1
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Peters AM. The physiological basis of renal nuclear medicine. Nucl Med Commun 2024; 45:745-757. [PMID: 38903047 DOI: 10.1097/mnm.0000000000001872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Renal physiology underpins renal nuclear medicine, both academic and clinical. Clearance, an important concept in renal physiology, comprises tissue uptake rate of tracer (tissue clearance), disappearance rate from plasma (plasma clearance), appearance rate in urine (urinary clearance) and disappearance rate from tissue. In clinical research, steady-state plasma clearances of para-amino-hippurate and inulin have been widely used to measure renal blood flow (RBF) and glomerular filtration rate (GFR), respectively. Routinely, GFR is measured at non-steady state as plasma clearance of a filtration agent, such as technetium-99m diethylenetriaminepentaacetic acid. Scaled to three-dimensional whole body metrics rather than body surface area, GFR in women is higher than in men but declines faster with age. Age-related decline is predominantly from nephron loss. Tubular function determines parenchymal transit time, which is important in renography, and the route of uptake of technetium-99m dimercaptosuccinic acid, which is via filtration. Resistance to flow is defined according to the pressure-flow relationship but in renography, only transit time can be measured, which, being equal to urine flow divided by collecting system volume, introduces further uncertainty because the volume is also unmeasurable. Tubuloglomerular feedback governs RBF and GFR, is regulated by the macula densa, mediated by adenosine and renin, and can be manipulated with proximal tubular sodium-glucose cotransporter-2 inhibitors. Other determinants of renal haemodynamics include prostaglandins, nitric oxide and dopamine, while protein meal and amino acid infusion are used to measure renal functional reserve. In conclusion, for measuring renal responses to exogenous agents, steady-state para-amino-hippurate and inulin clearances should be replaced with rubidium-82 and gallium-68 EDTA for measuring RBF and GFR.
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2
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Bibeau-Delisle A, Bouabdallaoui N, Lamarche C, Harel F, Pelletier-Galarneau M. Assessment of renal perfusion with 82-rubidium PET in patients with normal and abnormal renal function. Nucl Med Commun 2024:00006231-990000000-00328. [PMID: 39155795 DOI: 10.1097/mnm.0000000000001890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2024]
Abstract
BACKGROUND Noninvasive measurement of renal blood flow (RBF) and renal vascular resistance (RVR) is challenging, yet critical in renal pathologies. This study evaluates the correlation between serum renal function markers and RBF/RVR assessed using rubidium PET. METHODS Dynamic images from 53 patients who underwent rubidium PET for nonrenal indications were analyzed. RBF was determined using a one-compartment model, and RVR was calculated by dividing mean arterial pressure by RBF. RESULTS The study included 51 patients (31 females and 20 males). Among them, 35 had normal renal function [estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m2], and 16 had abnormal renal function (eGFR <60 ml/min/1.73 m2). Patients with normal renal function had significantly higher RBF [median (interquartile range): 443 (297-722) vs 173 (108-380) ml/min/100 g, P = 0.022] and lower RVR [19.1 (12.4-27.2) vs 49.6 (24.4-85.7) mmHg×min×g/ml, P = 0.0011) compared with those with abnormal renal function. There was a moderate correlation between RBF and eGFR (r = 0.62, P < 0.0001) and between RVR and eGFR (r = -0.59, P < 0.0001) in both groups. Among patients with normal renal function, RBF was negatively correlated with age (r = -0.51, P = 0.0017) but there was no correlation among patients with abnormal renal function (r = 0.21, P = 0.44). CONCLUSION PET-measured RBF and RVR correlate with renal function markers and differ significantly by renal function status. Further studies are needed to validate rubidium PET's precision and clinical applicability.
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Affiliation(s)
| | | | - Caroline Lamarche
- Department of Medicine, Hôpital Maisonneuve-Rosemont Research Center, Université de Montréal, Montreal, Quebec, Canada
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3
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Alhummiany B, Sharma K, Buckley DL, Soe KK, Sourbron SP. Physiological confounders of renal blood flow measurement. MAGMA (NEW YORK, N.Y.) 2024; 37:565-582. [PMID: 37971557 PMCID: PMC11417086 DOI: 10.1007/s10334-023-01126-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 09/26/2023] [Accepted: 10/12/2023] [Indexed: 11/19/2023]
Abstract
OBJECTIVES Renal blood flow (RBF) is controlled by a number of physiological factors that can contribute to the variability of its measurement. The purpose of this review is to assess the changes in RBF in response to a wide range of physiological confounders and derive practical recommendations on patient preparation and interpretation of RBF measurements with MRI. METHODS A comprehensive search was conducted to include articles reporting on physiological variations of renal perfusion, blood and/or plasma flow in healthy humans. RESULTS A total of 24 potential confounders were identified from the literature search and categorized into non-modifiable and modifiable factors. The non-modifiable factors include variables related to the demographics of a population (e.g. age, sex, and race) which cannot be manipulated but should be considered when interpreting RBF values between subjects. The modifiable factors include different activities (e.g. food/fluid intake, exercise training and medication use) that can be standardized in the study design. For each of the modifiable factors, evidence-based recommendations are provided to control for them in an RBF-measurement. CONCLUSION Future studies aiming to measure RBF are encouraged to follow a rigorous study design, that takes into account these recommendations for controlling the factors that can influence RBF results.
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Affiliation(s)
- Bashair Alhummiany
- Department of Biomedical Imaging Sciences, University of Leeds, Leeds, LS2 9NL, UK.
| | - Kanishka Sharma
- Department of Imaging, Infection, Immunity and Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - David L Buckley
- Department of Biomedical Imaging Sciences, University of Leeds, Leeds, LS2 9NL, UK
| | - Kywe Kywe Soe
- Department of Imaging, Infection, Immunity and Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Steven P Sourbron
- Department of Imaging, Infection, Immunity and Cardiovascular Disease, The University of Sheffield, Sheffield, UK.
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4
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Slart RHJA, Bengel FM, Akincioglu C, Bourque JM, Chen W, Dweck MR, Hacker M, Malhotra S, Miller EJ, Pelletier-Galarneau M, Packard RRS, Schindler TH, Weinberg RL, Saraste A, Slomka PJ. Total-Body PET/CT Applications in Cardiovascular Diseases: A Perspective Document of the SNMMI Cardiovascular Council. J Nucl Med 2024:jnumed.123.266858. [PMID: 38388512 DOI: 10.2967/jnumed.123.266858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/11/2024] [Indexed: 02/24/2024] Open
Abstract
Digital PET/CT systems with a long axial field of view have become available and are emerging as the current state of the art. These new camera systems provide wider anatomic coverage, leading to major increases in system sensitivity. Preliminary results have demonstrated improvements in image quality and quantification, as well as substantial advantages in tracer kinetic modeling from dynamic imaging. These systems also potentially allow for low-dose examinations and major reductions in acquisition time. Thereby, they hold great promise to improve PET-based interrogation of cardiac physiology and biology. Additionally, the whole-body coverage enables simultaneous assessment of multiple organs and the large vascular structures of the body, opening new opportunities for imaging systemic mechanisms, disorders, or treatments and their interactions with the cardiovascular system as a whole. The aim of this perspective document is to debate the potential applications, challenges, opportunities, and remaining challenges of applying PET/CT with a long axial field of view to the field of cardiovascular disease.
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Affiliation(s)
- Riemer H J A Slart
- Medical Imaging Centre, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands;
- Biomedical Photonic Imaging Group, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Frank M Bengel
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Cigdem Akincioglu
- Division of Nuclear Medicine, Medical Imaging, Western University, London, Ontario, Canada
| | - Jamieson M Bourque
- Departments of Medicine (Cardiology) and Radiology, University of Virginia, Charlottesville, Virginia
| | - Wengen Chen
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Marc R Dweck
- British Heart Foundation Centre for Cardiovascular Science, Edinburgh Heart Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Marcus Hacker
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | | | - Edward J Miller
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut; Department of Radiology and Biomedical Imaging, Yale School of Medicine, and Department of Internal Medicine, Yale University, New Haven, Connecticut
| | | | - René R S Packard
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California
| | - Thomas H Schindler
- Mallinckrodt Institute of Radiology, Division of Nuclear Medicine, Cardiovascular Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Richard L Weinberg
- Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Antti Saraste
- Turku PET Centre and Heart Center, Turku University Hospital and University of Turku, Turku, Finland; and
| | - Piotr J Slomka
- Division of Artificial Intelligence in Medicine, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California
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5
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Knuuti J, Tuisku J, Kärpijoki H, Iida H, Maaniitty T, Latva-Rasku A, Oikonen V, Nesterov SV, Teuho J, Jaakkola MK, Klén R, Louhi H, Saunavaara V, Nuutila P, Saraste A, Rinne J, Nummenmaa L. Quantitative Perfusion Imaging with Total-Body PET. J Nucl Med 2023; 64:11S-19S. [PMID: 37918848 DOI: 10.2967/jnumed.122.264870] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 10/04/2023] [Indexed: 11/04/2023] Open
Abstract
Recently, PET systems with a long axial field of view have become the current state of the art. Total-body PET scanners enable unique possibilities for scientific research and clinical diagnostics, but this new technology also raises numerous challenges. A key advantage of total-body imaging is that having all the organs in the field of view allows studying biologic interaction of all organs simultaneously. One of the new, promising imaging techniques is total-body quantitative perfusion imaging. Currently, 15O-labeled water provides a feasible option for quantitation of tissue perfusion at the total-body level. This review summarizes the status of the methodology and the analysis and provides examples of preliminary findings on applications of quantitative parametric perfusion images for research and clinical work. We also describe the opportunities and challenges arising from moving from single-organ studies to modeling of a multisystem approach with total-body PET, and we discuss future directions for total-body imaging.
