To explore how the joint-teaching mode of tomographic-radiologic anatomy and topographic anatomy in a way of case-based learning (CBL) promotes the education of medical students.

Objective:To explore the value of MRI features in predicting the pathological grade of rectal neuroendocrine tumors and to develop a predicting model.Methods:A retrospective analysis was performed on 30 cases of rectal neuroendocrine tumors confirmed by surgery and pathology between 2013 and 2019. All of them underwent plain rectal MRI, DWI and dynamic contrast-enhanced MRI. The clinical features and MRI characteristics (ie. tumor location, maximum tumor diameter, boundary, growth pattern, enhancement of three-staged lesions, and the lymph node metastasis) were analyzed by statistical methods to evaluate the difference between different tumor pathologic grades (G1, G2 and G3). Characteristics with statistical significance were analyzed by collinearity diagnostics, and stepwise regression method was used to select independent predictors. Ordinal logistic regression analysis was then conducted to develop the predicting model.Results:Maximum tumor diameter, tumor boundary, growth pattern, mr-T, mr-N, EMVI, MRF, T2WI signal intensity, tumor enhancement degree in venous phase and distant metastasis were closely correlated with the pathological grade of rectal neuroendocrine tumors ( P<0.001, 0.001, 0.001, <0.001, 0.001, 0.004, 0.024, 0.015, 0.001, and <0.001, respectively). The mr-T and tumor enhancement degree in venous phase were identified as the independent predictors to construct the prediction model. The model got ideal performance in predicting the grades, with the areas under the receiver operating characteristic (ROC) curves (AUCs) of 0.945, 0.624 and 0.896, the sensitivities were 75.0%, 85.7%, and 90.9% and corresponding specificities were 88.9%, 52.6% and 93.3% for G1, G2 and G3 rectal neuroendocrine tumors, respectively. Conclusion:The model based on mr-T and tumor enhancement degree in venous phase can serve as a clinical tool for predicting the pathological grade of rectal neuroendocrine tumors.

Objective:To explore the value of MRI features in predicting the pathological grade of rectal neuroendocrine tumors and to develop a predicting model.Methods:A retrospective analysis was performed on 30 cases of rectal neuroendocrine tumors confirmed by surgery and pathology between 2013 and 2019. All of them underwent plain rectal MRI, DWI and dynamic contrast-enhanced MRI. The clinical features and MRI characteristics (ie. tumor location, maximum tumor diameter, boundary, growth pattern, enhancement of three-staged lesions, and the lymph node metastasis) were analyzed by statistical methods to evaluate the difference between different tumor pathologic grades (G1, G2 and G3). Characteristics with statistical significance were analyzed by collinearity diagnostics, and stepwise regression method was used to select independent predictors. Ordinal logistic regression analysis was then conducted to develop the predicting model.Results:Maximum tumor diameter, tumor boundary, growth pattern, mr-T, mr-N, EMVI, MRF, T2WI signal intensity, tumor enhancement degree in venous phase and distant metastasis were closely correlated with the pathological grade of rectal neuroendocrine tumors ( P<0.001, 0.001, 0.001, <0.001, 0.001, 0.004, 0.024, 0.015, 0.001, and <0.001, respectively). The mr-T and tumor enhancement degree in venous phase were identified as the independent predictors to construct the prediction model. The model got ideal performance in predicting the grades, with the areas under the receiver operating characteristic (ROC) curves (AUCs) of 0.945, 0.624 and 0.896, the sensitivities were 75.0%, 85.7%, and 90.9% and corresponding specificities were 88.9%, 52.6% and 93.3% for G1, G2 and G3 rectal neuroendocrine tumors, respectively. Conclusion:The model based on mr-T and tumor enhancement degree in venous phase can serve as a clinical tool for predicting the pathological grade of rectal neuroendocrine tumors.

