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Purpose <p>To evaluate the value of dual-energy computed tomography (DECT) combined with the iterative metal artifact reduction (iMAR) for postoperative endovascular aortic repair (EVAR) CT angiography (CTA) surveillance.</p> Methods <p>In this prospective study, post-EVAR CTA surveillance was performed using a Siemens Force CT (100/150 kVp dual-energy). Images were reconstructed as conventional mixed and 40–190&#xa0;keV virtual monoenergetic images (VMIs), with and without iMAR. Image quality was assessed via quantitative parameters and 5-point subjective scores, with clinical data and radiation dose recorded simultaneously. Diagnostic performance was referenced to surgical/DSA findings and blinded expert adjudication. Statistical analysis was performed via two-way repeated-measures ANOVA with post-hoc paired t-tests or Wilcoxon tests for quantitative parameters, While subjective scores were analyzed using the Friedman test with post-hoc Wilcoxon signed-rank tests. P values were Bonferroni-corrected; corrected <i>P</i> &lt; 0.05 indicated significance.</p> Results <p>Fifty post-EVAR patients (82% male; 68.7 ± 8.9 years) received safe radiation doses; stent type yielded no quantitative differences (<i>P</i> &gt; 0.05). iMAR-DECT synergistically enhanced image quality, with improvements correlating positively with artifact severity while sparing normal tissues for iMAR. Energy levels dominated the trend: most parameters declined rapidly at 40–70&#xa0;keV but plateaued beyond 100&#xa0;keV. iMAR significantly outperformed non-iMAR in scores of artifact reduction (plateauing at 150–190&#xa0;keV) and vessel visibility (peaking at 90&#xa0;keV, <i>P</i> &lt; 0.01). For diagnosis, iMAR+DECT converted five false negatives into true positives (endoleaks, thrombosis, infection), showing a trend toward higher sensitivity than those for non-iMAR+DECT (<i>P</i> &gt; 0.05, large effect size).</p> Conclusion <p>The integration of DECT-VMIs with the iMAR algorithm appears to improve image quality in post-EVAR CTA by effectively reducing stent-related metal artifacts while enhancing vascular and soft-tissue visualization. Based on our quantitative and qualitative assessments, an energy level of 90&#xa0;keV (effective range 80–100&#xa0;keV) may be considered optimal to optimize diagnostic evaluation, pending validation in larger, multi-center cohorts.</p>

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Dual-energy CT with metal artifact reduction for post-EVAR CTA surveillance: a prospective study with image quality analysis

  • 期刊论文

  • 发表日期：

    2026年7月16日

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  • Dingxiang Xie,
  • Xiaofang Chen,
  • Jinzhu Wang,
  • Chao Jiang,
  • Lina Chen,
  • Jing Zhao,
  • Zhiman Lai,
  • Hui Ma

摘要

Purpose

To evaluate the value of dual-energy computed tomography (DECT) combined with the iterative metal artifact reduction (iMAR) for postoperative endovascular aortic repair (EVAR) CT angiography (CTA) surveillance.

Methods

In this prospective study, post-EVAR CTA surveillance was performed using a Siemens Force CT (100/150 kVp dual-energy). Images were reconstructed as conventional mixed and 40–190 keV virtual monoenergetic images (VMIs), with and without iMAR. Image quality was assessed via quantitative parameters and 5-point subjective scores, with clinical data and radiation dose recorded simultaneously. Diagnostic performance was referenced to surgical/DSA findings and blinded expert adjudication. Statistical analysis was performed via two-way repeated-measures ANOVA with post-hoc paired t-tests or Wilcoxon tests for quantitative parameters, While subjective scores were analyzed using the Friedman test with post-hoc Wilcoxon signed-rank tests. P values were Bonferroni-corrected; corrected P < 0.05 indicated significance.

Results

Fifty post-EVAR patients (82% male; 68.7 ± 8.9 years) received safe radiation doses; stent type yielded no quantitative differences (P > 0.05). iMAR-DECT synergistically enhanced image quality, with improvements correlating positively with artifact severity while sparing normal tissues for iMAR. Energy levels dominated the trend: most parameters declined rapidly at 40–70 keV but plateaued beyond 100 keV. iMAR significantly outperformed non-iMAR in scores of artifact reduction (plateauing at 150–190 keV) and vessel visibility (peaking at 90 keV, P < 0.01). For diagnosis, iMAR+DECT converted five false negatives into true positives (endoleaks, thrombosis, infection), showing a trend toward higher sensitivity than those for non-iMAR+DECT (P > 0.05, large effect size).

Conclusion

The integration of DECT-VMIs with the iMAR algorithm appears to improve image quality in post-EVAR CTA by effectively reducing stent-related metal artifacts while enhancing vascular and soft-tissue visualization. Based on our quantitative and qualitative assessments, an energy level of 90 keV (effective range 80–100 keV) may be considered optimal to optimize diagnostic evaluation, pending validation in larger, multi-center cohorts.