scholarly journals Comparison of image quality and radiation dose using different pre-ASiR-V and post-ASiR-V levels in coronary computed tomography angiography

2020 ◽  
pp. 1-10
Author(s):  
Yongxia Zhao ◽  
Dongxue Li ◽  
Zhichao Liu ◽  
Xue Geng ◽  
Tianle Zhang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Radiation Dose ◽  
Computed Tomography Angiography ◽  
Coronary Computed Tomography Angiography ◽  
Effective Radiation Dose ◽  
Dose Length Product ◽  
Coronary Computed Tomography ◽  
Significant Difference ◽  
Noise Ratio

OBJECTIVE: To determine the optimal pre-adaptive and post-adaptive level statistical iterative reconstruction V (ASiR-V) for improving image quality and reducing radiation dose in coronary computed tomography angiography (CCTA). METHODS: The study was divided into two parts. In part I, 150 patients for CCTA were prospectively enrolled and randomly divided into 5 groups (A, B, C, D, and E) with progressive scanning from 40% to 80% pre-ASiR-V with 10% intervals and reconstructing with 70% post-ASiR-V. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective image quality was assessed using a 5-point scale. The CT dose index volume (CTDIvol) and dose-length product (DLP) of each patient were recorded and the effective radiation dose (ED) was calculated after statistical analysis by optimizing for the best pre-ASiR-V value with the lowest radiation dose while maintaining overall image quality. In part II, the images were reconstructed with the recommended optimal pre-ASiR-V values in part I (D group) and 40%–90% of post-ASiR-V. The reconstruction group (D group) was divided into 6 subgroups (interval 10%, D0:40% post-ASiR-V, D1:50% post - ASiR-V, D2:60% post-ASiR-V, D3:70% post-ASiR-V, D4:80% post-ASiR-V, and D5:90% post-ASiR-V).The SNR and CNR of D0-D5 subgroups were calculated and analyzed using one-way analysis of variance, and the consistency of the subjective scores used the k test. RESULTS: There was no significant difference in the SNRs, CNRs, and image quality scores among A, B, C, and D groups (P > 0.05). The SNR, CNR, and image quality scores of the E group were lower than those of the A, B, C, and D groups (P < 0.05). The mean EDs in the B, C, and D groups were reduced by 7.01%, 13.37%, and 18.87%, respectively, when compared with that of the A group. The SNR and CNR of the D4–D5 subgroups were higher than the D0-D3 subgroups, and the image quality scores of the D4 subgroups were higher than the other subgroups (P < 0.05). CONCLUSION: The wide-detector combined with 70% pre-ASiR-V and 80% post-ASiR-V significantly reduces the radiation dose of CCTA while maintaining overall image quality as compared with the manufacture’s recommendation of 40% pre-ASiR-V.

An open label, prospective, multicenter, non-interventional study of iodixanol 270 mg I/mL for use in individuals undergoing computed tomography angiography in real-world clinical practice

2018 ◽  
Vol 60 (2) ◽  
pp. 177-185
Author(s):  
Xiangying Du ◽  
Bin Lu ◽  
Daoyu Hu ◽  
Bin Song ◽  
Kuncheng Li
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Radiation Dose ◽  
Iterative Reconstruction ◽  
Computed Tomography Angiography ◽  
Pulmonary Arteries ◽  
Open Label ◽  
Tube Voltage ◽  
Effective Radiation Dose ◽  
Noise Ratio