Objective:To explore the diagnostic accuracy improved by magnetic resonance imaging (MRI) biomarkers for lymph node metastasis in T1-2 stage rectal cancer before treatment.Methods:Medical records of 327 patients with T1-2 rectal cancer who underwent pretreatment MRI and rectal tumor resection between January 2015 and November 2019 were retrospectively analyzed. Fifty-seven cases were divided into the lymph node metastasis group (N+ group) while other 270 cases in the non-lymph node metastasis group (N-group) according to the pathologic diagnosis. Two radiologist evaluated the tumor characteristics of MRI images. The relationship of the clinical and imaging characteristics of lymph node metastasis was assessed by using univariate analysis and multivariable logistic regression analysis. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic abilities for the differentiation of N- from N+ tumors.Results:Among the 327 patients, MR-N evaluation was positive in 67 cases, which was statistically different from the pathological diagnosis ( P<0.001). The sensitivity, specificity and accuracy of MRI for lymph node metastasis were 45.6%, 84.8% and 78.0%, respectively. Multivariate regression analysis showed that tumor morphology ( P=0.002), including mucus or not ( P<0.001), and MR-N evaluation ( P<0.001) were independent influencing factors for stage T1-2 rectal cancer with lymph node metastasis. The area under the ROC curve of rectal cancer with lymph node metastasis analyzed by the logistic regression model was 0.786 (95% CI: 0.720~0.852). Conclusions:Tumor morphology, including mucus or not, and MR-N evaluation can serve as independent biomarkers for differentiation of N- and N+ tumors. The model combined with these biomarkers facilitates to improve the diagnostic accuracy of lymph node metastasis in T1-2 rectal cancers by using MRI.

Objective:To explore the diagnostic accuracy improved by magnetic resonance imaging (MRI) biomarkers for lymph node metastasis in T1-2 stage rectal cancer before treatment.Methods:Medical records of 327 patients with T1-2 rectal cancer who underwent pretreatment MRI and rectal tumor resection between January 2015 and November 2019 were retrospectively analyzed. Fifty-seven cases were divided into the lymph node metastasis group (N+ group) while other 270 cases in the non-lymph node metastasis group (N-group) according to the pathologic diagnosis. Two radiologist evaluated the tumor characteristics of MRI images. The relationship of the clinical and imaging characteristics of lymph node metastasis was assessed by using univariate analysis and multivariable logistic regression analysis. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic abilities for the differentiation of N- from N+ tumors.Results:Among the 327 patients, MR-N evaluation was positive in 67 cases, which was statistically different from the pathological diagnosis ( P<0.001). The sensitivity, specificity and accuracy of MRI for lymph node metastasis were 45.6%, 84.8% and 78.0%, respectively. Multivariate regression analysis showed that tumor morphology ( P=0.002), including mucus or not ( P<0.001), and MR-N evaluation ( P<0.001) were independent influencing factors for stage T1-2 rectal cancer with lymph node metastasis. The area under the ROC curve of rectal cancer with lymph node metastasis analyzed by the logistic regression model was 0.786 (95% CI: 0.720~0.852). Conclusions:Tumor morphology, including mucus or not, and MR-N evaluation can serve as independent biomarkers for differentiation of N- and N+ tumors. The model combined with these biomarkers facilitates to improve the diagnostic accuracy of lymph node metastasis in T1-2 rectal cancers by using MRI.