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Affiliation(s)
- Juhani Knuuti
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland;
- Department of Clinical Physiology, Nuclear Medicine, and PET, Turku University Hospital, Turku, Finland; and
| | - Jouni Tuisku
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Henri Kärpijoki
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Hidehiro Iida
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Teemu Maaniitty
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
- Department of Clinical Physiology, Nuclear Medicine, and PET, Turku University Hospital, Turku, Finland; and
| | - Aino Latva-Rasku
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Vesa Oikonen
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Sergey V Nesterov
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Jarmo Teuho
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Maria K Jaakkola
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Riku Klén
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Heli Louhi
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Virva Saunavaara
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Pirjo Nuutila
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Antti Saraste
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
- Heart Center, Turku University Hospital and University of Turku, Turku, Finland
| | - Juha Rinne
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
| | - Lauri Nummenmaa
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
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Brown JM, Park MA, Kijewski MF, Weber BN, Yang Y, Martell L, Perillo A, Barrett L, Parks S, Hainer J, Dorbala S, Blankstein R, Di Carli MF. Feasibility of Simultaneous Quantification of Myocardial and Renal Perfusion With Cardiac Positron Emission Tomography. Circ Cardiovasc Imaging 2023; 16:e015324. [PMID: 37655498 PMCID: PMC10529360 DOI: 10.1161/circimaging.123.015324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 08/11/2023] [Indexed: 09/02/2023]
Abstract
BACKGROUND Given the central importance of cardiorenal interactions, mechanistic tools for evaluating cardiorenal physiology are needed. In the heart and kidneys, shared pathways of neurohormonal activation, hypertension, and vascular and interstitial fibrosis implicate the relevance of systemic vascular health. The availability of a long axial field of view positron emission tomography (PET)/computed tomography (CT) system enables simultaneous evaluation of cardiac and renal blood flow. METHODS This study evaluated the feasibility of quantification of renal blood flow using data acquired during routine, clinically indicated 13N-ammonia myocardial perfusion PET/CT. Dynamic PET image data were used to calculate renal blood flow. Reproducibility was assessed by the intraclass correlation coefficient among 3 independent readers. PET-derived renal blood flow was correlated with imaging and clinical parameters in the overall cohort and with histopathology in a small companion study of patients with a native kidney biopsy. RESULTS Among 386 consecutive patients with myocardial perfusion PET/CT, 296 (76.7%) had evaluable images to quantify renal perfusion. PET quantification of renal blood flow was highly reproducible (intraclass correlation coefficient 0.98 [95% CI, 0.93-0.99]) and was correlated with the estimated glomerular filtration rate (r=0.64; P<0.001). Compared across vascular beds, resting renal blood flow was correlated with maximal stress myocardial blood flow and myocardial flow reserve (stress/rest myocardial blood flow), an integrated marker of endothelial health. In patients with kidney biopsy (n=12), resting PET renal blood flow was strongly negatively correlated with histological interstitial fibrosis (r=-0.85; P<0.001). CONCLUSIONS Renal blood flow can be reliably measured from cardiac 13N-ammonia PET/CT and allows for simultaneous assessment of myocardial and renal perfusion, opening a potential novel avenue to interrogate the mechanisms of emerging therapies with overlapping cardiac and renal benefits.
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Affiliation(s)
- Jenifer M. Brown
- Heart and Vascular Center, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Mi-Ae Park
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Marie Foley Kijewski
- Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Brittany N. Weber
- Heart and Vascular Center, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Yihe Yang
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell Health, Manhasset, NY, USA
| | - Laurel Martell
- Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Anna Perillo
- Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Leanne Barrett
- Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Sean Parks
- Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Jon Hainer
- Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Sharmila Dorbala
- Heart and Vascular Center, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Ron Blankstein
- Heart and Vascular Center, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Marcelo F. Di Carli
- Heart and Vascular Center, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Cardiovascular Imaging Program, Departments of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
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7
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Päivärinta J, Anastasiou IA, Koivuviita N, Sharma K, Nuutila P, Ferrannini E, Solini A, Rebelos E. Renal Perfusion, Oxygenation and Metabolism: The Role of Imaging. J Clin Med 2023; 12:5141. [PMID: 37568543 PMCID: PMC10420088 DOI: 10.3390/jcm12155141] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 08/02/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023] Open
Abstract
Thanks to technical advances in the field of medical imaging, it is now possible to study key features of renal anatomy and physiology, but so far poorly explored due to the inherent difficulties in studying both the metabolism and vasculature of the human kidney. In this narrative review, we provide an overview of recent research findings on renal perfusion, oxygenation, and substrate uptake. Most studies evaluating renal perfusion with positron emission tomography (PET) have been performed in healthy controls, and specific target populations like obese individuals or patients with renovascular disease and chronic kidney disease (CKD) have rarely been assessed. Functional magnetic resonance (fMRI) has also been used to study renal perfusion in CKD patients, and recent studies have addressed the kidney hemodynamic effects of therapeutic agents such as glucagon-like receptor agonists (GLP-1RA) and sodium-glucose co-transporter 2 inhibitors (SGLT2-i) in an attempt to characterise the mechanisms leading to their nephroprotective effects. The few available studies on renal substrate uptake are discussed. In the near future, these imaging modalities will hopefully become widely available with researchers more acquainted with them, gaining insights into the complex renal pathophysiology in acute and chronic diseases.
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Affiliation(s)
- Johanna Päivärinta
- Department of Medicine, Division of Nephrology, Turku University Hospital, 20521 Turku, Finland; (J.P.); (N.K.)
| | - Ioanna A. Anastasiou
- 1st Department of Propaedeutic and Internal Medicine, Medical School, National and Kapodistrian University of Athens, Laiko General Hospital, 11527 Athens, Greece;
| | - Niina Koivuviita
- Department of Medicine, Division of Nephrology, Turku University Hospital, 20521 Turku, Finland; (J.P.); (N.K.)
| | - Kanishka Sharma
- Department of Imaging, Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield S10 2TN, UK;
| | - Pirjo Nuutila
- Turku PET Centre, 20521 Turku, Finland;
- Department of Endocrinology, Turku University Hospital, 20521 Turku, Finland
| | - Ele Ferrannini
- CNR, Institute of Clinical Physiology, 56124 Pisa, Italy;
| | - Anna Solini
- Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, 56124 Pisa, Italy;
| | - Eleni Rebelos
- Turku PET Centre, 20521 Turku, Finland;
- Department of Clinical and Experimental Medicine, University of Pisa, 56124 Pisa, Italy
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8
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Langaa SS, Mose FH, Fynbo CA, Theil J, Bech JN. Reliability of rubidium-82 PET/CT for renal perfusion determination in healthy subjects. BMC Nephrol 2022; 23:379. [DOI: 10.1186/s12882-022-02962-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 10/05/2022] [Indexed: 11/29/2022] Open
Abstract
Abstract
Background
Changes in renal perfusion may play a pathophysiological role in hypertension and kidney disease, however to date, no method for renal blood flow (RBF) determination in humans has been implemented in clinical practice. In a previous study, we demonstrated that estimation of renal perfusion based on a single positron emission tomography/computed tomography (PET/CT) scan with Rubidium-82 (82Rb) is feasible and found an approximate 5% intra-assay coefficient of variation for both kidneys, indicative of a precise method.This study’s aim was to determine the day-to day variation of 82Rb PET/CT and to test the method’s ability to detect increased RBF induced by infusion of amino acids.
Methods
Seventeen healthy subjects underwent three dynamic 82Rb PET/CT scans over two examination days comprising: Day A, a single 8-minute dynamic scan and Day B, two scans performed before (baseline) and after RBF stimulation by a 2-hour amino acid-infusion. The order of examination days was determined by randomization. Time activity curves for arterial and renal activity with a 1-tissue compartment model were used for flow estimation; the K1 kinetic parameter representing renal 82Rb clearance. Day-to-day variation was calculated based on the difference between the unstimulated K1 values on Day A and Day B and paired t-testing was performed to compare K1 values at baseline and after RBF stimulation on Day B.
Results
Day-to-day variation was observed to be 5.5% for the right kidney and 6.0% for the left kidney (n = 15 quality accepted scans). K1 values determined after amino acid-infusion were significantly higher than pre-infusion values (n = 17, p = 0.001). The mean percentage change in K1 from baseline was 13.2 ± 12.9% (range − 10.4 to 35.5) for the right kidney; 12.9 ± 13.2% (range − 15.7 to 35.3) for the left kidney.
Conclusion
Day-to-day variation is acceptably low. A significant K1 increase from baseline is detected after application of a known RBF stimulus, indicating that 82Rb PET/CT scanning can provide a precise method for evaluation of RBF and it is able to determine changes herein.
Clinical Trial Registration
EU Clinical Trials Register, 2017-005008-88. Registered 18/01/2018.
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Werner RA, Pomper MG, Buck AK, Rowe SP, Higuchi T. SPECT and PET Radiotracers in Renal Imaging. Semin Nucl Med 2022; 52:406-418. [DOI: 10.1053/j.semnuclmed.2021.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/06/2021] [Indexed: 12/24/2022]
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10
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The utilization of positron emission tomography in the evaluation of renal health and disease. Clin Transl Imaging 2021. [DOI: 10.1007/s40336-021-00469-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Abstract
Purpose
Positron emission tomography (PET) is a nuclear imaging technique that uses radiotracers to visualize metabolic processes of interest across different organs, to diagnose and manage diseases, and monitor therapeutic response. This systematic review aimed to characterize the value of PET for the assessment of renal metabolism and function in subjects with non-oncological metabolic disorders.
