Risk factor analysis for major mediastinal vessel invasion in thymic epithelial tumors based on multi-slice CT Imaging.

Objective: To explore the characteristics and risk factors for major mediastinal vessel invasion in different risk grades of thymic epithelial tumors (TETs) based on computed tomography (CT) imaging, and to develop prediction models of major mediastinal artery and vein invasion. Methods: One hundred and twenty-two TET patients confirmed by histopathological analysis who underwent thorax CT were enrolled in this study. Clinical and CT data were retrospectively reviewed for these patients. According to the abutment degree between the tumor and major mediastinal vessels, the arterial invasion was divided into grade I, II, and III (< 25%, 25 - 49%, and ≥ 50%, respectively); the venous invasion was divided into grade I and II (< 50% and ≥ 50%). The degree of vessel invasion was compared among different defined subtypes or stages of TETs using the chi-square tests. The risk factors associated with TET vascular invasion were identified using multivariate logistic regression analysis. Results: Based on logistic regression analysis, male patients (ß = 1.549; odds ratio, 4.824) and the pericardium or pleural invasion (ß = 2.209; odds ratio, 9.110) were independent predictors of 25% artery invasion, and the midline location (ß = 2.504; odds ratio, 12.234) and mediastinal lymphadenopathy (ß = 2.490; odds ratio, 12.06) were independent predictors of 50% artery invasion. As for 50% venous invasion, the risk factors include midline location (ß = 2.303; odds ratio, 10.0), maximum tumor diameter larger than 5.9 cm (ß = 4.038; odds ratio, 56.736), and pericardial or pleural effusion (ß = 1.460; odds ratio, 4.306). The multivariate logistic model obtained relatively high predicting efficacy, and the area under the curve (AUC), sensitivity, and specificity were 0.944, 84.6%, and 91.7% for predicting 50% artery invasion, and 0.913, 81.8%, and 86.0% for 50% venous invasion in TET patients, respectively. Conclusion: Several CT features can be used as independent predictors of ≥50% artery or venous invasion. A multivariate logistic regression model based on CT features is helpful in predicting the vascular invasion grades in patients with TET.

Differentiating thymoma, thymic carcinoma and lymphoma based on collagen fibre patterns with T2- and diffusion-weighted magnetic resonance imaging.

OBJECTIVES: The amount and distribution of intratumoural collagen fibre vary among different thymic tumours, which can be clearly detected with T2- and diffusion-weighted MR images. To explore the incidences of collagen fibre patterns (CFPs) among thymomas, thymic carcinomas and lymphomas on imaging, and to evaluate the efficacy and reproducibility of CFPs in differential diagnosis of thymic tumours. MATERIALS AND METHODS: Three hundred and ninety-eight patients with pathologically diagnosed thymoma, thymic carcinoma and lymphoma who underwent T2- and diffusion-weighted MR imaging were retrospectively enrolled. CFPs were classified into four categories: septum sign, patchy pattern, mixed pattern and no septum sign. The incidences of CFPs were compared among different thymic tumours, and the efficacy and reproducibility in differentiating the defined tumour types were analysed. RESULTS: There were significant differences in CFPs among thymomas, thymic squamous cell carcinomas (TSCCs), other thymic carcinomas and neuroendocrine tumours (OTC&NTs) and thymic lymphomas. Septum signs were found in 209 (86%) thymomas, which differed between thymomas and any other thymic neoplasms (all p < 0.005). The patchy, mixed patterns and no septum sign were mainly seen in TSCCs (80.3%), OTC&NTs (78.9%) and thymic lymphomas (56.9%), respectively. The consistency of different CFP evaluation between two readers was either good or excellent. CFPs achieved high efficacy in identifying the thymic tumours. CONCLUSION: The CFPs based on T2- and diffusion-weighted MR imaging were of great value in the differential diagnosis of thymic tumours. KEY POINTS: • Significant differences are found in intratumoural collagen fibre patterns among thymomas, thymic squamous cell carcinomas, other thymic carcinomas and neuroendocrine tumours and thymic lymphomas. • The septum sign, patchy pattern, mixed pattern and no septum sign are mainly seen in thymomas (86%), thymic squamous cell carcinomas (80.3%), other thymic carcinomas and neuroendocrine tumours (79%) and thymic lymphomas (57%), respectively. • The collagen fibre patterns have high efficacy and reproducibility in differentiating thymomas, thymic squamous cell carcinomas and thymic lymphomas.

