Work

Absolute Temperature Mapping Using Chiral Terbium Parashift Complexes for MRI Thermometry

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide A noninvasive imaging approach for absolute temperature mapping has been demonstrated using Parashift molecular imaging probes for MRI. Temperature readout is achieved by exploiting the chemical shift difference between the CH 2 SAP and CH 3 TSAP resonances of two nonexchanging (SAP and TSAP) isomers of a single chiral lanthanide complex, without the need for external calibration. Variable-temperature NMR analyses of [LnL] − complexes─derived from S -tetraethyl cyclen─identified the CH 2 SAP and CH 3 TSAP resonances as optimal reporters for Parashift spectral imaging, owing to their large hyperfine shifts and narrow spectral line widths. Temperature coefficients as high as 0.46 ppm K –1 were observed for individual resonances of the square antiprismatic (SAP) isomer of [DyL] −, while normalized coefficients (temperature shift per unit line width) reached 1.7 K –1 for [TmL] − . Among the complexes studied, [TbL] − emerged as the most suitable for temperature imaging, considering the overall temperature sensitivity of the chemical shift difference. In phantom imaging experiments at 9.4 T (preclinical field) temperature variations across phantom tubes were successfully mapped with a resolution of 0.1 K.

Source: Chemical & Biomedical Imaging

DOI: 10.1021/cbmi.5c00144

Authors: Carlson Alexander, Huishan Li, Peter Harvey, Galina E. Pavlovskaya, Nicola J. Rogers, David Parker