Methods
This review was conducted and reported in accordance with the PRISMA statement. Research articles reporting “kidney” or “renal” metabolism evaluated with PET imaging between 1980 and 2021 were systematically searched in Medline/PubMed, Science Direct, and the Cochrane Library. Search results were exported and stored in RefWorks, the duplicates were removed, and eligible studies were identified, evaluated, and summarized.
Results
Thirty reports met the inclusion criteria. The majority of the studies were prospective (73.33%, n = 22) in nature. The most utilized PET radiotracers were 15O-labeled radio water (H215O, n = 14) and 18F-fluorodeoxyglucose (18F-FDG, n = 8). Other radiotracers used in at least one study were 14(R,S)-(18)F-fluoro-6-thia-heptadecanoic acid (18F-FTHA), 18F-Sodium Fluoride (18F-NaF), 11C-acetate, 68-Gallium (68Ga), 13N-ammonia (13N-NH3), Rubidium-82 (82Rb), radiolabeled cationic ferritin (RadioCF), 11C‐para-aminobenzoic acid (11C-PABA), Gallium-68 pentixafor (68Ga-Pentixafor), 2-deoxy-2-F-fluoro-d-sorbitol (F-FDS) and 55Co-ethylene diamine tetra acetic acid (55Co-EDTA).
Conclusion
PET imaging provides an effective modality for evaluating a range of metabolic functions including glucose and fatty acid uptake, oxygen consumption and renal perfusion. Multiple positron emitting radiolabeled racers can be used for renal imaging in clinical settings. PET imaging thus holds the potential to improve the diagnosis of renal disorders, and to monitor disease progression and treatment response.
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11
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Toyama Y, Werner RA, Ruiz-Bedoya CA, Ordonez AA, Takase K, Lapa C, Jain SK, Pomper MG, Rowe SP, Higuchi T. Current and future perspectives on functional molecular imaging in nephro-urology: theranostics on the horizon. Theranostics 2021; 11:6105-6119. [PMID: 33897902 PMCID: PMC8058716 DOI: 10.7150/thno.58682] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/21/2021] [Indexed: 01/01/2023] Open
Abstract
In recent years, a paradigm shift from single-photon-emitting radionuclide radiotracers toward positron-emission tomography (PET) radiotracers has occurred in nuclear oncology. Although PET-based molecular imaging of the kidneys is still in its infancy, such a trend has emerged in the field of functional renal radionuclide imaging. Potentially allowing for precise and thorough evaluation of renal radiotracer urodynamics, PET radionuclide imaging has numerous advantages including precise anatomical co-registration with CT images and dynamic three-dimensional imaging capability. In addition, relative to scintigraphic approaches, PET can allow for significantly reduced scan time enabling high-throughput in a busy PET practice and further reduces radiation exposure, which may have a clinical impact in pediatric populations. In recent years, multiple renal PET radiotracers labeled with 11C, 68Ga, and 18F have been utilized in clinical studies. Beyond providing a precise non-invasive read-out of renal function, such radiotracers may also be used to assess renal inflammation. This manuscript will provide an overview of renal molecular PET imaging and will highlight the transformation of conventional scintigraphy of the kidneys toward novel, high-resolution PET imaging for assessing renal function. In addition, future applications will be introduced, e.g. by transferring the concept of molecular image-guided diagnostics and therapy (theranostics) to the field of nephrology.
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Affiliation(s)
- Yoshitaka Toyama
- Department of Nuclear Medicine, University Hospital Wuerzburg, Wuerzburg, Germany
- Department of Diagnostic Radiology, Tohoku University, Sendai, Japan
| | - Rudolf A. Werner
- Department of Nuclear Medicine, University Hospital Wuerzburg, Wuerzburg, Germany
- Comprehensive Heart Failure Center, University Hospital Wuerzburg, Wuerzburg Germany
- Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Camilo A. Ruiz-Bedoya
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Alvaro A. Ordonez
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Kei Takase
- Department of Diagnostic Radiology, Tohoku University, Sendai, Japan
| | - Constantin Lapa
- Nuclear Medicine, Medical Faculty, University of Augsburg, Augsburg, Germany
| | - Sanjay K. Jain
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Martin G. Pomper
- Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The James Buchanan Brady Urological Institute and Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Steven P. Rowe
- Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The James Buchanan Brady Urological Institute and Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Takahiro Higuchi
- Department of Nuclear Medicine, University Hospital Wuerzburg, Wuerzburg, Germany
- Comprehensive Heart Failure Center, University Hospital Wuerzburg, Wuerzburg Germany
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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12
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Gregg S, Keramida G, Peters AM. 82 Rb tissue kinetics in humans. Clin Physiol Funct Imaging 2021; 41:245-252. [PMID: 33506589 DOI: 10.1111/cpf.12691] [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: 06/21/2020] [Revised: 12/13/2020] [Accepted: 01/22/2021] [Indexed: 11/28/2022]
Abstract
AIM The study aim was to compare the kinetics of the potassium analogue, 82 Rb, between spleen, liver and kidney. METHODS Patients had myocardial stress/rest perfusion imaging using adenosine (n = 45) or regadenoson (n = 33) for stressing. Hepatic arterial (HAP), splenic (SP) and renal (RP) perfusions were measured from first-pass and blood 82 Rb clearances (Ki) from Gjedde-Patlak-Rutland graphical analysis of data between 1 and 2 min postinjection, using regions of interest over left ventricular cavity or abdominal aorta to monitor arterial concentration. Tissue 82 Rb extraction efficiency (E) was calculated as [Ki/perfusion]*100. Tissue extracellular fluid volume (ECV) was derived from the GPR plot intercept. RESULTS SP (24%) and RP (23%) increased after regadenoson but decreased (-41% and -19%) after adenosine. HAP increased after adenosine (91%) and regadenoson (68%). Resting E was high in kidney (69%) and low in spleen (26%). After adenosine, it increased to 91% in kidney and 49% in spleen. Assuming an arterial contribution of 25% to hepatic blood flow, resting E in liver was estimated as 23%. Relationships between Ki and perfusion in spleen and kidney were consistent with the Crone-Renkin equation (Ki = [1 - A.e-B/perfusion ]*perfusion), with respective values of A of 0.95 and 0.94 and B of 31 and 186 ml/min/100 ml. Splenic ECV decreased following adenosine from 62 to 39 ml/100 ml and showed a logarithmic correlation with SP. CONCLUSION Kidney, spleen and liver display contrasting tissue kinetics. E is high in kidney and low in spleen and liver. Spleen is erectile, collapsing when perfusion decreases.
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Affiliation(s)
- Sima Gregg
- Department of Nuclear Medicine, Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - Georgia Keramida
- Department of Nuclear Medicine, Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - A Michael Peters
- Department of Nuclear Medicine, King's College Hospital NHS Foundation Trust, London, UK
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Päivärinta J, Oikonen V, Räisänen-Sokolowski A, Tolvanen T, Löyttyniemi E, Iida H, Nuutila P, Metsärinne K, Koivuviita N. Renal vascular resistance is increased in patients with kidney transplant. BMC Nephrol 2019; 20:437. [PMID: 31775670 PMCID: PMC6882025 DOI: 10.1186/s12882-019-1617-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 11/08/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Despite improvement in short-term outcome of kidney transplants, the long-term survival of kidney transplants has not changed over past decades. Kidney biopsy is the gold standard of transplant pathology but it's invasive. Quantification of transplant blood flow could provide a novel non-invasive method to evaluate transplant pathology. The aim of this retrospective cross-sectional pilot study was to evaluate positron emission tomography (PET) as a method to measure kidney transplant perfusion and find out if there is correlation between transplant perfusion and histopathology. METHODS Renal cortical perfusion of 19 kidney transplantation patients [average time from transplantation 33 (17-54) months; eGFR 55 (47-69) ml/min] and 10 healthy controls were studied by [15 O]H2O PET. Perfusion and Doppler resistance index (RI) of transplants were compared with histology of one-year protocol transplant biopsy. RESULTS Renal cortical perfusion of healthy control subjects and transplant patients were 2.7 (2.4-4.0) ml min- 1 g- 1 and 2.2 (2.0-3.0) ml min- 1 g- 1, respectively (p = 0.1). Renal vascular resistance (RVR) of the patients was 47.0 (36.7-51.4) mmHg mL- 1min- 1g- 1 and that of the healthy 32.4 (24.6-39.6) mmHg mL- 1min-1g-1 (p = 0.01). There was a statistically significant correlation between Doppler RI and perfusion of transplants (r = - 0.51, p = 0.026). Transplant Doppler RI of the group of mild fibrotic changes [0.73 (0.70-0.76)] and the group of no fibrotic changes [0.66 (0.61-0.72)] differed statistically significantly (p = 0.03). No statistically significant correlation was found between cortical perfusion and fibrosis of transplants (p = 0.56). CONCLUSIONS [15 O]H2O PET showed its capability as a method in measuring perfusion of kidney transplants. RVR of transplant patients with stage 2-3 chronic kidney disease was higher than that of the healthy, although kidney perfusion values didn't differ between the groups. Doppler based RI correlated with perfusion and fibrosis of transplants.
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Affiliation(s)
- Johanna Päivärinta
- Department of Nephrology, Turku University Hospital, PL 52,Kiinanmyllykatu 4-8, 20521, Turku, Finland.
