CEST MRI in the Management/Diagnosis of Neuroinfectious Diseases

Abstract

Chemical exchange saturation transfer (CEST) MRI is a novel technique that allows for the specific imaging of certain molecules that contain exchangeable protons. Neuroimaging is a major contributor to diagnosing and monitoring infections of the central nervous system (CNS). This review focuses on summarizing the current literature surrounding the use of CEST MRI imaging in diagnosing, monitoring, and treating CNS infections. BacCEST is a new technique to detect bacterial infection in organs at profound levels. This technique allows for the specific pathogen causing the infection to be understood, allowing for tailored antibiotic therapies. The bacCEST signal is also directly proportional to the number of bacterial cells; this means it can be used over periods to track response to treatment via cell numbers. The results show that most of the research in this area has focused on infections of the brain parenchyma (e.g., encephalitis) and that most studies investigate the use of CEST in animal models, with a minority exploring the application of CEST to human participants. The common neuroinfectious disease presentations relevant to clinical medicine are also briefly described, as well as the traditional and modern imaging techniques used to visualize them.

Keywords: CEST; MRI; infectious diseases; neuroimaging.

Figure 2

Glutamate chemical exchange saturation transfer (gluCEST) in patients. (A) Differential images comparing encephalitis and lacunar infarct. (B) Images showing encephalitis before and after immunoglobulin therapy [46] (Images obtained from an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)).

Figure 1

CEST mechanism. Radiofrequency is used to saturate an amine group present in a substance, which reduces the signal of that substance. As a result, a saturated hydrogen proton is transferred to water. The process then continues with a concurrent reduction in the water signal. Adapted from [1]. reated in BioRender. Bach, H. (2025) https://BioRender.com/h42n006.