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Hamelink TL, Ogurlu B, Pamplona CC, Castelein J, Bennedsgaard SS, Qi H, Weiss T, Lantinga VA, Pool MBF, Laustsen C, Jespersen B, Leuvenink HGD, Ringgaard S, Borra RJH, Keller AK, Moers C. Magnetic resonance imaging as a noninvasive adjunct to conventional assessment of functional differences between kidneys in vivo and during ex vivo normothermic machine perfusion. Am J Transplant 2024:S1600-6135(24)00272-7. [PMID: 38615901 DOI: 10.1016/j.ajt.2024.04.001] [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: 02/27/2024] [Revised: 03/26/2024] [Accepted: 04/07/2024] [Indexed: 04/16/2024]
Abstract
Normothermic machine perfusion (NMP) is increasingly considered for pretransplant kidney quality assessment. However, fundamental questions about differences between in vivo and ex vivo renal function, as well as the impact of ischemic injury on ex vivo physiology, remain unanswered. This study utilized magnetic resonance imaging (MRI), alongside conventional parameters to explore differences between in vivo and ex vivo renal function and the impact of warm ischemia on a kidney's behavior ex vivo. Renal MRI scans and samples were obtained from living pigs (n = 30) in vivo. Next, kidney pairs were procured and exposed to minimal, or 75 minutes of warm ischemia, followed by 6 hours of hypothermic machine perfusion. Both kidneys simultaneously underwent 6-hour ex vivo perfusion in MRI-compatible NMP circuits to obtain multiparametric MRI data. Ischemically injured ex vivo kidneys showed a significantly altered regional blood flow distribution compared to in vivo and minimally damaged organs. Both ex vivo groups showed diffusion restriction relative to in vivo. Our findings underscore the differences between in vivo and ex vivo MRI-based renal characteristics. Therefore, when assessing organ viability during NMP, it should be considered to incorporate parameters beyond the conventional functional markers that are common in vivo.
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Affiliation(s)
- Tim L Hamelink
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
| | - Baran Ogurlu
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Carolina C Pamplona
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Johannes Castelein
- Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Haiyun Qi
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Thomas Weiss
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - 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
| | - Christoffer Laustsen
- Department of Clinical Medicine, MR Research Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Bente Jespersen
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Henri G D Leuvenink
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Steffen Ringgaard
- Department of Clinical Medicine, MR Research Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Ronald J H Borra
- Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Anna K Keller
- Department of Urology, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Cyril Moers
- Department of Surgery - Organ Donation and Transplantation, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
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Jesrani AK, Faiq SM, Rashid R, Kalwar TA, Mohsin R, Aziz T, Khan NA, Mubarak M. Comparison of resistive index and shear-wave elastography in the evaluation of chronic kidney allograft dysfunction. World J Transplant 2024; 14:89255. [PMID: 38576755 PMCID: PMC10989465 DOI: 10.5500/wjt.v14.i1.89255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/18/2024] [Accepted: 02/27/2024] [Indexed: 03/15/2024] Open
Abstract
BACKGROUND Detection of early chronic changes in the kidney allograft is important for timely intervention and long-term survival. Conventional and novel ultrasound-based investigations are being increasingly used for this purpose with variable results. AIM To compare the diagnostic performance of resistive index (RI) and shear wave elastography (SWE) in the diagnosis of chronic fibrosing changes of kidney allograft with histopathological results. METHODS This is a cross-sectional and comparative study. A total of 154 kidney transplant recipients were included in this study, which was conducted at the Departments of Transplantation and Radiology, Sindh Institute of Urology and Transplan tation, Karachi, Pakistan, from August 2022 to February 2023. All consecutive patients with increased serum creatinine levels and reduced glomerular filtration rate (GFR) after three months of transplantation were enrolled in this study. SWE and RI were performed and the findings of these were evaluated against the kidney allograft biopsy results to determine their diagnostic utility. RESULTS The mean age of all patients was 35.32 ± 11.08 years. Among these, 126 (81.8%) were males and 28 (18.2%) were females. The mean serum creatinine in all patients was 2.86 ± 1.68 mg/dL and the mean estimated GFR was 35.38 ± 17.27 mL/min/1.73 m2. Kidney allograft biopsy results showed chronic changes in 55 (37.66%) biopsies. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of SWE for the detection of chronic allograft damage were 93.10%, 96.87%%, 94.73%, and 95.87%, respectively, and the diagnostic accuracy was 95.45%. For RI, the sensitivity, specificity, PPV, and NPV were 76.92%, 83.33%, 70.17%, and 87.62%, respectively, and the diagnostic accuracy was 81.16%. CONCLUSION The results from this study show that SWE is more sensitive and specific as compared to RI in the evaluation of chronic allograft damage. It can be of great help during the routine follow-up of kidney transplant recipients for screening and early detection of chronic changes and selecting patients for allograft biopsy.