Objective: To evaluate the value of T2WI signal intensity related parameters that can be obtained by magnetic resonance imaging (MRI) for predicting pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanved rectal cancer (LARC). Methods: Signal Intensity of Tumor (SIT) and Signal Intensity of Tumor/Muscle (SIT/M) of MR T2WI before and after neoadjuvant chemoradiotherapy of 101 patients with locally advanced rectal cancer were evaluated by two experienced readers independently. Signal Intensity of Tumor Reduction Rate (SITRR) and Signal Intensity of Tumor/Muscle Reduction Rate (SIT/MRR) were calculated. The difference of related parameters of T2WI tumor signal intensity between the pCR and the non-pCR group were analyzed. Receiver operating characteristic (ROC) analysis was used to assess the diagnostic performance for predicting pCR. Results: Of the 101 patients, 18 were in pCR group and 83 were in non-pCR group. In all patients, the SITpre, SITpost, SITRR, SIT/Mpre, SIT/Mpost and SIT/MRR measured by reader 1 were 197.0 (133.0), 144.2 (69.7), 0.4% (0.5%), 2.6 (0.6), 3.0 (2.3) and 0.4 (0.2)% in pCR group, and 227.0 (99.0), 205 (95.4), 0.1% (0.6%), 2.6 (0.6), 2.6 (1) in non-pCR group, respectively. SITpre, SITpost, SITRR, SIT/Mpre, SIT/Mpost and SIT/MRR measured by reader 2 were 193.0 (135.0), 143.0 (69.8), 0.4% (0.2%), 2.6 (0.6), 1.5 (0.5) and 0.39% (0.2%) in pCR group, and 234.0(108.0), 203(96.5), 0.1% (0.3%), 2.6 (0.6%), 1.7 (0.7) and 0.25% (0.2%) in non-pCR group, respectively. Between the pCR and non-pCR group, there were significant differences in SITpost, SIT/Mpost and SIT/MRR measured by both readers (all P<0.01), but there was no significant differences in SITpre and SIT/Mpre (P>0.05). The difference of SITRR measured by reader 1 was not statistically significant (P=0.415), while the difference of SITRR measured by reader 2 was statistically significant (P=0.001). In patients with rectal non-mucinous adenocarcinoma, SITpost, SIT/Mpost, SITRR and SIT/MRR measured by two physicians were still statistically significant between the pCR and non-pCR group (all P<0.01), but SITpre and SIT/Mpre had no significant difference (P>0.05). ROC curve analysis showed that in all patients, the area under curve (AUC) of SITpost, SIT/Mpost and SIT/MRR for predicting pCR to neoadjuvant chemoradiotherapy in locally advanced rectal cancer was 0.694-0.762, the sensitivity was 68.2%-77.3%, and the specificity was 63.6%-77.3%. In rectal non-mucinous adenocarcinoma patients, the AUC, sensitivity and specificity was 0.704-0.764, 62.7%-78.9% and 66.2%-84.2%, respectively. Conclusions T2WI signal intensity related parameters are potential predictors for pCR in locally advanced rectal cancer after neoadjuvant chemoradiptherapy. The predictive value is higher in non-mucinous adenocarcinoma.

