ABSTRACT
PURPOSE: To compare quantitative and qualitative parameters obtained from digital subtraction angiography (DSA) with multislice computed tomographic angiography (MSCTA) in the follow-up of superficial femoral artery (SFA) stents. METHODS: Thirteen patients who had SMART stents implanted in the SFA were examined systematically with DSA and MSCTA (16-row scanner) at 6 months. Quantitative analysis and morphological assessment were performed on DSA images by an independent core laboratory, while the MSCTA images were analyzed by 2 radiologists in consensus. DSA measurements included stent length, minimal lumen diameter and reference diameter at mid stent and 5 mm either side of the stent, and percentage of stenosis. For MSCTA images, lumen area and the minimum, maximum, and mean diameters were also recorded. The images were analyzed qualitatively for diameter stenosis (<50%, 50% to 70%, 71% to 99%, and occlusion), bends, fractures, and calcifications. RESULTS: There were no statistical differences between lengths of stented segments, diameter measurements, or percentages of stenosis from DSA and MSCTA images. The Bland-Altman method showed good agreement between the 2 methods of measurement. MSCTA detected in-stent proliferation with a diameter stenosis <50% in all 13 cases diagnosed on DSA (there was no stenosis >50%). There were no bends or stent fractures on either set of images. The agreement between DSA and MSCTA for the presence and grading of calcifications was moderate (kappa=0.5). CONCLUSION: MSCTA provided quantitative and qualitative data comparable with DSA in the analysis of SFA nitinol stents.
Subject(s)
Alloys , Angiography, Digital Subtraction , Femoral Artery/diagnostic imaging , Femoral Artery/surgery , Stents , Tomography, X-Ray Computed , Aged , Aged, 80 and over , Atherosclerosis/diagnostic imaging , Atherosclerosis/surgery , Blood Vessel Prosthesis Implantation , Calcinosis/diagnostic imaging , Calcinosis/surgery , Female , Femoral Artery/pathology , Follow-Up Studies , Humans , Male , Middle Aged , Radiographic Image Interpretation, Computer-Assisted , Research Design , Severity of Illness Index , Tomography, X-Ray Computed/methods , Treatment OutcomeABSTRACT
PURPOSE: To present an optimized protocol for acquisition and reconstruction of multidetector computed tomographic angiographic (CTA) images of the stents most commonly used in renal arteries. TECHNIQUE: CTA was performed on a 16-detector row CT scanner using 0.75-mm collimation. Multiplanar reformatted images perpendicular to the stents and 2-dimensional curved reformatted images were displayed. Two different view windows ("vascular" and "stent") were used, each adapted to the stent density, the vascular wall density, and the aortic enhancement. Five different types of stainless steel balloon-expandable stents were examined; all caused discernable artifacts. These artifacts became more prominent as the stent density increased, becoming most significant when 2 stents were positioned one inside the other. The "stent" window allowed better appreciation of the stent shape and its position compared to the aortic wall and ostial calcifications. The "vascular" window afforded a better view of the vascular lumen, in addition to visualizing the stent in several planes. CONCLUSIONS: Multidetector CTA using dedicated acquisition and reconstruction protocols is capable of visualizing the vascular lumen of different types of renal stents while avoiding metallic artifacts.
