germany
| | - P. B. Persson
- Institute of Physiology; Charité - Universitätsmedizin Berlin; Campus Mitte, and Center for Cardiovascular Research; Berlin; Germany
| | - E. Seeliger
- Institute of Physiology; Charité - Universitätsmedizin Berlin; Campus Mitte, and Center for Cardiovascular Research; Berlin; Germany
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Pruijm M, Hofmann L, Vogt B, Muller ME, Piskunowicz M, Stuber M, Burnier M. Renal tissue oxygenation in essential hypertension and chronic kidney disease. Int J Hypertens 2013; 2013:696598. [PMID: 23509612 DOI: 10.1155/2013/696598] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Accepted: 01/09/2013] [Indexed: 01/13/2023] Open
Abstract
Animal studies suggest that renal tissue hypoxia plays an important role in the development of renal damage in hypertension and renal diseases, yet human data were scarce due to the lack of noninvasive methods. Over the last decade, blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI), detecting deoxyhemoglobin in hypoxic renal tissue, has become a powerful tool to assess kidney oxygenation noninvasively in humans. This paper provides an overview of BOLD-MRI studies performed in patients suffering from essential hypertension or chronic kidney disease (CKD). In line with animal studies, acute changes in cortical and medullary oxygenation have been observed after the administration of medication (furosemide, blockers of the renin-angiotensin system) or alterations in sodium intake in these patient groups, underlining the important role of renal sodium handling in kidney oxygenation. In contrast, no BOLD-MRI studies have convincingly demonstrated that renal oxygenation is chronically reduced in essential hypertension or in CKD or chronically altered after long-term medication intake. More studies are required to clarify this discrepancy and to further unravel the role of renal oxygenation in the development and progression of essential hypertension and CKD in humans.
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Pruijm M, Hofmann L, Zanchi A, Maillard M, Forni V, Muller ME, Wuerzner G, Vogt B, Stuber M, Burnier M. Blockade of the renin-angiotensin system and renal tissue oxygenation as measured with BOLD-MRI in patients with type 2 diabetes. Diabetes Res Clin Pract 2013; 99:136-44. [PMID: 23245807 DOI: 10.1016/j.diabres.2012.11.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 10/23/2012] [Accepted: 11/08/2012] [Indexed: 12/20/2022]
Abstract
AIM To assess whether blockade of the renin-angiotensin system (RAS), a recognized strategy to prevent the progression of diabetic nephropathy, affects renal tissue oxygenation in type 2 diabetes mellitus (T2DM) patients. METHODS Prospective randomized 2-way cross over study; T2DM patients with (micro)albuminuria and/or hypertension underwent blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) at baseline, after one month of enalapril (20 mgqd), and after one month of candesartan (16 mgqd). Each BOLD-MRI was performed before and after the administration of furosemide. The mean R₂* (=1/T₂*) values in the medulla and cortex were calculated, a low R₂* indicating high tissue oxygenation. RESULTS Twelve patients (mean age: 60 ± 11 years, eGFR: 62 ± 22 ml/min/1.73 m(2)) completed the study. Neither chronic enalapril nor candesartan intake modified renal cortical or medullary R₂* levels. Furosemide significantly decreased cortical and medullary R₂* levels suggesting a transient increase in renal oxygenation. Medullary R₂* levels correlated positively with urinary sodium excretion and systemic blood pressure, suggesting lower renal oxygenation at higher dietary sodium intake and blood pressure; cortical R₂* levels correlated positively with glycemia and HbA1c. CONCLUSION RAS blockade does not seem to increase renal tissue oxygenation in T2DM hypertensive patients. The response to furosemide and the association with 24 h urinary sodium excretion emphasize the crucial role of renal sodium handling as one of the main determinants of renal tissue oxygenation.
