Figure 1.
Schematic of various liposomal-Gd agents.
Core-encapsulated gadolinium (CE-Gd) liposomes contain conventional low molecular-weight Gd-chelates in the core interior of the liposomes, surface-conjugate gadolinium (SC-Gd) liposomes contain Gd-chelates conjugated on the internal and external surface of the liposome bilayer, Dual-Gd liposomes contain both core-encapsulated and surface-conjugated Gd-chelates. The stars represent Gd-chelates.
Table 1.
Characterization of liposomal-Gd formulations.
Figure 2.
T1 relaxivity of liposomal-Gd formulations on a per Gadolinium basis.
Measurements were performed at 1.5 Tesla MR field strength in bovine plasma at 37°C. Each value is significantly different (p<0.05).
Figure 3.
T1 relaxation rates (R1) of liposomal-Gd formulations for different lipid doses.
Measurements were performed at 1.5 Tesla MR field strength in bovine plasma at 37°C. For each lipid dose, the R1 values were significantly different for each of the liposomal-Gd agent (* corresponds to p<0.05).
Figure 4.
T1 relaxivity of liposomal-Gd formulations on a per nanoparticle basis.
Figure 5.
In vivo comparison of liposomal-Gd contrast agents.
Coronal maximum intensity projection (MIP) images of the head and thorax in mice acquired pre-contrast, post CE-Gd liposomes, post SC-Gd liposomes and post Dual-Gd liposomes. The contrast agents were administered intravenously at a lipid dose of 200 mg/kg. Please note the increased signal in the vessels compared to background and the high vessel conspicuity for smaller vessels (arrows in the Dual-Gd image). All images were acquired in different animals using the 3D-FSPGR sequence. The MIP images are presented at identical gray-scale levels.
Figure 6.
In vivo comparison of signal to noise ratios (SNR) (Fig. A) and contrast to noise ratios (CNR) (Fig. B) for different liposomal-Gd agents.
Each agent was administered in mice at a lipid dose of 200 mg/kg. There was significant difference within the SNRs and CNRs of various contrast agents (p<0.05).