MR image-guided endovascular procedures with the ultrasmall superparamagnetic iron oxide SH U 555 C as an intravascular contrast agent: study in pigs.
OBJECTIVE
To evaluate the feasibility of using the ultrasmall superparamagnetic iron oxide (USPIO) SH U 555 C as an intravascular contrast agent for magnetic resonance (MR) image-guided vascular procedures with an open MR imaging system.


METHODS
All experiments were performed with MR imaging at 0.2 T. MR image-guided interventions were performed in USPIO-enhanced vessels in four pigs. With near real-time MR image guidance (acquisition time, 0.64 second per section), the splenic and renal arteries were consecutively catheterized by using a susceptibility artifact-based catheter-guide wire combination. Angioplasty and stent implantation were performed four times in the renal artery and twice in the iliac artery. Intraaortal signal intensity (SI) was measured during the interventions.


RESULTS
After administration of SH U 555 C (40 micromol of iron per kilogram of body weight), a three-dimensional MR angiographic sequence was performed that allowed visualization of the abdominal and pelvic vessels that were as small as 2 mm in diameter. Catheterization, angioplasty, and stent implantation were successfully guided in the USPIO-enhanced vasculature. Sixty minutes after contrast agent injection, the mean aortic SI was 70% of the maximum measured enhancement levels.


CONCLUSIONS
One intravenous injection of SH U 555 C enabled long, continuous intravascular SI enhancement at MR angiography, and, in combination with susceptibility artifact-based device tracking, the injection allowed the performance of MR imaging-guided intravascular interventions in an open MR imaging system.
Wacker
Frank K
FK
Department of Radiology-MRI, Bolwell B 124, University Hospitals of Cleveland, Case Western Reserve University, 11100 Euclid Ave, Cleveland, OH 44106, USA. wackerfrank@web.de
Reither
Klaus
K
Ebert
Wolfgang
W
Wendt
Michael
M
Lewin
Jonathan S
JS
Wolf
Karl-Juergen
KJ
D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage*; D003911:Dextrans; D005240:Feasibility Studies; D052203:Ferrosoferric Oxide; D007501:Iron / Q000008:administration & dosage*; D018810:Magnetic Resonance Angiography / Q000295:instrumentation*; D058185:Magnetite Nanoparticles; D010087:Oxides / Q000008:administration & dosage*; D013552:Swine
D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide