scholarly journals Hyperpolarized Carbon (13C) MRI of the Kidneys: Basic Concept

2021 ◽  
pp. 267-278
Author(s):  
Cornelius von Morze ◽  
Galen D. Reed ◽  
Zhen J. Wang ◽  
Michael A. Ohliger ◽  
Christoffer Laustsen
Keyword(s):  
Renal Disease ◽  
Kidney Injury ◽  
Central Carbon Metabolism ◽  
General Concept ◽  
The European Union ◽  
Clinical Markers ◽  
Renal Metabolism ◽  
Kidney Structure ◽  
Renal Mri ◽  
And Function

AbstractExisting clinical markers for renal disease are limited. Hyperpolarized (HP) 13C MRI is based on the technology of dissolution dynamic nuclear polarization (DNP) and provides new avenues for imaging kidney structure, function, and most notably, renal metabolism, addressing some of these prior limitations. Changes in kidney structure and function associated with kidney disease can be evaluated using [13C]urea, a metabolically inert tracer. Metabolic changes can be assessed using [1-13C]pyruvate and a range of other rapidly metabolized small molecules, which mainly probe central carbon metabolism. Results from numerous preclinical studies using a variety of these probes demonstrated that this approach holds great potential for monitoring renal disease, although more work is needed to bridge intelligently into clinical studies. Here we introduce the general concept of HP 13C MRI and review the most relevant probes and applications to renal disease, including kidney cancer, diabetic nephropathy and ischemic kidney injury.This chapter is based upon work from the PARENCHIMA COST Action, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.

scholarly journals Hyperpolarized Carbon (13C) MRI of the Kidney: Experimental Protocol

2021 ◽  
pp. 481-493
Author(s):  
Christoffer Laustsen ◽  
Cornelius von Morze ◽  
Galen D. Reed
Keyword(s):  
Medical Imaging ◽  
Imaging Modality ◽  
The European Union ◽  
Experimental Protocol ◽  
Renal Metabolism ◽  
Experimental Protocols ◽  
Renal Mri ◽  
And Function ◽  
The Cost

AbstractAlterations in renal metabolism are associated with both physiological and pathophysiologic events. The existing noninvasive analytic tools including medical imaging have limited capability for investigating these processes, which potentially limits current understanding of kidney disease and the precision of its clinical diagnosis. Hyperpolarized 13C MRI is a new medical imaging modality that can capture changes in the metabolic processing of certain rapidly metabolized substrates, as well as changes in kidney function. Here we describe experimental protocols for renal metabolic [1-13C]pyruvate and functional 13C-urea imaging step-by-step. These methods and protocols are useful for investigating renal blood flow and function as well as the renal metabolic status of rodents in vivo under various experimental (patho)physiological conditions.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This experimental protocol is complemented by two separate chapters describing the basic concept and data analysis.

scholarly journals Quantitative Assessment of Renal Perfusion and Oxygenation by Invasive Probes: Basic Concepts

2021 ◽  
pp. 89-107
Author(s):  
Kathleen Cantow ◽  
Roger G. Evans ◽  
Dirk Grosenick ◽  
Thomas Gladytz ◽  
Thoralf Niendorf ◽  
...  
Keyword(s):  
Kidney Injury ◽  
Tissue Perfusion ◽  
Renal Perfusion ◽  
Renal Tissue ◽  
Acute Injury ◽  
The European Union ◽  
Advantages And Disadvantages ◽  
Tissue Hypoperfusion ◽  
Renal Mri ◽  
The Cost

AbstractRenal tissue hypoperfusion and hypoxia are early key elements in the pathophysiology of acute kidney injury of various origins, and may also promote progression from acute injury to chronic kidney disease. Here we describe basic principles of methodology to quantify renal hemodynamics and tissue oxygenation by means of invasive probes in experimental animals. Advantages and disadvantages of the various methods are discussed in the context of the heterogeneity of renal tissue perfusion and oxygenation.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by a separate chapter describing the experimental procedure and data analysis.

scholarly journals Ultrasound and Photoacoustic Imaging of the Kidney: Basic Concepts and Protocols

2021 ◽  
pp. 109-130
Author(s):  
Sandra Meyer ◽  
Dieter Fuchs ◽  
Martin Meier
Keyword(s):  
Photoacoustic Imaging ◽  
Renal Ultrasound ◽  
The European Union ◽  
Additional Information ◽  
Long Time ◽  
Molecular Information ◽  
Basic Concepts ◽  
Renal Mri ◽  
And Function ◽  
The Cost

AbstractNoninvasive, robust, and reproducible methods to image kidneys are provided by different imaging modalities. A combination of modalities (multimodality) can give better insight into structure and function and to understand the physiology of the kidney. Magnetic resonance imaging can be complemented by a multimodal imaging approach to obtain additional information or include interventional procedures. In the clinic, renal ultrasound has been essential for the diagnosis and management of kidney disease and for the guidance of invasive procedures for a long time. Adapting ultrasound to preclinical requirements and for translational research, the combination with photoacoustic imaging expands the capabilities to obtain anatomical, functional, and molecular information from animal models. This chapter describes the basic concepts of how to image kidneys using different and most appropriate modalities.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.