MR imaging of thymomas: a combined radiomics nomogram to predict histologic subtypes.

OBJECTIVES: Accurately predicting the WHO classification of thymomas is urgently needed to optimize individualized therapeutic strategies. We aimed to develop and validate a combined radiomics nomogram for personalized prediction of histologic subtypes in patients with thymomas. METHODS: A total of 182 thymoma patients were divided into training (n = 128) and test (n = 54) cohorts. Radiomics features were extracted from T2-weighted, T2-weighted fat suppression, and diffusion-weighted images to establish a radiomics signature in the training cohort. Multivariate logistic regression analysis was used to develop a combined radiomics nomogram that incorporated clinical, conventional MR imaging variables, apparent diffusion coefficient (ADC) value, and radiomics signature. The efficacy of clinical, conventional MR imaging, or ADC model was also evaluated respectively. The performances of different models were compared by receiver operating characteristic analysis and Delong test. The discrimination, calibration, and clinical usefulness of the combined radiomics nomogram were assessed. RESULTS: The radiomics signature, consisting of 14 features, achieved favorable predictive efficacy in differentiating low-risk from high-risk thymomas, outperforming clinical, conventional MR imaging, and ADC models. The combined radiomics nomogram incorporating tumor shape, ADC value, and radiomics signature yielded the best performance (training cohort: area under the curve [AUC] = 0.946, test cohort: AUC = 0.878). The calibration curve and decision curve analysis indicated the clinical utility of the combined radiomics nomogram. CONCLUSIONS: The radiomics signature is a useful tool that can be used to predict histologic subtypes of thymomas. The combined radiomics nomogram improved the individualized subtype prediction in patients with thymomas. KEY POINTS: • Fourteen robust features were selected to develop a radiomics signature for preoperative prediction of thymoma subtype. • MRI-based radiomics signature can differentiate low-risk thymomas from high-risk thymomas with favorable predictive efficacy compared with clinical, conventional MR imaging, and ADC models. • Combined radiomics nomogram based on tumor shape, ADC value, and radiomics signature could improve the individualized subtype prediction in patients with thymomas.

[Effects of organic fertilizer on soil environment and yield of tomato under year-round cultivation]. / æœ‰æœºè‚¥å¯¹è®¾æ–½ç•ªèŒ„å‘¨å¹´æ ½åŸ¹åœŸå£¤çŽ¯å¢ƒå’Œäº§é‡çš„å½±å“.

The early-spring and autumn-winter tomato in greenhouse is the main planting patterns of protected vegetable in North China. Taking the customary fertilization amount of farmers under this planting pattern as control (CK, 100% chemical fertilizer), six organic fertilizer replacing chemical fertilizer treatments were set, namely, 15% (T1), 30% (T2), 45% (T3), 60% (T4), 75% (T5), 100% organic fertilizer (T6), to examine the replacing effects on soil environment and tomato yield. The results showed that soil bacteria increased with increasing organic fertilizer amount, the actinomycetes wers up to 12.12×106 cfu·g-1 under T1 treatment which was the highest one. Combined application of organic fertilizer could increase soil urease activity, decrease catalase activity, increase soil organic matter, and enhance the concentrations of available phosphorus and available potassium, indicating that organic fertilizer had significant effects on soil physical and chemical properties, soil enzyme activity and nutrient accumulation. The invertase activity and available phosphorus content under T1 treatment were the highest, being 1.36 mg·g-1 and 305.4 mg·kg-1, respectively, while the available potassium content of T2 treatment was the highest (582.6 g·kg-1). In addition, T2 had the largest percentage of >0.25 mm water-stable agglomerate (94.2%). Compared with CK, the application of organic fertilizer could improve tomato quality and increase yield. The lycopene content of T1 was the highest (5.69), the sugar-acid ratio of T1 and T2 was 8.19 and 8.70, respectively, with better tastes. The yield of T1 was the highest, followed by T2 treatment, which was 16.6% and 5.8% higher than that of CK, respectively. It suggested that reducing the application rate of chemical fertilizers by 15%-30% with organic fertilizer was a preferred fertilization measure in this planting pattern.

