Open AccessA comparison of iopromide and iopamidol, two acidoCEST MRI contrast media that measure tumor extracellular pH
Author(s) -
Moon Brianna F.,
Jones Kyle M.,
Chen Liu Qi,
Liu Peilu,
Randtke Edward A.,
Howison Christine M.,
Pagel Mark D.
Publication year - 2015
Publication title -
contrast media & molecular imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.714
H-Index - 50
eISSN - 1555-4317
pISSN - 1555-4309
DOI - 10.1002/cmmi.1647
Subject(s) - iopromide , iopamidol , chemistry , in vivo , extracellular fluid , iodinated contrast , nuclear medicine , extracellular , medicine , radiology , contrast medium , computed tomography , biochemistry , microbiology and biotechnology , biology
Acidosis within tumor and kidney tissues has previously been quantitatively measured using a molecular imaging technique known as acidoCEST MRI. The previous studies used iopromide and iopamidol, two iodinated contrast agents that are approved for clinical CT diagnoses and have been repurposed for acidoCEST MRI studies. We aimed to compare the performance of the two agents for measuring pH by optimizing image acquisition conditions, correlating pH with a ratio of CEST effects from an agent, and evaluating the effects of concentration, endogenous T 1 relaxation time and temperature on the pH–CEST ratio correlation for each agent. These results showed that the two agents had similar performance characteristics, although iopromide produced a pH measurement with a higher dynamic range while iopamidol produced a more precise pH measurement. We then compared the performance of the two agents to measure in vivo extracellular pH (pHe) within xenograft tumor models of Raji lymphoma and MCF‐7 breast cancer. Our results showed that the pHe values measured with each agent were not significantly different. Also, iopromide consistently measured a greater region of the tumor relative to iopamidol in both tumor models. Therefore, an iodinated contrast agent for acidoCEST MRI should be selected based on the measurement properties needed for a specific biomedical study and the pharmacokinetic properties of a specific tumor model. Copyright © 2015 John Wiley & Sons, Ltd.