Objective To find out the clinical indicators related to prognosis in patients with acute mushroom poisoning, and approach its correlation with prognosis. Methods Clinical data of patients with mushroom poisoning admitted to the First Hospital of China Medical University, the Ninth People's Hospital of Shenyang, Xiuyan Central People's Hospital, and Fushun Central Hospital from August 2015 to August 2017 were retrospectively analyzed. The biochemical indicators within 24 hours after admission, sequential organ failure assessment (SOFA) score, model for end-stage liver disease (MELD) score, whether plasmapheresis (PE) was carried out or not and 28-day prognosis of patients were collected. According to prognosis, the patients were divided into death group and survival group, and the differences in above parameters between the two groups were compared. Spearman or Pearson correlation method was used to analyze the relationship between MELD score and prognosis. Receiver operating characteristic (ROC) curve was used to analyze the prognostic value of MELD score for prognosis. Further analysis of the patients receiving PE treatment was conducted. Results A total of four Liaoning hospitals with 89 patients with mushroom poisoning were enrolled, with 6 died within 28 days, and 83 survived. There were 17 patients with severely impaired liver and coagulant functions accepted PE treatment, with 6 patients died within 28 days, and 11 survived. ① In 89 patients, compared with survival group, MELD score, prothrombin time (PT), activated partial thromboplastin time (APTT), total bilirubin (TBil), international normalized ratio (INR), blood glucose (Glu), alanine aminotransferase (ALT), γ-glutamyltransferase (GGT) in death group were significantly increased [MELD score: 32.34 (28.31, 41.06) vs. 8.76 (3.77, 21.19), PT (s): 53.5 (52.4, 113.2) vs. 14.5 (13.8, 19.5), APTT (s): 58.6 (48.9, 70.8) vs. 36.9 (34.4, 43.2), TBil (μmol/L): 134.8 (31.3, 155.6) vs. 21.5 (15.1, 41.4), INR: 6.0 (5.6, 14.7) vs. 1.2 (1.1, 1.5), Glu (mmol/L): 9.2 (9.0, 11.0) vs. 6.6 (5.7, 7.8), ALT (U/L):5 923.0 (1 105.0, 6 000.0) vs. 35.0 (18.0, 1 767.0), GGT (U/L): 49.0 (32.0, 57.0) vs. 25.0 (16.0, 41.0), all P < 0.05], but the prothrombin activity (PTA), albumin (ALB), serum Na+, Cl- were significantly decreased [PTA: 13.0% (6.0%, 14.0%) vs. 80.0% (61.0%, 87.0%), ALB (g/L): 31.1 (29.8, 39.0) vs. 42.4 (37.9, 44.3), Na+(mmol/L): 126.5 (122.4, 131.0) vs. 137.0 (134.9, 141.0), Cl- (mmol/L): 93.5 (87.6, 95.0) vs. 104.0 (101.3, 106.0), all P < 0.05]. Spearson correlation analysis showed that MELD score of patients with mushroom poisoning was positively correlated with the 28-day mortality (r = 0.423, P = 0.001). ROC curve analysis showed that the area under ROC curve (AUC) of MELD score for prognosis of patients with mushroom poisoning was 0.926; when the cut-off value was 27.30, the sensitivity was 100%, and the specificity was 84.3%. ② In 17 patients who accepted PE treatment, compared with survival group, the MELD score, TBil, Glu, and ALT in the death group were significantly increased [MELD score: 36.81±5.18 vs. 29.01±5.23, TBil (μmol/L): 145.2±13.9 vs. 93.2±44.0, Glu (mmol/L): 9.1±1.9 vs. 6.0±2.7, ALT (U/L): 5 961.5±44.5 vs. 3 932.9±1 625.7, all P < 0.05], and Cl- was significantly lowered (mmol/L: 94.3±1.2 vs. 100.5±5.7, P < 0.05), but SOFA score showed no significant difference (5.83±2.71 vs. 5.91±1.58, P > 0.05). Correlation analysis showed that the MELD score in patients with mushroom poisoning who accepted PE treatment was positively correlated with 28-day mortality (r = 0.355, P = 0.001), but no correlation with SOFA score was found (r = 0.427, P = 0.087). ROC curve analysis showed that the AUC of MELD score in the prediction of mushroom poisoning patients undergoing PE treatment was 0.545; when the cut-off value was 32.19, the sensitivity was 33.3%, and the specificity was 100%. Conclusions In mushroom poisoning patients, especially those undergoing PE treatment, the higher the MELD score, the higher the mortality is. MELD score could assess the prognosis of patients with acute mushroom poisoning.

Objective To compare the predictive value of radiomics signature extracted from MRI plain and enhancement sequence for the disease-free survival (DFS) of rectal cancer. Methods We retrospectively analyzed fifty-one patients with rectal adenocarcinoma confirmed by biopsy from October 2010 to December 2013 in Cancer Hospital Chinese Academy of Medical Sciences.All patients underwent neoadjuvant chemotherapy(nCRT)followed total mesorectal excision(TME),and MRI scans were performed before nCRT.Follow-up time for the survival patients were more than 3 years.The image segmentation was performed on the T2WI sequence of the small FOV and the multi-phase enhancement sequence venous phase,respectively.Least absolute shrinkage and selection operator(LASSO)Cox regression was applied to extract radiomics features and the imaging signature was constructed. According to the radiomics score of each patient,the patients were divided into the high risk group with shorter DFS and the low risk group with longer DFS. A 3-year DFS was calculated for radiomics signature using the Kaplan-Meier product limit method with univariate log-rank analysis testing for differences in the training and validation cohort, respectively. And the predictive ability of the model was evaluated by concordance index (C-index). Results The training set and the validation set were 36 and 15 cases, respectively. During follow-up 32 patients experienced relapse(26 distant,3 local and 3 both),and 19 cases were censored.Twelve features were extracted in the enhanced sequence.The radiomics signatures were significant for DFS in the training set and the validation set(P=0.000 2 and 0.009 1,respectively).The C-index of the model were 0.904 and 0.700 in the training set and the validation set, respectively. The model has the better ability to predict survival.Two features were extracted in the plain sequence.The radiomic signature was significant for DFS in the training set(P=0.005 0),while the radiomics signature was not significant for DFS in the validation set (P=0.767 0). The C-index of the model were 0.711 and 0.500 in the training set and the validation set, respectively.Conclusions Radiomics signature extracted from MRI venous phase enhancement sequence superior to plain sequence for predicting the DFS of rectal cancer before nCRT.