scholarly journals Reversible (Patho)Physiologically Relevant Test Interventions: Rationale and Examples

2021 ◽  
pp. 57-73
Author(s):  
Kathleen Cantow ◽  
Mechthild Ladwig-Wiegard ◽  
Bert Flemming ◽  
Andrea Fekete ◽  
Adam Hosszu ◽  
...  
Keyword(s):  
Kidney Injury ◽  
Renal Tissue ◽  
Renal Hemodynamics ◽  
Acute Injury ◽  
The European Union ◽  
Tissue Hypoperfusion ◽  
Renal Mri ◽  
The Individual ◽  
The Cost ◽  
Specific Control

AbstractRenal tissue hypoperfusion and hypoxia are early key elements in the pathophysiology of acute kidney injury of various origins, and may also promote progression from acute injury to chronic kidney disease. Here we describe test interventions that are used to study the control of renal hemodynamics and oxygenation in experimental animals in the context of kidney-specific control of hemodynamics and oxygenation. The rationale behind the use of the individual tests, the physiological responses of renal hemodynamics and oxygenation, the use in preclinical studies, and the possible application in humans are discussed.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers.

scholarly journals Experimental Protocol for MRI Mapping of the Blood Oxygenation-Sensitive Parameters T2* and T2 in the Kidney

2021 ◽  
pp. 403-417
Author(s):  
Andreas Pohlmann ◽  
Kaixuan Zhao ◽  
Sean B. Fain ◽  
Pottumarthi V. Prasad ◽  
Thoralf Niendorf
Keyword(s):  
Kidney Injury ◽  
Absolute Quantification ◽  
Blood Oxygenation ◽  
The European Union ◽  
Experimental Protocol ◽  
Contrast Mechanism ◽  
Oxygenation Level ◽  
Fraction Of Inspired Oxygen ◽  
Renal Mri

AbstractRenal hypoxia is generally accepted as a key pathophysiologic event in acute kidney injury of various origins, and has also been suggested to play a role in the development of chronic kidney disease. Here we describe a step-by-step experimental protocol for indirect monitoring of renal blood oxygenation in rodents via the deoxyhemoglobin sensitive MR parameters T2* and T2—a contrast mechanism known as the blood oxygenation level dependent (BOLD) effect. Since an absolute quantification of renal oxygenation from T2*/T2 remains challenging, the effects of controlled and standardized variations in the fraction of inspired oxygen are used for bench marking. This MRI method may be useful for investigating renal blood oxygenation of small rodents in vivo under various experimental (patho)physiological conditions.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This experimental protocol chapter is complemented by two separate chapters describing the basic concept and data analysis.

scholarly journals Essential Practical Steps for MRI of the Kidney in Experimental Research

2021 ◽  
pp. 349-367
Author(s):  
Andreas Pohlmann ◽  
João S. Periquito ◽  
Thoralf Niendorf
Keyword(s):  
Structural Information ◽  
Imaging Techniques ◽  
The European Union ◽  
European Cooperation ◽  
Slice Orientation ◽  
Magnetic Resonance Imaging Mri ◽  
Preclinical Mri ◽  
Renal Mri ◽  
And Function ◽  
The Cost

AbstractMagnetic resonance imaging (MRI) is an emerging method to obtain valuable functional and structural information about the kidney noninvasively. Before performing specialized MR measurements for probing tissue structure and function, some essential practical steps are needed, which are common for most applications. Here we describe in a step-by-step manner how to (1) achieve the double-oblique slice orientation coronal-to-the-kidney, (2) adapt the scan protocol for avoiding aortic flow artifacts and covering both kidneys, (3) perform localized shimming on the kidney, and (4) check perfusion in the large renal blood vessels using time-of-flight (TOF) angiography. The procedures are tailored to preclinical MRI but conceptionally are also applicable to human MRI.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This experimental protocol chapter explains the initial and essential MRI steps that precede specific functional and structural MR imaging techniques (T1- and T2*-mapping, DWI, ASL, etc.), which are described in separate chapters.

scholarly journals Effects of acid aspiration-induced acute lung injury on kidney function

2008 ◽  
Vol 294 (4) ◽  
pp. F900-F908 ◽  
Author(s):  
Jeffrey B. Hoag ◽  
Manchang Liu ◽  
R. Blaine Easley ◽  
Martin F. Britos-Bray ◽  
Priya Kesari ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Animal Models ◽  
Lung Injury ◽  
Small Animal ◽  
Kidney Injury ◽  
Structure And Function ◽  
Acid Aspiration ◽  
Kidney Structure ◽  
Small Animal Models ◽  
And Function

