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Niendorf T, Gladytz T, Cantow K, Klein T, Tasbihi E, Velasquez Vides JR, Zhao K, Millward JM, Waiczies S, Seeliger E. MRI of kidney size matters. MAGMA (NEW YORK, N.Y.) 2024:10.1007/s10334-024-01168-5. [PMID: 38960988 DOI: 10.1007/s10334-024-01168-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 05/06/2024] [Accepted: 05/15/2024] [Indexed: 07/05/2024]
Abstract
OBJECTIVE To highlight progress and opportunities of measuring kidney size with MRI, and to inspire research into resolving the remaining methodological gaps and unanswered questions relating to kidney size assessment. MATERIALS AND METHODS This work is not a comprehensive review of the literature but highlights valuable recent developments of MRI of kidney size. RESULTS The links between renal (patho)physiology and kidney size are outlined. Common methodological approaches for MRI of kidney size are reviewed. Techniques tailored for renal segmentation and quantification of kidney size are discussed. Frontier applications of kidney size monitoring in preclinical models and human studies are reviewed. Future directions of MRI of kidney size are explored. CONCLUSION MRI of kidney size matters. It will facilitate a growing range of (pre)clinical applications, and provide a springboard for new insights into renal (patho)physiology. As kidney size can be easily obtained from already established renal MRI protocols without the need for additional scans, this measurement should always accompany diagnostic MRI exams. Reconciling global kidney size changes with alterations in the size of specific renal layers is an important topic for further research. Acute kidney size measurements alone cannot distinguish between changes induced by alterations in the blood or the tubular volume fractions-this distinction requires further research into cartography of the renal blood and the tubular volumes.
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Affiliation(s)
- Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany.
- Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.
| | - Thomas Gladytz
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - Kathleen Cantow
- Institute of Translational Physiology, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
| | - Tobias Klein
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
- Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- Digital Health-Machine Learning Research Group, Hasso Plattner Institute for Digital Engineering, University of Potsdam, Potsdam, Germany
| | - Ehsan Tasbihi
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Jose Raul Velasquez Vides
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
- Institute for Medical Engineering, Otto Von Guericke University, Magdeburg, Germany
| | - Kaixuan Zhao
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Jason M Millward
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
- Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sonia Waiczies
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125, Berlin, Germany
- Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Erdmann Seeliger
- Institute of Translational Physiology, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
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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 2024; 65:397-405. [PMID: 38146146 DOI: 10.1177/02841851231217052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [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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Peng J, Gao J, Hong Y, Wu Z, Chen G, Lu G. The value of functional magnetic resonance imaging in evaluating renal allograft function. Asian J Surg 2024; 47:1740-1745. [PMID: 38176978 DOI: 10.1016/j.asjsur.2023.12.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/05/2023] [Accepted: 12/15/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND To explore the value of arterial spin labeled (ASL) and blood oxygen level dependent (BOLD) imaging in evaluating allogeneic kidney function after renal transplantation. METHODS One hundred and thirty-five renal transplant patients were included. Demographic and imaging data were collected. Transplanted renal function, pathology, ASL and BOLD parameters were obtained. The patients were divided into normal, mild and severe injury group. The correlation between BOLD/ASL parameters and clinical data were evaluated. The prediction models were based on ASL and BOLD parameters using multivariate logistic analysis. Cox proportional hazards regression model was used to analyze the effects of gender, age, ASL and BOLD on the survival of renal transplant patients. RESULTS ASL and BOLD parameters were independently associated with renal function injury and renal allograft positive pathology. The AUC of prediction model for renal allograft function based on ASL and BOLD parameters was 0.85, while the AUC based on BOLD parameters was 0.70. Renal transplantation time showed a positive correlation with age, BOLD parameters and SCr,while a negative correlation with ASL parameters and eGFR. ASL parameter was positively correlated with eGFR and negatively correlated with Scr. BOLD parameter was negatively correlated with eGFR, ASL and positively correlated with Scr. Cox proportional hazards regression model showed that the increase of age could reduce the risk of renal function injury and positive pathology. CONCLUSIONS ASL and BOLD were associated with renal function injury and renal allograft positive pathology. ASL and BOLD had some value in predicting renal allograft function.
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Affiliation(s)
- Jin Peng
- Department of Tumor and Vascular Intervention, Chenggong Hospital, Xiamen University, Xiamen, Fujian, 361003, China
| | - Juan Gao
- Department of Radiology, Jinling Hospital, Nanjing University, Nanjing, Jiangsu, 210006, China
| | - Yajun Hong
- Department of Medical Record Statistics, Zhongshan Hospital, Fudan University (Xiamen Branch), Fujian, 361015, China
| | - Zhengcan Wu
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, 210006, China
| | - Guozhong Chen
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, 210006, China.
| | - Guangming Lu
- Department of Radiology, Jinling Hospital, Nanjing University, Nanjing, Jiangsu, 210006, China.
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Bane O, Lewis SC, Lim RP, Carney BW, Shah A, Fananapazir G. Contemporary and Emerging MRI Strategies for Assessing Kidney Allograft Complications: Arterial Stenosis and Parenchymal Injury, From the AJR Special Series on Imaging of Fibrosis. AJR Am J Roentgenol 2024; 222:e2329418. [PMID: 37315018 PMCID: PMC11006565 DOI: 10.2214/ajr.23.29418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
MRI plays an important role in the evaluation of kidney allografts for vascular complications as well as parenchymal insults. Transplant renal artery stenosis, the most common vascular complication of kidney transplant, can be evaluated by MRA using gadolinium and nongadolinium contrast agents as well as by unenhanced MRA techniques. Parenchymal injury occurs through a variety of pathways, including graft rejection, acute tubular injury, BK polyomavirus infection, drug-induced interstitial nephritis, and pyelonephritis. Investigational MRI techniques have sought to differentiate among these causes of dysfunction as well as to assess the degree of interstitial fibrosis or tubular atrophy (IFTA)-the common end pathway for all of these processes-which is currently evaluated by invasively obtained core biopsies. Some of these MRI sequences have shown promise in not only assessing the cause of parenchymal injury but also assessing IFTA noninvasively. This review describes current clinically used MRI techniques and previews promising investigational MRI techniques for assessing complications of kidney grafts.
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Affiliation(s)
- Octavia Bane
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Sara C Lewis
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Ruth P Lim
- Department of Radiology and Department of Surgery, University of Melbourne, Austin Health, Melbourne, Australia
| | - Benjamin W Carney
- Department of Radiology, University of California Davis Medical Center, 4860 Y St, Ste 3100, Sacramento, CA 95816
| | - Amar Shah
- Department of Radiology, Mayo Clinic Arizona, Phoenix, AZ
| | - Ghaneh Fananapazir
- Department of Radiology, University of California Davis Medical Center, 4860 Y St, Ste 3100, Sacramento, CA 95816
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Bane O, Seeliger E, Cox E, Stabinska J, Bechler E, Lewis S, Hickson LJ, Francis S, Sigmund E, Niendorf T. Renal MRI: From Nephron to NMR Signal. J Magn Reson Imaging 2023; 58:1660-1679. [PMID: 37243378 PMCID: PMC11025392 DOI: 10.1002/jmri.28828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
Renal diseases pose a significant socio-economic burden on healthcare systems. The development of better diagnostics and prognostics is well-recognized as a key strategy to resolve these challenges. Central to these developments are MRI biomarkers, due to their potential for monitoring of early pathophysiological changes, renal disease progression or treatment effects. The surge in renal MRI involves major cross-domain initiatives, large clinical studies, and educational programs. In parallel with these translational efforts, the need for greater (patho)physiological specificity remains, to enable engagement with clinical nephrologists and increase the associated health impact. The ISMRM 2022 Member Initiated Symposium (MIS) on renal MRI spotlighted this issue with the goal of inspiring more solutions from the ISMRM community. This work is a summary of the MIS presentations devoted to: 1) educating imaging scientists and clinicians on renal (patho)physiology and demands from clinical nephrologists, 2) elucidating the connection of MRI parameters with renal physiology, 3) presenting the current state of leading MR surrogates in assessing renal structure and functions as well as their next generation of innovation, and 4) describing the potential of these imaging markers for providing clinically meaningful renal characterization to guide or supplement clinical decision making. We hope to continue momentum of recent years and introduce new entrants to the development process, connecting (patho)physiology with (bio)physics, and conceiving new clinical applications. We envision this process to benefit from cross-disciplinary collaboration and analogous efforts in other body organs, but also to maximally leverage the unique opportunities of renal physiology. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 2.
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Affiliation(s)
- Octavia Bane
- Department of Diagnostic, Molecular and Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York City, New York, USA
- Icahn School of Medicine at Mount Sinai, BioMedical Engineering and Imaging Institute, New York City, New York, USA
| | - Erdmann Seeliger
- Institute of Translational Physiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Eleanor Cox
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Julia Stabinska
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Eric Bechler
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Sara Lewis
- Department of Diagnostic, Molecular and Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York City, New York, USA
| | - LaTonya J Hickson
- Division of Nephrology and Hypertension, Mayo Clinic, Jacksonville, Florida, USA
| | - Sue Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Eric Sigmund
- Bernard and Irene Schwartz Center for Biomedical Imaging Center for Advanced Imaging Innovation and Research (CAI2R), New York University Langone Health, New York City, New York, USA
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
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Schutter R, van Varsseveld OC, Lantinga VA, Pool MBF, Hamelink TH, Potze JH, Leuvenink HGD, Laustsen C, Borra RJH, Moers C. Magnetic resonance imaging during warm ex vivo kidney perfusion. Artif Organs 2023; 47:105-116. [PMID: 35996889 PMCID: PMC10086841 DOI: 10.1111/aor.14391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/30/2022] [Accepted: 08/02/2022] [Indexed: 01/04/2023]
Abstract
BACKGROUND The shortage of donor organs for transplantation remains a worldwide problem. The utilization of suboptimal deceased donors enlarges the pool of potential organs, yet consequently, clinicians face the difficult decision of whether these sub-optimal organs are of sufficient quality for transplantation. Novel technologies could play a pivotal role in making pre-transplant organ assessment more objective and reliable. METHODS Ex vivo normothermic machine perfusion (NMP) at temperatures around 35-37°C allows organ quality assessment in a near-physiological environment. Advanced magnetic resonance imaging (MRI) techniques convey unique information about an organ's structural and functional integrity. The concept of applying magnetic resonance imaging during renal normothermic machine perfusion is novel in both renal and radiological research and we have developed the first MRI-compatible NMP setup for human-sized kidneys. RESULTS We were able to obtain a detailed and real-time view of ongoing processes inside renal grafts during ex vivo perfusion. This new technique can visualize structural abnormalities, quantify regional flow distribution, renal metabolism, and local oxygen availability, and track the distribution of ex vivo administered cellular therapy. CONCLUSION This platform allows for advanced pre-transplant organ assessment, provides a new realistic tool for studies into renal physiology and metabolism, and may facilitate therapeutic tracing of pharmacological and cellular interventions to an isolated kidney.
