Carotid Artery Stent Implantation: Evaluation with Multi–Detector Row CT Angiography and Virtual Angioscopy—Initial Experience

Abstract

Approval for this HIPAA-compliant study was obtained from the institutional review board; informed consent was not required for retrospective review of patient studies that had been performed for clinical evaluation. The purpose of this study was to retrospectively compare the accuracy of intrastent luminal diameter, as measured on transverse computed tomographic (CT) angiograms and virtual angioscopic views, with the manufacturer's specifications for phantom diameter and with digital subtraction angiographic (DSA) measurements of stent diameter obtained in patients. Intrastent diameter was measured by using standard and stent-optimized reconstruction kernels with three window settings. Endoluminal virtual angioscopic views of the stent-containing vessels were also generated. Measurements at CT angiography were compared with known specifications for the phantom and with DSA measurements in patients. Erroneous measurements of intrastent diameter occurred when a standard kernel and nonoptimized window settings were used. A set of parameters that minimized error relative to measurements obtained at DSA was also identified. Virtual angioscopy helped demonstrate morphologic aspects of stenosis that were otherwise difficult to appreciate.

Frequency and Consequences of Early In-stent Lesions after Carotid Artery Stent Placement

“…Such artifacts may have resulted in an underestimation of the occurrence of early in-stent lesions. The sensitivity and specificity of multidetector CT in assessing the patency of the carotid stents are unknown, but there is evidence that multidetector CT can asses the in-stent diameter accurately (32). In addition, we could only hypothesize on the nature of the in-stent lesions, because it was impossible to obtain pathologic proof.…”

Endovascular Treatment of Carotid and Vertebral Pseudoaneurysms with Covered Stents

“…While digital subtraction angiography is known as the gold standard for evaluation of arterial stenosis, Orbach et al 17 have shown that by using stent-optimized reconstruction kernels, CTA can approximate the accuracy of digital subtraction angiography for the evaluation of bare metal stents. Although in our experience CT and US were both useful, we believe that US is the examination of choice if the stent is not obscured by the skull base or thoracic inlet.…”

Imaging in Endovascular Therapy:Our Future

“…Meticulous attention to detail (reconstruction kernels and windowing) is required to avoid erroneous in-stent measurement. 36…”