Predicting pathological subtypes and stages of thymic epithelial tumors using DWI: value of combining ADC and texture parameters.

OBJECTIVES: To explore the value of combining apparent diffusion coefficients (ADC) and texture parameters from diffusion-weighted imaging (DWI) in predicting the pathological subtypes and stages of thymic epithelial tumors (TETs). METHODS: Fifty-seven patients with TETs confirmed by pathological analysis were retrospectively enrolled. ADC values and optimal texture feature parameters were compared for differences among low-risk thymoma (LRT), high-risk thymoma (HRT), and thymic carcinoma (TC) by one-way ANOVA, and between early and advanced stages of TETs were tested using the independent samples t test. Receiver operating characteristic (ROC) curve analysis was performed to determine the differentiating efficacy. RESULTS: The ADC values in LRT and HRT were significantly higher than the values in TC (p = 0.004 and 0.001, respectively), also in early stage, values were significantly higher than ones in advanced stage of TETs (p < 0.001). Among all texture parameters analyzed in order to differentiate LRT from HRT and TC, the V312 achieved higher diagnostic efficacy with an AUC of 0.875, and combination of ADC and V312 achieved the highest diagnostic efficacy with an AUC of 0.933, for differentiating the LRT from HRT and TC. Furthermore, combination of ADC and V1030 achieved a relatively high differentiating ability with an AUC of 0.772, for differentiating early from advanced stages of TETs. CONCLUSIONS: Combination of ADC and DWI texture parameters improved the differentiating ability of TET grades, which could potentially be useful in clinical practice regarding the TET evaluation before treatment. KEY POINTS: • DWI texture analysis is useful in differentiating TET subtypes and stages. • Combination of ADC and DWI texture parameters may improve the differentiating ability of TET grades. • DWI texture analysis could potentially be useful in clinical practice regarding the TET evaluation before treatment.

Iodine Quantification Using Dual-Energy Computed Tomography for Differentiating Thymic Tumors.

The aim of the study was to explore the efficacy of iodine quantification with dual-energy computed tomography (DECT) in differentiating thymoma, thymic carcinoma, and thymic lymphoma. MATERIALS AND METHODS: Fifty-seven patients with pathologically confirmed low-risk thymoma (n = 16), high-risk thymoma (n = 15), thymic carcinoma (n = 14), and thymic lymphoma (n = 12) underwent chest contrast-enhanced DECT scan were enrolled in this study. Tumor DECT parameters including iodine-related Hounsfield unit (IHU), iodine concentration (IC), mixed HU (MHU), and iodine ratio in dual phase, slope of energy spectral HU curve (λ), and virtual noncontrast (VNC) were compared for differences among 4 groups by one-way analysis of variance. Receiver operating characteristic curve was used to determine the efficacy for differentiating the low-risk thymoma from other thymic tumor by defined parameters. RESULTS: According to quantitative analysis, dual-phase IHU, IC, and MHU values in patients with low-risk thymoma were significantly increased compared with patients with high-risk thymoma, thymic carcinoma, and thymic lymphoma (P < 0.05/4).The venous phase IHU value yielded the highest performance with area under the curve of 0.893, 75.0% sensitivity, and 89.7% specificity for differentiating the low-risk thymomas from high-risk thymomas or thymic carcinoma at the cutoff value of 34.3 HU. When differentiating low-risk thymomas from thymic lymphoma, the venous phase IC value obtained the highest diagnostic efficacy with the area under the curve of 0.969, and sensitivity, specificity, and cutoff value were 87.5%, 100.0%, and 1.25 mg/mL, respectively. CONCLUSIONS: Iodine quantification with DECT may be useful for differentiating the low-risk thymomas from other thymic tumors.