Acute lung injury (ALI) in combination with acute kidney injury carries a mortality approaching 80% in the intensive care unit. Recently, attention has focused on the interaction of the lung and kidney in the setting of ALI and mechanical ventilation (MV). Small animal models of ALI and MV have demonstrated changes in inflammatory mediators, water channels, apoptosis, and function in the kidney early in the course of injury. The purpose of this investigation was to test the hypothesis that ALI and injurious MV cause early, measurable changes in kidney structure and function in a canine HCl aspiration model of ALI when hemodynamics and arterial blood gas tensions are carefully controlled. Intratracheal HCl induced profound ALI as demonstrated by increased shunt fraction and airway pressures compared with sham injury. Sham-injured animals had similar mean arterial pressure and arterial Pco2 and HCO3 levels compared with injured animals. Measurements of renal function including renal blood flow, urine flow, serum creatinine, glomerular filtration rate, urine albumin-to-creatinine ratio, and kidney histology scores were not different between groups. With maintenance of hemodynamic parameters and alveolar ventilation, ALI and injurious MV do not alter kidney structure and function early in the course of injury in this acid aspiration canine model. Kidney injury in large animal models may be more similar to humans and may differ from results seen in small animal models.

scholarly journals Monitoring Renal Hemodynamics and Oxygenation by Invasive Probes: Experimental Protocol

2021 ◽  
pp. 327-347
Author(s):  
Kathleen Cantow ◽  
Mechthild Ladwig-Wiegard ◽  
Bert Flemming ◽  
Andreas Pohlmann ◽  
Thoralf Niendorf ◽  
...  
Keyword(s):  
Small Animal ◽  
Kidney Injury ◽  
Renal Perfusion ◽  
Renal Tissue ◽  
Renal Hemodynamics ◽  
Acute Injury ◽  
The European Union ◽  
Experimental Protocol ◽  
Integrative Physiology ◽  
Renal Mri

AbstractRenal tissue hypoperfusion and hypoxia are early key elements in the pathophysiology of acute kidney injury of various origins, and may also promote progression from acute injury to chronic kidney disease. Here we describe methods to study control of renal hemodynamics and tissue oxygenation by means of invasive probes in anesthetized rats. Step-by-step protocols are provided for two setups, one for experiments in laboratories for integrative physiology and the other for experiments within small-animal magnetic resonance scanners.This publication is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This experimental protocol chapter is complemented by a separate chapter describing the basic concepts of quantitatively assessing renal perfusion and oxygenation with invasive probes.

scholarly journals Analysis Protocols for MRI Mapping of the Blood Oxygenation–Sensitive Parameters T2* and T2 in the Kidney

2021 ◽  
pp. 591-610
Author(s):  
João S. Periquito ◽  
Ludger Starke ◽  
Carlota M. Santos ◽  
Andreia C. Freitas ◽  
Nuno Loução ◽  
...  
Keyword(s):  
Data Analysis ◽  
Model Fitting ◽  
Kidney Injury ◽  
Blood Oxygenation ◽  
The European Union ◽  
Contrast Mechanism ◽  
Oxygenation Level ◽  
Quality Checks ◽  
Renal Mri ◽  
Sensitive Parameters

AbstractRenal hypoxia is generally accepted as a key pathophysiologic event in acute kidney injury of various origins and has also been suggested to play a role in the development of chronic kidney disease. Here we describe step-by-step data analysis protocols for MRI monitoring of renal oxygenation in rodents via the deoxyhemoglobin concentration sensitive MR parameters T2* and T2—a contrast mechanism known as the blood oxygenation level dependent (BOLD) effect.This chapter describes how to use the analysis tools provided by vendors of animal and clinical MR systems, as well as how to develop an analysis software. Aspects covered are: data quality checks, data exclusion, model fitting, fitting algorithm, starting values, effects of multiecho imaging, and result validation.This chapter is based upon work from the PARENCHIMA COST Action, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This experimental protocol chapter is complemented by two separate chapters describing the basic concept and data analysis.

scholarly journals Analysis Methods for Hyperpolarized Carbon (13C) MRI of the Kidney

2021 ◽  
pp. 697-710
Author(s):  
Galen D. Reed ◽  
Natalie J. Korn ◽  
Christoffer Laustsen ◽  
Cornelius von Morze
Keyword(s):  
Imaging Modality ◽  
Functional Information ◽  
The European Union ◽  
Experimental Procedure ◽  
European Cooperation ◽  
Renal Mri ◽  
And Function ◽  
The Cost ◽  
Analysis Protocol

AbstractHyperpolarized 13C MR is a novel medical imaging modality with substantially different signal dynamics as compared to conventional 1H MR, thus requiring new methods for processing the data in order to access and quantify the embedded metabolic and functional information. Here we describe step-by-step analysis protocols for functional renal hyperpolarized 13C imaging. These methods are useful for investigating renal blood flow and function as well as metabolic status of rodents in vivo under various experimental physiological conditions.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This analysis protocol chapter is complemented by two separate chapters describing the basic concept and experimental procedure.

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