- Department of Medicine, University of Turku, Turku, Finland.
| | - Vesa Oikonen
- Turku PET Centre, University of Turku, Turku, Finland
| | - Anne Räisänen-Sokolowski
- Department of Pathology, Helsinki University Hospital and Helsinki University, Helsinki, Finland
| | - Tuula Tolvanen
- Turku PET Centre, University of Turku, Turku, Finland
- Department of Medical Physics, Turku University Hospital, Turku, Finland
| | | | - Hidehiro Iida
- Turku PET Centre, University of Turku, Turku, Finland
| | - Pirjo Nuutila
- Department of Medicine, University of Turku, Turku, Finland
- Turku PET Centre, University of Turku, Turku, Finland
| | - Kaj Metsärinne
- Department of Nephrology, Turku University Hospital, PL 52,Kiinanmyllykatu 4-8, 20521, Turku, Finland
| | - Niina Koivuviita
- Department of Nephrology, Turku University Hospital, PL 52,Kiinanmyllykatu 4-8, 20521, Turku, Finland
- Department of Medicine, University of Turku, Turku, Finland
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Wang H, Dong W, Zhao Q, Lu K, Guo X, Liu H, Wu Z, Li S. Synthesis of N-(6-[ 18F]Fluoropyridin-3-yl)glycine as a potential renal PET agent. Nucl Med Biol 2019; 76-77:21-27. [PMID: 31648134 DOI: 10.1016/j.nucmedbio.2019.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/20/2019] [Accepted: 09/27/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Given the requirements of high sensitivity and spatial resolution, the development of new positron emission tomography (PET) agents is required for PET renography. The objective of this study was to investigate a new fluorine-18 labeled hippurate analogue of picolinamide, N-(6-[18F]Fluoropyridin-3-yl)glycine, as a new renal PET agent for evaluating renal function. METHODS N-(6-[18F]Fluoropyridin-3-yl)glycine was prepared via a two-step reaction, including the nucleophilic substitution reaction of Br with 18F using methyl 2-(6-bromonicotinamido)acetate as a precursor followed the hydrolysis with sodium hydroxide and purification by preparative-HPLC. The in vitro and in vivo stability were determined using HPLC, and the plasma protein binding (PPB) and erythrocyte uptake of N-(6-[18F]Fluoropyridin-3-yl)glycine were determined using blood collected from healthy rats at 5 min post-injection. Biodistribution and dynamic micro-PET/CT imaging studies were conducted in healthy rats. RESULTS N-(6-[18F]Fluoropyridin-3-yl)glycine was prepared within 45 min with an uncorrected radiochemical yield of 24.5 ± 6.7% (n = 6, based on [18F]F-) and a radiochemical purity of >98%. N-(6-[18F]Fluoropyridin-3-yl)glycine demonstrated good stability both in vitro and in vivo. The results of the biodistribution and dynamic micro-PET/CT imaging studies in normal rats indicated that N-(6-[18F]Fluoropyridin-3-yl)glycine was rapidly and exclusively excreted via the renal-urinary pathway. CONCLUSION N-(6-[18F]Fluoropyridin-3-yl)glycine is has been shown to be a promising renal PET agent and warrants further evaluation of renal function.
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Affiliation(s)
- Hongliang Wang
- Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Shanxi Key Laboratory of Molecular Imaging, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Molecular Imaging Precision Medicine Collaborative Innovation Center of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China.
| | - Weixuan Dong
- Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China
| | - Qinan Zhao
- Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China
| | - Keyi Lu
- Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Shanxi Key Laboratory of Molecular Imaging, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Molecular Imaging Precision Medicine Collaborative Innovation Center of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China
| | - Xiaoshan Guo
- Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Shanxi Key Laboratory of Molecular Imaging, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Molecular Imaging Precision Medicine Collaborative Innovation Center of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China
| | - Haiyan Liu
- Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Shanxi Key Laboratory of Molecular Imaging, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Molecular Imaging Precision Medicine Collaborative Innovation Center of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China
| | - Zhifang Wu
- Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Shanxi Key Laboratory of Molecular Imaging, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Molecular Imaging Precision Medicine Collaborative Innovation Center of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China.
| | - Sijin Li
- Department of Nuclear Medicine, First Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Shanxi Key Laboratory of Molecular Imaging, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China; Molecular Imaging Precision Medicine Collaborative Innovation Center of Shanxi Medical University, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China.
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15
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Päivärinta J, Koivuviita N, Oikonen V, Iida H, Liukko K, Manner I, Löyttyniemi E, Nuutila P, Metsärinne K. The renal blood flow reserve in healthy humans and patients with atherosclerotic renovascular disease measured by positron emission tomography using [ 15O]H 2O. EJNMMI Res 2018; 8:45. [PMID: 29892792 PMCID: PMC5995766 DOI: 10.1186/s13550-018-0395-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 05/07/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Microvascular function plays an important role in ARVD (atherosclerotic renovascular disease). RFR (renal flow reserve), the capacity of renal vasculature to dilate, is known to reflect renal microvascular function. In this pilot study, we assessed PET (positron emission tomography)-based RFR values of healthy persons and renal artery stenosis patients. Seventeen patients with ARVD and eight healthy subjects were included in the study. Intravenous enalapril 1 mg was used as a vasodilatant, and the maximum response (blood pressure and RFR) to it was measured at 40 min. Renal perfusion was measured by means of oxygen-15-labeled water PET. RFR was calculated as a difference of stress flow and basal flow and was expressed as percent [(stress blood flow - basal blood flow)/basal blood flow] × 100%. RESULTS RFR of the healthy was 22%. RFR of the stenosed kidneys of bilateral stenosis patients (27%) was higher than that of the stenosed kidneys of unilateral stenosis patients (15%). RFR of the contralateral kidneys of unilateral stenosis patients was 21%. There was no difference of statistical significance between RFR values of ARVD subgroups or between ARVD subgroups and the healthy. In the stenosed kidneys of unilateral ARVD patients, stenosis grade of the renal artery correlated negatively with basal (p = 0.04) and stress flow (p = 0.02). Dispersion of RFR values was high. CONCLUSIONS This study is the first to report [15O]H2O PET-based RFR values of healthy subjects and ARVD patients in humans. The difference between RFR values of ARVD patients and the healthy did not reach statistical significance perhaps because of high dispersion of RFR values. [15O]H2O PET is a valuable non-invasive and quantitative method to evaluate renal blood flow though high dispersion makes imaging challenging. Larger studies are needed to get more information about [15O]H2O PET method in evaluation of renal blood flow.
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Affiliation(s)
- Johanna Päivärinta
- Department of Nephrology, Division of Medicine, Turku University Hospital, PL 52, Kiinamyllynkatu 4-8, 20521, Turku, Finland.
- Department of Medicine, University of Turku, Turku, Finland.
| | - Niina Koivuviita
- Department of Nephrology, Division of Medicine, Turku University Hospital, PL 52, Kiinamyllynkatu 4-8, 20521, Turku, Finland
| | - Vesa Oikonen
- Turku PET Centre, University of Turku, Turku, Finland
| | - Hidehiro Iida
- Turku PET Centre, University of Turku, Turku, Finland
| | - Kaisa Liukko
- Turku PET Centre, University of Turku, Turku, Finland
| | - Ilkka Manner
- Department of Radiology, Turku University Hospital, Turku, Finland
| | | | - Pirjo Nuutila
- Turku PET Centre, University of Turku, Turku, Finland
| | - Kaj Metsärinne
- Department of Nephrology, Division of Medicine, Turku University Hospital, PL 52, Kiinamyllynkatu 4-8, 20521, Turku, Finland
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Karakatsanis NA, Casey ME, Lodge MA, Rahmim A, Zaidi H. Whole-body direct 4D parametric PET imaging employing nested generalized Patlak expectation-maximization reconstruction. Phys Med Biol 2016; 61:5456-85. [PMID: 27383991 DOI: 10.1088/0031-9155/61/15/5456] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Whole-body (WB) dynamic PET has recently demonstrated its potential in translating the quantitative benefits of parametric imaging to the clinic. Post-reconstruction standard Patlak (sPatlak) WB graphical analysis utilizes multi-bed multi-pass PET acquisition to produce quantitative WB images of the tracer influx rate K i as a complimentary metric to the semi-quantitative standardized uptake value (SUV). The resulting K i images may suffer from high noise due to the need for short acquisition frames. Meanwhile, a generalized Patlak (gPatlak) WB post-reconstruction method had been suggested to limit K i bias of sPatlak analysis at regions with non-negligible (18)F-FDG uptake reversibility; however, gPatlak analysis is non-linear and thus can further amplify noise. In the present study, we implemented, within the open-source software for tomographic image reconstruction platform, a clinically adoptable 4D WB reconstruction framework enabling efficient estimation of sPatlak and gPatlak images directly from dynamic multi-bed PET raw data with substantial noise reduction. Furthermore, we employed the optimization transfer methodology to accelerate 4D expectation-maximization (EM) convergence by nesting the fast image-based estimation of Patlak parameters within each iteration cycle of the slower projection-based estimation of dynamic PET images. The novel gPatlak 4D method was initialized from an optimized set of sPatlak ML-EM iterations to facilitate EM convergence. Initially, realistic simulations were conducted utilizing published (18)F-FDG kinetic parameters coupled with the XCAT phantom. Quantitative analyses illustrated enhanced K i target-to-background ratio (TBR) and especially contrast-to-noise ratio (CNR) performance for the 4D versus the indirect methods and static SUV. Furthermore, considerable convergence acceleration was observed for the nested algorithms involving 10-20 sub-iterations. Moreover, systematic reduction in K i % bias and improved TBR were observed for gPatlak versus sPatlak. Finally, validation on clinical WB dynamic data demonstrated the clinical feasibility and superior K i CNR performance for the proposed 4D framework compared to indirect Patlak and SUV imaging.
