David Planer MD, Presenter: Nothing to Disclose

Galit Kafri PhD, Abstract Co-Author: Nothing to Disclose

Raz Carmi PhD, Abstract Co-Author: Employee, Koninklijke Philips Electronics NV, Haifa, Israel

Amiaz Altman PhD, Abstract Co-Author: Employee, Koninklijke Philips Electronics NV, Haifa, Israel

Jacob Sosna MD, Abstract Co-Author: Consultant, ActiViews Ltd Advisory Board, CMT Medical Technologies Ltd Research grant, Koninklijke Philips Electronics NV

To demonstrate in vivo kinetics and distribution of iodine based nanoparticulate contrast (NPC) compared to standard contrast agent in rabbits.

N1177 NPC (NanoScan Imaging, Landsdale, PA) a macrophage specific contrast agent or standard iodinated contrast at a dose equivalent of 250 mg iodine per kg body weight was injected intravenously into the marginal ear vein of 17 NZW rabbits. Repeated total body scan of the rabbits in predetermined time points were performed at MDCT (Brilliance,Philips Healthcare, Cleveland, OH) with the following parameters: KvP 140 kV; 300 mAs; rotation time 1 sec; Slice thickness 3mm with increment of 1.5 mm; pitch 0.97. Densities in ROIs placed in selected organs of the rabbits were measured at CT scans acquired at each time point (1,5,10,20,30, 60,120,180 min and 24h). Time / density graphs were drawn and 3d reconstruction were prepared on a CT dedicated work station (EBW, Philips Healthcare).

NPC had a significantly longer intravascular half life compared with standard contrast. While in both contrast agents the peak concentration in the aorta was demonstrated one minute after injection. NPC was present both in the arterial and venous vasculature for 30 minutes post injection and returned to baseline only 2 hours after injection enabling 3D reconstructions of the aorta and its branches. In addition, there was an extremely high absorbance by the spleen (an organ rich in macrophages) reaching its peak density of around 1000 HU two hours post injection with a slow clearance (680 HU, 24 hours post injection). While the standard contrast was cleared almost exclusively by the kidneys, NPC was cleared both by the liver and the kidneys.  

NPC has distinctive features including long intravascular half life, hepatic clearance and accumulation in macrophages.

Nanoparticulate contrast can potentially be used as a blood pool agent in humans and enable single, non timed CT scan with visulaization of the arterial and venous vasculature.

Planer, D, Kafri, G, Carmi, R, Altman, A, Sosna, J, Iodine-based Nanoparticulate Intravenous Contrast for MDCT: Kinetics and Distribution Assessment.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8007561.html