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 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 MRI Mapping of the Blood Oxygenation Sensitive Parameter T2* in the Kidney: Basic Concept

2021 ◽  
pp. 171-185
Author(s):  
Lu-Ping Li ◽  
Bradley Hack ◽  
Erdmann Seeliger ◽  
Pottumarthi V. Prasad
Keyword(s):  
Data Acquisition ◽  
Blood Oxygenation ◽  
The European Union ◽  
Noninvasive Method ◽  
Bold Mri ◽  
Oxygenation Level ◽  
Technical Issues ◽  
Renal Mri ◽  
The Cost

AbstractThe role of hypoxia in renal disease and injury has long been suggested but much work still remains, especially as it relates to human translation. Invasive pO2 probes are feasible in animal models but not for human use. In addition, they only provide localized measurements. Histological methods can identify hypoxic tissue and provide a spatial distribution, but are invasive and allow only one-time point. Blood oxygenation level dependent (BOLD) MRI is a noninvasive method that can monitor relative oxygen availability across the kidney. It is based on the inherent differences in magnetic properties of oxygenated vs. deoxygenated hemoglobin. Presence of deoxyhemoglobin enhances the spin–spin relaxation rate measured using a gradient echo sequence, known as R2* (= 1/T2*). While the key interest of BOLD MRI is in the application to humans, use in preclinical models is necessary primarily to validate the measurement against invasive methods, to better understand physiology and pathophysiology, and to evaluate novel interventions. Application of MRI acquisitions in preclinical settings involves several challenges both in terms of logistics and data acquisition. This section will introduce the concept of BOLD MRI and provide some illustrative applications. The following sections will discuss the technical issues associated with data acquisition and analysis.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 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 Dynamic Contrast Enhanced (DCE) MRI-Derived Renal Perfusion and Filtration: Experimental Protocol

2021 ◽  
pp. 429-441
Author(s):  
Pietro Irrera ◽  
Lorena Consolino ◽  
Walter Dastrù ◽  
Michael Pedersen ◽  
Frank G. Zöllner ◽  
...  
Keyword(s):  
Renal Perfusion ◽  
The European Union ◽  
Experimental Protocol ◽  
Small Molecular Weight ◽  
Dce Mri ◽  
Dynamic Contrast Enhanced ◽  
Contrast Enhanced ◽  
Renal Mri ◽  
The Cost

AbstractDynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can provide a noninvasive way for assessing renal functional information following the administration of a small molecular weight gadolinium-based contrast agent. This method may be useful for investigating renal perfusion and glomerular filtration rates of rodents in vivo under various experimental (patho)physiological conditions. Here we describe a step-by-step protocol for DCE-MRI studies in small animals providing practical notes on acquisition parameters, sequences, T1 mapping approaches and procedures.This chapters 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 Sodium (23Na) MRI of the Kidney: Experimental Protocol

2021 ◽  
pp. 473-480
Author(s):  
James T. Grist ◽  
Esben Søvsø Hansen ◽  
Frank G. Zöllner ◽  
Christoffer Laustsen
Keyword(s):  
Kidney Injury ◽  
The European Union ◽  
Experimental Protocol ◽  
European Cooperation ◽  
Sodium Gradient ◽  
Renal Mri ◽  
The Individual ◽  
Sodium Handling ◽  
23Na Mri ◽  
Protocol Review

AbstractSodium handling is a key physiological hallmark of renal function. Alterations are generally considered a pathophysiologic event associated with kidney injury, with disturbances in the corticomedullary sodium gradient being indicative of a number of conditions. This experimental protocol review describes the individual steps needed to perform 23Na MRI; allowing accurate monitoring of the renal sodium distribution in a step-by-step experimental protocol for rodents.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 Fluorine (19F) MRI for Assessing Inflammatory Cells in the Kidney: Experimental Protocol

