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Objective:To explore the value of conventional MRI radiomics for predicting occult cervical lymph nodes (LNs) metastases in early-stage oral tongue squamous cell carcinoma (OTSCC).Methods:The preoperative MRI data of 77 cases of early-stage OTSCCs (cT1-2N0M0) in Shanghai Ninth People′s Hospital from January 2015 to December 2019 were retrospectively analyzed. All patients underwent primary lesion resection with selective neck dissection and the pathologic reports of LNs couldal be obtained. In total, 168 LNs (51 positive and 117 negative metastases) were enrolled and allocated into training set ( n=112) and validation set ( n=56) with a ratio of 2∶1 using random number table. The volumes of interest of LNs on T 2WI and contrast enhanced T 1WI (ceT 1WI) were delineated by two doctors using ITK-SNAP software. The 1 046 radiomics features of each sequence were extracted using 3D Slicer software. Data dimension reduction was done by inter-observer agreement analysis and univariate analysis. The least absolute shrinkage and selection operator regression analysis were used for selecting optimal feature subsets and constructing radiomics signature for each sequence. Mann-Whitney U test was used to compare the differences of node size and radiomics scores between the LNs with positive and negative metastases. The receiver operating characteristic (ROC) curve was used to explore the performance of LNs size, T 2WI radiomics signature and ceT 1WI radiomics signature in predicting occult LNs metastases. Stepwise logistic regression was used to determine the independent predictors. Results:Fifteen and 10 optimal features were selected to construct radiomics signature for T 2WI and ceT 1WI respectively. The short diameter, T 2WI radiomics signature and ceT 1WI radiomics signature showed significant differences between LNs with positive and negative metastases in the both training and validation sets (all P<0.05), with the areas under the ROC curve of 0.67, 0.83 and 0.82 in the training set, and 0.69, 0.78 and 0.70 in the validation set, respectively. In the stepwise logistic regression analysis, T 2WI radiomics signature was identified as the independent predictor in the both sets (training set: OR=5.92, P<0.001; validation set: OR=2.53, P=0.012). Conclusion:Conventional MRI radiomics can provide a good potential to predict occult LNs metastases in early-stage OTSCC.
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Objective To explore the value of texture analysis on ADC maps in the preoperative prediction of histological grade of tongue and mouth floor squamous cell carcinoma (SCC). Methods Forty?nine pathologically confirmed tongue and mouth floor SCC with definite grading from May 2015 to June 2018 were retrospectively analyzed, including 21 cases of gradeⅠ, 21 cases of gradeⅡand 7 cases of gradeⅢ. All subjects underwent preoperative MRI examination with DWI included. Two doctors delineated whole tumor region of interest and extracted texture parameters by the 3D Slicer software, including 8 histogram parameters, 11 grey?level co?occurrence matrix (GLCM) parameters and 7 gray?level run?length matrix (GLRLM) parameters. Intraclass correlation coefficient (ICC) was used to evaluate the inter?observer delineation agreement, and the texture parameters with excellent reproducibility (ICC>0.8) were used for analysis only. Mann?Whitney U test was used to compare the differences of ADC texture parameters between grade Ⅰ and grade Ⅱ?Ⅲ SCCs. Stepwise logistic regression was used to determine the independent predictors and to build combined model. ROC analysis was used to explore the performance of texture parameter and model in predicting histological grade of tongue and mouth floor SCCs. Pearson correlation coefficient was used to evaluate the correlation between texture parameters with statistical significance. Results (1) Excellent inter?observer delineation agreement (ICC: 0.81-0.98) was observed in 69.23% (18/26) texture parameters, including 6 histogram parameters, 7 GLCM parameters and 5 GLRLM parameters. (2) Among histogram parameters, significantly higher 10 percentile ADC value (ADC10) and significantly lower energy and entropy were shown in gradeⅠcompared with gradeⅡandⅢSCCs (all P<0.05). Among GLCM parameters, significantly lower joint entropy, difference entropy, sum entropy, difference variance, difference average and contrast were shown in grade Ⅰ SCCs (all P<0.05). Among GLRLM parameters, significantly lower gray?level nonuniformity and run?length nonuniformity were shown in gradeⅠSCCs (all P<0.05). ADC10 and entropy were identified as independent predictors. The ADC10 and entropy were 960(913, 1 178)×10?6mm2/s and 4.32(4.06, 4.76) in gradeⅠSCCs, and 888(816, 987)×10?6mm2/s and 4.88(4.57, 5.29) in gradeⅡ?ⅢSCCs respectively. The area under ROC curve (AUC) of ADC10, entropy and combined model were 0.72, 0.75, 0.81. (3) Significant correlation (|r|≥0.5) was observed among 52.73% (29/55)texture parameters with statistical significance. Conclusion Texture analysis on ADC maps can provide more quantitative information, which can be more accurately in discriminating grade Ⅰfrom gradeⅡ?Ⅲtongue and mouth floor SCCs.