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Affiliation(s)
- Ameet Kumar Jesrani
- Department of Radiology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Syed M Faiq
- Department of Radiology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Rahma Rashid
- Department of Pathology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Tariq Ali Kalwar
- Department of Transplantation, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Rehan Mohsin
- Department of Urology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Tahir Aziz
- Department of Transplantation, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Nida Amin Khan
- Department of Radiology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
| | - Muhammed Mubarak
- Department of Pathology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan
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Wu M, Zhang JL. MR Perfusion Imaging for Kidney Disease. Magn Reson Imaging Clin N Am 2024; 32:161-170. [PMID: 38007278 DOI: 10.1016/j.mric.2023.09.004] [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: 11/27/2023]
Abstract
Renal perfusion reflects overall function of a kidney. As an important indicator of kidney diseases, renal perfusion can be noninvasively measured by multiple methods of MR imaging, such as dynamic contrast-enhanced MR imaging, intravoxel incoherent motion analysis, and arterial spin labeling method. In this article we introduce the principle of the methods, review their recent technical improvements, and then focus on summarizing recent applications of the methods in assessing various renal diseases. By this review, we demonstrate the capability and clinical potential of the imaging methods, with the hope of accelerating their adoption to clinical practice.
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Affiliation(s)
- Mingyan Wu
- Central Research Institute, UIH Group, Shanghai, China; School of Biomedical Engineering Building, Room 409, 393 Huaxia Middle Road, Shanghai 201210, China
| | - Jeff L Zhang
- School of Biomedical Engineering, ShanghaiTech University, Room 409, School of Biomedical Engineering Building, 393 Huaxia Middle Road, Shanghai 201210, China.
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Artificial Intelligence Algorithm-Based MRI in the Diagnosis of Complications after Renal Transplantation. CONTRAST MEDIA & MOLECULAR IMAGING 2022; 2022:8930584. [PMID: 36072641 PMCID: PMC9398844 DOI: 10.1155/2022/8930584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/24/2022] [Accepted: 07/14/2022] [Indexed: 11/17/2022]
Abstract
This study was to explore the diagnostic value of magnetic resonance imaging (MRI) optimized by residual segmentation attention dual channel network (DRSA-U-Net) in the diagnosis of complications after renal transplantation and to provide a more effective examination method for clinic. 89 patients with renal transplantation were selected retrospectively, and all underwent MRI. The patients were divided into control group (conventional MRI image diagnosis) and observation group (MRI image diagnosis based on DRSA-U-Net). The accuracy of MRI images in the two groups was evaluated according to the comprehensive diagnostic results. The root mean square error (RMSE) and peak signal-to-noise ratio (PSNR) of DRSA-U-Net on T1WI and T2WI sequences were better than those of U-Net and dense U-Net
; comprehensive examination showed that 39 patients had obstruction between ureter and bladder anastomosis, 13 cases had rejection, 10 cases had perirenal hematoma, 5 cases had renal infarction, and 22 cases had no complications; the diagnostic sensitivity, specificity, accuracy, and consistency of the observation group were higher than those of the control group
. In the control group, the sensitivity, specificity, and accuracy in the diagnosis of complications after renal transplantation were 66.5%, 84.1%, and 78.32%, respectively; in the observation group, the sensitivity, specificity, and accuracy in the diagnosis were 67.8%, 86.7%, and 80.6%, respectively. DRSA-U-Net denoising algorithm can clearly display the information of MRI images on the kidney, ureter, and surrounding tissues, improve its diagnostic accuracy in complications after renal transplantation, and has good clinical application value.