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Affiliation(s)
- Nicolas A Karakatsanis
- Division of Nuclear Medicine and Molecular Imaging, School of Medicine, University of Geneva, Geneva, CH-1211, Switzerland
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Juárez-Orozco LE, Szymanski MK, Hillege HL, Kruizinga S, Noordzij W, Koole M, Tio RA, Alexanderson E, Dierckx RAJO, Slart RHJA. Imaging of cardiac and renal perfusion in a rat model with 13N–NH3 micro-PET. Int J Cardiovasc Imaging 2014; 31:213-9. [DOI: 10.1007/s10554-014-0538-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 09/13/2014] [Indexed: 11/30/2022]
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Koivuviita N, Liukko K, Kudomi N, Oikonen V, Tertti R, Manner I, Vahlberg T, Nuutila P, Metsärinne K. The effect of revascularization of renal artery stenosis on renal perfusion in patients with atherosclerotic renovascular disease. Nephrol Dial Transplant 2012; 27:3843-8. [PMID: 22785108 DOI: 10.1093/ndt/gfs301] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Only a small fraction of patients with atherosclerotic renovascular disease (ARVD) treated with revascularization have improved renal function after the procedure. It has been suggested that this may be due to effects of renal microvascular disease. Our aim was to measure the effect of renal artery stenosis (RAS) revascularization on renal perfusion in patients with renovascular disease. METHODS Seventeen renovascular disease patients were treated by dilatation of unilateral (N = 8) or bilateral (N = 9) RAS (N = 23 kidneys), mainly because of uncontrolled or refractory hypertension. The patients were studied before and after (103 ± 29 days) the procedure. Renal perfusion was measured using quantitative positron emission tomography (PET) perfusion imaging. RESULTS Although renal perfusion correlated inversely with the degree of RAS in patients with renovascular disease, it did not change after revascularization. CONCLUSIONS Our data support the notion of former clinical trials that angiographic severity of RAS does not determine the response to revascularization. Quantitative PET perfusion imaging is a promising tool to noninvasively measure renal perfusion for the assessment of physiological impact of RAS.
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Affiliation(s)
- Niina Koivuviita
- Department of Medicine, Turku University Hospital, Turku, Finland.
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In vivo, label-free, three-dimensional quantitative imaging of kidney microcirculation using Doppler optical coherence tomography. J Transl Med 2011; 91:1596-604. [PMID: 21808233 PMCID: PMC3312876 DOI: 10.1038/labinvest.2011.112] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Doppler optical coherence tomography (DOCT) is a functional extension of optical coherence tomography (OCT) and is currently being employed in several clinical arenas to quantify blood flow in vivo. In this study, the objective was to investigate the feasibility of DOCT to image kidney microcirculation, specifically, glomerular blood flow. DOCT is able to capture three-dimensional (3D) data sets consisting of a series of cross-sectional images in real time, which enables label-free and non-destructive quantification of glomerular blood flow. The kidneys of adult, male Munich-Wistar rats were exposed through laparotomy procedure after being anesthetized. Following exposure of the kidney beneath the DOCT microscope, glomerular blood flow was observed. The effects of acute mannitol and angiotensin II infusion were also observed. Glomerular blood flow was quantified for the induced physiological states and compared with baseline measurements. Glomerular volume, cumulative Doppler volume, and Doppler flow range parameters were computed from 3D OCT/DOCT data sets. Glomerular size was determined from OCT, and DOCT readily revealed glomerular blood flow. After infusion of mannitol, a significant increase in blood flow was observed and quantified, and following infusion of angiontensin II, a significant decrease in blood flow was observed and quantified. Also, blood flow histograms were produced to illustrate differences in blood flow rate and blood volume among the induced physiological states. We demonstrated 3D DOCT imaging of rat kidney microcirculation in the glomerulus in vivo. Dynamic changes in blood flow were detected under altered physiological conditions demonstrating the real-time imaging capability of DOCT. This method holds promise to allow non-invasive imaging of kidney blood flow for transplant graft evaluation or monitoring of altered-renal hemodynamics related to disease progression.
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Lemoine S, Papillard M, Belloi A, Rognant N, Fouque D, Laville M, Rouvière O, Juillard L. Renal perfusion: noninvasive measurement with multidetector CT versus fluorescent microspheres in a pig model. Radiology 2011; 260:414-20. [PMID: 21673226 DOI: 10.1148/radiol.11101317] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To validate the measurement of renal perfusion with multidetector computed tomography (CT) with a low-rate injection of contrast medium (ie, 3 mL/sec) through a catheter placed peripherally with gamma variate extended modeling in a pig model, compared with a reference method of fluorescent microspheres. MATERIALS AND METHODS This study was approved by the Institutional Animal Care and Use Committee. Renal perfusion was measured in 10 anesthetized pigs simultaneously with multidetector CT and with fluorescent microspheres, which are the reference standard for measuring regional renal perfusion. In each pig, measurements were obtained under three conditions. These were dopamine infusion, dopamine infusion with vascular expansion, and angiotensin II infusion. Aortic and cortical time-attenuation curves were modeled to measure renal perfusion with the gamma variate model. The renal perfusion measurements with the multidetector CT and that with microspheres were compared with least squares regression analysis and Bland-Altman plots. RESULTS Perfusion as measured with multidetector CT and that as measured with microspheres were strongly correlated (ρ = 0.93, P < .0001). Multidetector CT renal perfusion with dopamine infusion (3.13 mL/min/g ± 0.53) was not changed after volume expansion (3.37 mL/min/g ± 0.75, P = .35) but was significantly decreased after angiotensin II injection (2.01 mL/min/g ± 0.57, P = .0001). CONCLUSION Multidetector CT provides reliable measurements of single-kidney perfusion with peripheral low-rate contrast medium injection.
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Affiliation(s)
- Sandrine Lemoine
- Department of Nephrology, Hôpital Edouard Herriot, Hospices Civils de Lyon, 5 place d'Arsonval, Pavillon P, 69437, Cedex 03, Lyon, France
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Damkjær M, Vafaee M, Møller ML, Braad PE, Petersen H, Høilund-Carlsen PF, Bie P. Renal cortical and medullary blood flow responses to altered NO availability in humans. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1449-55. [PMID: 20881099 DOI: 10.1152/ajpregu.00440.2010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this study was to quantify regional renal blood flow in humans. In nine young volunteers on a controlled diet, the lower abdomen was CT-scanned, and regional renal blood flow was determined by positron emission tomography (PET) scanning using H(2)(15)O as tracer. Measurements were performed at baseline, during constant intravenous infusion of nitric oxide (NO) donor glyceryl nitrate and after intravenous injection of NO synthase inhibitor N(ω)-monomethyl-L-arginine (L-NMMA). Using the CT image, the kidney pole areas were delineated as volumes of interest (VOI). In the data analysis, tissue layers with a thickness of one voxel were eliminated stepwise from the external surface of the VOI (voxel peeling), and the blood flow subsequently was determined in each new, reduced VOI. Blood flow in the shrinking VOIs decreased as the number of cycles of voxel peeling increased. After 4-5 cycles, blood flow was not reduced further by additional voxel peeling. This volume-insensitive flow was measured to be 2.30 ± 0.17 ml·g tissue(-1)·min(-1) during the control period; it increased during infusion of glyceryl nitrate to 2.97 ± 0.18 ml·g tissue(-1)·min(-1) (P < 0.05) and decreased after L-NMMA injection to 1.57 ± 0.17 ml·g tissue(-1)·min(-1) (P < 0.05). Cortical blood flow was 4.67 ± 0.31 ml·g tissue(-1)·min(-1) during control, unchanged by glyceryl nitrate, and decreased after L-NMMA [3.48 ± 0.23 ml·(g·min)(-1), P < 0.05]. PET/CT scanning allows identification of a renal medullary region in which the measured blood flow is 1) low, 2) independent of reduction in the VOI, and 3) reactive to changes in systemic NO supply. The technique seems to provide indices of renal medullary blood flow in humans.
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Affiliation(s)
- Mads Damkjær
- Institute of Molecular Medicine, Univ. of Southern Denmark, 21 J. B. Winsloews Vej, DK-5000 Odense, Denmark
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Absolute Quantification of Regional Renal Blood Flow in Swine by Dynamic Contrast-Enhanced Magnetic Resonance Imaging Using a Blood Pool Contrast Agent. Invest Radiol 2009; 44:125-34. [PMID: 19151609 DOI: 10.1097/rli.0b013e318193598c] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Parametric renal blood flow imaging using [15O]H2O and PET. Eur J Nucl Med Mol Imaging 2008; 36:683-91. [DOI: 10.1007/s00259-008-0994-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Accepted: 10/17/2008] [Indexed: 10/21/2022]
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Szabo Z, Xia J, Mathews WB. Radiopharmaceuticals for renal positron emission tomography imaging. Semin Nucl Med 2008; 38:20-31. [PMID: 18096461 DOI: 10.1053/j.semnuclmed.2007.09.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Radiopharmaceuticals for functional renal imaging, including renal blood flow, renal blood volume, glomerular excretion, and metabolism have been available for some time. This review outlines radiopharmaceuticals for functional renal imaging as well as those that target pertinent molecular constituents of renal injury and repair. The angiotensin and endothelin receptors are particularly appealing molecular targets for renal imaging because of their association with renal physiology and pathology. Other targets such as the vascular endothelial growth factor (VEGF) receptor, integrin, or phosphatidylserine have been investigated at length for cancer imaging, but they are just as important constituents of the renal injury/repair process. Various diseases can involve identical mechanisms, such as angiogenesis and apoptosis, and radiopharmaceuticals developed for these processes in other organs can also be used for renal imaging. The sensitivity and spatial resolution of positron emission tomography makes it an ideal tool for molecular and functional kidney imaging. Radiopharmaceutical development for the kidneys must focus on achieving high target selectivity and binding affinity, stability and slow metabolism in vivo, and minimal nonspecific accumulation and urinary excretion.