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Affiliation(s)
- Rianne Schutter
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Otis C van Varsseveld
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Veerle A Lantinga
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Merel B F Pool
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Tim H Hamelink
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan Hendrik Potze
- Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Henri G D Leuvenink
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Christoffer Laustsen
- Department of Clinical Medicine, The MR Research Center, Aarhus University, Aarhus, Denmark
| | - Ronald J H Borra
- Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Cyril Moers
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Chiang HJ, Chou MC, Chuang YH, Li CW, Lin CC, Eng HL, Chen CL, Cheng YF. Use of blood oxygen level-dependent magnetic resonance imaging to detect acute cellular rejection post-liver transplantation. Eur Radiol 2022; 32:4547-4554. [PMID: 35247088 DOI: 10.1007/s00330-022-08574-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/04/2022] [Accepted: 01/07/2022] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Acute cellular rejection (ACR) is a major immune occurrence post-liver transplant that can cause abnormal liver function. Blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) can be used to evaluate liver disease, but it has not been utilized in the diagnosis of ACR post-liver transplant. Therefore, the purpose of this study is to evaluate the diagnostic performance of BOLD MRI and to monitor treatment response in recipients with ACR. METHODS This prospective study was approved by the local institutional review board. Fifty-five recipients with highly suspected ACR were enrolled in this study. Each patient underwent hepatic BOLD MRI, blood biochemistry, and biopsy before treatment. Of 55 patients, 19 recipients with ACR received a follow-up MRI after treatment. After obtaining the R2* maps, five regions-of-interest were placed on liver parenchyma to estimate the mean R2* values for statistical analysis. Receiver operating characteristic curve (ROC) analysis was performed to assess the diagnostic performance of R2* values in detecting patients with ACR. RESULTS The histopathologic results showed that 27 recipients had ACR (14 mild, 11 moderate, and 2 severe) and their hepatic R2* values were significantly lower than those of patients without ACR. ROC analysis revealed that the sensitivity and specificity of the R2* values for detection of ACR were 82.1% and 89.9%, respectively. Moreover, the R2* values and liver function in patients with ACR significantly increased after immunosuppressive treatment. CONCLUSION The non-invasive BOLD MRI technique may be useful for assessment of hepatic ACR and monitoring of treatment response after immunosuppressive therapy. KEY POINTS • Patients with acute cellular rejection post-liver transplant exhibited significantly decreased R2* values in liver parenchyma. • R2* values and liver function were significantly increased after immunosuppressive therapy. • R2* values were constructive indicators in detecting acute cellular rejection due to their high sensitivity and specificity.
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Affiliation(s)
- Hsien-Jen Chiang
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ming-Chung Chou
- Department of Medical Imaging and Radiological Sciences, College of Health Science, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Center for Big Data Research, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Hsuan Chuang
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chun-Wei Li
- Department of Medical Imaging and Radiological Sciences, College of Health Science, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chih-Che Lin
- Liver Transplantation Center, Department of Surgery, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Hock-Liew Eng
- Department of Pathology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chao-Long Chen
- Liver Transplantation Center, Department of Surgery, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yu-Fan Cheng
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, 123 Ta-Pei Road, Niao-Sung, Kaohsiung, 833, Taiwan.
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Hysi E, Kaur H, Young A. Evolving Medical Imaging Techniques for the Assessment of Delayed Graft Function: A Narrative Review. Can J Kidney Health Dis 2021; 8:20543581211048341. [PMID: 34707880 PMCID: PMC8544764 DOI: 10.1177/20543581211048341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 09/04/2021] [Indexed: 11/15/2022] Open
Abstract
Purpose of review Delayed graft function (DGF) is a significant complication that contributes to poorer graft function and shortened graft survival. In this review, we sought to evaluate the current and emerging role of medical imaging modalities in the assessment of DGF and how it may guide clinical management. Sources of information PubMed, Google Scholar, and ClinicalTrial.gov up until February 2021. Methods This narrative review first examined the pathophysiology of DGF and current clinical management. We then summarized relevant studies that utilized medical imaging to assess posttransplant renal complications, namely, DGF. We focused our attention on noninvasive, evolving imaging modalities with the greatest potential for clinical translation, including contrast-enhanced ultrasound (CEUS) and multiparametric magnetic resonance imaging (MRI). Key findings A kidney biopsy in the setting of DGF can be used to assess the degree of ischemic renal injury and to rule out acute rejection. Biopsies are accompanied by complications and may be limited by sampling bias. Early studies on CEUS and MRI have shown their potential to distinguish between the 2 most common causes of DGF (acute tubular necrosis and acute rejection), but they have generally included only small numbers of patients and have not kept pace with more recent technical advances of these imaging modalities. There remains unharnessed potential with CEUS and MRI, and more robust clinical studies are needed to better evaluate their role in the current era. Limitations The adaptation of emerging approaches for imaging DGF will depend on additional clinical trials to study the feasibility and diagnostic test characteristics of a given modality. This is limited by access to devices, technical competence, and the need for interdisciplinary collaborations to ensure that such studies are well designed to appropriately inform clinical decision-making.
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Affiliation(s)
- Eno Hysi
- Division of Nephrology, St. Michael's Hospital, Unity Health Toronto, ON, Canada.,Li Ka Shing Knowledge Institute, Keenan Research Centre for Biomedical Sciences, St. Michael's Hospital, Unity Health Toronto, ON, Canada
| | - Harmandeep Kaur
- Li Ka Shing Knowledge Institute, Keenan Research Centre for Biomedical Sciences, St. Michael's Hospital, Unity Health Toronto, ON, Canada
| | - Ann Young
- Division of Nephrology, St. Michael's Hospital, Unity Health Toronto, ON, Canada.,Li Ka Shing Knowledge Institute, Keenan Research Centre for Biomedical Sciences, St. Michael's Hospital, Unity Health Toronto, ON, Canada.,Division of Nephrology, Department of Medicine, University of Toronto, ON, Canada
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9
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Mendes GF, Falsarella PM, Garcia RG, Sanches LG, Baroni RH. Evaluation of the blood-oxygen-level-dependent (BOLD) sequence with 3 Tesla device in renal transplant patients in the assessment of early allograft disfunction, correlated with biopsy. EINSTEIN-SAO PAULO 2021; 19:eAO6069. [PMID: 34431851 PMCID: PMC8362909 DOI: 10.31744/einstein_journal/2021ao6069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 03/26/2021] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate the ability of blood-oxygen-level-dependent (BOLD) magnetic resonance imaging at 3 Tesla to measure tissue oxygen bioavailability based on R2* values, and to differentiate between acute tubular necrosis and acute rejection compared to renal biopsy (gold standard). METHODS A prospective, single-center study, with patients submitted to renal transplantation between 2013 and 2014, who developed graft dysfunction less than 4 weeks after transplantation. All patients were submitted to abdominal magnetic resonance imaging at 3 Tesla using the same protocol, followed by two BOLD sequences and kidney biopsy. RESULTS Twelve male (68.75%) and three female (31.25%) patients were included. A total of 19 percutaneous renal biopsies were performed (four patients required a second biopsy due to changes in clinical findings). Pathological findings revealed ten cases of acute tubular necrosis, four cases of acute rejection, and five cases with other (miscellaneous) diagnoses. Comparison between the four groups of interest failed to reveal significant differences (p=0.177) in cortical R2* values, whereas medullary R2* values differed significantly (p=0.033), with lower values in the miscellaneous diagnoses and the acute tubular necrosis group. CONCLUSION BOLD magnetic resonance imaging at 3 Tesla is a feasible technique that uses indirect tissue oxygen level measurements to differentiate between acute rejection and acute tubular necrosis in renal grafts.
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Ghonge NP, Goyal N, Vohra S, Chowdhury V. Renal transplant evaluation: multimodality imaging of post-transplant complications. Br J Radiol 2021; 94:20201253. [PMID: 34233470 DOI: 10.1259/bjr.20201253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
With advancements in surgical techniques and immuno-suppression, renal transplantation is established as the most effective treatment option in patients with end-stage renal disease. Early detection of renal allograft complications is important for long-term graft survival. Late clinical presentation often causes diagnostic delays till the time allograft failure is advanced and irreversible. Imaging plays a key role in routine surveillance and in management of acute or chronic transplant dysfunction. Multimodality imaging approach is important with ultrasound-Doppler as the first-line imaging study in immediate, early and late post-transplant periods. Additional imaging studies are often required depending on clinical settings and initial ultrasound. Renal functional MRI is a rapidly growing field that has huge potential for early diagnosis of transplant dysfunction. Multiparametric MRI may be integrated in clinical practice as a noninvasive and comprehensive "one-stop" modality for early diagnosis and longitudinal monitoring of renal allograft dysfunctions, which is essential for guiding appropriate interventions to delay or prevent irreversible renal damage. With rapidly increasing numbers of renal transplantation along with improved patient survival, it is necessary for radiologists in all practice settings to be familiar with the normal appearances and imaging spectrum of anatomical and functional complications in a transplant kidney. Radiologist"s role as an integral part of multidisciplinary transplantation team continues to grow with increasing numbers of successful renal transplantation programs across the globe.
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Affiliation(s)
- Nitin P Ghonge
- Department of Radiology, Indraprastha Apollo Hospital, New Delhi, India
| | - Nidhi Goyal
- Department of Radiology, Indraprastha Apollo Hospital, New Delhi, India
| | - Sandeep Vohra
- Department of Radiology, Indraprastha Apollo Hospital, New Delhi, India
| | - Veena Chowdhury
- Department of Radiology, Indraprastha Apollo Hospital, New Delhi, India
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11
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Abstract
Interstitial fibrosis with tubule atrophy (IF/TA) is the response to virtually any sustained kidney injury and correlates inversely with kidney function and allograft survival. IF/TA is driven by various pathways that include hypoxia, renin-angiotensin-aldosterone system, transforming growth factor (TGF)-β signaling, cellular rejection, inflammation and others. In this review we will focus on key pathways in the progress of renal fibrosis, diagnosis and therapy of allograft fibrosis. This review discusses the role and origin of myofibroblasts as matrix producing cells and therapeutic targets in renal fibrosis with a particular focus on renal allografts. We summarize current trends to use multi-omic approaches to identify new biomarkers for IF/TA detection and to predict allograft survival. Furthermore, we review current imaging strategies that might help to identify and follow-up IF/TA complementary or as alternative to invasive biopsies. We further discuss current clinical trials and therapeutic strategies to treat kidney fibrosis.Supplemental Visual Abstract; http://links.lww.com/TP/C141.