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Affiliation(s)
- Menno Pruijm
- Service of Nephrology, University Hospital, Lausanne, Switzerland
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Evans RG, Ince C, Joles JA, Smith DW, May CN, O'Connor PM, Gardiner BS. Haemodynamic influences on kidney oxygenation: Clinical implications of integrative physiology. Clin Exp Pharmacol Physiol 2013; 40:106-22. [DOI: 10.1111/1440-1681.12031] [Citation(s) in RCA: 178] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 10/21/2012] [Accepted: 11/15/2012] [Indexed: 01/08/2023]
Affiliation(s)
- Roger G Evans
- Department of Physiology; Monash University; Melbourne; Victoria; Australia
| | - Can Ince
- Department of Translational Physiology; Academic Medical Center; University of Amsterdam; Amsterdam; The Netherlands
| | - Jaap A Joles
- Department of Nephrology and Hypertension; University Medical Center; Utrecht; The Netherlands
| | - David W Smith
- School of Computer Science and Software Engineering; The University of Western Australia; Perth; Western Australia; Australia
| | - Clive N May
- Florey Institute of Neuroscience and Mental Health; University of Melbourne; Melbourne; Victoria; Australia
| | - Paul M O'Connor
- Department of Physiology; Georgia Health Sciences University; Augusta; GA; USA
| | - Bruce S Gardiner
- School of Computer Science and Software Engineering; The University of Western Australia; Perth; Western Australia; Australia
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Haneder S, Michaely HJ, Schoenberg SO, Konstandin S, Schad LR, Siebenlist K, Wertz H, Wenz F, Lohr F, Boda-Heggemann J. Assessment of renal function after conformal radiotherapy and intensity-modulated radiotherapy by functional 1H-MRI and 23Na-MRI. Strahlenther Onkol 2012; 188:1146-54. [PMID: 23111472 DOI: 10.1007/s00066-012-0254-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 09/24/2012] [Indexed: 01/24/2023]
Abstract
PURPOSE Adjuvant radiochemotherapy (RCHT) improves survival of patients with locally advanced gastric cancer. Conventional three-dimensional conformal radiotherapy (3D-CRT) results in ablative doses to a significant amount of the left kidney, while image-guided intensity-modulated radiotherapy (IG-IMRT) provides excellent target coverage with improved kidney sparing. Few long-term results on IMRT for gastric cancer, however, have been published. Functional magnetic resonance imaging (fMRI) at 3.0 T including blood oxygenation-level dependent (BOLD) imaging, diffusion-weighted imaging (DWI) and, for the first time, (23)Na imaging was used to evaluate renal status after radiotherapy with 3D-CRT or IG-IMRT. PATIENTS AND METHODS Four disease-free patients (2 after 3D-CRT and 2 after IMRT; FU for all patients > 5 years) were included in this feasibility study. Morphological sequences, axial DWI images, 2D-gradient echo (GRE)-BOLD images, and (23)Na images were acquired. Mean values/standard deviations for ((23)Na), the apparent diffusion coefficient (ADC), and R2* values were calculated for the upper/middle/lower parts of both kidneys. Corticomedullary (23)Na-concentration gradients were determined. RESULTS Surprisingly, IG-IMRT patients showed no morphological alterations and no statistically significant differences of ADC and R2* values in all renal parts. Values for mean corticomedullary (23)Na-concentration matched those for healthy volunteers. Results were similar in 3D-CRT patients, except for the cranial part of the left kidney. This was atrophic and presented significantly reduced functional parameters (p = 0.001-p = 0.033). Reduced ADC values indicated reduced cell density and reduced extracellular space. Cortical and medullary R2* values of the left cranial kidney in the 3D-CRT group were higher, indicating more deoxygenated hemoglobin due to reduced blood flow/oxygenation. ((23)Na) of the renal cranial parts in the 3D-CRT group was significantly reduced, while the expected corticomedullary (23)Na-concentration gradient was partially conserved. CONCLUSIONS Functional MRI can assess postradiotherapeutic renal changes. As expected, marked morphological/functional effects were observed in high-dose areas (3D-CRT), while, unexpectedly, no alteration in kidney function was observed in IG-IMRT patients, supporting the hypothesis that reducing total/fractional dose to the renal parenchyma by IMRT is clinically beneficial.
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Affiliation(s)
- S Haneder
- Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
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