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Affiliation(s)
- Zsolt Szabo
- Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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Green MA, Mathias CJ, Willis LR, Handa RK, Lacy JL, Miller MA, Hutchins GD. Assessment of Cu-ETS as a PET radiopharmaceutical for evaluation of regional renal perfusion. Nucl Med Biol 2007; 34:247-55. [PMID: 17383574 DOI: 10.1016/j.nucmedbio.2007.01.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Revised: 12/19/2006] [Accepted: 01/02/2007] [Indexed: 10/23/2022]
Abstract
UNLABELLED The copper(II) complex of ethylglyoxal bis(thiosemicarbazone) (Cu-ETS) was evaluated as a positron emission tomography (PET) radiopharmaceutical for assessment of regional renal perfusion. METHODS The concordance of renal flow estimates obtained with 11- and 15-microm microspheres was confirmed in four immature farm pigs using co-injected (46)Sc- and (57)Co-microspheres administered into the left ventricle. With the use of both immature farm pigs (n=3) and mature Göttingen minipigs (n=6), regional renal radiocopper uptake following intravenous [(64)Cu]Cu-ETS administration was compared to microsphere measurements of renal perfusion. The distribution and kinetics of [(64)Cu]Cu-ETS were further studied by PET imaging of the kidneys. The rate of [(64)Cu]Cu-ETS decomposition by blood was evaluated in vitro, employing octanol extraction to recover intact [(64)Cu]Cu-ETS. RESULTS The co-injected 11- and 15-microm microspheres provided similar estimates of renal flow. A linear relationship was observed between the renal uptake of intravenous [(64)Cu]Cu-ETS and regional renal perfusion measured using microspheres. [(64)Cu]Cu-ETS provided high-quality PET kidney images demonstrating the expected count gradient from high-flow outer cortex to low-flow medulla. When incubated with pig blood in vitro at 37 degrees C, the [(64)Cu]Cu-ETS radiopharmaceutical was observed to decompose with a half-time of 2.8 min. CONCLUSION Cu-ETS appears suitable for use as a PET radiopharmaceutical for evaluation of regional renal perfusion, affording renal uptake of radiocopper that varies linearly with microsphere perfusion measurements. Quantification of renal perfusion (in ml min(-1) g(-1)) with [(60,61,62,64)Cu]Cu-ETS will require correcting the arterial input function for the fraction of blood radiocopper remaining present as the intact Cu-ETS radiopharmaceutical, since the Cu-ETS chelate has limited chemical stability in blood. Rapid octanol extraction of blood samples appears suitable as an approach to capturing the actual blood concentration of [(60/61/62/64)Cu]Cu-ETS.
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Affiliation(s)
- Mark A Green
- Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907-2091, USA.
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Abstract
Positron emission tomography (PET) is perfectly suited for quantitative imaging of the kidneys, and the recent improvements in detector technology, computer hardware, and image processing software add to its appeal. Multiple positron emitting radioisotopes can be used for renal imaging. Some, including carbon-11, nitrogen-13, and oxygen-15, can be used at institutions with an on-site cyclotron. Other radioisotopes that may be even more useful in a clinical setting are those that either can be obtained from radionuclide generators (rubidium-82, copper-62) or have a sufficiently long half-life for transportation (fluorine-18). The clinical use of functional renal PET studies (blood flow, glomerular filtration rate) has been slow, in part because of the success of concurrent technologies, including single-photon emission computed tomography (SPECT) and planar gamma camera imaging. Renal blood flow studies can be performed with O-15-labeled water, N-13-labeled ammonia, rubidium-82, and copper-labeled PTSM. With these tracers, renal blood flow can be quantified using a modified microsphere kinetic model. Glomerular filtration can be imaged and quantified with gallium-68 EDTA or cobalt-55 EDTA. Measurements of renal blood flow with PET have potential applications in renovascular disease, in transplant rejection or acute tubular necrosis, in drug-induced nephropathies, ureteral obstruction, before and after revascularization, and before and after the placement of ureteral stents. The most important clinical application for imaging glomerular function with PET would be renovascular hypertension. Molecular imaging of the kidneys with PET is rather limited. At present, research is focused on the investigation of metabolism (acetate), membrane transporters (organic cation and anion transporters, pepT1 and pepT2, GLUT, SGLT), enzymes (ACE), and receptors (AT1R). Because many nephrological and urological disorders are initiated at the molecular and organelle levels and may remain localized at their origin for an extended period of time, new disease-specific molecular probes for PET studies of the kidneys need to be developed. Future applications of molecular renal imaging are likely to involve studies of tissue hypoxia and apoptosis in renovascular renal disease, renal cancer, and obstructive nephropathy, monitoring the molecular signatures of atherosclerotic plaques, measuring endothelial dysfunction and response to balloon revascularization and restenosis, molecular assessment of the nephrotoxic effects of cyclosporine, anticancer drugs, and radiation therapy. New radioligands will enhance the staging and follow-up of renal and prostate cancer. Methods will be developed for investigation of the kinetics of drug-delivery systems and delivery and deposition of prodrugs, reporter gene technology, delivery of gene therapy (nuclear and mitochondrial), assessment of the delivery of cellular, viral, and nonviral vectors (liposomes, polycations, fusion proteins, electroporation, hematopoietic stems cells). Of particular importance will be investigations of stem cell kinetics, including local presence, bloodborne migration, activation, seeding, and its role in renal remodeling (psychological, pathological, and therapy induced). Methods also could be established for investigating the role of receptors and oncoproteins in cellular proliferation, apoptosis, tubular atrophy, and interstitial fibrosis; monitoring ras gene targeting in kidney diseases, assessing cell therapy devices (bioartificial filters, renal tubule assist devices, and bioarticial kidneys), and targeting of signal transduction moleculas with growth factors and cytokines. These potential new approaches are, at best, in an experimental stage, and more research will be needed for their implementation.
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Affiliation(s)
- Zsolt Szabo
- Division of Nuclear Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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Juillard L, Janier MF, Fouque D, Cinotti L, Maakel N, Le Bars D, Barthez PY, Pozet N, Laville M. Dynamic renal blood flow measurement by positron emission tomography in patients with CRF. Am J Kidney Dis 2002; 40:947-54. [PMID: 12407639 DOI: 10.1053/ajkd.2002.36325] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Positron emission tomography (PET) is a functional imaging device that allows dynamic regional blood flow measurements. We performed a study to test whether PET could detect acute changes in renal blood flow (RBF) in patients with chronic renal failure (CRF). METHODS RBF was measured by means of PET (PET-RBF) using oxygen 15-labeled water (H2(15)O) in eight men with hypertension and moderate CRF before and 5, 40, 80, and 120 minutes after the injection of quinaprilat (10 mg intravenously). Effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) were measured simultaneously by para-aminohippuric acid (PAH-ERPF) and inulin clearances before and 20, 60, 100, and 140 minutes after quinaprilat injection. RESULTS Baseline RBF and ERPF were decreased in all patients (221 +/- 20 mL/min/100 g and 225 +/- 38 mL/min/1.73 m2, respectively). PET-RBF increased significantly after quinaprilat injection (+15%, +26%, +19%, and +23% versus baseline; P < 0.003). PAH-ERPF did not increase significantly (-6%, +12%, +20%, and +15% versus baseline; P = 0.15). GFR (50.1 +/- 8.9 mL/min/1.73 m2 at baseline) did not change significantly after quinaprilat injection; however, filtration fraction (GFR-ERPF ratio) decreased significantly from 0.23% +/- 0.02% to 0.20% +/- 0.02% (P = 0.0004). Mean arterial pressure decreased significantly after quinaprilat injection (P < 0.005). CONCLUSION This study dynamically measured RBF by means of PET in patients with CRF for the first time. It showed that RBF rapidly increased after quinaprilat injection. PET using H2(15)O is a powerful method for the noninvasive measurement of dynamic changes in RBF that remain undetected by PAH clearance.
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Abstract
Functional alterations in the renal circulation that can contribute to abnormal renal perfusion have been demonstrated in various models of renal injury. To detect impairments in renal vascular function, renal flow reserve can be determined by repeated measurements of renal blood flow (RBF) during pharmacological challenge with short-acting vasodilators that should increase RBF in kidneys that are not severely damaged structurally. Among the invasive techniques for such measurements, the most readily available is probably the intravascular Doppler, which can be employed during renal angiography for rapid evaluation of changes in RBF during intrarenal injections of vasoactive substances. High-resolution tomographic imaging techniques, like electron-beam x-ray computed tomography, further offer the potential for noninvasive measurements of renal parenchymal perfusion and function, in association with either intrarenal or systemic injections of vasoactive substances. Acetylcholine is a potent short-acting renal vasodilator that can be useful to assess the response of the renal microcirculation, define renal flow reserve, and examine the endothelium-dependent responses of RBF. Such assessments of the function of the renal circulation can assist in evaluation of patients with systemic or renal disease for early detection and monitoring of renovascular injury.
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Affiliation(s)
- L O Lerman
- Department of Internal Medicine, Division of Hypertension, Mayo Clinic, Rochester, Minnesota, USA.
