Objective:To investigate the application value of a joint prediction model based on lymph node imaging features in evaluating lymph node metastasis of locally advanced rectal cancer (LARC) patients after neoadjuvant chemoradiotherapy (nCRT).Methods:The retrospective cohort study was conducted. The clinicopathological data of 215 LARC patients who were admitted to Peking University Cancer Hospital & Institute from July 2010 to June 2015 were collected. There were 131 males and 84 females, aged (56.7±10.1)years. All 215 patients were randomly divided into a training set of 143 cases and a testing set of 72 cases using a 2∶1 ratio of random seed numbers. The training set was used to construct the prediction model, and the testing set was used to validate the performance of prediction model. Observation indicators: (1) lymph node metastasis in LARC patients after nCRT; (2) imaging feature selection and model construction and evaluation. Com-parison of measurement data with normal distribution between groups was conducted using the independent sample t test. Comparison of measurement data with skewed distribution between groups was conducted using the Mann-Whitney U test. Comparison of count data between groups was conducted using the chi-square test. Univariate and multivariate analyses were conducted using the Logistic regression model. Performance evaluation of prediction model was conducted using the receiver operating characteristic (ROC) curve. The area under the curve (AUC), accuracy, sensitivity, and specificity were calculated. Calibration curves and decision curves were used to evaluate the consistency and clinical application value of the prediction model. Results:(1) Lymph node metastasis in LARC patients after nCRT. Of the 215 LARC patients after nCRT, results of postoperative pathological examination showed that there were 162 cases with negative lymph node metastasis and 53 cases with positive lymph node metastasis, showing significant differences in age and maximum short-axis diameter of lymph node between them ( t=2.178, Z=-5.305, P<0.05). (2) Imaging feature selection and model construction and evaluation. Forty-one imaging features were extracted from the 215 LARC patients after nCRT, including 9 gray-level first-order features, 24 gray-level co-occurrence matrix features and 8 shape features. The score of lymph node (LNscore) in 162 cases with negative lymph node metastasis and 53 cases with positive lymph node metastasis were 0.18(0.10,0.33) and 0.39(0.23,0.54), respectively, showing a significant difference between them ( Z=-5.487, P<0.05). Results of multivariate analysis showed that maximum short-axis diameter of lymph node and LNscore were independent factors influencing lymph node metastasis of LARC patients after nCRT ( odds ratio=1.277, 25.514, 95% confidence interval as 1.010-1.614, 2.003-324.964, P<0.05). A Logistic regression joint prediction model was constructed by incorporating the maximum short-axis diameter of lymph node and LNscore. The ROC curves results showed that the AUC, accuracy, sensitivity, and specificity of the joint prediction model in the training set were 0.779 (95% confidence interval as 0.702-0.844), 72.7%, 71.4%, and 73.2%, respectively. The above indicators in the testing set were 0.805 (95% confidence interval as 0.694-0.889), 80.6%, 66.7%, and 85.2%, respectively. Calibration curves in both training set and test set showed good agreement with the ideal curve, indicating high calibration. Decision curves demonstrated the model′s clinical utility with a high net benefit. Conclusion:The maximum short-axis diameter of lymph node and LNscore are independent factors influencing lymph node metastasis of LARC patients after nCRT. The joint prediction model constructed based on the above indicators can be used to predict lymph node metastasis in LARC patients after nCRT.

