New metallic MR stents for artifact-free coronary MR angiography: feasibility study in a swine model.
OBJECTIVE
The objective of this study was to investigate the potential for artifact-free coronary magnetic resonance angiography (cMRA) in the presence of dedicated metallic MR stents in vitro and in a swine model.


METHODS
All investigations were performed at 1.5 T, applying a standard cMRA gradient echo sequence with a T2 preparation pulse. Two prototypes of each hand-woven, mechanically woven, and lasered Aachen Resonance Coronary MR Stents made out of an MR-compatible metallic alloy and dilated to 2.5 mm and 4 mm were examined in a water bath.


RESULTS
Artifact behavior was judged independently by 2 radiologists as showing "no artifacts" for all tested stent types. Signal-to-noise ratios inside and outside of the stents were measured yielding a Pearson correlation coefficient of 0.98 (y = 1.22 + 0.92x). Nineteen stents (8 hand woven, 3 mechanically woven, 8 lasered) were deployed in coronary arteries of 19 domestic pigs and were examined by cMRA. Artifact behavior of the stents was analyzed by measuring the signal-to-noise ratio at the stent positions and compared with signal-to-noise ratio measurements outside of the stents, yielding a Pearson correlation coefficient of 0.90 (y = -0.75 + 1.06x).


CONCLUSIONS
All 3 prototypes of coronary MR stents allowed complete visualization of the stent lumen and consequently determination of stent patency by cMRA.
Buecker
Arno
A
Clinic of Diagnostic Radiology, University of Technology, Pauwelsstrasse 30, D-52057 Aachen, Germany. buecker@rad.rwth-aachen.de
Spuentrup
Elmar
E
Ruebben
Alexander
A
Mahnken
Andreas
A
Nguyen
Trung Hieu
TH
Kinzel
Sylvia
S
Günther
Rolf W
RW
D000818:Animals; D016477:Artifacts; D017023:Coronary Angiography; D005240:Feasibility Studies; D006801:Humans; D018810:Magnetic Resonance Angiography; D023421:Models, Animal; D015607:Stents; D013552:Swine