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Renal Transplant Pathology: Demographic Features and Histopathological Analysis of the Causes of Graft Dysfunction. Int J Nephrol 2020; 2020:7289701. [PMID: 33489373 PMCID: PMC7787863 DOI: 10.1155/2020/7289701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 11/08/2020] [Accepted: 11/20/2020] [Indexed: 01/05/2023] Open
Abstract
Background Renal transplant has emerged as a preferred treatment modality in cases of end-stage renal disease; however, a small percentage of cases suffer from graft dysfunction. Aim To evaluate the renal transplant biopsies and analyze the various causes of graft dysfunction. Materials and Methods 163 renal transplant biopsies, reported between 2014 and 2019 and who fulfilled the inclusion criteria, were evaluated with respect to demographics, clinical, histological, and immunohistochemical features. Results Of 163 patients, 26 (16%) were females and 137 (84%) were males with a mean age of 34 ± 7 years. 53 (32.5%) cases were of rejection (ABMR and TCMR), 1 (0.6%) was borderline, 15 were of IFTA, and rest of 94 cases (57.7%) belonged to the others category. SCr (serum creatinine) in cases of rejection was 3.85 ± 0.55 mg/dl. Causes of early graft dysfunction included active ABMR (7.1 ± 4.7 months), acute TCMR (5.5 months), and acute tubular necrosis (after 6 ± 2.2 months of transplant) while the causes of late rejection were CNIT and IFTA (34 ± 4.7 and 35 ± 7.8 months, respectively). Conclusion Renal graft dysfunction still remains a concerning area for both clinicians and patients. Biopsy remains the gold standard for diagnosing the exact cause of graft dysfunction and in planning further management.
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13
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Shehata M, Ghazal M, Khalifeh HA, Khalil A, Shalaby A, Dwyer AC, Bakr AM, Keynton R, El-Baz A. A DEEP LEARNING-BASED CAD SYSTEM FOR RENAL ALLOGRAFT ASSESSMENT: DIFFUSION, BOLD, AND CLINICAL BIOMARKERS. PROCEEDINGS. INTERNATIONAL CONFERENCE ON IMAGE PROCESSING 2020; 2020:355-359. [PMID: 34720753 PMCID: PMC8553095 DOI: 10.1109/icip40778.2020.9190818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Recently, studies for non-invasive renal transplant evaluation have been explored to control allograft rejection. In this paper, a computer-aided diagnostic system has been developed to accommodate with an early-stage renal transplant status assessment, called RT-CAD. Our model of this system integrated multiple sources for a more accurate diagnosis: two image-based sources and two clinical-based sources. The image-based sources included apparent diffusion coefficients (ADCs) and the amount of deoxygenated hemoglobin (R2*). More specifically, these ADCs were extracted from 47 diffusion weighted magnetic resonance imaging (DW-MRI) scans at 11 different b-values (b0, b50, b100, …, b1000 s/mm2), while the R2* values were extracted from 30 blood oxygen level-dependent MRI (BOLD-MRI) scans at 5 different echo times (2ms, 7ms, 12ms, 17ms, and 22ms). The clinical sources included serum creatinine (SCr) and creatinine clearance (CrCl). First, the kidney was segmented through the RT-CAD system using a geometric deformable model called a level-set method. Second, both ADCs and R2* were estimated for common patients (N = 30) and then were integrated with the corresponding SCr and CrCl. Last, these integrated biomarkers were considered the discriminatory features to be used as trainers and testers for future deep learning-based classifiers such as stacked auto-encoders (SAEs). We used a k-fold cross-validation criteria to evaluate the RT-CAD system diagnostic performance, which achieved the following scores: 93.3%, 90.0%, and 95.0% in terms of accuracy, sensitivity, and specificity in differentiating between acute renal rejection (AR) and non-rejection (NR). The reliability and completeness of the RT-CAD system was further accepted by the area under the curve score of 0.92. The conclusions ensured that the presented RT-CAD system has a high reliability to diagnose the status of the renal transplant in a non-invasive way.
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Affiliation(s)
- Mohamed Shehata
- BioImaging Lab, Bioengineering Department, University of Louisville, Louisville, KY, USA
| | - Mohammed Ghazal
- Faculty of Engineering, Abu Dhabi University, Abu Dhabi, UAE
| | | | - Ashraf Khalil
- Faculty of Engineering, Abu Dhabi University, Abu Dhabi, UAE
| | - Ahmed Shalaby
- BioImaging Lab, Bioengineering Department, University of Louisville, Louisville, KY, USA
| | - Amy C Dwyer
- Pediatric Nephrology Unit, Mansoura University Children's Hospital, University of Mansoura, Egypt
| | - Ashraf M Bakr
- Kidney Disease Program, University of Louisville, Louisville, KY, USA
| | - Robert Keynton
- BioImaging Lab, Bioengineering Department, University of Louisville, Louisville, KY, USA
| | - Ayman El-Baz
- BioImaging Lab, Bioengineering Department, University of Louisville, Louisville, KY, USA
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14
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Yu YM, Ni QQ, Wang ZJ, Chen ML, Zhang LJ. Multiparametric Functional Magnetic Resonance Imaging for Evaluating Renal Allograft Injury. Korean J Radiol 2020; 20:894-908. [PMID: 31132815 PMCID: PMC6536799 DOI: 10.3348/kjr.2018.0540] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 12/19/2018] [Indexed: 02/06/2023] Open
Abstract
Kidney transplantation is the treatment of choice for patients with end-stage renal disease, as it extends survival and increases quality of life in these patients. However, chronic allograft injury continues to be a major problem, and leads to eventual graft loss. Early detection of allograft injury is essential for guiding appropriate intervention to delay or prevent irreversible damage. Several advanced MRI techniques can offer some important information regarding functional changes such as perfusion, diffusion, structural complexity, as well as oxygenation and fibrosis. This review highlights the potential of multiparametric MRI for noninvasive and comprehensive assessment of renal allograft injury.
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Affiliation(s)
- Yuan Meng Yu
- Department of Medical Imaging, Jinling Hospital, Clinical School of Southern Medical University, Nanjing, China
| | - Qian Qian Ni
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Zhen Jane Wang
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA
| | - Meng Lin Chen
- Medical Imaging Teaching and Research Office, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Long Jiang Zhang
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China.
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15
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Shehata M, Shalaby A, Switala AE, El-Baz M, Ghazal M, Fraiwan L, Khalil A, El-Ghar MA, Badawy M, Bakr AM, Dwyer A, Elmaghraby A, Giridharan G, Keynton R, El-Baz A. A multimodal computer-aided diagnostic system for precise identification of renal allograft rejection: Preliminary results. Med Phys 2020; 47:2427-2440. [PMID: 32130734 DOI: 10.1002/mp.14109] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 02/18/2020] [Accepted: 02/18/2020] [Indexed: 12/26/2022] Open
Abstract
PURPOSE Early assessment of renal allograft function post-transplantation is crucial to minimize and control allograft rejection. Biopsy - the gold standard - is used only as a last resort due to its invasiveness, high cost, adverse events (e.g., bleeding, infection, etc.), and the time for reporting. To overcome these limitations, a renal computer-assisted diagnostic (Renal-CAD) system was developed to assess kidney transplant function. METHODS The developed Renal-CAD system integrates data collected from two image-based sources and two clinical-based sources to assess renal transplant function. The imaging sources were the apparent diffusion coefficients (ADCs) extracted from 47 diffusion-weighted magnetic resonance imaging (DW-MRI) scans at 11 different b-values (b0, b50, b100, ..., b1000 s/mm 2 ), and the transverse relaxation rate (R2*) extracted from 30 blood oxygen level-dependent MRI (BOLD-MRI) scans at 5 different echo times (TEs = 2, 7, 12, 17, and 22 ms). Serum creatinine (SCr) and creatinine clearance (CrCl) were the clinical sources for kidney function evaluation. The Renal-CAD system initially performed kidney segmentation using the level-set method, followed by estimation of the ADCs from DW-MRIs and the R2* from BOLD-MRIs. ADCs and R2* estimates from 30 subjects that have both types of scans were integrated with their associated SCr and CrCl. The integrated biomarkers were then used as our discriminatory features to train and test a deep learning-based classifier, namely stacked autoencoders (SAEs) to differentiate non-rejection (NR) from acute rejection (AR) renal transplants. RESULTS Using a leave-one-subject-out cross-validation approach along with SAEs, the Renal-CAD system demonstrated 93.3% accuracy, 90.0% sensitivity, and 95.0% specificity in differentiating AR from NR. Robustness of the Renal-CAD system was also confirmed by the area under the curve value of 0.92. Using a stratified tenfold cross-validation approach, the Renal-CAD system demonstrated its reproducibility and robustness by a diagnostic accuracy of 86.7%, sensitivity of 80.0%, specificity of 90.0%, and AUC of 0.88. CONCLUSION The obtained results demonstrate the feasibility and efficacy of accurate, noninvasive identification of AR at an early stage using the Renal-CAD system.
