Aim: To assess the reproducibility of quantitative analysis of optical frequency domain imaging (OFDI) acquired at different pullback speeds (20, 30, 40 mm/sec), as well as the impact of cardiac motion artefact on three-dimensional (3D) reconstructions.
Methods and results: A total of 36 OFDI pullbacks were obtained pre- and post-stent implantation at the pullback speeds of 20, 30 and 40 mm/sec in non-diseased swine coronary arteries. The amount of x-ray contrast needed for blood clearance during OFDI imaging was recorded. Three-dimensional images of stented segments were rendered and artefacts on 3D images were assessed. Lumen areas (LA) were measured on each individual frame in pre- and post-stent pullbacks. The volume of contrast used with a pullback speed of 40 mm/sec was significantly smaller than with those of 30 and 20 mm/sec (10.8±1.8, 12.9±1.6, 15.9±2.6 ml, p<0.01, respectively). Three-dimensional reconstruction was feasible in all pullbacks. Faster pullback speeds resulted in a smaller number of artefacts. For quantitative measurement, a total of 7,426 frames were analysed. In non-stented vessels, LA derived from corresponding selected frames increased significantly with increasing pullback speeds (6.35±2.14 vs. 6.58±2.10 mm2 for 20 vs. 30 mm/sec [p<0.001], 6.36±2.13 vs. 6.75±2.09 mm2 for 20 vs. 40 mm/sec [p<0.001]), whereas in stented vessels there was no significant difference in mean LA between the three different pullback speeds (6.75±1.30 vs. 6.78±1.36 mm2 for 20 vs. 30 mm/sec [NS], 6.74±1.30 vs. 6.76±1.31 mm2 for 20 vs. 40 mm/sec [NS]).
Conclusions: Quantitative analysis of OFDI obtained at different pullback speeds in non-stented coronary arteries could potentially vary in LA measurement. OFDI with high-speed pullback allows quantitative analysis of stented vessels while reducing the amount of contrast and cardiac motion artefacts.