The value of orthopedic metal artifact reduction technology in dual-layer detector CT for improving postoperative CT image quality in patients with lumbar internal fixation implants
10.3760/cma.j.cn112149-20241223-00754
- VernacularTitle:双层探测器CT去金属伪影技术改善腰椎内固定植入患者术后CT图像质量的价值
- Author:
Yuting WEN
1
;
Yu YANG
;
Xinyue LI
;
Yan ZHENG
;
Xuelin PAN
;
Xiaodi ZHANG
;
Huafeng CUI
;
Zhenlin LI
Author Information
1. 四川大学华西医院放射科，成都 610041
- Publication Type:Journal Article
- Keywords:
Tomography, X-ray computed;
Dual-layer detector;
Virtual monoenergetic imaging;
Orthopedic metal artifact reduction algorithms;
Image quality assessment
- From:
Chinese Journal of Radiology
2025;59(5):591-598
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the clinical utility of dual-layer detector CT integrated with virtual monoenergetic imaging (VMI) and an orthopedic metal artifact reduction (O-MAR) algorithm in improving the image quality of patients after lumbar pedicle screw fixation surgery, and to analyze its impact on different types of artifacts and image quality of different tissues.Methods:The study was a prospective study, The study enrolled patients who underwent lumbar pedicle screw fixation at West China Hospital of Sichuan University between March and September 2024. All patients underwent lumbar CT scans using a dual-layer detector system, and four image sets were reconstructed. CLumbar routine scans were performed using dual-layer detector CT, and four image sets were reconstructed:onventional images (CI non-O-MAR), conventional images with O-MAR (CI O-MAR), virtual monoenergetic images (VMI non-O-MAR), and VMI with O-MAR (VMI O-MAR). Objective metrics including artifact index (AI), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were quantified, alongside subjective image quality assessment. One-way ANOVA or Friedman test were used to compare the objective evaluation indicators of image quality between VMI non-O-MAR and VMI O-MAR at different energy levels. Paired t-test or Wilcoxon signed-rank test was used for CI non-O-MAR/VMI non-O-MAR versus CI O-MAR/VMI O-MAR comparisons. Results:A total of 30 patients were included, and all underwent internal fixation with titanium alloy pedicle screws. Objective analysis revealed that in both high-and low-density artifact regions, the AI values of the VMI O-MAR group decreased with the increase of energy levels, and were significantly lower than those of the corresponding VMI non-O-MAR group, with a statistically significant difference (all P<0.001). When the energy level≥140 keV, the AI value of the VMI O-MAR group was simultaneously lower than that of the CI non-O-MAR group and the CI O-MAR group, with statistically significant differences (all P<0.05). The SNR and CNR on the vertebral bodies in the VMI non-O-MAR group and the VMI O-MAR group showed a decreasing trend with increasing energy levels, and were always lower than those in the CI group at high energy levels (100-180 keV) (all P<0.05). At high energy levels (100-180 keV), the SNR of VMI O-MAR in the intervertebral disc and intraspinal tissues was higher than that of the VMI non-O-MAR group, with statistically significant differences (all P<0.05). Compared to other groups, subjective analysis indicated that the 140 keV VMI combined with O-MAR group received the highest image quality scores ( P<0.05). Conclusions:The combined application of VMI and O-MAR technology effectively reduces metal artifacts in post-lumbar fixation CT images. The 140 keV VMI with O-MAR reconstruction provides superior image quality and enhances diagnostic confidence.