Background Concern about radiation exposure is leading to an increasing interest in low-concentration contrast medium administration. Purpose To evaluate the image quality and safety profile after administration of iodixanol 270 mg I/mL at 100-kVp tube voltage with iterative reconstruction in subjects undergoing computed tomography angiography (CTA). Material and Methods Patients who completed CTA examination using iodixanol 270 mg I/mL and 100-kVp tube voltage along with iterative reconstruction for coronary, aortic, head and neck, renal, or pulmonary arteries were included. Image quality was qualitatively and quantitatively evaluated. Incidence of adverse events (AEs) and adverse drug reactions (ADRs) within seven days and radiation dose were also analyzed. Results A total of 4513 individuals in 42 centers in China were enrolled, among which 4367 were included in efficacy analysis. The mean image quality score was 4.8 ± 0.45 across all arteries (all above 4.6) and 99.7% of the individuals’ images were classified as evaluable. The CT attenuation, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in the regions of interest (ROIs) were 431.79 ± 99.018, 18.29 ± 11.947, and 28.21 ± 19.535 HU, respectively. Of all the participants, 68 (1.5%) and 65 (1.4%) experienced AEs and ADRs, respectively. No serious AEs or AEs leading to discontinuation occurred. The average effective radiation dose was 3.13 ± 2.550 mSv. Conclusion Iodixanol 270 mg I/mL in combination with 100-kVp tube voltage and iterative reconstruction could be safely applied in CTA and yield high-quality and evaluable images with reduced radiation dose.

scholarly journals Low Dose versus Standard Single Heartbeat Acquisition Coronary Computed Tomography Angiography

2018 ◽  
Vol 8 ◽  
pp. 52
Author(s):  
Ernesto Di Cesare ◽  
Alessandra Di Sibio ◽  
Antonio Gennarelli ◽  
Margherita Di Luzio ◽  
Ines Casazza ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Comparative Analysis ◽  
Image Quality ◽  
Radiation Dose ◽  
Effective Dose ◽  
Computed Tomography Angiography ◽  
Coronary Computed Tomography Angiography ◽  
Ct Scanner ◽  
Diagnostic Quality ◽  
Coronary Computed Tomography

Purpose: The aim of this study was to compare image quality and mean radiation dose between two groups of patients undergoing coronary computed tomography angiography (CCTA) using a 640-slice CT scanner with two protocols with different noise level thresholds expressed as standard deviation (SD). Materials and Methods: Two-hundred and sixty-eight patients underwent a CCTA with 640 slice CT scanner. In the experimental group (135 patients), an SD 51 protocol was employed; in the control group (133 patients), an SD 33 protocol was used. Mean effective dose and image quality with both objective and subjective measures were assessed. Image quality was subjectively assessed using a five-point scoring system. Segments scoring 2, 3, and 4 were considered having diagnostic quality, while segments scoring 0 and 1 were considered having nondiagnostic quality. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) between the two groups as well as the effective radiation dose (ED) was finally assessed. Results: Comparative analysis considering diagnostic quality (2, 3, and 4 score) and nondiagnostic (score 0 and 1) quality demonstrated that image quality of SD 51 group is not significantly lower than that of S33 group. The noise was significantly higher in the SD 51 group than in the SD 33 group (P < 0.0001). The SNR and CNR were higher in the SD 33 group than in SD 51 group (P < 0.0001). Mean effective dose was 49% lower in the SD 51 group than in SD 33 group; indeed mean effective dose was 1.43 mSv ± 0.67 in the SD 51 group while it was 2.8 mSv ± 0.57 in the SD 33 group. Conclusion: Comparative analysis shows that using a 640-slice CT with a 51 SD protocol, it is possible to reduce the mean radiation dose while maintaining good diagnostic image quality.

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

2020 ◽  
Vol 93 (1115) ◽  
pp. 20200078
Author(s):  
Annelisa Moura Garcia ◽  
Antonildes N. Assunção-Jr ◽  
Roberto Nery Dantas-Jr ◽  
Jose Rodrigues Parga ◽  
Fernando Ganem
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Computed Tomography Angiography ◽  
Coronary Computed Tomography Angiography ◽  
Coronary Cta ◽  
Double Blind ◽  
Coronary Computed Tomography ◽  
Significant Difference ◽  
Stent Diameter ◽  
Stent Lumen

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.

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