Stent evaluation by coronary computed tomography angiography: a comparison between Iopamidol-370 and Ioversol-320 hypo-osmolar iodine concentration contrasts

Abstract

Objective: Qualitative and quantitative image analysis between Iopamidol-370 and Ioversol-320 in stents´ evaluation by coronary computed tomography angiography (CTA). Methods: Sixty-five patients with low-risk stable angina undergoing stent follow-up with coronary CTA were assigned to Iopamidol I-370 (n = 33) or Ioversol I-320 (n = 32) in this prospective, double-blind, non-inferiority, randomized trial. Stent lumen image quality was graded by 5-point Likert Scale. Lumen mean attenuation was measured at native coronary segments: pre-stent, post-stent, distal segments and at coronary plaques. Lumen attenuation increase (LAI) ratio was calculated for all stents. Heart rate (HR) variation, premature heart beats (PHB), heat sensation (HS), blooming and beam hardening were also assessed. Results: Image quality was similar between groups, with no significant difference (Likert score 4.48 ± 0.75 vs 4.54 ± 0.65, p = 0.5). There were similarities in LAI ratio between I-370 and I-320 (0.39 ± 0.42 vs 0.48 ± 0.44 HU, p = 0.08). Regarding lumen mean attenuation at native coronary segments, a significant difference was observed, with I-320 presenting lower values, including contrast mean attenuation in distal segments. After statistical multivariate analysis, three variables correlated with stent image quality: 1) stent diameter, 2) HR variation and 3) stent lumen LAI ratio. Conclusions: There was no significant difference between Iopamidol-370 mgI ml−1 and Ioversol-320 mgI ml−1 contrasts regarding overall stent lumen image quality, which was mainly influenced by stent diameter, HR and LAI ratio. Advances in knowledge: Coronary CTA allows adequate stents' visualization and image quality is influenced by stent diameter, HR variation and LAI ratio. Stents' image quality showed no difference between different concentration contrasts (I-370 vs. I-320); however, higher concentration contrasts may provide an improved overall visualization, especially regarding coronary distal segments.

Exploring the best monochromatic energy level in dual energy spectral imaging for coronary stents after percutaneous coronary intervention

“…Although there has been continuous improvement in CT scanning technology in recent years, overestimation of the CT value in the stent caused by the beam hardening artifacts of the wire harness and the partial volume effect leads to the unclear display of the in-stent lumen and the stent structure itself 5 , 6 . At present, noninvasive assessment of restenosis after PCI remains challenging 7 . It has been proven that dual-energy spectral CT imaging can reduce the beam hardening effect, which is expected to be an effective method for noninvasive in-stent lumen observation 8 – 10 .…”