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Objective To evaluate the value of conventional and functional MRI in the diagnosis of orbital solitary fibrous tumor (SFT).Methods MR images of 8 patients with pathologically confirmed orbital SFT were analyzed retrospectively.The lesion shape, size,location and signal features on conventional MRI were evaluated.Apparent diffusion coefficient(ADC)values and DCE-MRI parameters(time-signal intensity curve pattern,maximum ratio of enhancement and washout ratio)were calculated.Results The majority of tumors(6/8)showed regular shape with maximum diameters varying from 2.5 cm to 3.7 cm.Of 8 cases,there was 1 case in intraconal space,2 cases involved with intra and extraconal space,5 cases in extraconal space.On T1WI,all lesions demonstrated isointense to gray matter.On T2WI,5 lesions showed isointensity and 3 lesions showed slight hypointensity,of which 6 cases showed heterogeneous signal.After contrast enhancement,8 lesions showed marked enhancement.Plateau pattern of time-signal intensity curve was observed in 6 cases with maximum ratio of enhancement of 1.37 ± 0.54 and washout ratio of 6.58% ± 3.66%.Mean ADC value was(1.28 ± 0.25)×10-3mm2/s.Conclusion Combination of conventional MRI,DWI and DCE-MRI can assist the diagnosis of orbital SFT.
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Objective To discuss the application value of texture analysis of conventional MRI in differential diagnosis of orbital lymphoma from inflammatory pseudotumor.Methods The conventional MRI data of 15 patients with lymphoma and 17 patients with inflammatory pseudotumor proven by pathology or clinical follow-up were retrospectively reviewed.The texture features of lesions based on axial T1WI,fat-saturated T2WI and contrast enhanced fat-saturated T1WI were extracted by manually drawn ROIs with software MaZda.The subsets of optimized texture parameters were chosen by four different methods:Fisher coefficient,probability of classification error and average correlation coefficient (POE+ ACC),mutual information measure (MI) and the combination of the above three methods (FPM),respectively.Linear discriminant analysis (LDA) and nonlinear discriminant analysis (NDA) were performed for texture classification.The texture features from the sequence with the best classification result of orbital lymphoma and inflammatory pseudotumor were compared.Results The optimal texture parameters were mainly derived from co occurrence matrix and run-length matrix on T1WI and T2WI.The optimal texture parameters were mainly derived from co-occurrence matrix and histogram on contrast enhanced T1WI.The best classification of MRI texture was obtained within T2WI with lowest classification error of 1.56％ achieved by FPM in combination with NDA.Comparing the texture parameters of orbital lymphoma and inflammatory pseudotumor on T2WI,the angular second moment and long length emphasis were significantly higher in orbital lymphoma (both P＜0.005),while the entropy and short length emphasis were significantly lower in orbital lymphoma (both P＜0.005).Conclusion It is feasible to use texture analysis on conventional MRI for the differentiation of orbital lymphoma and inflammatory pseudotumor.