Advances in molecular imaging of kidney diseases.

Background Diagnosing and monitoring kidney diseases traditionally rely on blood and urine analyses and invasive procedures such as kidney biopsies, the latter offering limited possibilities for longitudinal monitoring and a comprehensive understanding of disease dynamics. Current non-invasive methods lack specificity in capturing intrarenal molecular processes, hindering patient stratification and patient monitoring in clinical practice and clinical trials. Summary Molecular imaging enables non-invasive and quantitative assessment of physiological and pathological molecular processes. By using specific molecular probes and imaging technologies, e.g., magnetic resonance imaging (MRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT), or ultrasound (US), molecular imaging allows the detection and longitudinal monitoring of disease activity with spatial and temporal resolution of different kidney diseases and disease-specific pathways. Several approaches have already shown promising results in kidneys and exploratory clinical studies, and validation is needed before implementation in clinical practice. Key messages Molecular imaging offers a non-invasive assessment of intrarenal molecular processes, overcoming the limitations of current diagnostic methods. It has the potential to serve as companion diagnostics, not only in clinical trials, aiding in patient stratification and treatment response assessment. By guiding therapeutic interventions, molecular imaging might contribute to the development of targeted therapies for kidney diseases.