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Affiliation(s)
- Mohamed Shehata
- BioImaging Lab, Department of Bioengineering, University of Louisville, Louisville, KY, 40208, USA
| | - Ahmed Shalaby
- BioImaging Lab, Department of Bioengineering, University of Louisville, Louisville, KY, 40208, USA
| | - Andrew E Switala
- BioImaging Lab, Department of Bioengineering, University of Louisville, Louisville, KY, 40208, USA
| | - Maryam El-Baz
- BioImaging Lab, Department of Bioengineering, University of Louisville, Louisville, KY, 40208, USA
| | - Mohammed Ghazal
- Electrical and Computer Engineering Department, Abu Dhabi University, Abu Dhabi, 59911, UAE
| | - Luay Fraiwan
- Electrical and Computer Engineering Department, Abu Dhabi University, Abu Dhabi, 59911, UAE
| | - Ashraf Khalil
- Computer Science and Information Technology Department, Abu Dhabi University, Abu Dhabi, 59911, UAE
| | - Mohamed Abou El-Ghar
- Urology and Nephrology Center, Radiology Department, Mansoura University, Mansoura, 35516, Egypt
| | - Mohamed Badawy
- Urology and Nephrology Center, Radiology Department, Mansoura University, Mansoura, 35516, Egypt
| | - Ashraf M Bakr
- Pediatric Nephrology Unit, Mansoura University Children's Hospital, University of Mansoura, Mansoura, 35516, Egypt
| | - Amy Dwyer
- Kidney Disease Program, University of Louisville, Louisville, KY, 40202, USA
| | - Adel Elmaghraby
- Computer Engineering and Computer Science Department, University of Louisville, Louisville, KY, 40208, USA
| | | | - Robert Keynton
- Department of Bioengineering, University of Louisville, Louisville, KY, 40208, USA
| | - Ayman El-Baz
- Department of Bioengineering, University of Louisville, Louisville, KY, 40208, USA.,200 E Shipp Ave, Lutz 390 Hall, Room 419, Louisville, KY, 40208, USA
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16
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Schutter R, Lantinga VA, Borra RJH, Moers C. MRI for diagnosis of post-renal transplant complications: current state-of-the-art and future perspectives. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2019; 33:49-61. [PMID: 31879853 DOI: 10.1007/s10334-019-00813-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/27/2019] [Accepted: 11/30/2019] [Indexed: 02/07/2023]
Abstract
Kidney transplantation has developed into a widespread procedure to treat end stage renal failure, with transplantation results improving over the years. Postoperative complications have decreased over the past decades, but are still an important cause of morbidity and mortality. Early accurate diagnosis and treatment is the key to prevent renal allograft impairment or even graft loss. Ideally, a diagnostic tool should be able to detect post-transplant renal dysfunction, differentiate between the different causes and monitor renal function during and after therapeutic interventions. Non-invasive imaging modalities for diagnostic purposes show promising results. Magnetic resonance imaging (MRI) techniques have a number of advantages, such as the lack of ionizing radiation and the possibility to obtain relevant tissue information without contrast, reducing the risk of contrast-induced nephrotoxicity. However, most techniques still lack the specificity to distinguish different types of parenchymal diseases. Despite some promising outcomes, MRI is still barely used in the post-transplantation diagnostic process. The aim of this review is to survey the current literature on the relevance and clinical applicability of diagnostic MRI modalities for the detection of various types of complications after kidney transplantation.
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Affiliation(s)
- Rianne Schutter
- University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
| | - Veerle A Lantinga
- University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Ronald J H Borra
- University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Cyril Moers
- University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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17
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Shehata M, Shalaby A, Ghazal M, Abou El-Ghar M, Badawy MA, Beache G, Dwyer A, El-Melegy M, Giridharan G, Keynton R, El-Baz A. EARLY ASSESSMENT OF RENAL TRANSPLANTS USING BOLD-MRI: PROMISING RESULTS. PROCEEDINGS. INTERNATIONAL CONFERENCE ON IMAGE PROCESSING 2019; 2019:1395-1399. [PMID: 34690556 DOI: 10.1109/icip.2019.8803042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Non-invasive evaluation of renal transplant function is essential to minimize and manage renal rejection. A computer-assisted diagnostic (CAD) system was developed to evaluate kidney function post-transplantation. The developed CAD system utilizes the amount of blood-oxygenation extracted from 3D (2D + time) blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) to estimate renal function. BOLD-MRI scans were acquired at five different echo-times (2, 7, 12, 17, and 22) ms from 15 transplant patients. The developed CAD system first segments kidneys using the level-sets method followed by estimation of the amount of deoxyhemoglobin, also known as apparent relaxation rate (R2*). These R2* estimates were used as discriminatory features (global features (mean R2*) and local features (pixel-wise R2*)) to train and test state-of-the-art machine learning classifiers to differentiate between non-rejection (NR) and acute renal rejection. Using a leave-one-out cross-validation approach along with an artificial neural network (ANN) classifier, the CAD system demonstrated 93.3% accuracy, 100% sensitivity, and 90% specificity in distinguishing AR from non-rejection . These preliminary results demonstrate the efficacy of the CAD system to detect renal allograft status non-invasively.
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Affiliation(s)
- M Shehata
- Bioengineering Department, University of Louisville, Louisville, KY, USA
| | - A Shalaby
- Bioengineering Department, University of Louisville, Louisville, KY, USA
| | - M Ghazal
- Electrical and Computer Engineering Department, Abu Dhabi University, Abu Dhabi, UAE.,Bioengineering Department, University of Louisville, Louisville, KY, USA
| | - M Abou El-Ghar
- Radiology Department, Urology and Nephrology Center, Mansoura University, Mansoura, Egypt
| | - M A Badawy
- Radiology Department, Urology and Nephrology Center, Mansoura University, Mansoura, Egypt
| | - G Beache
- Radiology Department, University of Louisville, Louisville, KY, USA
| | - A Dwyer
- Kidney Disease Program, University of Louisville, Louisville, KY, USA
| | - M El-Melegy
- Department of Electrical Engineering, Assiut University, Assiut, Egypt
| | - G Giridharan
- Bioengineering Department, University of Louisville, Louisville, KY, USA
| | - R Keynton
- Bioengineering Department, University of Louisville, Louisville, KY, USA
| | - A El-Baz
- Bioengineering Department, University of Louisville, Louisville, KY, USA
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18
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Wang W, Yu Y, Wen J, Zhang M, Chen J, Cheng D, Zhang L, Liu Z. Combination of Functional Magnetic Resonance Imaging and Histopathologic Analysis to Evaluate Interstitial Fibrosis in Kidney Allografts. Clin J Am Soc Nephrol 2019; 14:1372-1380. [PMID: 31416890 PMCID: PMC6730521 DOI: 10.2215/cjn.00020119] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 07/11/2019] [Indexed: 12/26/2022]
Abstract
BACKGROUND AND OBJECTIVES Recent developments indicated that functional magnetic resonance imaging (MRI) could potentially provide noninvasive assessment of kidney interstitial fibrosis in patients with kidney diseases, but direct evidence from histopathology is scarce. We aimed to explore the diagnostic utilities of functional MRI for the evaluation of kidney allograft interstitial fibrosis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We prospectively examined 103 kidney transplant recipients who underwent for-cause biopsies and 20 biopsy-proven normal subjects with functional MRI. Histomorphometric analyses of interstitial fibrosis and peritubular capillary densities were performed on digitally scanned Masson's trichrome- and CD34-stained slides, respectively. The performances of functional MRI to discriminate interstitial fibrosis were assessed by calculating the area under the curve using receiver-operating characteristic curve. RESULTS Main pathologic findings in this single-center cohort were representative of common diagnostic entities in the kidney allografts, with rejection (32%) and glomerulonephritides (31%) accounting for the majority of diagnoses. Apparent diffusion coefficient from diffusion-weighted imaging correlated with interstitial fibrosis (ρ=-0.77; P<0.001). Additionally, decreased arterial spin labelings were accompanied by peritubular capillary density reductions (r=0.77; P<0.001). Blood oxygen level-dependent (BOLD) imaging demonstrated cortical hypoxia with increasing interstitial fibrosis (ρ=0.61; P<0.001). The area under the curve for the discrimination of ≤25% versus >25% interstitial fibrosis and ≤50% versus >50% interstitial fibrosis were 0.87 (95% confidence interval [95% CI], 0.79 to 0.93) and 0.88 (95% CI, 0.80 to 0.93) by apparent diffusion coefficient, 0.92 (95% CI, 0.85 to 0.97) and 0.94 (95% CI, 0.87 to 0.98) by arterial spin labeling, 0.81 (95% CI, 0.72 to 0.88) and 0.86 (95% CI, 0.78 to 0.92) by perfusion fraction, 0.79 (95% CI, 0.69 to 0.87) and 0.85 (95% CI, 0.76 to 0.92) by BOLD imaging, respectively. CONCLUSIONS Functional MRI measurements were strongly correlated with kidney allograft interstitial fibrosis. The performances of functional MRI for discriminating ≤50% versus >50% interstitial fibrosis were good to excellent.
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Affiliation(s)
- Wei Wang
- National Clinical Research Center of Kidney Diseases, Jinling Clinical Medical College of Nanjing Medical University, Nanjing, China
| | - Yuanmeng Yu
- Department of Medical Imaging, Jinling Hospital, Clinical School of Southern Medical University, Nanjing, China
| | - Jiqiu Wen
- National Clinical Research Center of Kidney Diseases, Nanjing University School of Medicine, Nanjing, China; and
| | - Mingchao Zhang
- National Clinical Research Center of Kidney Diseases, Nanjing University School of Medicine, Nanjing, China; and
| | - Jinsong Chen
- National Clinical Research Center of Kidney Diseases, Nanjing University School of Medicine, Nanjing, China; and
| | - Dongrui Cheng
- National Clinical Research Center of Kidney Diseases, Nanjing University School of Medicine, Nanjing, China; and
| | - Longjiang Zhang
- Department of Medical Imaging, Jinling Hospital, Clinical School of Southern Medical University, Nanjing, China; .,Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Zhihong Liu
- National Clinical Research Center of Kidney Diseases, Jinling Clinical Medical College of Nanjing Medical University, Nanjing, China; .,National Clinical Research Center of Kidney Diseases, Nanjing University School of Medicine, Nanjing, China; and
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19
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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] [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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20
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Gondalia R, Vernuccio F, Marin D, Bashir MR. The role of MR imaging in the assessment of renal allograft vasculature. Abdom Radiol (NY) 2018; 43:2589-2596. [PMID: 29700591 DOI: 10.1007/s00261-018-1611-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Renal allograft dysfunction after transplantation is a relatively common occurrence with various potential etiologies. Vascular etiologies are of particular importance as early surgical or minimally invasive intervention can, in some cases, salvage the graft. Diagnosis of vascular pathology resulting in allograft dysfunction requires a thorough workup, of which imaging is a key component. Generally, ultrasound is the first-line imaging modality. More recently, MRI has been shown to be an effective and safe modality for diagnosis of vascular pathology after renal transplantation, particularly for diagnosis of transplant renal artery stenosis. This review will summarize imaging modalities that are most commonly used in evaluating vascular pathology after renal transplantation, with a focus on the various contrast- and non-contrast-enhanced MR techniques described in the literature and used at our institution. Of particular interest is the relatively recent utilization of the non-gadolinium containing iron-based contrast agent, ferumoxytol, in time-resolved contrast-enhanced MR angiography.
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Affiliation(s)
- Raj Gondalia
- Department of Radiology, Duke University Medical Center, Box 3808 Erwin Road, Durham, NC, 27710, USA.
| | - Federica Vernuccio
- Department of Radiology, Duke University Medical Center, Box 3808 Erwin Road, Durham, NC, 27710, USA
- Section of Radiology -Di.Bi.Med, University Hospital "Paolo Giaccone", 90129, Palermo, Italy
| | - Daniele Marin
- Department of Radiology, Duke University Medical Center, Box 3808 Erwin Road, Durham, NC, 27710, USA
| | - Mustafa R Bashir
- Department of Radiology, Duke University Medical Center, Box 3808 Erwin Road, Durham, NC, 27710, USA
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Abstract
Renal transplantation is the therapy of choice for patients with end-stage renal diseases. Improvement of immunosuppressive therapy has significantly increased the half-life of renal allografts over the past decade. Nevertheless, complications can still arise. An early detection of allograft dysfunction is mandatory for a good outcome. New advances in magnetic resonance imaging (MRI) have enabled the noninvasive assessment of different functional renal parameters in addition to anatomic imaging. Most of these techniques were widely tested on renal allografts in past decades and a lot of clinical data are available. The following review summarizes the comprehensive, functional MRI techniques for the noninvasive assessment of renal allograft function and highlights their potential for the investigations of different etiologies of graft dysfunction.
