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Objective:To develop and validate a MRI-based radiomics nomogram combining with radiomics signature and clinical factors for the preoperative differentiation of benign parotid gland tumors (BPGT) and malignant parotid gland tumors (MPGT).Methods:From January 2015 to May 2020, 86 patients with parotid tumors confirmed by surgical pathology in the Affiliated Hospital of Qingdao University were enrolled as training sets, and 35 patients in the University of Hong Kong-Shenzhen Hospital from January 2013 to January 2020 were enrolled as independent external validation sets. The logistic regression was used to establish a clinical-factors model based on demographics and MRI findings. Radiomics features were extracted from preoperative T 1WI and fat-saturated T 2WI (fs-T 2WI), a radiomics signature model was constructed, and a radiomics score (Rad-Score) was calculated. A combined diagnostic model and nomogram combining with the Rad-score and independent clinical factors was constructed using multivariate logistic regression analysis. The receiver operating characteristic (ROC) analysis was used to evaluate the performance of each model and DeLong test was used for comparison of area under the ROC curve (AUC). Results:The logistic regression results showed that deep lobe involvement (OR=3.285, P=0.040) and surrounding tissue invasion (OR=15.919, P=0.013) were independent factors for MPGT and constructed the clinical-factors model. A total of 19 features were extracted from the joint T 1WI and fs-T 2WI to build the radiomics signature model. The combined diagnostic model and nomogram incorporating deep lobe involvement, surrounding tissue invasion and Rad-score were established. The AUCs of the clinical-factors model, radiomics signature model and combined diagnostic model for differentiating BPGT from MPGT for the training and validation sets were 0.758, 0.951, 0.953 and 0.752, 0.941 and 0.964 respectively. The AUCs of the radiomics signature model and the combined diagnostic model were significantly higher than those of the clinical-factors model for both training and validation sets (training set: Z=3.95, 4.31, both P<0.001; validation set: Z=2.16, 2.67, P=0.031, 0.008). There was no statistical difference in AUCs between the radiomics signature model and combined diagnostic model (training set: Z=0.39, P=0.697; validation set: Z=1.10, P=0.273). Conclusions:The MRI-based radiomics signature model and radiomics nomogram incorporating deep lobe involvement, surrounding tissue invasion, and Rad-score showed favorable predictive efficacy for differentiating BPGT from MPGT.
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Objective To investigate the differential diagnostic value of 18F-fluorodeoxyglucose (FDG) PET/CT for benign and malignant vertebral compression fractures in patients with malignant tumor.Methods From August 2007 to July 2016,79 patients with vertebral compression fractures were enrolled.Patients were divided into 3 groups based on clinical follow-up or pathological results:osteoporosis group (n =40;13 males,27 females,median age:77 years),metastasis group (n=27;18 males,9 females,median age:64 years) and myeloma group (n=12;7 males,5 females,median age:67.5 years).Characteristics of 18 F-FDG PET/CT imaging and maximum standardized uptake value (SUVmax) of involved vertebrae were compared using x2 test,one-way analysis of variance and the least significant difference t test.SUVmax of normal L2 vertebral body was regarded as the control.Results (1) There were 53,41 and 16 compression fractures identified in osteoporosis group,metastasis group and myeloma group,respectively.No paravertebral soft tissue mass or spinal accessory involvement was found in osteoporosis group.In metastasis group,14(34.15％,14/41) paravertebral soft tissue masses and 28 spinal accessory involvements (68.29％,28/41) were detected,and the numbers were 2 (2/16) and 16 (16/16) for myeloma group respectively.There were significant differences for paravertebral soft tissue masses and spinal accessory involvements among 3 groups (x2 values:21.75,73.10,both P＜0.01).(2)In osteoporosis group,all lesions displayed strip-like (100％,53/53) 18F-FDG accumulation.In metastasis group,there were nodular accumulation (12.20％,5/41),bulk accumulation (43.90％,18/41),and irregular accumulation (43.90％,18/41).In myeloma group,the 18 F-FDG accumulation were strip-like (14/16) and irregular (2/16).The accumulation patterns among 3 groups were significantly different (x2=103.67,P＜0.01).(3)SUVmax of osteoporosis group,metastasis group,myeloma group and control group was 4.00±0.14,7.33±4.05,4.17±0.39 and 2.33±0.06,respectively (F=46.45,P＜0.01).The SUVmax between each 2 groups were significant (t values:12.38-29.51,all P＜0.05) except for that between osteoporosis group and myeloma group (t=0.26,P＞0.05).Conclusions Strip-like 18F-FDG accumulation,SUVmax of vertebral body,paravertebral soft tissue masses and spinal accessory involvements in 18F-FDG PET/CT imaging are important for differential diagnosis of benign and malignant compression fractures.
