[Examination of accuracy and factors influencing optical coherence tomography(OCT)measurements]

Optical coherence tomography (OCT) is a new imaging modality with increasing clinical application. In the present study, we examined the accuracy and factors influencing the OCT measurements (luminal diameter, area, and stent strut thickness).

We evaluated several luminal sizes of phantom model by OCT with several situations (frame-rate: 8.2 or 15.6 F/s; pullback-speed: 1.0 or 2.0 mm/s; position of Image Wire: in-center; off-center) and compared them with the actual value and the intravascular ultrasound measurements. We also evaluated the accuracy of the stent strut thickness (5 bare metal stents and 2 drug eluting stents) in stents that were implanted to phantom models.

The accuracy of OCT measurements was affected by frame-rate and the position of OCT Image Wire. The distortion and the change in brightness of the OCT image were detected when the Image Wire was positioned off-center, especially at low frame-rate. In this condition, OCT measured the luminal diameter and area larger than the actual size. As for the strut thickness, when we unified the measurement points of the stent strut surface, the precision of the OCT measurements was satisfactory.

We revealed that the precision of the OCT measurements was satisfactory. However, we should note that the OCT measurements were affected by frame-rate and position of the Image Wire.