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22
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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] [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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23
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Renal scintigraphy for post-transplant monitoring after kidney transplantation. Transplant Rev (Orlando) 2018; 32:102-109. [DOI: 10.1016/j.trre.2017.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/30/2017] [Accepted: 12/18/2017] [Indexed: 01/22/2023]
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24
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Taffel MT, Nikolaidis P, Beland MD, Blaufox MD, Dogra VS, Goldfarb S, Gore JL, Harvin HJ, Heilbrun ME, Heller MT, Khatri G, Preminger GM, Purysko AS, Smith AD, Wang ZJ, Weinfeld RM, Wong-You-Cheong JJ, Remer EM, Lockhart ME. ACR Appropriateness Criteria ® Renal Transplant Dysfunction. J Am Coll Radiol 2018; 14:S272-S281. [PMID: 28473084 DOI: 10.1016/j.jacr.2017.02.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 02/20/2017] [Accepted: 02/21/2017] [Indexed: 02/06/2023]
Abstract
Renal transplantation is the treatment of choice in patients with end-stage renal disease because the 5-year survival rates range from 72% to 99%. Although graft survival has improved secondary to the introduction of newer immunosuppression drugs and the advancements in surgical technique, various complications still occur. Ultrasound is the first-line imaging modality for the evaluation of renal transplants in the immediate postoperative period and for long-term follow-up. In addition to depicting many of the potential complications of renal transplantation, ultrasound can also guide therapeutic interventions. Nuclear medicine studies, CT, and MRI are often helpful as complementary examinations for specific indications. Angiography remains the reference standard for vascular complications and is utilized to guide nonsurgical intervention. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
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Affiliation(s)
| | - Myles T Taffel
- Principal Author, George Washington University Hospital, Washington, District of Columbia.
| | - Paul Nikolaidis
- Panel Vice-chair, Northwestern University, Chicago, Illinois
| | | | - M Donald Blaufox
- Albert Einstein College of Medicine, Bronx, New York; Society of Nuclear Medicine and Molecular Imaging
| | - Vikram S Dogra
- University of Rochester Medical Center, Rochester, New York
| | - Stanley Goldfarb
- University of Pennsylvania School of Medicine, Philadelphia; Pennsylvania, American Society of Nephrology
| | - John L Gore
- University of Washington, Seattle, Washington; American Urological Association
| | | | | | | | | | - Glenn M Preminger
- Duke University Medical Center, Durham, North Carolina; American Urological Association
| | | | - Andrew D Smith
- The University of Mississippi Medical Center, Jackson, Mississippi
| | - Zhen J Wang
- University of California San Francisco School of Medicine, San Francisco, California
| | - Robert M Weinfeld
- Oakland University William Beaumont School of Medicine, Troy, Michigan
| | | | | | - Mark E Lockhart
- Panel Chair, University of Alabama at Birmingham, Birmingham, Alabama
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25
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Hall ME, Jordan JH, Juncos LA, Hundley WG, Hall JE. BOLD magnetic resonance imaging in nephrology. Int J Nephrol Renovasc Dis 2018; 11:103-112. [PMID: 29559807 PMCID: PMC5856054 DOI: 10.2147/ijnrd.s112299] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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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26
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Organ-specific responses during brain death: increased aerobic metabolism in the liver and anaerobic metabolism with decreased perfusion in the kidneys. Sci Rep 2018. [PMID: 29535334 PMCID: PMC5849719 DOI: 10.1038/s41598-018-22689-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Hepatic and renal energy status prior to transplantation correlates with graft survival. However, effects of brain death (BD) on organ-specific energy status are largely unknown. We studied metabolism, perfusion, oxygen consumption, and mitochondrial function in the liver and kidneys following BD. BD was induced in mechanically-ventilated rats, inflating an epidurally-placed Fogarty-catheter, with sham-operated rats as controls. A 9.4T-preclinical MRI system measured hourly oxygen availability (BOLD-related R2*) and perfusion (T1-weighted). After 4 hrs, tissue was collected, mitochondria isolated and assessed with high-resolution respirometry. Quantitative proteomics, qPCR, and biochemistry was performed on stored tissue/plasma. Following BD, the liver increased glycolytic gene expression (Pfk-1) with decreased glycogen stores, while the kidneys increased anaerobic- (Ldha) and decreased gluconeogenic-related gene expression (Pck-1). Hepatic oxygen consumption increased, while renal perfusion decreased. ATP levels dropped in both organs while mitochondrial respiration and complex I/ATP synthase activity were unaffected. In conclusion, the liver responds to increased metabolic demands during BD, enhancing aerobic metabolism with functional mitochondria. The kidneys shift towards anaerobic energy production while renal perfusion decreases. Our findings highlight the need for an organ-specific approach to assess and optimise graft quality prior to transplantation, to optimise hepatic metabolic conditions and improve renal perfusion while supporting cellular detoxification.
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27
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Vanmassenhove J, Kielstein J, Jörres A, Biesen WV. Management of patients at risk of acute kidney injury. Lancet 2017; 389:2139-2151. [PMID: 28561005 DOI: 10.1016/s0140-6736(17)31329-6] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 04/01/2017] [Accepted: 04/04/2017] [Indexed: 02/02/2023]
Abstract
Acute kidney injury (AKI) is a multifaceted syndrome that occurs in different settings. The course of AKI can be variable, from single hit and complete recovery, to multiple hits resulting in end-stage renal disease. No interventions to improve outcomes of established AKI have yet been developed, so prevention and early diagnosis are key. Awareness campaigns and education for health-care professionals on diagnosis and management of AKI-with attention to avoidance of volume depletion, hypotension, and nephrotoxic interventions-coupled with electronic early warning systems where available can improve outcomes. Biomarker-based strategies have not shown improvements in outcome. Fluid management should aim for early, rapid restoration of circulatory volume, but should be more limited after the first 24-48 h to avoid volume overload. Use of balanced crystalloid solutions versus normal saline remains controversial. Renal replacement therapy should only be started on the basis of hard criteria, but should not be delayed when criteria are met. On the basis of recent evidence, the risk of contrast-induced AKI might be overestimated for many conditions.
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Affiliation(s)
| | - Jan Kielstein
- Medical Clinic V, Nephrology, Hypertension and Blood Purification, Academic Teaching Hospital Braunschweig, Braunschweig, Germany
| | - Achim Jörres
- Department of Medicine 1, Nephrology, Transplantation and Medical Intensive Care, University Witten/Herdecke, Medical Centre Cologne Merheim, Cologne, Germany
| | - Wim Van Biesen
- Renal Division, Ghent University Hospital, Ghent, Belgium.
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28
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van Eijs MJM, van Zuilen AD, de Boer A, Froeling M, Nguyen TQ, Joles JA, Leiner T, Verhaar MC. Innovative Perspective: Gadolinium-Free Magnetic Resonance Imaging in Long-Term Follow-Up after Kidney Transplantation. Front Physiol 2017; 8:296. [PMID: 28559850 PMCID: PMC5432553 DOI: 10.3389/fphys.2017.00296] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/24/2017] [Indexed: 12/23/2022] Open
Abstract
Since the mid-1980s magnetic resonance imaging (MRI) has been investigated as a non- or minimally invasive tool to probe kidney allograft function. Despite this long-standing interest, MRI still plays a subordinate role in daily practice of transplantation nephrology. With the introduction of new functional MRI techniques, administration of exogenous gadolinium-based contrast agents has often become unnecessary and true non-invasive assessment of allograft function has become possible. This raises the question why application of MRI in the follow-up of kidney transplantation remains restricted, despite promising results. Current literature on kidney allograft MRI is mainly focused on assessment of (sub) acute kidney injury after transplantation. The aim of this review is to survey whether MRI can provide valuable diagnostic information beyond 1 year after kidney transplantation from a mechanistic point of view. The driving force behind chronic allograft nephropathy is believed to be chronic hypoxia. Based on this, techniques that visualize kidney perfusion and oxygenation, scarring, and parenchymal inflammation deserve special interest. We propose that functional MRI mechanistically provides tools for diagnostic work-up in long-term follow-up of kidney allografts.
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Affiliation(s)
- Mick J M van Eijs
- Department of Nephrology and Hypertension, University Medical Center UtrechtUtrecht, Netherlands
| | - Arjan D van Zuilen
- Department of Nephrology and Hypertension, University Medical Center UtrechtUtrecht, Netherlands
| | - Anneloes de Boer
- Department of Radiology, University Medical Center UtrechtUtrecht, Netherlands
| | - Martijn Froeling
- Department of Radiology, University Medical Center UtrechtUtrecht, Netherlands
| | - Tri Q Nguyen
- Department of Pathology, University Medical Center UtrechtUtrecht, Netherlands
| | - Jaap A Joles
- Department of Nephrology and Hypertension, University Medical Center UtrechtUtrecht, Netherlands
| | - Tim Leiner
- Department of Radiology, University Medical Center UtrechtUtrecht, Netherlands
| | - Marianne C Verhaar
- Department of Nephrology and Hypertension, University Medical Center UtrechtUtrecht, Netherlands
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29
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Towards non-invasive diagnostic techniques for early detection of acute renal transplant rejection: A review. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2017. [DOI: 10.1016/j.ejrnm.2016.11.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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30
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Kidney Transplantation: Multiparametric Functional Magnetic Resonance Imaging for Assessment of Renal Allograft Pathophysiology in Mice. Invest Radiol 2016; 51:58-65. [PMID: 26371534 DOI: 10.1097/rli.0000000000000205] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The aims of this experimental study were to investigate renal allograft pathophysiology by multiparametric functional magnetic resonance imaging (MRI) and to directly correlate MRI parameters with renal histopathology in mouse models of allogenic and isogenic kidney transplantation (ktx). MATERIALS AND METHODS Allograft rejection was induced by transplantation of C57BL/6 (B6) donor kidneys into BALB/c recipients (allogenic ktx). B6 mice that received B6 kidneys served as controls (isogenic ktx). Three weeks after ktx, MRI was performed using a 7-T small-animal scanner. Flow sensitive alternating inversion recovery echoplanar imaging arterial spin labeling, multiecho turbo spin echo, and diffusion-weighted imaging sequences were acquired. Maps of renal perfusion, T2 and T1 relaxation times, and apparent diffusion coefficients were calculated. Histological changes in the kidney were evaluated according to Banff criteria. Renal cell infiltrates and fibrosis were quantified by immunohistochemistry. Differences between groups were assessed using the Mann-Whitney U test, and the correlation of MRI parameters with renal histopathology was determined by Spearman correlation analysis. RESULTS After allogenic, but not isogenic, ktx, animals developed acute allograft rejection. Allogenic grafts were infiltrated by macrophages and T-lymphocytes and exhibited marked renal fibrosis. Magnetic resonance imaging revealed stronger impairment of renal perfusion (56 ± 7 vs 293 ± 44 mL/[min × 100 g]; P < 0.01) and more pronounced increases in T2 (60.1 ± 2.0 vs 45.7 ± 1.2 milliseconds, P < 0.01) and T1 relaxation times (1938 ± 53 vs 1350 ± 27 milliseconds, P < 0.01) in allogenic than in isogenic kidneys. Apparent diffusion coefficient was reduced to 1.39 ± 0.14 × 10(-3) mm2/s in kidneys with an acute rejection and was 1.83 ± 0.05 × 10(-3) mm2/s in isogenic kidneys without rejection (P < 0.05). Magnetic resonance imaging parameters significantly correlated with the amount of cellular infiltration and renal fibrosis observed histologically. CONCLUSIONS Functional MRI allows detection of acute renal allograft rejection after allogenic ktx in mice. Functional MRI parameters correlate with cell infiltrates and fibrosis. Thus, MRI may be used noninvasively and longitudinally to investigate mechanisms of renal allograft rejection and evaluate novel therapeutic strategies in experimental studies.