Objective:To investigate the application value of a joint prediction model based on lymph node imaging features in evaluating lymph node metastasis of locally advanced rectal cancer (LARC) patients after neoadjuvant chemoradiotherapy (nCRT).Methods:The retrospective cohort study was conducted. The clinicopathological data of 215 LARC patients who were admitted to Peking University Cancer Hospital & Institute from July 2010 to June 2015 were collected. There were 131 males and 84 females, aged (56.7±10.1)years. All 215 patients were randomly divided into a training set of 143 cases and a testing set of 72 cases using a 2∶1 ratio of random seed numbers. The training set was used to construct the prediction model, and the testing set was used to validate the performance of prediction model. Observation indicators: (1) lymph node metastasis in LARC patients after nCRT; (2) imaging feature selection and model construction and evaluation. Com-parison of measurement data with normal distribution between groups was conducted using the independent sample t test. Comparison of measurement data with skewed distribution between groups was conducted using the Mann-Whitney U test. Comparison of count data between groups was conducted using the chi-square test. Univariate and multivariate analyses were conducted using the Logistic regression model. Performance evaluation of prediction model was conducted using the receiver operating characteristic (ROC) curve. The area under the curve (AUC), accuracy, sensitivity, and specificity were calculated. Calibration curves and decision curves were used to evaluate the consistency and clinical application value of the prediction model. Results:(1) Lymph node metastasis in LARC patients after nCRT. Of the 215 LARC patients after nCRT, results of postoperative pathological examination showed that there were 162 cases with negative lymph node metastasis and 53 cases with positive lymph node metastasis, showing significant differences in age and maximum short-axis diameter of lymph node between them ( t=2.178, Z=-5.305, P<0.05). (2) Imaging feature selection and model construction and evaluation. Forty-one imaging features were extracted from the 215 LARC patients after nCRT, including 9 gray-level first-order features, 24 gray-level co-occurrence matrix features and 8 shape features. The score of lymph node (LNscore) in 162 cases with negative lymph node metastasis and 53 cases with positive lymph node metastasis were 0.18(0.10,0.33) and 0.39(0.23,0.54), respectively, showing a significant difference between them ( Z=-5.487, P<0.05). Results of multivariate analysis showed that maximum short-axis diameter of lymph node and LNscore were independent factors influencing lymph node metastasis of LARC patients after nCRT ( odds ratio=1.277, 25.514, 95% confidence interval as 1.010-1.614, 2.003-324.964, P<0.05). A Logistic regression joint prediction model was constructed by incorporating the maximum short-axis diameter of lymph node and LNscore. The ROC curves results showed that the AUC, accuracy, sensitivity, and specificity of the joint prediction model in the training set were 0.779 (95% confidence interval as 0.702-0.844), 72.7%, 71.4%, and 73.2%, respectively. The above indicators in the testing set were 0.805 (95% confidence interval as 0.694-0.889), 80.6%, 66.7%, and 85.2%, respectively. Calibration curves in both training set and test set showed good agreement with the ideal curve, indicating high calibration. Decision curves demonstrated the model′s clinical utility with a high net benefit. Conclusion:The maximum short-axis diameter of lymph node and LNscore are independent factors influencing lymph node metastasis of LARC patients after nCRT. The joint prediction model constructed based on the above indicators can be used to predict lymph node metastasis in LARC patients after nCRT.

Objective: To compare the characteristics of MRI signals in different therapeutic effect of desmoid-type fibromatosis (DF). Methods: One hundred and twenty-four DF patients with pathologically proven postoperative recurrent lesions from Peking University Cancer Hospital from 2008 to 2015 were enrolled in the study. All patients had baseline MRI scans, followed by once MRI scan at least every six months, and the follow-up period was three years. All patients had MRI images at the end of the third year. The therapeutic effect was evaluated by response evaluation criteria in solid tumors (RECIST) criteria, and the patients were divided into three groups: progressive disease (PD), stable disease (SD) and partial response (PR). Differences in features in the PD, SD, and PR groups were compared using one-way analysis of variance, Kruskal-Wallis, or Chi-square test. Multiple comparisons were performed using Bonferroni to correct P values. The spearman correlation coefficient was used to test the correlation between signal score and tumor maximum diameter. Results: Among the 124 patients, 17 experienced PD, 37 exhibited SD and 70 exhibited PR. There were no significant differences in age, gender distribution and the location of lesion among three groups (P>0.05). The difference of treatment strategies was statistically significant (P<0.05). The difference of tumor maximum diameter of baseline and the last follow-up MRI scan was also statistically significant between three groups (P<0.05). There was no significant differences in T₂ scores and enhancement scores of baseline MRI scan among the PD, SD, and PR groups (P>0.05). At the last follow-up MRI scan, the T₂ signal scores, the changes of T₂ signal, the scores of enhancement and the changes of enhancement of the PD, SD, and PR groups were significantly different among three groups (P<0.05). At the last follow-up MRI scan, the tumor maximum diameter was positively correlated with the score of T₂ signal (r=0.434, P<0.01), and the tumor maximum diameter was positively correlated with the score of enhancement (r=0.743, P<0.01). Conclusion MRI has great value in evaluating the therapeutic effect of DF.

