全模型迭代重建算法评价125I粒子植入术后CT图像

目的 探讨全模型迭代重建（IMR）算法评价¹²⁵I粒子植入术后图像的应用价值。方法 收集接受¹²⁵I粒子植入术及术后CT随访的16例腹部肿瘤患者，对扫描原始数据分别以滤波反投影法（FBP）、IMR和高级重建迭代（iDose⁴）算法进行重建，比较3种重建方法图像的噪声、伪影指数（AI）、CNR和主观评分。结果 FBP重建图像的噪声、CNR及AI分别为（58.65±4.03） HU、1.09±0.43和51.60±9.23，iDose⁴图像分别为（48.38±5.34） HU、1.29±0.48和43.77±4.91，IMR图像分别为（41.46±3.44） HU、1.58±0.56和38.51±4.64，3种重建方法图像的噪声、CNR及AI两两比较差异均有统计学意义（P均<0.05）。IMR图像的主观图像质量评分显著高于FBP和iDose⁴算法图像（调整后P<0.001，P=0.011）。结论 IMR算法获得的图像质量较高，可有效减少¹²⁵I粒子伪影，为¹²⁵I粒子植入术后随访与疗效评估提供了更佳方法。

Model-based knowledge-based iterative reconstruction in evaluation of CT images after 125I seeds implantation

Objective To investigate the application value of model-based knowledge-based iterative reconstruction (IMR) in evaluation of CT images after ¹²⁵I seeds implantation.Methods Totally 16 patients with abdominal tumors and CT follow-up after ¹²⁵I seeds implantation were enrolled. CT data were reconstructed with the filtered back projection (FBP), IMR and iDose⁴ iterative reconstruction technique, respectively. The differences of noise, artifact index (AI), CNR and subjective scores were compared among three methods.Results The noise, CNR and AI of FBP images were (58.65±4.03)HU, 1.09±0.43 and 51.60±9.23, of iDose⁴ images were (48.38±5.34)HU, 1.29±0.48 and 43.77±4.91, of IMR images were (41.46±3.44)HU, 1.58±0.56 and 38.51±4.64, respectively. The differences of pairwise comparisons among three methods on noise, AI and CNR were statistically different (all P<0.05). The objective scores of IMR images were higher than those of FBP and iDose⁴ images (adjust P<0.001, P=0.011).Conclusion The images reconstructed with IMR have high quality, and can reduce the artifact of particle ¹²⁵I effectively, therefore providing a better approach for postoperative follow-up and curative effect evaluation after ¹²⁵I seeds implantation.