Objective: To compare the diagnostic value of T2 weighted imaging (T2WI), diffusion-weighted imaging (DWI), and T2WI+ DWI magnetic resonance imaging (MRI) for staging of rectal cancers for improving the accuracy of tumor staging. Methods: From January 2011 to December 2013, 120 cases of rectal cancers proved by colonoscopy without receiving any anti-tumor treatment were enrolled retrospectively. The MRI data for these patients were divided into three groups, ie., T2WI, DWI and T2WI+ DWI, for evaluating the tumor stages. The results were compared with histopathologic findings. The sensitivity and specificity were calculated and compared with chi-square test. The nodal staging was predicted by using T2WI+ DWI. Results: The accuracy for prediction of tumor staging was 83.3%, 65.0% and 92.5% for T2WI, DWI, and T2WI+ DWI respectively. The specificity for evaluating T1 and T2 stage, and the sensitivity for evaluating T3 by DWI was significantly lower than those using T2WI and T2WI+ DWI in rectal cancers. The sensitivity for evaluation of T2 by DWI was lower than that using T2WI+ DWI (63.0% vs. 88.9%). The sensitivity for evaluation T2 and specificity for T3 by T2WI+ DWI was higher than thouse using T2WI only (88.9% vs. 51.9%, 94.0% vs. 72.0%). The accuracy for prediction of nodal staging by using T2WI+ DWI was 62.1% (72/116). Conclusions T2WI is the key sequence for staging of rectal cancers. Although the diagnostic accuracy was not good by using DWI alone, the combination of T2WI and DWI can improve the accuracy significantly for tumor staging in rectal cancers, whereas the nodal staging was still a hard task for radiologists.

Objective To compare the diagnostic value of T2 weighted imaging ( T2WI) , diffusion?weighted imaging ( DWI) , and T2WI+DWI magnetic resonance imaging ( MRI) for staging of rectal cancers for improving the accuracy of tumor staging. Methods From January 2011 to December 2013, 120 cases of rectal cancers proved by colonoscopy without receiving any anti?tumor treatment were enrolled retrospectively. The MRI data for these patients were divided into three groups, ie., T2WI, DWI and T2WI+DWI, for evaluating the tumor stages. The results were compared with histopathologic findings. The sensitivity and specificity were calculated and compared with chi?square test. The nodal staging was predicted by using T2WI+DWI. Results The accuracy for prediction of tumor staging was 83. 3％, 65. 0％ and 92. 5％ for T2WI, DWI, and T2WI+DWI respectively. The specificity for evaluating T1 and T2 stage, and the sensitivity for evaluating T3 by DWI was significantly lower than those using T2WI and T2WI+DWI in rectal cancers. The sensitivity for evaluation of T2 by DWI was lower than that using T2WI+DWI ( 63. 0％ vs. 88.9％) . The sensitivity for evaluation T2 and specificity for T3 by T2WI+DWI was higher than thouse using T2WI only (88.9％ vs. 51.9％, 94.0％ vs. 72.0％). The accuracy for prediction of nodal staging by using T2WI+DWI was 62.1％ ( 72/116) . Conclusions T2WI is the key sequence for staging of rectal cancers. Although the diagnostic accuracy was not good by using DWI alone, the combination of T2WI and DWI can improve the accuracy significantly for tumor staging in rectal cancers, whereas the nodal staging was still a hard task for radiologists.