- Meeting abstract
- Open Access
2119 Visualization of micro-vasculature using FeCo-core/graphitic-carbon-shell nanocrystals and high-resolution 3D spiral imaging
© Lee et al; licensee BioMed Central Ltd. 2008
- Published: 22 October 2008
- Contrast Agent
- High Resolution Image
- Base Contrast Agent
- SPGR Sequence
- Maximum Slew
Non-invasive visualization of small vessel structures has been difficult due to insufficient contrast between small vessels and background tissue, and limited spatial resolution of MRI. Here, we present a method to non-invasively visualize small vascular structures in-vivo, in live animals using novel contrast agents combined with fast, high resolution image encoding methods.
To evaluate the use of 1) the FeCo-Core/Graphitic-Carbon-Shell nanocrystal contrast agent  and 2) the high resolution encoding enabled by 3D spiral acquisition and small surface coils for the visualization of microvasculature in-vivo.
Normal and stenosis induced white rabbits with body weight of ~4 kg were first catheterized in the ear vein. Through the catheter, 9.6 cc of 5 mM concentration FeCo nanocrystal contrast agent was injected followed by 1 cc of saline injection. Immediately before and after the injection, a small volume covered by a 1 inch custom made surface coil was imaged using spectral-spatial excitation and 3D spiral readout. The spatial resolution was 78 × 78 × 500 um3 with volume coverage of 4 × 4 × 1 cm3. The scan time was 2 min 40 sec for a single volume and the scan was repeated 9 times over 24 min to improve SNR. A whole body volume scan using a fat-saturated 3D SPGR sequence was also performed using a standard GE head coil 1 hour before and after the injection. All the experiments were conducted using a GE 1.5 T EXCITE whole body system with a maximum gradient of 40 mT/m and maximum slew rate of 150 T/m/s.
The FeCo contrast agent provides several advantages for high resolution vessel imaging; strong relaxivity, relatively long circulation time compared to conventional Gd based contrast agent, and small nano-scale size. These properties allow sufficient contrast in the small vessels for a long enough time to acquire high resolution images. The high resolution 3D spiral imaging technique combined with this FeCo contrast agent demonstrates great potential to visualize microvasculature in-vivo.
In this paper, we present a method to non-invasively visualize small vascular structures (~78 um) in-vivo, in live animals using novel FeCo-Core/Graphitic-Carbon-Shell nanocrystal contrast agents combined with fast, high resolution 3D spiral encoding methods.