Abstract #4291

Making the Transfer: Exploiting Hyperpolarized Bicarbonate-CO2 Exchange for Increased Signal-to-Noise pH Imaging

David E Korenchan¹, Jeremy W Gordon¹, Sukumar Subramaniam¹, Renuka Sriram¹, Peder E Z Larson^1,2, Dan B Vigneron^1,2, Robert R Flavell¹, and John Kurhanewicz^1,2

¹Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, ²Bioengineering, University of California, Berkeley and University of California, San Francisco, San Francisco, CA, United States

Hyperpolarized (HP) [¹³C]bicarbonate MR imaging can map pH in vivo, but images generally suffer from low CO₂ signal-to-noise ratio (SNR). However, rapid bicarbonate-CO₂ chemical exchange can increase CO₂ SNR via exchange-mediated polarization transfer. We exploit this phenomenon for HP [¹³C]bicarbonate imaging to boost CO₂ SNR by 2.2-fold at pH 7.6, where CO₂ SNR is lowest in the physiologic range, by acquiring and summing multiple transients. Tip angles and delays are chosen using a priori knowledge of exchange rate to increase SNR while mitigating pH error. This approach can potentially improve imaging SNR in vivo for studying extracellular acidosis in cancer.

How to access this content:

For one year after publication, abstracts and videos are only open to registrants of this annual meeting. Registrants should use their existing login information. Non-registrant access can be purchased via the ISMRM E-Library.

After one year, current ISMRM & ISMRT members get free access to both the abstracts and videos. Non-members and non-registrants must purchase access via the ISMRM E-Library.

After two years, the meeting proceedings (abstracts) are opened to the public and require no login information. Videos remain behind password for access by members, registrants and E-Library customers.

Click here for more information on becoming a member.