Shao Wu Wang MD, Abstract Co-Author: Nothing to Disclose

Song Chen, Abstract Co-Author: Nothing to Disclose

Mingqian Tan, Presenter: Nothing to Disclose

A new of high r1 relaxivity, water-soluble, gadolinium-containing carbon dots(Gd-CDots) nanoparticles with blue fluorescence as T1WI contrast agents was used in MRI angiography.

The Gd-CDots nanoparticles were synthesized by Citric acid monohydrate and gadolinium chloride through a one-step heated hydrothermally at 200 °C for 8 h. The gadolinium with different concentrations were examined by a 3T MRI scanner using T1WI and T2WI, IR turbo spin echo sequence and multi-echo T2WI . R1 and R2 relaxivities were calculated by fitting signal changes in multi-IR T1WI and multi-TE T2WI using simple exponential equations. The rats were injection of the Gd-CDots and Gd-BOPTA into tail vein. Fat suppressed T2WI were obtained to investigate the contrast changes in liver, kidney, muscle and aorta at the different time points.

The prepared Gd-CDots with different concentration of Gd has an r1 value of 14.5 mM-1s-1,17.3 mM-1s-1, 14.1 mM-1s-1, 33.4 mM-1s-1, r2 value of 18.0 mM-1s-1, 19.8 mM-1s-1, 15.9 mM-1s-1, 38.0 mM-1s-1 and r1/r2 ratio of 1.24, 1.13, 1.13, 1.14, which is competitive with commercial Gd-based contrast agent. Significant T1 contrast enhancement in the kidney and liver were evidenced in in vivo MRI after injection of Gd-CDots in rat through tail vein, similar to that observed in Gd-BOPTA enhanced MRI. The positive contrast enhancement is attributed to the small size and the reduced susceptibility of the nanoparticles, as well as the excellent colloidal stability in physiological environment. Firstly, the liver displayed significantly increased signal changes. Moreover, the kidney and bladder were observed increased signal changes, strongly suggesting renal excretion of the Gd-CDots nanoparticles. Gd-CDots has a much longer blood retention time than small molecule Gd for prolonged imaging time for organs of interest, providing a potential long half time T1WI contrast agents for imaging of vascular of disease tissues.

Gd-CDots has a much longer blood retention time than small molecule Gd for prolonged imaging time for organs of interest, providing a potential long half time T1WI contrast agents for MRI Angiography.

The Gd-containing nanoparticles exhibit excellent T1 contrast in vivo MRI studies, especially for kidney and liver, providing a potential long half contract agent for MRI Angiography.

Wang, S, Chen, S, Tan, M, High r1 Relaxivity Gadolinium-Containing Carbon Dots Nanoparticles as Contrast Agent for MRI Angiography.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007710.html