Optimized intravenous Flat Detector CT for non-invasive visualization of intracranial stents: first results.
OBJECTIVE
As stents for treating intracranial atherosclerotic stenosis may develop in-stent re-stenosis (ISR) in up to 30%, follow-up imaging is mandatory. Residual stenosis (RS) is not rare. We evaluated an optimised Flat Detector CT protocol with intravenous contrast material application (i.v. FD-CTA) for non-invasive follow-up.


METHODS
In 12 patients with intracranial stents, follow-up imaging was performed using i.v. FD-CTA. MPR, subtracted MIP and VRT reconstructions were used to correlate to intra-arterial angiography (DSA). Two neuroradiologists evaluated the images in anonymous consensus reading and calculated the ISR or RS. Correlation coefficients and a Wilcoxon test were used for statistical analysis.


RESULTS
In 4 patients, no stenosis was detected. In 6 patients RS and in two cases ISR by intima hyperplasia perfectly visible on MPR reconstructions of i.v. FD-CTA were detected. Wilcoxon's test showed no significant differences between the methods (p > 0.05). We found a high correlation with coefficients of the pairs DSA/ FD-CT MIP r = 0.91, DSA/ FD-CT MPR r = 0.82 and FD-CT MIP/ FD-CT MPR r = 0.8.


CONCLUSIONS
Intravenous FD-CTA could clearly visualise the stent and the lumen, allowing ISR or RS to be recognised. FD-CTA provides a non-invasive depiction of intracranial stents and might replace DSA for non-invasive follow-up imaging.
Struffert
Tobias
T
Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany. tobias.struffert@uk-erlangen.de
Kloska
Stephan
S
Engelhorn
Tobias
T
Deuerling-Zheng
Yu
Y
Ott
Sabine
S
Doelken
Marc
M
Saake
Marc
M
Köhrmann
Martin
M
Doerfler
Arnd
A
D000368:Aged; D001807:Blood Vessel Prosthesis; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D002533:Cerebral Angiography / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015607:Stents; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*; D014963:X-Ray Intensifying Screens