Impact of different reconstruction algorithms on PET image quality and diagnostic efficiency in patients with temporal lobe epilepsy
10.3760/cma.j.cn321828-20240108-00010
- VernacularTitle:不同重建方法对颞叶癫痫患者FDG PET图像质量及诊断效能的影响
- Author:
Kun SHANG
1
;
Jie HU
;
Zhenming WANG
;
Jingjuan WANG
;
Bixiao CUI
;
Xiaoyin XU
;
Jie LU
Author Information
1. 首都医科大学宣武医院放射与核医学科、磁共振成像脑信息学北京市重点实验室，北京 100053
- Keywords:
Epilepsy, temporal lobe;
Image processing, computer-assisted;
Positron-emission tomography;
Fluorodeoxyglucose F18
- From:
Chinese Journal of Nuclear Medicine and Molecular Imaging
2024;44(11):678-683
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the value of time-of-flight (TOF) combined with point spread function (PSF) reconstruction for the improvement of brain PET images and lesion localization in patients with temporal lobe epilepsy (TLE).Methods:A retrospective collection of brain 18F-FDG PET imaging data of 52 hospitalized patients with TLE (30 males, 22 females, age: (26.7±7.1) years) and 26 healthy volunteers (14 males, 12 females, age: ( 31.7±6.8) years) from Xuanwu Hospital between 2017 and 2019 was conducted. Images were reconstructed and divided into 4 groups based on different algorithms: ordered subset expectation maximization (OSEM), OSEM+ TOF, OSEM+ PSF, and OSEM+ TOF+ PSF. The image quality, clarity, noise, and the clarity of lesion display of all subjects were visually analyzed using a four-point scale. The signal-to-noise ratio (SNR), contrast, and asymmetry index (AI) of the lesions were calculated. Differences in visual scores, SNR, contrast, and AI among the 4 groups were analyzed using one-way analysis of variance. The ROC curve was used to analyze the efficiency of PET images in localization of epileptogenic foci. Results:The visual score of OSEM+ TOF+ PSF group was the highest (4.0±0.0) among healthy volunteers; compared with OSEM group, OSEM+ TOF+ PSF group showed lower SNR (decreased by 46.6%; the lower the SNR value, the better the image quality) and contrast (increased by 29.8%). Visual assessment of PET images of patients with TLE showed that the scores of OSEM+ TOF+ PSF group , OSEM+ PSF group , OSEM+ TOF group and OSEM group were decreased in order (4.0±0.0 vs 3.4±0.5 vs 2.3±0.4 vs 1.0±0.0; F=884.0, P<0.001); SNRs of those 4 groups were increased in order ((5.2±2.4)% vs (6.2±2.4)% vs (7.9±2.6)% vs (8.9±3.5)%; F=18.82, P<0.001). The contrast and AI of the lesions in 4 groups were as follows: OSEM+ TOF+ PSF (contrast: 0.81±0.03; AI: 0.28±0.05) > OSEM+ TOF (0.74±0.05; 0.23±0.06) > OSEM+ PSF (0.72±0.06; 0.22±0.07) > OSEM (0.64±0.05; 0.19±0.06) ( F values: 107.10, 19.94, both P<0.001). MRI found unilateral hippocampal sclerosis in 32 patients, and the rest 20 patients with TLE were MRI-negative. ROC curve analysis showed that visual analysis and SUV ratio (SUVR) of lesion/contralateral ROI based on OSEM+ TOF+ PSF PET image could localize epileptogenic foci efficiently, with AUC of 0.874 in MRI-positive patients, and AUC of 0.932 in MRI-negative patients. Conclusions:The application of TOF and PSF significantly improves the quality of PET images. The combined use of both techniques yields the best results and aids in the localization of epileptogenic foci in patients with TLE.