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David E, Del Gaudio G, Drudi FM, Dolcetti V, Pacini P, Granata A, Pretagostini R, Garofalo M, Basile A, Bellini MI, D’Andrea V, Scaglione M, Barr R, Cantisani V. Contrast Enhanced Ultrasound Compared with MRI and CT in the Evaluation of Post-Renal Transplant Complications. Tomography 2022; 8:1704-1715. [PMID: 35894008 PMCID: PMC9326620 DOI: 10.3390/tomography8040143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/13/2022] [Accepted: 06/15/2022] [Indexed: 11/26/2022] Open
Abstract
Renal transplantation (RT) is the treatment of choice for end-stage renal disease, significantly improving patients’ survival and quality of life. However, approximately 3–23% of patients encounter post-operative complications, and radiology plays a major role for their early detection and treatment or follow-up planning. CT and MRI are excellent imaging modalities to evaluate renal transplant post-operative course; nevertheless, they are both associated with a high cost and low accessibility, as well as some contraindications, making them not feasible for all patients. In particular, gadolinium-based contrast can lead to the rare condition of nephrogenic systemic fibrosis, and iodine-based contrast can lead to contrast-induced nephropathy (CIN). CT also exposes the patients who may require multiple examinations to ionizing radiation. Therefore, considering the overall advantages and disadvantages, contrast-enhanced ultrasound (CEUS) is presently considered an effective first-line imaging modality for post-operative early and long-term follow-up in RT, reducing the need for biopsies and providing adequate guidance for drainage procedures. Hence, this paper aims to review the updated knowledge on CEUS compared with CT and MRI for the evaluation of RT renal transplant complications; advantages, limitations, and possible recommendations are provided.
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Affiliation(s)
- Emanuele David
- Department of Translational and Precision Medicine, Sapienza University of Rome, 00185 Rome, Italy
- Unit of Radiology, Papardo Hospital, 98158 Messina, Italy
- Correspondence: (E.D.); (V.C.)
| | - Giovanni Del Gaudio
- Department of Radiology, Policlinico Umberto I, Sapienza University of Rome, 00185 Rome, Italy; (G.D.G.); (F.M.D.); (V.D.); (P.P.)
| | - Francesco Maria Drudi
- Department of Radiology, Policlinico Umberto I, Sapienza University of Rome, 00185 Rome, Italy; (G.D.G.); (F.M.D.); (V.D.); (P.P.)
| | - Vincenzo Dolcetti
- Department of Radiology, Policlinico Umberto I, Sapienza University of Rome, 00185 Rome, Italy; (G.D.G.); (F.M.D.); (V.D.); (P.P.)
| | - Patrizia Pacini
- Department of Radiology, Policlinico Umberto I, Sapienza University of Rome, 00185 Rome, Italy; (G.D.G.); (F.M.D.); (V.D.); (P.P.)
| | | | - Renzo Pretagostini
- General Surgery and Organ Transplantation Unit, Department of Surgery, Sapienza University of Rome, 00185 Rome, Italy; (R.P.); (M.G.)
| | - Manuela Garofalo
- General Surgery and Organ Transplantation Unit, Department of Surgery, Sapienza University of Rome, 00185 Rome, Italy; (R.P.); (M.G.)