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Objective To analyze the clinical value of digital breast tomosynthesis (DBT) compared with digital mammography (DM) and ultrasound for diagnosing non-calcified masses in dense breasts.Methods Images taken with DBT,DM and ultrasound of 1144 patients with non-calcified masses in dense breasts were retrospectively analyzed using breast imaging reporting and data system (BI-RADS).Taking histopathologic results as golden standards,the detection rate and diagnostic accuracy,sensitivity,specificity,false negative and BI-RADS category were evaluated and compared statistically.Results The detection rate of DBT,DM and ultrasound for non-calcified massed in dense breasts was 86.62％ (991/1 144),77.80％ (890/1 144) and 99.65％ (1 140/1 144),respectively (P＜0.05),while the diagnostic accuracy was 83.92％ (960/1 144),75.00％ (858/1 144) and 94.67％ (1 083/1 144),respectively (P＜0.01).The sensitivity of DBT,DM and ultrasound was 89.39％ (312/349),79.93％ (231/289) and 92.70％ (432/466),the specificity was 81.51％ (648/795),73.33％ (627/855) and 96.02％ (651/678),while the false negative rate was 10.60％(37/349),20.07％ (58/289) and 7.30％ (34/466),respectively.No significant difference was found for benign lesions among three examination methods (P=0.75),while there was significant difference for malignant lesions among three examination methods (P＜0.01),and the differences of ultrasonography with DM and DBT,DBT and DM in the for BI-RADS category of malignant lesions were statistically significant (all P＜0.016 7).Conclusion For suspected masses in dense breasts,DBT shows significant advantage than DM,while DBT has the similar advantage compared with ultrasound for the detection and diagnosis of non-calcified masses in dense breasts.
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Objective To investigate the effective indicators for the prognosis assessment in pa?tients with multiple myeloma (MM) by 18F?FDG PET/CT imaging. Methods A total of 36 patients(22 males, 14 females;median age 63.5 years) with MM confirmed by clinical or pathology from July 2007 to November 2014 were retrospectively reviewed. The number of lesions detected by PET/CT, the number of lesions with SUVmax>2.5, the SUVmax and MTV of each lesion were calculated. The correlation analysis was performed between the number of lesions detected by PET or CT,the number of lesions with SUVmax>2.5, the SUVmax , MTV and serumβ2?microglobulin (β2?M) , respectively. The patients were divided into differ?ent groups according to the development of lesions and the survival situation during the follow?up ( 4-92 months) . Kaplan?Meier analysis and multivariate Cox model were used to analyze the prognostic significance of the number of lesions detected by PET or CT and the number of lesions with SUVmax>2.5, the SUVmax and MTV. Results Both the number of lesions with SUVmax>2. 5 and MTV showed positive correlations with blood β2?M (r=0.776, 0.954, both P0.05) . The number of lesions with SUVmax>2.5 and MTV in the progressive group( n=14) were significantly higher than those in the regressive group(n=22):66.57±4.59 vs 31.95±4.75, t=4.95, P2.5 and MTV were significantly higher in the dead group(n=15) than those in the survival group(n=21):65.73±4.32 vs 30.90±4.87, t=5.10, P2. 5, and those were 114.74 and 105.48 cm3 for MTV, respectively. The progression?free survival rate was worse in the patients with higher index than those with lower value (χ2=18.20, 29.74, both P2.5 and MTV on 18 F?FDG PET/CT images could predict the progression?free survival and overall survival rates of patients with MM, which may provide accurate prognosis information.