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31
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Niles DJ, Artz NS, Djamali A, Sadowski EA, Grist TM, Fain SB. Longitudinal Assessment of Renal Perfusion and Oxygenation in Transplant Donor-Recipient Pairs Using Arterial Spin Labeling and Blood Oxygen Level-Dependent Magnetic Resonance Imaging. Invest Radiol 2016; 51:113-20. [PMID: 26561047 DOI: 10.1097/rli.0000000000000210] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVES The aims of this study were to assess renal function in kidney transplant recipients and their respective donors over 2 years using arterial spin labeling (ASL) and blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) and to prospectively evaluate the effect of losartan on functional MRI measures in recipients. MATERIALS AND METHODS The study included 15 matched pairs of renal transplant donors and recipients. Arterial spin labeling and BOLD MRI of the kidneys were performed on donors before transplant surgery (baseline) and on both donors and recipients at 3 months, 1 year, and 2 years after transplant. After 3 months, 7 of the 15 recipients were prescribed 25 to 50 mg/d losartan for the remainder of the study. A linear mixed-effects model was used to evaluate perfusion, R2*, estimated glomerular filtration rate, and fractional excretion of sodium for changes across time or associated with losartan treatment. RESULTS In donors, cortical perfusion in the remaining kidney decreased by 50 ± 19 mL/min per 100 g (11.8%) between baseline and 2 years (P < 0.05), while cortical R2* declined modestly by 0.7 ± 0.3 s-1 (5.6%; P < 0.05). In transplanted kidneys, cortical perfusion decreased markedly by 141 ± 21 mL/min per 100 g (34.2%) between baseline and 2 years (P < 0.001), while medullary R2* declined by 1.5 ± 0.8 s-1 (8.3%; P = 0.06). Single-kidney estimated glomerular filtration rate increased between baseline and 2 years by 17.7 ± 2.7 mL/min per 1.73 m (40.3%; P < 0.0001) in donors and to 14.6 ± 4.3 mL/min per 1.73 m (33.3%; P < 0.01) in recipients. Cortical perfusion at 1 and 2 years in recipients receiving 25 to 50 mg/d losartan was 62 ± 24 mL/min per 100 g higher than recipients not receiving the drug (P < 0.05). No significant effects of losartan were observed for any other markers of renal function. CONCLUSIONS The results suggest an important role for noninvasive functional monitoring with ASL and BOLD MRI in kidney transplant recipients and donors, and they indicate a potentially beneficial effect of losartan in recipients.
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Affiliation(s)
- David J Niles
- From the Departments of *Medical Physics, †Medicine, ‡Surgery, §Radiology, ∥Obstetrics and Gynecology, and ¶Biomedical Engineering, University of Wisconsin, Madison, WI
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32
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Hanssen O, Erpicum P, Lovinfosse P, Meunier P, Weekers L, Tshibanda L, Krzesinski JM, Hustinx R, Jouret F. Non-invasive approaches in the diagnosis of acute rejection in kidney transplant recipients. Part I. In vivo imaging methods. Clin Kidney J 2016. [PMID: 28643821 PMCID: PMC5469561 DOI: 10.1093/ckj/sfw062] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Kidney transplantation (KTx) represents the best available treatment for patients with end-stage renal disease. Still, full benefits of KTx are undermined by acute rejection (AR). The diagnosis of AR ultimately relies on transplant needle biopsy. However, such an invasive procedure is associated with a significant risk of complications and is limited by sampling error and interobserver variability. In the present review, we summarize the current literature about non-invasive approaches for the diagnosis of AR in kidney transplant recipients (KTRs), including in vivo imaging, gene expression profiling and omics analyses of blood and urine samples. Most imaging techniques, like contrast-enhanced ultrasound and magnetic resonance, exploit the fact that blood flow is significantly lowered in case of AR-induced inflammation. In addition, AR-associated recruitment of activated leukocytes may be detectable by 18F-fluoro-deoxy-glucose positron emission tomography. In parallel, urine biomarkers, including CXCL9/CXCL10 or a three-gene signature of CD3ε, IP-10 and 18S RNA levels, have been identified. None of these approaches has been adopted yet in the clinical follow-up of KTRs, but standardization of procedures may help assess reproducibility and compare diagnostic yields in large prospective multicentric trials.
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Affiliation(s)
- Oriane Hanssen
- Division of Nephrology, University of Liège Academic Hospital (ULg CHU), Avenue Hippocrate, 13, B-4000 Liège, Belgium
| | - Pauline Erpicum
- Division of Nephrology, University of Liège Academic Hospital (ULg CHU), Avenue Hippocrate, 13, B-4000 Liège, Belgium.,GIGA Cardiovascular Sciences, University of Liège, Liège, Belgium
| | - Pierre Lovinfosse
- Division of Nuclear Medicine, University of Liège Academic Hospital (ULg CHU), Liège, Belgium
| | - Paul Meunier
- Division of Radiology, University of Liège Academic Hospital (ULg CHU), Liège, Belgium
| | - Laurent Weekers
- Division of Nephrology, University of Liège Academic Hospital (ULg CHU), Avenue Hippocrate, 13, B-4000 Liège, Belgium
| | - Luaba Tshibanda
- Division of Radiology, University of Liège Academic Hospital (ULg CHU), Liège, Belgium
| | - Jean-Marie Krzesinski
- Division of Nephrology, University of Liège Academic Hospital (ULg CHU), Avenue Hippocrate, 13, B-4000 Liège, Belgium.,GIGA Cardiovascular Sciences, University of Liège, Liège, Belgium
| | - Roland Hustinx
- Division of Nuclear Medicine, University of Liège Academic Hospital (ULg CHU), Liège, Belgium
| | - François Jouret
- Division of Nephrology, University of Liège Academic Hospital (ULg CHU), Avenue Hippocrate, 13, B-4000 Liège, Belgium.,GIGA Cardiovascular Sciences, University of Liège, Liège, Belgium
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33
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Grenier N, Merville P, Combe C. Radiologic imaging of the renal parenchyma structure and function. Nat Rev Nephrol 2016; 12:348-59. [DOI: 10.1038/nrneph.2016.44] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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34
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Zhou HY, Chen TW, Zhang XM. Functional Magnetic Resonance Imaging in Acute Kidney Injury: Present Status. BIOMED RESEARCH INTERNATIONAL 2016; 2016:2027370. [PMID: 26925411 PMCID: PMC4746277 DOI: 10.1155/2016/2027370] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 01/05/2016] [Accepted: 01/06/2016] [Indexed: 12/27/2022]
Abstract
Acute kidney injury (AKI) is a common complication of hospitalization that is characterized by a sudden loss of renal excretory function and associated with the subsequent development of chronic kidney disease, poor prognosis, and increased mortality. Although the pathophysiology of renal functional impairment in the setting of AKI remains poorly understood, previous studies have identified changes in renal hemodynamics, perfusion, and oxygenation as key factors in the development and progression of AKI. The early assessment of these changes remains a challenge. Many established approaches are not applicable to humans because of their invasiveness. Functional renal magnetic resonance (MR) imaging offers an alternative assessment tool that could be used to evaluate renal morphology and function noninvasively and simultaneously. Thus, the purpose of this review is to illustrate the principle, application, and role of the techniques of functional renal MR imaging, including blood oxygen level-dependent imaging, arterial spin labeling, and diffusion-weighted MR imaging, in the management of AKI. The use of gadolinium in MR imaging may exacerbate renal impairment and cause nephrogenic systemic fibrosis. Therefore, dynamic contrast-enhanced MR imaging will not be discussed in this paper.
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Affiliation(s)
- Hai Ying Zhou
- Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, 63 Wenhua Road, Shunqing District, Nanchong, Sichuan 637000, China
| | - Tian Wu Chen
- Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, 63 Wenhua Road, Shunqing District, Nanchong, Sichuan 637000, China
| | - Xiao Ming Zhang
- Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, 63 Wenhua Road, Shunqing District, Nanchong, Sichuan 637000, China
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35
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Lanzman RS, Notohamiprodjo M, Wittsack HJ. [Functional magnetic resonance imaging of the kidneys]. Radiologe 2015; 55:1077-87. [PMID: 26628260 DOI: 10.1007/s00117-015-0044-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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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36
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Humphreys BD, Cantaluppi V, Portilla D, Singbartl K, Yang L, Rosner MH, Kellum JA, Ronco C. Targeting Endogenous Repair Pathways after AKI. J Am Soc Nephrol 2015; 27:990-8. [PMID: 26582401 DOI: 10.1681/asn.2015030286] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
AKI remains a highly prevalent disease associated with poor short- and long-term outcomes and high costs. Although significant advances in our understanding of repair after AKI have been made over the last 5 years, this knowledge has not yet been translated into new AKI therapies. A consensus conference held by the Acute Dialysis Quality Initiative was convened in April of 2014 and reviewed new evidence on successful kidney repair to identify the most promising pathways that could be translated into new treatments. In this paper, we provide a summary of current knowledge regarding successful kidney repair and offer a framework for conceptualizing the therapeutic targeting that may facilitate this process. We outline gaps in knowledge and suggest a research agenda to more efficiently bring new discoveries regarding repair after AKI to the clinic.
