Non-invasive molecular imaging of kidney diseases

• Published in: Nature reviews. Nephrology 2021-10, Vol.17 (10), p.688-703
• Main Authors: Klinkhammer, Barbara M., Lammers, Twan, Mottaghy, Felix M., Kiessling, Fabian, Floege, Jürgen, Boor, Peter
• Format: Article
• Language: English
• Subjects: 631/1647/245/2160; 692/4022/1585/1588/1351; 692/4022/1585/3182; 692/700/1421/2160; Care and treatment; Diagnosis; Humans; Kidney cancer; Kidney diseases; Kidney Diseases - diagnostic imaging; Kidney stones; Kidneys; Medical imaging; Medicine; Medicine & Public Health; Methods; Molecular diagnostic techniques; Molecular Imaging - methods; Nephrology; Review Article
• ISSN: 1759-5061; 1759-507X; 1759-507X
• DOI: 10.1038/s41581-021-00440-4

In nephrology, differential diagnosis or assessment of disease activity largely relies on the analysis of glomerular filtration rate, urinary sediment, proteinuria and tissue obtained through invasive kidney biopsies. However, currently available non-invasive functional parameters, and most serum and urine biomarkers, cannot capture intrarenal molecular disease processes specifically. Moreover, although histopathological analyses of kidney biopsy samples enable the visualization of pathological morphological and molecular alterations, they only provide information about a small part of the kidney and do not allow longitudinal monitoring. These limitations not only hinder understanding of the dynamics of specific disease processes in the kidney, but also limit the targeting of treatments to active phases of disease and the development of novel targeted therapies. Molecular imaging enables non-invasive and quantitative assessment of physiological or pathological processes by combining imaging technologies with specific molecular probes. Here, we discuss current preclinical and clinical molecular imaging approaches in nephrology. Non-invasive visualization of the kidneys through molecular imaging can be used to detect and longitudinally monitor disease activity and can therefore provide companion diagnostics to guide clinical trials, as well as the safe and effective use of drugs. In vivo non-invasive molecular imaging techniques have potential to improve clinical research and practices in nephrology. Here, the authors discuss the benefits and challenges of preclinical and clinical applications of molecular imaging to acute kidney injury and chronic kidney disease, transplantation and kidney cancer. Key points Today, nephrology relies on the analysis of glomerular filtration rate, urinary sediment, proteinuria and invasive kidney biopsies to assess disease activity; molecular imaging is a more specific non-invasive approach that visualizes pathological processes within the kidneys with high accuracy. 18 F-fluorodeoxyglucose–PET is currently the most commonly used approach of molecular kidney imaging, although it does not reflect a specific disease or pathway. Most clinical trials of molecular kidney imaging are performed in patients with renal cell carcinomas and promising targets include carbonic anhydrase 9 and prostate-specific membrane antigen. Molecular imaging of the kidneys is challenging because it is a major elimination organ and non-specific probe u