01-12-2015 | Original Article
Evaluation of In-Stent Restenosis After Stent Implantation in the Vertebral Artery Ostium by Multislice Computed Tomography Angiography: Factors Affecting Accurate Diagnosis
Published in: Clinical Neuroradiology | Issue 4/2015
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Purpose
Few articles have evaluated vertebral artery ostium stents using multislice computed tomography (CT). The purpose of our study was to evaluate the diagnostic performance of 64- and 16-slice CT for detecting significant in-stent restenosis after vertebral artery ostium stenting, and to identify factors affecting the accurate diagnosis by CT.
Methods
We reviewed 57 stents scanned using 64-slice CT and 34 stents using 16-slice CT. The accuracy of CT for diagnosing significant in-stent restenosis (≥ 50 % diameter narrowing) was calculated using conventional angiography as a reference standard. Possible factors influencing the diagnostic performance of CT were analyzed, such as CT scanner, image quality, and stent characteristics.
Results
With 64-slice CT, 46 (80.7 %) of 57 stents were classified as evaluable, while with 16-slice CT, 28 (82.3 %) of 34 stents were classified as evaluable. No stents with diameters ≤ 2.75 mm were evaluable. The respective results for 64- versus 16-slice CT were sensitivity 87.5 % (95 % confidence interval [CI] 47.3–99.7 %) versus 100 % (95 % CI 15.8–100.0 %), specificity 94.7 % (95 % CI 82.3 %–99.4 %) versus 96.2 % (95 % CI 80.4–99.9 %). Factors reducing the accurate diagnosis were those associated with poor image quality, a diameter ≤ 2.75 mm, and drug-eluting stent type (p < 0.05).
Conclusions
64-slice and 16-slice CT scans are adequate in stents with diameters > 2.75 mm for the evaluation of in-stent restenosis after stent implantation in the vertebral artery ostium.