2021 ◽  
pp. 495-507
Author(s):  
Min-Chi Ku ◽  
Adrian Schreiber ◽  
Paula Ramos Delgado ◽  
Philipp Boehm-Sturm ◽  
Ralph Kettritz ◽  
...  
Keyword(s):  
Inflammatory Cells ◽  
Antineutrophil Cytoplasmic Antibody ◽  
The European Union ◽  
Experimental Protocol ◽  
Noninvasive Technique ◽  
Renal Inflammation ◽  
Progression Of Kidney Disease ◽  
Life Threatening ◽  
Renal Mri

AbstractInflammation is one underlying contributing factor in the pathology of acute and chronic kidney disorders. Phagocytes such as monocytes, neutrophils and dendritic cells are considered to play a deleterious role in the progression of kidney disease but may also contribute to organ homeostasis. The kidney is a target of life-threatening autoimmune disorders such as the antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV). Neutrophils and monocytes express ANCA antigens and play an important role in the pathogenesis of AAV. Noninvasive in vivo methods that can quantify the distribution of inflammatory cells in the kidney as well as other organs in vivo would be vital to identify the causality and significance of inflammation during disease progression. Here we describe an noninvasive technique to study renal inflammation in rodents in vivo using fluorine (19F) MRI. In this protocol we chose a murine ANCA-AAV model of renal inflammation and made use of nanoparticles prepared from perfluoro-5-crown-15-ether (PFCE) for renal 19F 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 is complemented by two separate chapters describing the basic concept and data analysis.

scholarly journals Fluorine (19F) MRI to Measure Renal Oxygen Tension and Blood Volume: Experimental Protocol

2021 ◽  
pp. 509-518
Author(s):  
Lingzhi Hu ◽  
Hua Pan ◽  
Samuel A. Wickline
Keyword(s):  
Blood Volume ◽  
Spectral Signature ◽  
High Signal ◽  
The European Union ◽  
Experimental Protocol ◽  
Fluorine Nucleus ◽  
Imaging And Spectroscopy ◽  
Renal Mri ◽  
Kidney Imaging

AbstractFluorinated compounds feature favorable toxicity profile and can be used as a contrast agent for magnetic resonance imaging and spectroscopy. Fluorine nucleus from fluorinated compounds exhibit well-known advantages of being a high signal nucleus with a natural abundance of its stable isotope, a convenient gyromagnetic ratio close to that of protons, and a unique spectral signature with no detectable background at clinical field strengths. Perfluorocarbon core nanoparticles (PFC NP) are a class of clinically approved emulsion agents recently applied in vivo for ligand-targeted molecular imaging. The objective of this chapter is to outline a multinuclear 1H/19F MRI protocol for functional kidney imaging in rodents for mapping of renal blood volume and oxygenation (pO2) in renal disease models.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 a separate chapter describing the basic concept of functional imaging using fluorine (19F) MR methods.

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 Renal pH Mapping Using Chemical Exchange Saturation Transfer (CEST) MRI: Experimental Protocol

2021 ◽  
pp. 455-471
Author(s):  
Kowsalya Devi Pavuluri ◽  
Lorena Consolino ◽  
Dario Livio Longo ◽  
Pietro Irrera ◽  
Phillip Zhe Sun ◽  
...  
Keyword(s):  
Chemical Exchange ◽  
Kidney Diseases ◽  
Environmental Variable ◽  
Chemical Exchange Saturation Transfer ◽  
The European Union ◽  
Saturation Transfer ◽  
Experimental Protocol ◽  
Cest Mri ◽  
Renal Mri

AbstractChemical exchange saturation transfer (CEST) is recognized as one of the premier methods for measuring pH with this environmental variable expected to be an excellent biomarker for kidney diseases. Here we describe step-by-step CEST MRI experimental protocols for producing pH and perfusion maps for monitoring kidney pH homeostasis in rodents after administering iopamidol as contrast agent. Several CEST techniques, acquisition protocols and ratiometric approaches are described. The impact of length of acquisition time on the quality of the maps is detailed. These methods may be useful for investigating progression in kidney disease in vivo for rodent models.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 concepts 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.

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