Usefulness of Volume Perfusion Computed Tomography in Differentiating Histologic Subtypes of Thymic Epithelial Tumors.

PURPOSE: This study aimed to evaluate the usefulness of volume perfusion computed tomography (VPCT) parameters in differentiating the World Health Organization subtypes of thymic epithelial tumors. MATERIALS AND METHODS: This study was approved by the local ethics committee, and informed written consent was obtained. Fifty-one thymic epithelial tumor patients confirmed by histopathological analysis underwent conventional CT and a 48-second VPCT scan of the tumor bulk before any treatment. The VPCT parameters (blood volume [BV], blood flow [BF], mean transit time [MTT], and permeability [PMB]) based on volume of interest (VOI) or region of interest (ROI) were compared for differences among low-risk thymomas (LRTs; types A, AB, and B1), high-risk thymomas (HRTs; types B2 and B3) and thymic carcinomas (TCs) by one-way analysis of variance. RESULTS: The BVVOI, PMBVOI, BVROI, and PMBROI values in LRT were significantly higher than the values from HRT and thymic carcinoma (BVVOI: 13.75, 6.17, and 5.48 mL/100 mL; PMBVOI: 22.47, 9.56, and 13.37 mL/100 mL/min; BVROI: 14.75, 6.87, and 6.06 mL/100 mL; PMBROI: 24.05, 9.79, and 15.63 mL/100 mL/min, respectively; all P < 0.05/3). However, the BFVOI, MTTVOI, BFROI, and MTTROI values did not differ between LRT and HRT or thymic carcinoma groups (P > 0.05/3). CONCLUSIONS: These results suggest that VPCT could be useful in differentiating LRTs from HRTs and TCs preoperatively.

Intravoxel incoherent motion diffusion-weighted MR imaging parameters predict pathological classification in thymic epithelial tumors.

We evaluated the performance of intravoxel incoherent motion (IVIM) parameters for preoperatively predicting the subtype and Masaoka stage of thymic epithelial tumors (TETs). Seventy-seven patients with pathologically confirmed TETs underwent a diffusion weighted imaging (DWI) sequence with 9 b values. Differences in the slow diffusion coefficient (D), fast perfusion coefficient (D*), and perfusion fraction (f) IVIM parameters, as well as the multi b-value fitted apparent diffusion coefficient (ADCmb), were compared among patients with low-risk (LRT) and high-risk thymomas (HRT) and thymic carcinomas (TC), and between early stage (stages I and II) and advanced stage (stages III and IV) TET patients. ADCmb, D, and D* values were higher in the LRT group than in the HRT or TC group, but did not differ between the HRT and TC groups. The mean ADCmb, D, and D* values were higher in the early stage TETs group than the advanced stage TETs group. The f values did not differ among the groups. These results suggest that IVIM DWI could be used to preoperatively predict subtype and Masaoka stage in TET patients.

Study of the optimisation of puffing characteristics of potato cubes by spouted bed drying enhanced with microwave.

BACKGROUND: In commercial deep-fat frying of potato chips, the oil content of the final products ranges from 35 to 45 g 100 g(-1) (wet basis). High-temperature frying may cause the formation of acrylamide, making the products unhealthy to the consumer. The aim of this research was to explore a new method, spouted bed microwave drying, to produce healthier puffed snack potato cubes as possible alternatives to oil-fried potato chips. The influence of drying conditions of the spouted bed microwave drying on puffing characteristics of potato cubes were studied and compared with the direct microwave and hot air drying method. RESULTS: Tandem combination drying of microwave-enhanced spouted bed drying (MWSB) could achieve a good expansion ratio, breaking force and rehydration ratio. The puffing characteristics of potato cubes were significantly affected (P < 0.05) by moisture content before starting microwave power in spouted bed microwave drying, by microwave (MW) power, and by the original size of potato cubes. CONCLUSION: The optimum processing parameters were the moisture content at the start of microwave power (60%), the size of potato cubes (10-12 mm), and microwave power (2-2.5 W g(-1))

Research on focal nodular hyperplasia with MSCT and postprocessing.

