Factors That Influence Measurements and Accurate Evaluation of Stent Apposition by Optical Coherence Tomography Assessment Using a Phantom Model

Abstract

Background: Factors influencing measurements and accurate evaluation of stent apposition by optical coherence tomography (OCT) are not established. Methods and Results: Phantom models of known luminal sizes and lengths were evaluated by OCT under various conditions and measurements were compared with actual values. Stents implanted into phantom models were examined by OCT to validate the measurement point on the stent strut surface for accurate evaluation of stent apposition. Strut thickness was measured at 3 points (midpoint, inner and outer surfaces of the stent shadow). The precision of OCT measurements of lumen diameter and area was satisfactory when the image wire was positioned in the center, but the error and deviation were unsatisfactory when the image wire was positioned eccentrically using a low frame acquisition rate. Longitudinal OCT measurements were close to actual values under all conditions examined. Measurements from the midpoint of the stent shadow to the adjacent vessel wall surface coincided with actual stent thickness. Conclusions: Significant measurement error can occur if the image wire is positioned eccentrically with a lower frame acquisition rate than specified by the manufacturer. To accurately evaluate stent apposition, the stent surface should be measured from the center of the stent reflection. (Circ J 2009; 73: 1841 -1847

Automatic segmentation of in-vivo intra-coronary optical coherence tomography images to assess stent strut apposition and coverage

“…Hereto, measurements are performed in Cartesian (scan converted) images with a resolution of 1,024 9 1,024 pixels. Distances are analyzed as follows: the central point of every strut is identified [11] and from that point, the distance perpendicular to the lumen is computed. If more than one direction is perpendicular to the vessel boundary (in case of high curvature), the minimal distance is taken into account.…”

Optical Coherence Tomography-Derived Anatomical Criteria for Functionally Significant Coronary Stenosis Assessed by Fractional Flow Reserve

“…Furthermore, the TD-OCT image wire is often positioned eccentrically, especially in curved vessel segments, even though centering of the image wire over the entire length of the target segments is very important for obtaining more reliable cross-sectional images. This eccentric position of the image wire may have affected the quantitative analysis by TD-OCT. 30 Frequency-domain OCT (FD-OCT) has been developed to overcome many of the technical limitations of the current TD-OCT system, including higher frame rates (100 frame/s), a wider scan diameter (10 mm), and a faster image acquisition rate (20 mm/s) without the loss of image quality. It can be delivered as a rapid exchange catheter over a conventional coronary guidewire.…”

Comparison by Optical Coherence Tomography of Paclitaxel-Eluting Stents With Sirolimus-Eluting Stents Implanted in One Coronary Artery in One Procedure - 6-Month Follow-up -

“…23 To evaluate the radial unevenness of NIT (RUNIT), the difference between the maximum and minimum NIT was calculated for each cross-section and to evaluate the longitudinal axis unevenness of NIT (LUNIT), the difference between the maximum NIT and minimum NIT in the longitudinal axis was calculated for each stent. In addition, frequency of thrombus formation and low-density spots surrounding the strut were recorded.…”