| Objective:1.assessment of the effectiveness and value of PET / CT combined ROI delineation methods; 2.analysis based on 3D texture analysis of the diagnostic value of PET/CT images of solitary pulmonary nodules.Method:1. retrospectively collected 27 cases of abnormal metabolism of pulmonary lesions found in the patient’s image data, the use of artificial methods as the standard interpretation,obtain the single PET method, the single CT method and PET / CT combined method of ROI delineation’s DSC HD value respectively, Comparethe DSC values and HD value differencesof the three methods by variance analysis. According cells and histological results, the patients were divided into 2 groups of benign and malignant, obtain the value of DSC values and HD values of 2 groups by PET / CT combined ROI delineation method, Using t test to compare two groups DSC values and HD value differences. 2. retrospectively collected 367 cases from seven centers diagnosis or suspected cases of SPN, include single tracer FDG and dual tracer FDG-FLT PET / CT images and clinical data. Extract 3D texture parameters by the package, use the software package of Machine learning algorithms to calculate the degree of correlation characteristic parameters before 80,and obtainthe accuracy, specificity and sensitivity when different number of parameters included in the equation diagnostic respectively.Comparison the diagnostic performance of the two methods,with cells and histological results as the gold standard, manual interpretation method as a control group,using the chi-square test comparison the accuracy of them.Results: 1.27 cases of patients included total 32 lesions, 20 malignant lesions, 12benign lesions. When using single PET ROI delineation method, DSC value was 83.19±2.58, HD value was 5.15±0.42; when using single CT ROI delineation method, DSC value was88.01±2.56, HD value was4.98±0.37; when using PET / CT combined ROI delineation method, DSC value was91.38±2.23, HD value was4.54±0.30;P value <0.01 when comparethe DSC values and HD value differencesof the three methods by variance analysis. DSC value was 90.17 ± 1.85, HD value was 4.62 ± 0.32,whenuse PET / CT combined method in benign lesions ROI delineation; DSC value was 92.10±2.15, HD value was4.49±0.29,whenuse PET / CT combined method in malignantlesions ROI delineation.Compare DSC values and HD value differences between them by t test, P = 0.186 and 0.541 respectively.2. 367 cases of patientsincludedtotal 394 lesions. Extract 340 feature parameters from cases with single tracer FDG PET / CT examination;extract 681 feature parameters from cases with dual tracer FDG-FLT PET / CT examination.The accuracy, sensitivity and specificity were 69% ,67% and 75% in FDG single tracer PET / CT examination respectively;the accuracy, sensitivity and specificity were 83% ,81% and 85% in FDG-FLT dual tracer PET / CT examination respectively. The accuracy, sensitivity and specificity of the manual interpretation method control group with single tracer FDG PET / CT examination were 71% ,83% and 73% respectively, and with dual tracer FDG-FLT PET / CT examination were 71% ,83% and 73% respectively.Conclusion: 1.PET / CT combined ROI delineation method outperforms single modal ROI delineation method, especially for ill-defined or low contrast with the surrounding tissue lesions. Have a certain clinical application and research work potential.2.3D texture analysis and manual interpretation have similar diagnostic performance in the case of single tracer FDG PET / CT examination, but better than manual interpretation in cases of dual tracer FDG-FLT PET / CT examination.It provided significantly improved specificity, reduced the rate of misdiagnosis, and has little effect on subjective deviation, repeatability, and the work efficiency can be significantly improved, Have a certain clinical application and research work potential. |
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