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Middlekauff HR, Nitzsche EU, Hoh CK, Hamilton MA, Fonarow GC, Hage A, Moriguchi JD. Exaggerated muscle mechanoreflex control of reflex renal vasoconstriction in heart failure. J Appl Physiol (1985) 2001; 90:1714-9. [PMID: 11299260 DOI: 10.1152/jappl.2001.90.5.1714] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In heart failure (HF) patients, reflex renal vasoconstriction during exercise is exaggerated. We hypothesized that muscle mechanoreceptor control of renal vasoconstriction is exaggerated in HF. Nineteen HF patients and nineteen controls were enrolled in two exercise protocols: 1) low-level rhythmic handgrip (mechanoreceptors and central command) and 2) involuntary biceps contractions (mechanoreceptors). Renal cortical blood flow was measured by positron emission tomography, and renal cortical vascular resistance (RCVR) was calculated. During rhythmic handgrip, peak RCVR was greater in HF patients compared with controls (37 +/- 1 vs. 27 +/- 1 units; P < 0.01). Change in (Delta) RCVR tended to be greater as well but did not reach statistical significance (10 +/- 1 vs. 7 +/- 0.9 units; P = 0.13). RCVR was returned to baseline at 2-3 min postexercise in controls but remained significantly elevated in HF patients. During involuntary muscle contractions, peak RCVR was greater in HF patients compared with controls (36 +/- 0.7 vs. 24 +/- 0.5 units; P < 0.0001). The Delta RCVR was also significantly greater in HF patients compared with controls (6 +/- 1 vs. 4 +/- 0.6 units; P = 0.05). The data suggest that reflex renal vasoconstriction is exaggerated in both magnitude and duration during dynamic exercise in HF patients. Given that the exaggerated response was elicited in both the presence and absence of central command, it is clear that intact muscle mechanoreceptor sensitivity contributes to this augmented reflex renal vasoconstriction.
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Affiliation(s)
- H R Middlekauff
- Division of Cardiology, Department of Medicine, University of California, Los Angeles, California 90095, USA.
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Singh TP, Greer K, Muzik O, Hammond RL, Stephenson LW, Di Carli MF. Assessment of Skeletal Muscle Ventricle Tissue Blood Flow Using Positron Emission Tomography. Artif Organs 2001. [DOI: 10.1046/j.1525-1594.2001.025004306.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Singh TP, Greer K, Muzik O, Hammond RL, Stephenson LW, Di Carli MF. Assessment of Skeletal Muscle Ventricle Tissue Blood Flow Using Positron Emission Tomography. Artif Organs 2001. [DOI: 10.1046/j.1525-1594.2001.06673.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
| | | | | | | | | | - Marcelo F. Di Carli
- Department of Radiology,
- Department of Internal Medicine, Wayne State University School of Medicine; and the Positron Emission Tomography Center, Children's Hospital of Michigan, Detroit, Michigan, U.S.A
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Juillard L, Janier MF, Fouque D, Lionnet M, Le Bars D, Cinotti L, Barthez P, Gharib C, Laville M. Renal blood flow measurement by positron emission tomography using 15O-labeled water. Kidney Int 2000; 57:2511-8. [PMID: 10844620 DOI: 10.1046/j.1523-1755.2000.00110.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Only few noninvasive methods have the potential to quantitate renal blood flow (RBF) in humans. Positron emission tomography (PET) is a clinical imaging method that can be used to measure the tissue blood flow noninvasively. The purpose of this study was to validate PET measurement of RBF using 15O-labeled water (H215O), a tracer that allows repeated measurements at short time intervals. METHODS RBF was measured in six pigs by PET and by radioactive microspheres (MS). Three measurements were performed in each pig at baseline (BL), during vascular expansion and dopamine infusion (DA; 20 microg. kg-1. min-1 intravenously), and during angiotensin II (Ang II) infusion (50 ng. kg-1. min-1 intravenously). RBF was estimated from aortic and renal tracer kinetics using a model adapted from the blood flow model described by Kety and Smith. RESULTS PET and MS values correlated strongly (y = 0.79x + 42, r = 0.93, P < 0.0001) over the RBF range from 100 to 500 mL. min-1. 100 g-1. Pharmacologically induced changes were significant and were measured equally well by PET and MS: 38 and 39%, respectively, below BL (P < 0.005 and P < 0.05) under Ang II, and 47 and 48%, respectively, above BL (P < 0.005 and P < 0.01) under DA. A Bland and Altman representation showed a low average difference of -17 +/- 45 mL. min-1. 100 g-1 (mean +/- SD). CONCLUSION To our knowledge, this study provides the first validation of RBF measurement by PET using H215O over a large range of RBF values (100 to 500 mL. min-1. 100 g-1), which correspond to RBF values in both healthy subjects and in patients suffering from chronic renal failure.
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Affiliation(s)
- L Juillard
- Département de Néphrologie, Hôpital Edouard Herriot, Lyon, France.
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Middlekauff HR, Nitzsche EU, Hoh CK, Hamilton MA, Fonarow GC, Hage A, Moriguchi JD. Exaggerated renal vasoconstriction during exercise in heart failure patients. Circulation 2000; 101:784-9. [PMID: 10683353 DOI: 10.1161/01.cir.101.7.784] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND During static exercise in normal healthy humans, reflex renal cortical vasoconstriction occurs. Muscle metaboreceptors contribute importantly to this reflex renal vasoconstriction. In patients with heart failure, in whom renal vascular tone is already increased at rest, it is unknown whether there is further reflex renal vasoconstriction during exercise. METHODS AND RESULTS Thirty-nine heart failure patients (NYHA functional class III and IV) and 38 age-matched control subjects (controls) were studied. Renal blood flow was measured by dynamic positron emission tomography. Graded handgrip exercise and post-handgrip ischemic arrest were used to clarify the reflex mechanisms involved. During sustained handgrip (30% maximum voluntary contraction), peak renal vasoconstriction was significantly increased in heart failure patients compared with controls (70+/-13 versus 42+/-1 U, P=0.02). Renal vasoconstriction returned to baseline in normal humans by 2 to 5 minutes but remained significantly increased in heart failure patients at 2 to 5 minutes and had returned to baseline at 20 minutes. In contrast, during post-handgrip circulatory arrest, which isolates muscle metaboreceptors, peak renal vasoconstriction was not greater in heart failure patients than in normal controls. In fact, the increase in renal vasoconstriction was blunted in heart failure patients compared with controls (20+/-5 versus 30+/-2 U, P=0.05). CONCLUSIONS During sustained handgrip exercise in heart failure, both the magnitude and duration of reflex renal vasoconstriction are exaggerated in heart failure patients compared with normal healthy humans. The contribution of the muscle metaboreceptors to reflex renal vasoconstriction is blunted in heart failure patients compared with normal controls.
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Affiliation(s)
- H R Middlekauff
- Division of Cardiology, Department of Medicine, UCLA School of Medicine, Los Angeles, CA 90095, USA
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Abstract
The well-established role of the kidney in control of blood volume and ultimately arterial blood pressure has been underscored by the demonstration of alterations in renal hemodynamics and function recognized as responsible for these and other regulatory mechanisms. Nevertheless, the spatial complexity of intrarenal structure and function has made evident the need to study these separately in different regions of the intact kidney. Because of the introduction of x-rays, assessment of renal function has indeed been one of their attractive applications. However, despite the appeal of their noninvasiveness, several limitations confounded the different x-ray techniques used, most of which remained unresolved until the development of computed tomography. Furthermore, the development of fast imaging, which allows repetitive analysis of the same region of interest during the transit of contrast medium, holds a great potential to estimate intrarenal distribution of blood flow and the dynamic characteristics of tubular fluid flow in individual nephron segments. This latter assessment requires the administration of filterable x-ray contrast medium, which is cleared from the plasma almost exclusively by glomerular filtration, and the generation of contrast dilution curves. A historical review of the development and progress of the various x-ray techniques used will help understand the past and present of x-ray imaging, and will make it easier to envision the importance of their future roles in the study of renal physiology and pathophysiology.
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Affiliation(s)
- L O Lerman
- Department of Physiology and Biophysics, Mayo Clinic and Foundation, Rochester, Minnesota, USA
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Hoh CK, Seltzer MA, Franklin J, deKernion JB, Phelps ME, Belldegrun A. Positron emission tomography in urological oncology. J Urol 1998; 159:347-56. [PMID: 9649238 DOI: 10.1016/s0022-5347(01)63916-8] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE We provide scientists and clinicians with an introduction to the basic principles and methods of positron emission tomography (PET) and summarize the recent research and clinical applications of PET in the urological field. Specifically, we introduce PET so that the reader can understand and objectively review current and future articles that involve this imaging technology. MATERIALS AND METHODS The recent applications of PET in urology in the published literature were searched and reviewed. RESULTS In prostate carcinoma preliminary studies using radiotracer 18-fluoro-2-deoxyglucose (FDG) demonstrated that PET cannot reliably differentiate between primary prostate cancer and benign prostatic hyperplasia, and that PET is not as sensitive as bone scintigraphy for the detection of osseous metastases. However, PET may have a role in the detection of lymph node metastases in patients with prostate specific antigen relapse after primary local therapy. In renal cell carcinoma recent studies have shown the ability of FDG PET to detect primary and metastatic lesions and to monitor response to therapy. In the staging of testicular cancer FDG PET has been used to differentiate viable carcinoma from benign teratomas and/or fibrotic or necrotic changes. CONCLUSIONS Current developments in PET technology that accurately stage the extent of tumor before surgery as well as monitor effectiveness or ineffectiveness of new or current therapies may make PET a valuable tool in research and in the management of urological diseases.
