A liposomal nanoscale contrast agent for preclinical CT in mice.
OBJECTIVE
The goal of this study was to determine if an iodinated, liposomal contrast agent could be used for high-resolution, micro-CT of low-contrast, small-size vessels in a murine model.


METHODS
A second-generation, liposomal blood pool contrast agent encapsulating a high concentration of iodine (83-105 mg I/mL) was evaluated. A total of five mice weighing between 20 and 28 g were infused with equivalent volume doses (500 microL of contrast agent/25 g of mouse weight) and imaged with our micro-CT system for intervals of up to 240 min postinfusion. The animals were anesthetized, mechanically ventilated, and vital signs monitored allowing for simultaneous cardiac and respiratory gating of image acquisition.


RESULTS
Initial enhancement of about 900 H in the aorta was obtained, which decreased to a plateau level of approximately 800 H after 2 hr. Excellent contrast discrimination was shown between the myocardium and cardiac blood pool (650-700 H). No significant nephrogram was identified, indicating the absence of renal clearance of the agent.


CONCLUSIONS
The liposomal-based iodinated contrast agent shows long residence time in the blood pool, very high attenuation within submillimeter vessels, and no significant renal clearance rendering it an effective contrast agent for murine vascular imaging using a micro-CT scanner.
Mukundan
Srinivasan
S
Department of Radiology, Duke University Medical Center, Box 3808, Durham, NC 27705, USA.
Ghaghada
Ketan B
KB
Badea
Cristian T
CT
Kao
Chen-Yu
CY
Hedlund
Laurence W
LW
Provenzale
James M
JM
Johnson
G Allan
GA
Chen
Emmanuel
E
Bellamkonda
Ravi V
RV
Annapragada
Ananth
A
D000818:Animals; D003287:Contrast Media / Q000737:chemistry / Q000493:pharmacokinetics*; D007091:Image Processing, Computer-Assisted; D008081:Liposomes; D051379:Mice; D013902:Radiography, Thoracic; D014057:Tomography, X-Ray Computed; D014283:Triiodobenzoic Acids / Q000737:chemistry / Q000493:pharmacokinetics*
D003287:Contrast Media; D008081:Liposomes; D014283:Triiodobenzoic Acids; C044834:iodixanol