Natalia Ziółkowska1,2, Ladislav Androvič3, Lucie Woldřichová3, Martin Vít1,4, David Červený1,5, Olga Šebestová Janoušková3, Richard Laga3, and Daniel Jirák1,2
1Site of Computed Tomography, Magnetic Resonance Imaging, and Clinical and Experimental Spectroscopy, Institute for Clinical and Experimental Medicine, Prague, Czech Republic, 2Institute of Biophysics and Informatics, First Faculty of Medicine, Charles University, Prague, Czech Republic, 3Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic, 4Faculty of Mechatronics Informatics and Interdisciplinary Studies, Technical University of Liberec, Liberec, Czech Republic, 5Faculty of Health Studies, Technical University of Liberec, Prague, Czech Republic
1Site of Computed Tomography, Magnetic Resonance Imaging, and Clinical and Experimental Spectroscopy, Institute for Clinical and Experimental Medicine, Prague, Czech Republic, 2Institute of Biophysics and Informatics, First Faculty of Medicine, Charles University, Prague, Czech Republic, 3Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic, 4Faculty of Mechatronics Informatics and Interdisciplinary Studies, Technical University of Liberec, Liberec, Czech Republic, 5Faculty of Health Studies, Technical University of Liberec, Prague, Czech Republic
MR measurements of polymer-based 31P contrast
agent confirmed its good MR sensitivity with high signal-to-noise ratio in 31P
MR spectra and images, even for short acquisition times. 31P MR
spectroscopy confirmed large frequency offset of its Larmor frequency from biological 31P
signal.
Fig. 2 MRI
measured at 4.7T scanner using 1H/31P RF surface coil. Phantoms (cP=100mmol/L;
V=1.4ml in H2O) positioning
is visible on 1H MR image (RARE sequence; ST=1min; coronal plane) with
probes containing a phosphoester (P=O) group on the left and a phosphorothioate
(P=S) group on the right with water reference between them (A). Next, 31P
MRI (CSI
sequence; ST=3h) of polymers (B: P=O; C: P=S) are presented. In
the last image, overlapped 1H/31P MR images are shown (D);
31P signal is highlighted by green colour. SNR resulting from 31P
MR images is 5.4 for P=O polymer and 13.6 for P=S polymer.
Fig.1 31P MR spectra measured at 4.7T scanner using
1H/31P RF surface coil. Single-pulse sequence (TR=200ms; ST=3h)
was used for the measurement and spectra from both p(TMPC) and p(MPC) polymers (cP=100mmol/L; V=1.4ml in H2O) were
obtained during one measurement. Peak on the left with slightly lower amplitude
represents a polymer with a phosphoester group (P=O) with SNR=163.7; peak on the right represents
a polymer with a phosphorothioate group (P=S)
with SNR=195.1. The chemical shift between the peaks is 56.07ppm.