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Affiliation(s)
- Benjamin D Humphreys
- Renal Division, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri;
| | - Vincenzo Cantaluppi
- Nephrology, Dialysis and Kidney Transplantation Unit, Department of Medical Sciences, University of Torino, Azienda Ospedaliera Città della Salute e della Scienza 'Molinette,' Turin, Italy
| | - Didier Portilla
- Division of Nephrology, Center for Immunity, Inflammation and Regenerative Medicine, University of Virginia Health System, Charlottesville, Virginia
| | - Kai Singbartl
- Center for Critical Care Nephrology and Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Li Yang
- Renal Division, Peking University First Hospital, Beijing, China; and
| | - Mitchell H Rosner
- Division of Nephrology, Center for Immunity, Inflammation and Regenerative Medicine, University of Virginia Health System, Charlottesville, Virginia
| | - John A Kellum
- Center for Critical Care Nephrology and Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Claudio Ronco
- Department of Nephrology Dialysis and Transplantation, San Bortolo Hospital and the International Renal Research Institute, Vicenza, Italy
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37
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Wang YT, Li YC, Yin LL, Pu H, Chen JY. Functional assessment of transplanted kidneys with magnetic resonance imaging. World J Radiol 2015; 7:343-349. [PMID: 26516431 PMCID: PMC4620115 DOI: 10.4329/wjr.v7.i10.343] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/17/2015] [Accepted: 09/08/2015] [Indexed: 02/06/2023] Open
Abstract
Kidney transplantation has emerged as the treatment of choice for many patients with end-stage renal disease, which is a significant cause of morbidity and mortality. Given the shortage of clinically available donor kidneys and the significant incidence of allograft dysfunction, a noninvasive and accurate assessment of the allograft renal function is critical for postoperative management. Prompt diagnosis of graft dysfunction facilitates clinical intervention of kidneys with salvageable function. New advances in magnetic resonance imaging (MRI) technology have enabled the calculation of various renal parameters that were previously not feasible to measure noninvasively. Diffusion-weighted imaging provides information on renal diffusion and perfusion simultaneously, with quantification by the apparent diffusion coefficient, the decrease of which reflects renal function impairment. Diffusion-tensor imaging accounts for the directionality of molecular motion and measures fractional anisotropy of the kidneys. Blood oxygen level-dependent MR evaluates intrarenal oxygen bioavailability, generating the parameter of R2* (reflecting the concentration of deoxyhemoglobin). A decrease in R2* could happen during acute rejection. MR nephro-urography/renography demonstrates structural data depicting urinary tract obstructions and functional data regarding the glomerular filtration and blood flow. MR angiography details the transplant vasculature and is particularly suitable for detecting vascular complications, with good correlation with digital subtraction angiography. Other functional MRI technologies, such as arterial spin labeling and MR spectroscopy, are showing additional promise. This review highlights MRI as a comprehensive modality to diagnose a variety of etiologies of graft dysfunction, including prerenal (e.g., renal vasculature), renal (intrinsic causes) and postrenal (e.g., obstruction of the collecting system) etiologies.
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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] [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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Hueper K, Gueler F, Bräsen JH, Gutberlet M, Jang MS, Lehner F, Richter N, Hanke N, Peperhove M, Martirosian P, Tewes S, Vo Chieu VD, Großhennig A, Haller H, Wacker F, Gwinner W, Hartung D. Functional MRI detects perfusion impairment in renal allografts with delayed graft function. Am J Physiol Renal Physiol 2015; 308:F1444-51. [DOI: 10.1152/ajprenal.00064.2015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 04/28/2015] [Indexed: 11/22/2022] Open
Abstract
Delayed graft function (DGF) after kidney transplantation is not uncommon, and it is associated with long-term allograft impairment. Our aim was to compare renal perfusion changes measured with noninvasive functional MRI in patients early after kidney transplantation to renal function and allograft histology in biopsy samples. Forty-six patients underwent MRI 4–11 days after transplantation. Contrast-free MRI renal perfusion images were acquired using an arterial spin labeling technique. Renal function was assessed by estimated glomerular filtration rate (eGFR), and renal biopsies were performed when indicated within 5 days of MRI. Twenty-six of 46 patients had DGF. Of these, nine patients had acute rejection (including borderline), and eight had other changes (e.g., tubular injury or glomerulosclerosis). Renal perfusion was significantly lower in the DGF group compared with the group with good allograft function (231 ± 15 vs. 331 ± 15 ml·min−1·100 g−1, P < 0.001). Living donor allografts exhibited significantly higher perfusion values compared with deceased donor allografts ( P < 0.001). Renal perfusion significantly correlated with eGFR ( r = 0.64, P < 0.001), resistance index ( r = −0.57, P < 0.001), and cold ischemia time ( r = −0.48, P < 0.01). Furthermore, renal perfusion impairment early after transplantation predicted inferior renal outcome and graft loss. In conclusion, noninvasive functional MRI detects renal perfusion impairment early after kidney transplantation in patients with DGF.
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Affiliation(s)
- Katja Hueper
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Faikah Gueler
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | | | - Marcel Gutberlet
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Mi-Sun Jang
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Frank Lehner
- Department of General, Abdominal and Transplant Surgery, Hannover Medical School, Hannover, Germany
| | - Nicolas Richter
- Department of General, Abdominal and Transplant Surgery, Hannover Medical School, Hannover, Germany
| | - Nils Hanke
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Matti Peperhove
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Petros Martirosian
- Section on Experimental Radiology, University of Tübingen, Tübingen, Germany; and
| | - Susanne Tewes
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Van Dai Vo Chieu
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Anika Großhennig
- Institute for Biostatistics, Hannover Medical School, Hannover, Germany
| | - Hermann Haller
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Frank Wacker
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Wilfried Gwinner
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Dagmar Hartung
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
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Neugarten J, Golestaneh L. Blood oxygenation level-dependent MRI for assessment of renal oxygenation. Int J Nephrol Renovasc Dis 2014; 7:421-35. [PMID: 25473304 PMCID: PMC4247132 DOI: 10.2147/ijnrd.s42924] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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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Detection of renal allograft rejection using blood oxygen level-dependent and diffusion weighted magnetic resonance imaging: a retrospective study. BMC Nephrol 2014; 15:158. [PMID: 25270976 PMCID: PMC4192395 DOI: 10.1186/1471-2369-15-158] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 09/25/2014] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Acute rejection (AR) and acute tubular necrosis (ATN) are main causes of early renal allograft dysfunction. Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) and Diffusion weighted (DW) MRI can provide valuable information about changes of oxygen bioavailability and water diffusion by measuring R2* or apparent diffusion coefficient (ADC) respectively. We aimed to determine the value of BOLD MRI and DW MRI in detecting causes for early allograft dysfunction in renal allograft recipients. METHODS Fifty patients received renal allografts from deceased donors were analyzed, including 35 patients with normal renal function (control group), 10 AR patients and 5 ATN patients. Cortical R2* (CR2*) and medullary R2* (MR2*) were measured by BOLD MRI. Ten diffusion gradient b values (0, 5, 10, 20, 50, 100, 200, 400, 800, 1200s/mm2) were used in DW MRI. ADC values were measured in renal cortex (CADC) and medulla (MADC). CADCl and MADCl were measured under low b values (b ≤ 200 s/mm2), while CADCh and MADCh were measured under high b values (b > 200 s/mm2). RESULTS MR2* was significantly lower in AR group (18.2 ± 1.5/s) than control group (23.8 ± 5.0/s, p = 0.001) and ATN group (25.8 ± 5.0/s, p = 0.004). There was a tendency of lower levels on CADCl, MADCl, CADCh or MADCh in AR group than in control group. There were no differences on ADC values between AR group and ATN group. CONCLUSIONS BOLD MRI was a valuable method in detection of renal allografts with acute rejection.
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Song T, Lin T, Huang Z, Fu L, He S, Song B, Wei Q. Assessment of intrarenal oxygenation in renal donor with blood oxygenation level-dependent magnetic resonance imaging. Urology 2014; 83:1205.e1-5. [PMID: 24680611 DOI: 10.1016/j.urology.2014.01.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 11/28/2013] [Accepted: 01/07/2014] [Indexed: 02/08/2023]
Abstract
OBJECTIVE To examine change of the apparent relaxation rate R2* values in living kidney donors after uninephrectomy using blood oxygenation level-dependent magnetic resonance imaging. METHODS Between July 2011 and January 2012, 45 kidney donors were enrolled into this study. Blood oxygenation level-dependent magnetic resonance imaging scanning was performed before surgery, 3 and 7 days postoperatively. Participants were followed up for 1 year. RESULTS The R2* values in medulla (mR2*) were significantly greater than that of cortex (cR2*), both in resected kidney and remaining one. cR2* values of the remaining kidney was 17.52 ± 1.36 s(-1) and then decrease significantly by 8.97% to 15.95 ± 1.14 s(-1) at 3 days (P <.001) and by 7.82% to 16.15 ± of 1.05 s(-1) at 7 days. No significant modification occurred in mR2* after surgery. Multivariate regression analysis showed that the decrease in cR2* values of the remaining kidney was positively associated with sex (r = 0.418), body surface area (r = 0.307), and preoperative cR2* values (r = 0.659). Comparing with glomerular filtration rate at 7 days, a further increment in the glomerular filtration rate was noted at 1 year in patients with cR2* values decrease of ≥ 10% at 1 week (62.63 ± 11.69 vs 56.97 ± 7.51 mL/min/1.73 m(2), P = .02) but not in the other patients (66.43 ± 10.89 vs 62.78 ± 13.74, P = .064). CONCLUSION Kidney donation will induce early, profound oxygenation modification within the renal cortex of the remaining kidney. Donors with cR2* value decrease of ≥ 10% at 1 week have a more favorable renal function compensation at 1 year.
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Affiliation(s)
- Turun Song
- Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Tao Lin
- Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Zixing Huang
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Lei Fu
- Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Shaofeng He
- Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Bin Song
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Qiang Wei
- Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China.
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Zhang JL, Morrell G, Rusinek H, Sigmund EE, Chandarana H, Lerman LO, Prasad PV, Niles D, Artz N, Fain S, Vivier PH, Cheung AK, Lee VS. New magnetic resonance imaging methods in nephrology. Kidney Int 2014; 85:768-78. [PMID: 24067433 PMCID: PMC3965662 DOI: 10.1038/ki.2013.361] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 07/16/2013] [Accepted: 07/17/2013] [Indexed: 02/06/2023]
Abstract
Established as a method to study anatomic changes, such as renal tumors or atherosclerotic vascular disease, magnetic resonance imaging (MRI) to interrogate renal function has only recently begun to come of age. In this review, we briefly introduce some of the most important MRI techniques for renal functional imaging, and then review current findings on their use for diagnosis and monitoring of major kidney diseases. Specific applications include renovascular disease, diabetic nephropathy, renal transplants, renal masses, acute kidney injury, and pediatric anomalies. With this review, we hope to encourage more collaboration between nephrologists and radiologists to accelerate the development and application of modern MRI tools in nephrology clinics.
