BACKGROUND: Different iterative reconstruction (IR) techniques compensate increased noise from lower tube current-time product settings, yet the differences between IR settings remain unclear. OBJECTIVE: Aim of this study was to test whether different IR settings have a clinically relevant influence on image quality and on the diagnostic accuracy of low-dose CT angiography in patients with a stent. METHODS: Forty-two patients with 73 coronary stents were prospectively enrolled. Data were acquired with dual-source CT, and images were reconstructed with standard filtered back projection (FBP) and raw data-based IR with different settings (I3, I4, I5). Quantitative parameters, including CT-attenuation, noise, signal-to-noise ratio, contrast-to-noise ratio, as well as the presence of in-stent stenosis > 50% were determined. All patients had invasive angiography as reference standard. RESULTS: Mean effective dose was 0.32 ± 0.02 mSv. Image noise decreased significantly compared with FBP (I3 = 29%; I4 = 38% and I5 = 45%), whereas signal-to-noise and contrast-to-noise ratios increased significantly (all IR settings P < .01). Subjective image quality was superior with all IR settings (P < .01). FBP sensitivity, specificity, positive predictive value, and negative predictive value were 83%, 71%, 36%, and 96% per stent compared with 100%, 76%, 44%, and 100%, respectively, in IR reconstructions independent of the IR setting applied. CONCLUSION: In low-dose coronary CT angiography, higher IR settings significantly improved subjective and objective image quality but had no effect on accuracy.
BACKGROUND: Different iterative reconstruction (IR) techniques compensate increased noise from lower tube current-time product settings, yet the differences between IR settings remain unclear. OBJECTIVE: Aim of this study was to test whether different IR settings have a clinically relevant influence on image quality and on the diagnostic accuracy of low-dose CT angiography in patients with a stent. METHODS: Forty-two patients with 73 coronary stents were prospectively enrolled. Data were acquired with dual-source CT, and images were reconstructed with standard filtered back projection (FBP) and raw data-based IR with different settings (I3, I4, I5). Quantitative parameters, including CT-attenuation, noise, signal-to-noise ratio, contrast-to-noise ratio, as well as the presence of in-stent stenosis > 50% were determined. All patients had invasive angiography as reference standard. RESULTS: Mean effective dose was 0.32 ± 0.02 mSv. Image noise decreased significantly compared with FBP (I3 = 29%; I4 = 38% and I5 = 45%), whereas signal-to-noise and contrast-to-noise ratios increased significantly (all IR settings P < .01). Subjective image quality was superior with all IR settings (P < .01). FBP sensitivity, specificity, positive predictive value, and negative predictive value were 83%, 71%, 36%, and 96% per stent compared with 100%, 76%, 44%, and 100%, respectively, in IR reconstructions independent of the IR setting applied. CONCLUSION: In low-dose coronary CT angiography, higher IR settings significantly improved subjective and objective image quality but had no effect on accuracy.
Authors: Annemarie M den Harder; Dominika Suchá; Pieter J van Doormaal; Ricardo P J Budde; Pim A de Jong; Arnold M R Schilham; Johannes M P J Breur; Tim Leiner Journal: PLoS One Date: 2017-04-14 Impact factor: 3.240
Authors: Junjie Yang; Xiaobo Yang; Carlo N De Cecco; Taylor M Duguay; Zhiye Chen; Christian Tesche; U Joseph Schoepf; Yundai Chen Journal: Sci Rep Date: 2017-07-31 Impact factor: 4.379