| | - Antonio Basile
- Radiology Unit 1, Department of Medical Surgical Sciences and Advanced Technologies “GF Ingrassia”, University Hospital “Policlinico-Vittorio Emanuele”, University of Catania, 95123 Catania, Italy;
| | - Maria Irene Bellini
- Department of Surgical Sciences, Sapienza University of Rome, 00161 Rome, Italy; (M.I.B.); (V.D.)
| | - Vito D’Andrea
- Department of Surgical Sciences, Sapienza University of Rome, 00161 Rome, Italy; (M.I.B.); (V.D.)
| | - Mariano Scaglione
- Department of Surgery, Medicine and Pharmacy, University of Sassari, 07100 Sassari, Italy;
- Department of Radiology, James Cook University Hospital, Middlesbrough TS4 3BW, UK
- School of Health and Life Sciences, Teesside University, Tees Valley, Middlesbrough TS1 3BX, UK
- Department of Radiology, Sunderland Royal Hospital, NHS, Sunderland SR4 7TP, UK
| | - Richard Barr
- Department of Radiology, Northeastern Ohio Medical University, Youngstown, OH 44272, USA;
| | - Vito Cantisani
- Department of Radiology, Policlinico Umberto I, Sapienza University of Rome, 00185 Rome, Italy; (G.D.G.); (F.M.D.); (V.D.); (P.P.)
- Correspondence: (E.D.); (V.C.)
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Chhabra J, Karwarker GV, Rajamanuri M, Maligireddy AR, Dai E, Chahal M, Mannava SM, Alfonso M. The Role of Arterial Spin Labeling Functional MRI in Assessing Perfusion Impairment of Renal Allografts: A Systematic Review. Cureus 2022; 14:e25428. [PMID: 35769679 PMCID: PMC9236280 DOI: 10.7759/cureus.25428] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 05/28/2022] [Indexed: 11/05/2022] Open
Abstract
Arterial spin labeling (ASL) is a functional magnetic resonance imaging (fMRI) technique that uses water in arterial blood as a tracer to map an area of interest where the intravascular and extravascular compartments exchange. Our review article focuses primarily on the role of ASL fMRI in assessing perfusion impairment in renal allografts in order to take appropriate steps to eliminate the cause of perfusion impairment at an early stage, thereby extending graft life. The study also highlights various other fMRI techniques that are used to analyze other parameters that affect kidney transplants both acutely and chronically. We gathered our data in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and our search strategy included exclusion/inclusion criteria. Several databases were used in the search strategy, including PubMed, Cochrane, and Science Direct, and the Medical Subject Headings (MeSH) strategy was specifically used for PubMed, and two people scrutinized those papers to conclude that a total of 10 research papers are included in our study. This review article includes papers involving 20 to 98 subjects who had renal allografts within the previous six months and had renal cortical perfusion values measured by ASL fMRI ranging from 35 to 304 ml/100 g/min. Furthermore, when compared to healthy kidney transplant patients, renal ASL perfusion values were significantly lower in subjects with the functional imbalance of kidney transplants. It had a positive correlation with the estimated glomerular filtration rate (eGFR). To summarize, ASL fMRI is critical in detecting renal allograft perfusion impairment.