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Affiliation(s)
- Jeff L Zhang
- Department of Radiology, University of Utah, Salt Lake City, Utah, USA
| | - Glen Morrell
- Department of Radiology, University of Utah, Salt Lake City, Utah, USA
| | - Henry Rusinek
- Department of Radiology, New York University, New York, New York, USA
| | - Eric E Sigmund
- Department of Radiology, New York University, New York, New York, USA
| | - Hersh Chandarana
- Department of Radiology, New York University, New York, New York, USA
| | - Lilach O Lerman
- Department of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | | | - David Niles
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Nathan Artz
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Sean Fain
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - Alfred K Cheung
- Division of Nephrology and Hypertension, University of Utah, Salt Lake City, Utah, USA
| | - Vivian S Lee
- Department of Radiology, University of Utah, Salt Lake City, Utah, USA
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Lal H, Helavar RV, Gamanagatti S, Jain S, Kumar R. Imaging in renal transplant: Review. INDIAN JOURNAL OF TRANSPLANTATION 2014. [DOI: 10.1016/j.ijt.2014.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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45
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Zhang JL, Morrell G, Rusinek H, Warner L, Vivier PH, Cheung AK, Lerman LO, Lee VS. Measurement of renal tissue oxygenation with blood oxygen level-dependent MRI and oxygen transit modeling. Am J Physiol Renal Physiol 2014; 306:F579-87. [PMID: 24452640 DOI: 10.1152/ajprenal.00575.2013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Blood oxygen level-dependent (BOLD) MRI data of kidney, while indicative of tissue oxygenation level (Po2), is in fact influenced by multiple confounding factors, such as R2, perfusion, oxygen permeability, and hematocrit. We aim to explore the feasibility of extracting tissue Po2 from renal BOLD data. A method of two steps was proposed: first, a Monte Carlo simulation to estimate blood oxygen saturation (SHb) from BOLD signals, and second, an oxygen transit model to convert SHb to tissue Po2. The proposed method was calibrated and validated with 20 pigs (12 before and after furosemide injection) in which BOLD-derived tissue Po2 was compared with microprobe-measured values. The method was then applied to nine healthy human subjects (age: 25.7 ± 3.0 yr) in whom BOLD was performed before and after furosemide. For the 12 pigs before furosemide injection, the proposed model estimated renal tissue Po2 with errors of 2.3 ± 5.2 mmHg (5.8 ± 13.4%) in cortex and -0.1 ± 4.5 mmHg (1.7 ± 18.1%) in medulla, compared with microprobe measurements. After injection of furosemide, the estimation errors were 6.9 ± 3.9 mmHg (14.2 ± 8.4%) for cortex and 2.6 ± 4.0 mmHg (7.7 ± 11.5%) for medulla. In the human subjects, BOLD-derived medullary Po2 increased from 16.0 ± 4.9 mmHg (SHb: 31 ± 11%) at baseline to 26.2 ± 3.1 mmHg (SHb: 53 ± 6%) at 5 min after furosemide injection, while cortical Po2 did not change significantly at ∼58 mmHg (SHb: 92 ± 1%). Our proposed method, validated with a porcine model, appears promising for estimating tissue Po2 from renal BOLD MRI data in human subjects.
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Hueper K, Hartung D, Gutberlet M, Gueler F, Sann H, Husen B, Wacker F, Reiche D. Assessment of impaired vascular reactivity in a rat model of diabetic nephropathy: effect of nitric oxide synthesis inhibition on intrarenal diffusion and oxygenation measured by magnetic resonance imaging. Am J Physiol Renal Physiol 2013; 305:F1428-35. [DOI: 10.1152/ajprenal.00123.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Diabetes is associated with impaired vascular reactivity and the development of diabetic nephropathy. In a rat model of streptozotocin-induced diabetic nephropathy, the effects of systemic nitric oxide (NO) synthesis inhibition on intrarenal diffusion and oxygenation were determined by noninvasive magnetic resonance diffusion tensor imaging and blood O2 level-dependent (BOLD) imaging, respectively. Eight weeks after the induction of diabetes, 21 rats [ n = 7 rats each in the untreated control group, diabetes mellitus (DM) group, and DM with uninephrectomy (DM UNX) group] were examined by MRI. Diffusion tensor imaging and BOLD sequences were acquired before and after NO synthesis inhibition with N-nitro-l-arginine methyl ester (l-NAME). In the same rats, mean arterial pressure and vascular conductance were determined with and without the influence of l-NAME. In control animals, NO synthesis inhibition was associated with a significant increase of mean arterial pressure of 33.8 ± 4.3 mmHg ( P < 0.001) and a decrease of vascular conductance of −17.8 ± 2.0 μl·min−1·100 mmHg−1 ( P < 0.001). These changes were attenuated in both DM and DM UNX groups with no significant difference between before and after l-NAME measurements in DM UNX animals. Similarly, l-NAME challenge induced a significant reduction of renal transverse relaxation time (T2*) at MRI in control animals, indicating reduced renal oxygenation after l-NAME injection compared with baseline. DM UNX animals did not show a significant T2* reduction after NO synthesis inhibition in the renal cortex and attenuated T2* reduction in the outer medulla. MRI parameters of tissue diffusion were not affected by l-NAME in all groups. In conclusion, BOLD imaging proved valuable to noninvasively measure renal vascular reactivity upon NO synthesis inhibition in control animals and to detect impaired vascular reactivity in animals with diabetic nephropathy.
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Affiliation(s)
- Katja Hueper
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- REBIRTH Hannover, Hannover, Germany
| | - Dagmar Hartung
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- REBIRTH Hannover, Hannover, Germany
| | - Marcel Gutberlet
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- REBIRTH Hannover, Hannover, Germany
| | - Faikah Gueler
- Clinic for Nephrology, Hannover Medical School, Hannover, Germany
| | | | | | - Frank Wacker
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- REBIRTH Hannover, Hannover, Germany
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Okusa MD, Jaber BL, Doran P, Duranteau J, Yang L, Murray PT, Mehta RL, Ince C. Physiological biomarkers of acute kidney injury: a conceptual approach to improving outcomes. CONTRIBUTIONS TO NEPHROLOGY 2013; 182:65-81. [PMID: 23689656 DOI: 10.1159/000349967] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The past 5-10 years have brought significant advances in the identification and validation of novel biochemical biomarkers in the prevention and treatment of acute kidney injury (AKI). These biochemical biomarkers remain research tools but we anticipate that soon they will be employed in clinical practice. A Consensus Conference held by the Acute Dialysis Quality Initiative (ADQI) recently reviewed the evidence, and identified gaps and a research agenda. Furthermore, at this meeting was the birth of an initiative to comprehensively identify new opportunities to characterize the physiological changes during the course of AKI based upon a conceptual framework for the detection and monitoring of renal ischemia-reperfusion injury. This framework includes a transition from monitoring physiological biomarkers of adequate renal perfusion, to pathophysiologic biomarkers of renal hypoperfusion, and finally biomarkers of kidney cell structural injury/damage. Techniques to measure physiological changes in AKI include several physiological variables that might be used in an interactive way to supplement clinical information and biochemical damage biomarkers in the diagnosis and management of AKI. This review summarizes the spectrum of physiological parameters and potential new physiological methods that enable identification of high-risk patients for AKI, facilitate early diagnosis, and differential diagnosis to guide therapeutic management and prognostication. Finally, we propose a research agenda for the next 5 years to facilitate the development and validation of physiological biomarkers in AKI.
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Affiliation(s)
- Mark D Okusa
- Division of Nephrology and Center for Immunity, Inflammation and Regenerative Medicine, University of Virginia, Charlottesville, Va., USA.
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Zhang JL, Rusinek H, Chandarana H, Lee VS. Functional MRI of the kidneys. J Magn Reson Imaging 2013; 37:282-93. [PMID: 23355431 PMCID: PMC3558841 DOI: 10.1002/jmri.23717] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 05/02/2012] [Indexed: 12/20/2022] Open
Abstract
Renal function is characterized by different physiologic aspects, including perfusion, glomerular filtration, interstitial diffusion, and tissue oxygenation. Magnetic resonance imaging (MRI) shows great promise in assessing these renal tissue characteristics noninvasively. The last decade has witnessed a dramatic progress in MRI techniques for renal function assessment. This article briefly describes relevant renal anatomy and physiology, reviews the applications of functional MRI techniques for the diagnosis of renal diseases, and lists unresolved issues that will require future work.
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Affiliation(s)
- Jeff L Zhang
- Department of Radiology, University of Utah School of Medicine, Salt Lake City, Utah 84108, USA.
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Evaluation of transplanted kidneys using blood oxygenation level-dependent MRI at 3 T: a preliminary study. AJR Am J Roentgenol 2012; 198:1108-14. [PMID: 22528900 DOI: 10.2214/ajr.11.7253] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The objective of our study was to investigate the feasibility and reproducibility of blood oxygenation level-dependent (BOLD) MRI using different gradient echoes at 3 T in patients with renal allografts and healthy volunteers and to evaluate whether BOLD MRI can be used to distinguish between cases of acute allograft rejection and normally functioning allografts. SUBJECTS AND METHODS BOLD MRI at 3 T was performed of eight patients with normal allografts, four patients with acute allograft rejection, and 10 healthy volunteers. Multiple fast-field echo sequences were performed at gradient echoes of 8, 16, and 20 to obtain T2(*)-weighted images. The reproducibility of BOLD MRI was evaluated in patients with normal allografts. RESULTS Cortical and medullary R2(*) values were not significantly different between healthy volunteers and patients with normal allografts, but medullary R2(*) values were significantly greater than cortical R2(*) values in both groups for all three protocols (p < 0.01). Medullary R2(*) values were significantly lower in cases of acute allograft rejection than in normal allografts for all three protocols (p < 0.001). The mean difference in cortical or medullary R2(*) values was 3.8% or less in all protocols. CONCLUSION BOLD MRI performed using different gradient echoes at 3 T is feasible and reproducible in patients with renal allografts and can show significant changes in medullary oxygenation in patients with acute rejection.
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Rognant N, Lemoine S, Laville M, Juillard L. Évaluation du contenu tissulaire rénal en oxygène par la technique IRM BOLD. Nephrol Ther 2012; 8:212-5. [DOI: 10.1016/j.nephro.2011.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Accepted: 08/02/2011] [Indexed: 10/14/2022]
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