Multi-detector computed tomography to analyze in-stent restenoses at different heart rates.
OBJECTIVE
This study was performed to evaluate the visualization of coronary in-stent restenosis by multi-detector computed tomography (MDCT).


METHODS
A restenosis phantom with different stented stenoses was used. The phantom was placed into a dynamic heart phantom with heart rates from 40 to 120 bpm. MDCT was performed with two scan protocols: a standard and an ultra-high resolution scan protocol.


RESULTS
Using the ultra-high resolution protocol, artifacts occurred at 0.6 mm around the stent struts (p < 0.001). Artifacts compromised the discrimination between no stenosis and low-grade stenosis. Approximately 73% of the central lumen diameter was able to be assessed without limiting artifacts allowing the discrimination of no or low vs. moderate and high-grade stenoses (p < 0.05). Using the standard protocol in the dynamic phantom, the image quality and visibility of stenoses decreased with an increasing heart rate (p < 0.0002 and p < 0.004). This was able to be compensated by analysis in an appropriate RR-interval. At the optimal RR-interval, an assessment of the grade of stenoses > 30% was feasible up to 120 bpm.


CONCLUSIONS
Multi-detector computed tomography ultra-high resolution scans allowed the assessment of a wide range of degrees of in-stent restenoses. In this experimental setup, standard protocols allowed a discrimination of low, moderate and high-grade stenoses even at heart rates above 100 bpm.
Köster
R
R
Klinik und Poliklinik für Kardiologie und Angiologie, Universitäres Herzzentrum Hamburg. rkoester@uke.uni-hamburg.de
van Stevendaal
U
U
Grass
M
M
Yamamura
J
J
Kaehler
J
J
Adam
G
G
Meinertz
T
T
Begemann
P G
PG
D016477:Artifacts; D023903:Coronary Restenosis / Q000000981:diagnostic imaging*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015588:Observer Variation; D019047:Phantoms, Imaging; D012680:Sensitivity and Specificity; D015607:Stents; D036542:Tomography, Spiral Computed