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Affiliation(s)
- Jayksh Chhabra
- Internal Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | | | - Medha Rajamanuri
- Internal Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Anand Reddy Maligireddy
- Internal Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Eiman Dai
- Psychiatry, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Meher Chahal
- Psychiatry, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Sai Mahitha Mannava
- Pediatrics, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Michael Alfonso
- Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
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Stabinska J, Müller-Lutz A, Wittsack HJ, Tell C, Rump LC, Ertas N, Antoch G, Ljimani A. Two point Dixon-based chemical exchange saturation transfer (CEST) MRI in renal transplant patients on 3 T. Magn Reson Imaging 2022; 90:61-69. [PMID: 35476934 DOI: 10.1016/j.mri.2022.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/30/2022] [Accepted: 04/21/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE To assess the performance of two point (2-pt) Dixon-based chemical exchange saturation transfer (CEST) imaging for fat suppression in renal transplant patients. METHODS The 2-pt Dixon-based CEST MRI was validated in an egg-phantom and in fourteen renal transplant recipients (5 females and 9 males; age range: 23-78 years; mean age: 51 ± 16.8). All CEST experiments were performed on a 3 T clinical MRI scanner using a dual-echo CEST sequence. The 2-pt Dixon technique was applied to generate water-only CEST images at different frequency offsets, which were further used to calculate the z-spectra. The magnetization transfer ratio asymmetry (MTRasym) values in the frequency ranges of hydroxyl, amine and amide protons were estimated in the renal cortex and medulla. RESULTS Results of the in vitro experiments suggest that the 2-pt Dixon technique enables effective fat peak removal and does not introduce additional asymmetries to the z-spectrum. Accordingly, our results in vivo show that the fat-corrected amide proton transfer (APT) effect in the kidney is significantly higher compared to that obtained from the CEST data acquired close to the in-phase condition both in the renal cortex (-0.1 [0.7] vs. -0.7 [1.2], P = 0.029) and medulla (0.3 [0.8] vs. 0.01 [1.3], P = 0.049), indicating that the 2-pt Dixon-based CEST method increases the specificity of the APT contrast by correcting the fat-induced artifacts. CONCLUSION Combination of the dual-echo CEST acquisition with Dixon post-processing provides effective water-fat separation, allowing more accurate quantification of the APT CEST effect in the transplanted kidney.
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Affiliation(s)
- Julia Stabinska
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany.
| | - Anja Müller-Lutz
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany.
| | - Hans-Jörg Wittsack
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany.
| | - Christian Tell
- Department of Nephrology, Medical Faculty, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany.
| | - Lars Christian Rump
- Department of Nephrology, Medical Faculty, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany.
| | - Neslihan Ertas
- Department of Vascular and Endovascular Surgery, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany.
| | - Gerald Antoch
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany.
| | - Alexandra Ljimani
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany.
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Multiparametric Functional MRI of the Kidney: Current State and Future Trends with Deep Learning Approaches. ROFO-FORTSCHR RONTG 2022; 194:983-992. [PMID: 35272360 DOI: 10.1055/a-1775-8633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Until today, assessment of renal function has remained a challenge for modern medicine. In many cases, kidney diseases accompanied by a decrease in renal function remain undetected and unsolved, since neither laboratory tests nor imaging diagnostics provide adequate information on kidney status. In recent years, developments in the field of functional magnetic resonance imaging with application to abdominal organs have opened new possibilities combining anatomic imaging with multiparametric functional information. The multiparametric approach enables the measurement of perfusion, diffusion, oxygenation, and tissue characterization in one examination, thus providing more comprehensive insight into pathophysiological processes of diseases as well as effects of therapeutic interventions. However, application of multiparametric fMRI in the kidneys is still restricted mainly to research areas and transfer to the clinical routine is still outstanding. One of the major challenges is the lack of a standardized protocol for acquisition and postprocessing including efficient strategies for data analysis. This article provides an overview of the most common fMRI techniques with application to the kidney together with new approaches regarding data analysis with deep learning. METHODS This article implies a selective literature review using the literature database PubMed in May 2021 supplemented by our own experiences in this field. RESULTS AND CONCLUSION Functional multiparametric MRI is a promising technique for assessing renal function in a more comprehensive approach by combining multiple parameters such as perfusion, diffusion, and BOLD imaging. New approaches with the application of deep learning techniques could substantially contribute to overcoming the challenge of handling the quantity of data and developing more efficient data postprocessing and analysis protocols. Thus, it can be hoped that multiparametric fMRI protocols can be sufficiently optimized to be used for routine renal examination and to assist clinicians in the diagnostics, monitoring, and treatment of kidney diseases in the future. KEY POINTS · Multiparametric fMRI is a technique performed without the use of radiation, contrast media, and invasive methods.. · Multiparametric fMRI provides more comprehensive insight into pathophysiological processes of kidney diseases by combining functional and structural parameters.. · For broader acceptance of fMRI biomarkers, there is a need for standardization of acquisition, postprocessing, and analysis protocols as well as more prospective studies.. · Deep learning techniques could significantly contribute to an optimization of data acquisition and the postprocessing and interpretation of larger quantities of data.. CITATION FORMAT · Zhang C, Schwartz M, Küstner T et al. Multiparametric Functional MRI of the Kidney: Current State and Future Trends with Deep Learning Approaches. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1775-8633.
