Exploring the CEST Properties of Salicylic Acid: Implications for Enhanced MRI Sensitivity

Motivation: The unique properties of CEST agents provide innovative avenues for enhancing MRI sensitivity in soft tissue imaging. Goal(s): This study focuses on investigating CEST imaging characteristics of salicylic acid (SA), a primary metabolite of aspirin. Approach: We measured the proton exchange rate of SA and assessed its CEST contrast in vitro, and evaluated the impact of pH and saturation conditions. Results: Our findings revealed that SA exhibits a significant CEST effect at 9.3 ppm, the largest reported among organic diaCEST agents. The proton exchange rate of SA was highly pH-dependent, with increased contrast observed under optimal saturation conditions. Impact: These insights into SA as a low-toxicity probe highlight its potential to improve CEST methodologies, paving the way for further research on its pharmacokinetics and applications in MRI.