NaDyF4 Nanoparticles as T2 Contrast Agents for Ultrahigh Field Magnetic Resonance Imaging.
A major limitation of the commonly used clinical MRI contrast agents (CAs) suitable at lower magnetic field strengths (<3.0 T) is their inefficiency at higher fields (>7 T), where next-generation MRI scanners are going. We present dysprosium nanoparticles (β-NaDyF4 NPs) as T2 CAs suitable at ultrahigh fields (9.4 T). These NPs effectively enhance T2 contrast at 9.4 T, which is 10-fold higher than the clinically used T2 CA (Resovist). Evaluation of the relaxivities at 3 and 9.4 T show that the T2 contrast enhances with an increase in NP size and field strength. Specifically, the transverse relaxivity (r2) values at 9.4 T were ∼64 times higher per NP (20.3 nm) and ∼6 times higher per Dy(3+) ion compared to that at 3 T, which is attributed to the Curie spin relaxation mechanism. These results and confirming phantom MR images demonstrate their effectiveness as T2 CAs in ultrahigh field MRIs.
†Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, British Columbia, Canada V8W 3V6.
Gautom Kumar
GK
Das
†Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, British Columbia, Canada V8W 3V6.
Noah J J
NJ
Johnson
†Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, British Columbia, Canada V8W 3V6.
Jordan
J
Cramen
‡Institute for Biodiagnostics (West), National Research Council of Canada, Calgary, Alberta, Canada T2N 4N1.
Barbara
B
Blasiak
‡Institute for Biodiagnostics (West), National Research Council of Canada, Calgary, Alberta, Canada T2N 4N1.
Peter
P
Latta
‡Institute for Biodiagnostics (West), National Research Council of Canada, Calgary, Alberta, Canada T2N 4N1.
Boguslaw
B
Tomanek
†Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, British Columbia, Canada V8W 3V6.
Frank C J M
FC
van Veggel
contrast agents; dysprosium; high-field MRI; lanthanide nanoparticles; relaxivity