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A Review of Current and Emerging Trends in Donor Graft-Quality Assessment Techniques. J Clin Med 2022; 11:jcm11030487. [PMID: 35159939 PMCID: PMC8836899 DOI: 10.3390/jcm11030487] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 02/07/2023] Open
Abstract
The number of patients placed on kidney transplant waiting lists is rapidly increasing, resulting in a growing gap between organ demand and the availability of kidneys for transplantation. This organ shortage has forced medical professionals to utilize marginal kidneys from expanded criteria donors (ECD) to broaden the donor pool and shorten wait times for patients with end-stage renal disease. However, recipients of ECD kidney grafts tend to have worse outcomes compared to those receiving organs from standard criteria donors (SCD), specifically increased risks of delayed graft function (DGF) and primary nonfunction incidence. Thus, representative methods for graft-quality assessment are strongly needed, especially for ECDs. Currently, graft-quality evaluation is limited to interpreting the donor’s recent laboratory tests, clinical risk scores, the visual evaluation of the organ, and, in some cases, a biopsy and perfusion parameters. The last few years have seen the emergence of many new technologies designed to examine organ function, including new imaging techniques, transcriptomics, genomics, proteomics, metabolomics, lipidomics, and new solutions in organ perfusion, which has enabled a deeper understanding of the complex mechanisms associated with ischemia-reperfusion injury (IRI), inflammatory process, and graft rejection. This review summarizes and assesses the strengths and weaknesses of current conventional diagnostic methods and a wide range of new potential strategies (from the last five years) with respect to donor graft-quality assessment, the identification of IRI, perfusion control, and the prediction of DGF.
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Kidney Transplantation and Diagnostic Imaging: The Early Days and Future Advancements of Transplant Surgery. Diagnostics (Basel) 2020; 11:diagnostics11010047. [PMID: 33396860 PMCID: PMC7823312 DOI: 10.3390/diagnostics11010047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/27/2020] [Accepted: 12/28/2020] [Indexed: 12/23/2022] Open
Abstract
The first steps for modern organ transplantation were taken by Emerich Ullmann (Vienne, Austria) in 1902, with a dog-to-dog kidney transplant, and ultimate success was achieved by Joseph Murray in 1954, with the Boston twin brothers. In the same time period, the ground-breaking work of Wilhelm C. Röntgen (1895) and Maria Sklodowska-Curie (1903), on X-rays and radioactivity, enabled the introduction of diagnostic imaging. In the years thereafter, kidney transplantation and diagnostic imaging followed a synergistic path for their development, with key discoveries in transplant rejection pathways, immunosuppressive therapies, and the integration of diagnostic imaging in transplant programs. The first image of a transplanted kidney, a urogram with intravenous contrast, was shown to the public in 1956, and the first recommendations for transplantation diagnostic imaging were published in 1958. Transplant surgeons were eager to use innovative diagnostic modalities, with renal scintigraphy in the 1960s, as well as ultrasound and computed tomography in the 1970s. The use of innovative diagnostic modalities has had a great impact on the reduction of post-operative complications in kidney transplantation, making it one of the key factors for successful transplantation. For the new generation of transplant surgeons, the historical alignment between transplant surgery and diagnostic imaging can be a motivator for future innovations.
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