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Affiliation(s)
- C K Hoh
- Department of Urology, UCLA School of Medicine, Los Angeles, California, USA
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Middlekauff HR, Nguyen AH, Negrao CE, Nitzsche EU, Hoh CK, Natterson BA, Hamilton MA, Fonarow GC, Hage A, Moriguchi JD. Impact of acute mental stress on sympathetic nerve activity and regional blood flow in advanced heart failure: implications for 'triggering' adverse cardiac events. Circulation 1997; 96:1835-42. [PMID: 9323069 DOI: 10.1161/01.cir.96.6.1835] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Evidence is accumulating that specific "triggers," such as intense psychological stress, may precipitate myocardial infarction and sudden death. Patients with advanced heart failure have increased resting sympathoexcitation, which has been directly related to increased mortality. The impact of triggers on sympathetic nerve activity and regional blood flow in heart failure has not been examined in patients with heart failure. METHODS AND RESULTS Twenty-seven patients with heart failure (NYHA functional class III or IV) and 26 age-matched normal control subjects were studied. Muscle sympathetic nerve activity, heart rate, mean arterial pressure, forearm blood flow, and renal blood flow were measured during mental stress testing with mental arithmetic and Stroop color word test. Patients with heart failure had elevated levels of resting muscle sympathetic nerve activity and heart rate. Mental stress significantly increased muscle sympathetic nerve activity and heart rate in both patients with heart failure and control subjects, although the magnitude of increases tended to be blunted in patients with heart failure. Nevertheless, absolute levels of sympathetic activity in patients with heart failure remained significantly higher than levels in control subjects during mental stress. The decrease in renal blood flow in patients with heart failure was similar to that of control subjects, despite greater resting renal vasoconstriction. The increase in forearm blood flow during mental stress testing in patients with heart failure was blunted compared with that of control subjects. CONCLUSIONS Patients with heart failure do not have augmented muscle sympathetic nerve activity responses to mental stress, despite elevated resting levels of sympathetic activity, but they do have markedly higher absolute levels of sympathetic nerve activity during mental stress as well as at rest.
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Affiliation(s)
- H R Middlekauff
- Department of Medicine, University of California, Los Angeles School of Medicine, 90095, USA
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Middlekauff HR, Nitzsche EU, Nguyen AH, Hoh CK, Gibbs GG. Modulation of renal cortical blood flow during static exercise in humans. Circ Res 1997; 80:62-8. [PMID: 8978323 DOI: 10.1161/01.res.80.1.62] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
During static exercise, several reflex systems that increase sympathetic nerve activity, heart rate, arterial pressure, and cardiac output are activated. At rest, the renal circulation receives the most blood flow per tissue weight of any organ in the body. However, the renal circulatory response to static exercise has not been studied in humans because of technical limitations in methods for measuring rapid changes in renal blood flow. The aim of this study was to determine the renal blood flow response to static exercise in healthy humans and, specifically, to clarify the reflex mechanisms underlying this response. Renal cortical blood flow was measured using dynamic positron emission tomography and the blood flow agent oxygen-15 water. Graded handgrip exercise, posthandgrip circulatory arrest, and administration of intra-arterial adenosine were performed to clarify the mechanisms controlling renal blood flow during static exercise. The major new findings in this study are that in healthy humans (1) renal cortical blood flow decreases (basal versus handgrip, 4.4 +/- 0.1 versus 3.5 +/- 0.1 mL.min-1.g-1; P = .008) and renal cortical vascular resistance increases (basal versus handgrip, 17 +/- 1 versus 26 +/- 2 U; P = .01) in response to static handgrip exercise; (2) central command and/or the mechanoreflex contributes importantly to the early decrease in renal blood flow (basal versus handgrip, 4.2 +/- 0.2 versus 3.5 +/- 0.3 mL.min-1.g-1; P = .04) and to the increase in renal cortical vascular resistance (basal versus handgrip, 20 +/- 1 versus 25 +/- 2 U; P = .04); (3) the muscle metaboreflex contributes to further decreases in renal blood flow (basal versus posthandgrip circulatory arrest, 4.3 +/- 0.1 versus 3.5 +/- 0.2 mL.min-1.g-1; P = .002) and increases in renal cortical vascular resistance (basal versus handgrip, 18 +/- 1 versus 25 +/- 3 U; P = .002); and (4) exogenous adenosine activates the muscle metaboreflex producing reflex renal vasoconstriction and decreased renal blood flow, which may implicate endogenous adenosine generated during ischemic exercise as a potential activator of the muscle metaboreflex during ischemic handgrip exercise.
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Young LS, Regan MC, Barry MK, Geraghty JG, Fitzpatrick JM. Methods of renal blood flow measurement. UROLOGICAL RESEARCH 1996; 24:149-60. [PMID: 8839482 DOI: 10.1007/bf00304078] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Variations in regional renal blood flow have been implicated in a variety of disease states. Many techniques have been developed in an attempt to accurately assess these changes. The microsphere technique is the most widely used method at the present time. This technique allows focal measurements to be performed, but there is a conflict between the resolution of the method and the number of microspheres necessary in each sample. New imaging techniques such as tomography and autoradiography enable visual assessment of renal blood flow. Though there is no ideal method, these techniques have opened up new possibilities in the quantification of regional renal blood flow.
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Affiliation(s)
- L S Young
- Surgical Professional Unit, Mater Misericordiae Hospital, Dublin, Ireland
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Lerman LO, Flickinger AL, Sheedy PF, Turner ST. Reproducibility of human kidney perfusion and volume determinations with electron beam computed tomography. Invest Radiol 1996; 31:204-10. [PMID: 8721959 DOI: 10.1097/00004424-199604000-00004] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
RATIONALE AND OBJECTIVES Alterations in whole kidney, cortical, and medullary perfusion and volume play a pivotal role in various physiologic and pathophysiologic processes. Electron-beam computed tomography (EBCT) provides accurate measurements of these traits in animals, but their reproducibility in humans has not been established. METHODS Perfusion, volume, and flow measurements were obtained by EBCT in eight healthy human volunteers under controlled conditions on two consecutive days. RESULTS Mean values for whole kidney, cortical, and medullary perfusion and volume obtained with EBCT were similar in scan 1 and scan 2 (P > 0.1), and correlated highly. Coefficients of variation for the repeated measurements usually were less than 10%. Values obtained for renal regional perfusion and volume agreed with previously reported values. CONCLUSIONS Electron-beam computed tomography estimates of single whole kidney, cortical, and medullary perfusions and volumes are highly reproducible in normal humans, and may be useful to advance understanding of renal involvement in human disease.
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Affiliation(s)
- L O Lerman
- Department of Physiology and Biophysics, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA
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Middlekauff HR, Nitzsche EU, Hamilton MA, Schelbert HR, Fonarow GC, Moriguchi JD, Hage A, Saleh S, Gibbs GG. Evidence for preserved cardiopulmonary baroreflex control of renal cortical blood flow in humans with advanced heart failure. A positron emission tomography study. Circulation 1995; 92:395-401. [PMID: 7634454 DOI: 10.1161/01.cir.92.3.395] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND The effect of cardiopulmonary baroreflexes on the renal circulation in healthy humans and patients with heart failure is unknown because of the technical limitations of studying the renal circulation. Positron emission tomography (PET) imaging is a new method to measure renal cortical blood flow in humans that is precise, rapid, reproducible, and noninvasive. The purpose of this study was to compare the effect of acute cardiopulmonary baroreceptor unloading by phlebotomy on regional blood flow in healthy humans and humans with advanced heart failure. METHODS AND RESULTS We compared renal cortical blood flow and forearm blood flow in 10 healthy volunteers and 8 patients with heart failure (left ventricular ejection fraction, 0.24 +/- 0.02) during cardiopulmonary baroreceptor unloading with phlebotomy (450 mL). The major findings of this study are: (1) At rest, renal cortical blood flow is markedly diminished in humans with heart failure compared with healthy humans (heart failure, 2.4 +/- 0.1 versus healthy, 4.3 +/- 0.2 mL.min-1.g-1, P < .001). (2) In healthy humans, during phlebotomy, forearm blood flow decreased substantially (basal, 3.3 +/- 0.4 versus phlebotomy, 2.6 +/- 0.3 mL.min-1.100 mL-1, P = .02) and renal cortical blood flow decreased slightly but significantly (basal, 4.3 +/- 0.2 versus phlebotomy, 4.0 +/- 0.3 mL.min-1.g-1, P = .01). (3) The small magnitude of reflex renal vasoconstriction is not explained by the inability of the renal circulation to vasoconstrict, since the cold pressor stimulus induced substantial decreases in renal cortical blood flow in healthy subjects (basal, 4.4 +/- 0.1 versus cold pressor, 3.7 +/- 0.1 mL.min-1.g-1, P = .003). (4) In humans with heart failure, during phlebotomy, forearm blood flow did not change (basal, 2.6 +/- 0.3 versus phlebotomy, 2.7 +/- 0.2 mL.min-1.100 mL-1, P = NS), but renal cortical blood flow decreased slightly but significantly (basal, 2.4 +/- 0.1 versus phlebotomy, 2.1 +/- 0.1 mL.min-1.g-1, P = .01). (5) The cold pressor stimulus induced substantial decreases in renal cortical blood flow in patients with heart failure (basal, 2.9 +/- 0.1 versus cold pressor, 2.3 +/- 0.1 mL.min-1.g-1, P = .008). Thus, in patients with heart failure, there is an abnormality in cardiopulmonary baroreflex control of the forearm circulation but not the renal circulation. CONCLUSIONS This study demonstrates the power of PET imaging to study normal physiological and pathophysiological reflex control of the renal circulation in humans and describes the novel finding of selective dysfunction of cardiopulmonary baroreflex control of one vascular region but its preservation in another in patients with heart failure.
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