Optimization of 90Y PET/CT imaging based on the block-sequential regularized expectation maximization reconstruction algorithm
10.3760/cma.j.cn321828-20250307-00063
- VernacularTitle:基于块序列正则化期望最大化重建算法对 90Y PET/CT显像优化的研究
- Author:
Tiantian ZHANG
1
;
Ziwei LIANG
;
Zhongbin HANG
;
Yan ZHANG
;
Deqing LIU
;
Yuhang SHAN
;
Yong LIAO
;
Xin HUANG
;
Bin LIANG
;
Lin ZHANG
;
Xiaobin FENG
;
Zuoxiang HE
Author Information
1. 清华大学北京清华长庚医院核医学科，北京 102218
- Publication Type:Journal Article
- Keywords:
Liver neoplasms;
Brachytherapy;
Microspheres;
Yttrium radioisotopes;
Image processing, computer-assisted;
Positron-emission tomography;
Tomography, X-ray co
- From:
Chinese Journal of Nuclear Medicine and Molecular Imaging
2025;45(6):335-340
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To optimize the image quality of PET/CT following 90Y-selective internal radiation therapy ( 90Y-SIRT) using block-sequential regularized expectation maximization (BSREM) reconstruction algorithm, and to evaluate its impact of different β values on image quality and quantitative analysis. Methods:A retrospective study was conducted on 8 male patients with hepatic tumors (age: 62(52, 71) years) treated at Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua Medicine Tsinghua University, between June 2024 and January 2025. All patients were treated with 90Y resin microspheres (2.6(0.9, 3.6)GBq) and underwent post-treatment 90Y PET/CT liver imaging. Imaging data were reconstructed using BSREM with different noise penalty weighting factors ( β values: 0, 300, 1000, 1500, 2500, 3500, 4000, 6000, 8000, 10000). Visual assessment was independently performed by two nuclear medicine physicians, using a 4-point scale (1=worst, 4=best). The mean score was considered as the final score. The consistency of the 2 reviewers was calculated and analyzed by Kappa test. Visual scores of different β value groups were compared by Friedman test. The β value demonstrating highest mean score and optimal consistency was selected as the optimal. Quantitative analysis was performed using MIM software to calculate the maximum absorbed dose ( Dmax) and the mean absorbed dose ( Dmean) for tumor, normal liver, and whole liver regions, and the CV was used to evaluate the impact of β values. Results:The visual assessment consistency of reviewers in 3 β value groups (0, 3500, 6000) were the highest (7/8) (all kappa=0.88, all P<0.05). Visual scores of the 10 β value groups were significantly different ( χ2=28.74, P<0.001), and the visual scores of 2 β value groups (3500, 4000) were the highest, both of which were 4.0(4.0, 4.0). Overall, visual assessment identified β=3500 as the optimal. Quantitative analysis revealed that, (1) Dmax in all regions (tumor, normal liver, whole liver) decreased with the increasing β values, stabilizing when β>1000 ( CV 56%-67%); (2) Dmean remained stable across different β values ( CV 0.04%-5.00%). Conclusions:In BSREM reconstruction, β=3500 is the optimal parameter for improving 90Y-PET image quality. β values significantly affect Dmax (stabilizing at β > 1000), but have no significant impact on Dmean, suggesting that reconstruction parameters primarily influence dose distribution morphology rather than average dose assessments.
