Daniel Coman1,2, Garry Kiefer3,
Douglas L. Rothman, 2,4, Dean A. Sherry5,6, Fahmeed
Hyder, 2,4
1Diagnostic Radiology, Yale University,
New Haven, CT, United States; 2Quantitative Neuroscience with
Magnetic Resonance (QNMR), Yale University, New Haven, CT, United States; 3Macrocyclics,
Dallas, TX, United States; 4Diagnostic Radiology and Biomedical
Engineering, Yale University, New Haven, CT, United States; 5Advanced
Imaging Research Center, University of Texas Southwestern Medical Center,
Dallas, TX, United States; 6Radiology and Chemistry, University of
Texas Southwestern Medical Center, Dallas, TX, United States
Biosensor Imaging of Redundant Deviation of
Shifts (BIRDS) represents another
alternative to CEST imaging, using resonances from paramagnetic
lanthanide-based contrast agents (CAs). Although spatial resolution is high,
CEST data are qualitative because the signal attenuation remains relative
unless the CA concentration, temperature and pH are known. A typical BIRDS
experiment uses high-speed CSI because of favorable relaxation times for CAs.
A europium-based CA, EuDOTA-(gly) 4-, exhibits enhanced
CEST characteristics while still retaining high sensitivity to temperature
variations specific to BIRDS. Here, we illustrate the principles of combining
CEST and BIRDS to obtain optimal temperature measurements with improved
spatial resolution.