Renal pH Imaging Using Chemical Exchange Saturation Transfer (CEST) MRI: Basic Concept

AbstractMagnetic Resonance Imaging (MRI) has been actively explored in the last several decades for assessing renal function by providing several physiological information, including glomerular filtration rate, renal plasma flow, tissue oxygenation and water diffusion. Within MRI, the developing field of chemical exchange saturation transfer (CEST) has potential to provide further functional information for diagnosing kidney diseases. Both endogenous produced molecules as well as exogenously administered CEST agents have been exploited for providing functional information related to kidney diseases in preclinical studies. In particular, CEST MRI has been exploited for assessing the acid-base homeostasis in the kidney and for monitoring pH changes in several disease models. This review summarizes several CEST MRI procedures for assessing kidney functionality and pH, for monitoring renal pH changes in different kidney injury models and for evaluating renal allograft rejection.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.

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Analysis Protocol for the Quantification of Renal pH Using Chemical Exchange Saturation Transfer (CEST) MRI

Methods in Molecular Biology - Preclinical MRI of the Kidney ◽

10.1007/978-1-0716-0978-1_40 ◽

2021 ◽

pp. 667-688

Author(s):

Hahnsung Kim ◽

Yin Wu ◽

Daisy Villano ◽

Dario Livio Longo ◽

Michael T. McMahon ◽

...

Keyword(s):

Chemical Exchange ◽

Kidney Injury ◽

Chemical Exchange Saturation Transfer ◽

Saturation Transfer ◽

Ph Imaging ◽

Iodinated Contrast ◽

Cest Mri ◽

Renal Mri ◽

Analysis Protocol

AbstractThe kidney plays a major role in maintaining body pH homeostasis. Renal pH, in particular, changes immediately following injuries such as intoxication and ischemia, making pH an early biomarker for kidney injury before the symptom onset and complementary to well-established laboratory tests. Because of this, it is imperative to develop minimally invasive renal pH imaging exams and test pH as a new diagnostic biomarker in animal models of kidney injury before clinical translation. Briefly, iodinated contrast agents approved by the US Food and Drug Administration (FDA) for computed tomography (CT) have demonstrated promise as novel chemical exchange saturation transfer (CEST) MRI agents for pH-sensitive imaging. The generalized ratiometric iopamidol CEST MRI analysis enables concentration-independent pH measurement, which simplifies in vivo renal pH mapping. This chapter describes quantitative CEST MRI analysis for preclinical renal pH mapping, and their application in rodents, including normal conditions and acute kidney injury.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 analysis protocol chapter is complemented by two separate chapters describing the basic concepts and experimental procedure.

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

Methods in Molecular Biology - Preclinical MRI of the Kidney ◽

10.1007/978-1-0716-0978-1_27 ◽

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.

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