Three-dimensional MR angiography of a nitinol-based abdominal aortic stent graft: assessment of heating and imaging characteristics.
OBJECTIVE
To assess heating- and 3D MRA imaging characteristics of a commonly used aortic stent graft in a 1.5T MR-environment.


METHODS
A bifurcated stent graft (Vanguard; Boston Scientific, Oakland, N. J.) was evaluated in vitro regarding localized heating effects as well as imaging appearance using fast 3D GRE sequences. To quantitate stent related artifacts, stent wall thickness and luminal diameters were measured. Subsequently eight patients were imaged three months following placement of an aortic stentgraft with 3D MRA. Images were assessed for the presence of stent leaks, luminal patency, and stent configuration.


RESULTS
There were no temperature changes associated with the stent during scanning. Wall thickness measurements overestimated true stent thickness, resulting in minimal underestimation of luminal diameters on 3D MRA images. In vivo imaging confirmed these results. Stent patency was confirmed in all 8 patients.


CONCLUSIONS
Contrast-enhanced 3D MRA appears well suited for the evaluation of the abdominal and pelvic vasculature following aortic implantation of a Vanguard stent.
Hilfiker
P R
PR
Institute of Diagnostic Radiology, University Hospital Zurich, Rämistrasse 100, CH-8091 Zurich, Switzerland.
Quick
H H
HH
Pfammatter
T
T
Schmidt
M
M
Debatin
J F
JF
D000368:Aged; D000497:Alloys; D001012:Aorta, Abdominal / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation; D003287:Contrast Media; D019786:Gadolinium DTPA; D006361:Heating; D006801:Humans; D007275:Injections, Intravenous; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging; D011183:Postoperative Complications / Q000175:diagnosis*; D015203:Reproducibility of Results; D015607:Stents
D000497:Alloys; D003287:Contrast Media; C013616:nitinol; D019786:Gadolinium DTPA