Iterative reconstruction improves detection of in-stent restenosis by high-pitch dual-source coronary CT angiography

Abstract

Recent studies demonstrated that sinogram affirmed iterative reconstructions (SAFIRE) can produce higher-resolution images with greater robustness for the reduction of various imaging artefacts. Eighty-five patients were prospectively evaluated and underwent a high-pitch spiral acquisition CT scan. In-stent noise, signal-to-noise ratio(SNR), stent-lumen attenuation increase ratio (SAIR), and subjective image quality score were measured and compared between the SAFIRE and Filter back projection (FBP) reconstructions. Conventional coronary angiography served as the standard of reference. In 159 evaluated stents, SAFIRE was superior to FBP with regards to in-stent noise, SNR, SAIR, and image quality score. On per-stent analysis, SAFIRE vs. FBP reconstruction yielded 85% vs. 85%sensitivity, 89% vs. 78%specificity, 73% vs. 57%positive predictive value, 95% vs. 94%negative predictive value, and 0.87 vs. 0.82 area under curve, although these improvements did not reach statistical significance (P > 0.05). However, in the subgroup of small diameter stents (≤3 mm; n = 95), specificity(82% vs. 62%), positive predictive value(66% vs. 50%) and area under curve (0.81 vs. 0.70) improved significantly (P < 0.05) with SAFIRE. SAFIRE image reconstruction can thus improve the evaluation for ISR, especially in smaller stents.

Spectral Photon-Counting Computed Tomography for Coronary Stent Imaging

“…Therefore, further improvements in DLCT image quality by utilizing optimized acquisition and reconstruction parameters might be possiblehowever, the detector resolution would still be the limiting factor. Additionally, our results with a clear detection of the stenosis for 80% of the tested stents and a suspicion in 90% of the cases are in line with previous studies testing the diagnostic quality of different CT systems; 5,6,17 thus, the influence of our used acquisition and reconstruction parameters on the overall results is likely limited. For both systems, the thinnest possible slice was chosen which resulted in the SPCCT thickness being less than half the thickness of DLCT.…”

Technical development in cardiac CT: current standards and future improvements—a narrative review

“…IR have the enormous advantage of reducing dose preserving a good image quality, as demonstrated in the literature (29). Yang et al (30) demonstrated that IR improve in-stent restenosis evaluation in high pitch dual source CT (DSCT), with a better specificity (82% vs. 62%) and positive predictive value (66% vs. 50%) compared to FBP.…”

“…Yang et al (30) demonstrated the value of IR in improving detection of in-stent restenosis by high-pitch DSCT, especially in stents of smaller dimensions. Geyer et al (36), using a second generation DSCT upgraded with an integrated-circuit detector, studied the influence on coronary stent smaller than 3 millimetres together with IR; authors demonstrated that, in a heart-phantom movingmodel, IR improved sharpness, signal and contrast-to-noise ratio, reducing blurring and noise, if compared to FBP.…”

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

“…Iterative reconstruction was applied using a pre-reconstruction filter for image smoothing and high-frequency noise reduction (Saphyre 2) for both groups, as previously described. 11 Image evaluation With the use of axial and multiplanar reconstructions, two experienced physicians (>5 years of experience) performed coronary CTA image evaluation (both qualitative and quantitative) in dedicated workstations (Aquarius versions 4.7-4.11, Terarecon Inc., San Mateo, CA, USA). Disagreements between readers were solved by consensus and used for final analysis.…”