TY - JOUR
T1 - Modulation of CEST images in vivo by T 1 relaxation
T2 - A new approach in the design of responsive PARACEST agents
AU - Ratnakar, S. James
AU - Soesbe, Todd C.
AU - Lumata, Lloyd Laporca
AU - Do, Quyen N.
AU - Viswanathan, Subha
AU - Lin, Chien Yuan
AU - Sherry, A. Dean
AU - Kovacs, Zoltan
PY - 2013/10/9
Y1 - 2013/10/9
N2 - A novel approach for the design of responsive paramagnetic chemical exchange saturation transfer (PARACEST) magnetic resonance imaging (MRI) agents has been developed where the signal is "turned on" by altering the longitudinal relaxation time (T1) of bulk water protons. To demonstrate this approach, a model Eu(DOTA-tetraamide) complex (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) containing two nitroxide free radical units was synthesized. The nitroxide groups substantially shortened the T1 of the bulk water protons which, in turn, resulted in quenching of the CEST signal. Reduction of paramagnetic nitroxide moieties to a diamagnetic species resulted in the appearance of CEST. The modulation of CEST by T1 relaxation provides a new platform for designing biologically responsive MRI agents.
AB - A novel approach for the design of responsive paramagnetic chemical exchange saturation transfer (PARACEST) magnetic resonance imaging (MRI) agents has been developed where the signal is "turned on" by altering the longitudinal relaxation time (T1) of bulk water protons. To demonstrate this approach, a model Eu(DOTA-tetraamide) complex (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) containing two nitroxide free radical units was synthesized. The nitroxide groups substantially shortened the T1 of the bulk water protons which, in turn, resulted in quenching of the CEST signal. Reduction of paramagnetic nitroxide moieties to a diamagnetic species resulted in the appearance of CEST. The modulation of CEST by T1 relaxation provides a new platform for designing biologically responsive MRI agents.
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U2 - 10.1021/ja406738y
DO - 10.1021/ja406738y
M3 - Article
C2 - 24050192
AN - SCOPUS:84885630508
SN - 0002-7863
VL - 135
SP - 14904
EP - 14907
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 40
ER -