AIM: To investigate and evaluate the pathological features and diagnostic value of focal nodular hyperplasia (FNH) with multi-section spiral computed tomography (MSCT) and postprocessing. METHODS: A total of 25 patients with FNH who had undergone MSCT and postprocessing were included in the investigation. All patients had been pathologically or clinically confirmed with FNH. A number of 75 cases of hepatic carcinomas, hemangiomas and adenomas were randomly selected at a same period for a comparative study. RESULTS: There was a single focus in 22 cases and multiple foci in 3 cases. On the plain scan, 17 lesions showed hypodensity, 7 isodensity and 4 hyperdensity (the case with fatty liver). With contrast, 28 lesions were enhanced evenly or in the nodules in the arterial phase; 13 lesions still showed hyperdensity, 11 lesions isodensity and 4 lesions hypodensity in the parenchymatous phase; in the delayed phase only 5 lesions showed hyperdensity but 9 lesions showed isodensity or slight hypodensity and 14 lesions showed hypodensity. Twelve lesions of 28 had central asteroid scars. Thickened feeding arteries in postprocessing were seen in 24 lesions, and were integrated into the parenchymatous lesions with a gradual and smooth course. On the contrary, there were no artery penetrated into the lesion found in any of comparative hepatic tumors. CONCLUSION: Doctors could make a correct diagnosis and differentiation of FNH on evaluation of the characteristic appearance on MSCT with postprocessing.

[Triple-phase helical CT in the differential diagnosis between small hepatocellular carcinoma and small hepatic cavernous hemangioma].

OBJECTIVE: To scrutinize the enhancement pattern at hepatic arterial phase (HAP), portal venous phase (PVP) and delayed phase (DP) by helical CT examination in order to differentiate small hepatocellular carcinoma (SHCC) from small hepatic cavernous hemangioma (SHCH). METHODS: In 38 patients (41 lesions) with SHCC and 35 patients (45 lesions) with SHCH, the images at HAP, PVP and DP were recorded as to the characteristic of enhancements with the average CT value at the HAP monitored and compared. RESULTS: The enhancement patterns of SHCC at the HAP, PVP, and DP were assessed as hyper-hypo-hypodense in 20 lesions, hyper-iso-hypodense in 6 lesions, hyper-hyper-hypodense in 3 lesions, hyper-iso-isodense in 5 lesions, iso-hypo-hypodense in 3 lesions, and hypo-hypo-hypodense in 4 lesions. The enhancement patterns of the SHCH were assessed as a peripheral hyperdense nodular at HAP, then progressively enlarged at PVP and turned into a isodense or homogeneous hyperdense nodular at DP in 27 lesions, hyper-hyper-iso or hyperdense in 9 lesions, hyper-iso-isodense in 3 lesions, hypo-hypo-hypodense in 6 lesions. The enhancement CT values at the HAP of homogeneous hyperdense SHCC and SHCH were (40.4 +/- 15.5) Hounsfield Unit (HU) and (102.8 +/- 18.9) HU respectively (P < 0.01). CONCLUSION: Most of the small hepatocellular carcinoma and small hepatic cavernous hemangioma have typical appearance by triple-phase helical CT examination, and can easily and properly be diagnosed. But it is difficult to distinguish SHCC from SHCH with atypical appearance in isolated cases. Hence differentiation may be difficult. Therefore, further examinations such as MRI, ultra-sonography or isotope scintigraphy are helpful in the differential diagnosis.