Novel contrast agents for MR based on chemical exchange saturation transfer and its potential applications

This study aimed to investigate some small molecular compounds with an appropriate chemical exchange site that can be employed as negative contrast agents for magnetic resonance imaging. 17 kinds of small molecular substances were selected and the imaging were performed on 7.0T MR system. Except for biotin, a series of small molecular substances have the characteristics of CEST. Salicylic acid (9.3ppm), 5-aminosalicylic acid (8.0ppm), and olsalazinesodium (9.8ppm) have large frequency offset, with optimal pH value 6.4～6.8, which are ideal candidates for CEST contrast agents. Due to the differences of molecular structure, the CEST characteristics were different.