Objective: To explore the value of preoperative MRI in evaluating prognosis of resectable soft tissue sarcomas (STS) after surgery. Methods: Data of 70 STS patients confirmed pathologically who underwent radical surgery and preoperative MRI were retrospectively analyzed. The tumor sizes were measured, signal intensity heterogeneity at T2WI, tumor enhancement, peritumoral edema, peritumoral enhancement, vascular/nerve or bone invasion and other signs on MRI were evaluated. The progression free survival (PFS) were evaluated, and the impact factors of PFS after radical surgery of STS were analyzed by using univariate and multivariate analyses. Results: Among 70 patients, local relapses and metastatic relapses occurred in 14 (14/70, 20.00%) and 22 cases (22/70, 31.43%) during follow-up. The median progression time was 22 months, and 1-, 2- and 3- year PFS was 62.86% (44/70), 51.43% (36/70) and 51.43% (36/70), respectively. Age, histological grade, preoperative therapy, the longest diameter of tumor, signal intensity heterogeneity at T2WI, peritumoral edema, peritumoral enhancement, vascular/nerve or bone invasion, tail sign and intercompartmental extension were the impact factors for PFS of STS after radical surgery (all P<0.05). The longest diameter of tumor, peritumoral enhancement and vascular/nerve or bone invasion were independent predictors for PFS of STS patients after radical surgery (all P<0.05). Conclusion: MRI had important predictive value for prognosis of resectable STS. The longest diameter of tumor, peritumoral enhancement and vascular/nerve or bone invasion were independent predictors for PFS of STS patients after radical surgery.

Objective: To investigate the accuracy of MRI measurement of early cervical carcinoma invasion depth of stroma. Methods: Preoperative MRI data, including T2WI, DCE-MRI and DWI of 66 early cervical cancer patients were retrospectively analyzed. The maximum depth of cervical interstitial invasion was measured on MRI. The tumors were divided into infiltrating type (including deep infiltrating and two-way infiltrating)and intraluminal growth type. The consistency of MRI measurements and pathological results were analyzed, and the difference values of the maximum depth of cervical interstitial invasion measured by 3 kinds of MRI and pathological results were compared. Results: Among 66 patients, deep infiltrating was observed in 31 cases, two-way infiltrating in 17 and intraluminal growth type carcinoma in 18 cases. The maximum depth of cervical stromal infiltration measured on T2WI, DCE-MRI and DWI were all moderately consistent with pathological results (ICC=0.66, 0.57 and 0.60, all P<0.05). No statistical difference of the difference of MRI and pathological results was found (F=5.95, all P>0.05). MRI measurement of invasive tumors, especially for those with deep infiltrating had superior consistent with pathological results than that of intraluminal growth tumors. Conclusion: MRI has good accuracy in measuring the depth of interstitial invasion of early cervical cancer, for tumors with deep infiltrating is better than for intraluminal growth type tumors.

Objective: To investigate the clinical characteristics, treatment and prognosis of relapsed demyeli-nating disease (RDD) associated with myelin oligodendrocyte glycoprotein antibodies (MOG abs) children in southern China. Methods: Children with RDD associated with MOG abs at Department of Neurology in Guangzhou Women and Children′s Medical Center from January 2015 to December 2018 were retrospectively analyzed.The annualized relapse rates (ARRs) and expand disability status scale (EDSS) were used to assess the recurrence frequency and neurological dysfunction respectively. Results: Ten children were included with the age of (6.4±3.6) years old, and male to female ratio was 4∶6.(1)Clinical phenotype: all children had 24 episodes during follow-up, with acute disseminated encephalomyelitis (ADEM)(7/10 cases) and neuromyelitis optica spectrum disorders (NMOSD)(3/10 cases) on the first episode.Among 14 recurrent episodes, ADEM (9/14 times) was the most common, followed by optic neuritis(ON)(3/14 times)and brainstem encephalitis (2/14 times). By the final follow-up, the final diagnosis was multiphasic disseminated encephalomyelitis(MDEM)(6/10 cases), NMOSD(3/10 cases), ADEM-ON(1/10 case), respectively.(2)Laboratory examination: all the children had positive serum MOG abs in the acute stage.The serum MOG abs titer high group(≥1∶640)(6 cases)on the first episode complicated ON (3 cases) and long segment myelitis (3 cases) more common than those of low group(1∶320)(4 cases). (3)Imaging changes: 25 times of bain magnetic resonance imaging (MRI) were performed in the acute stage, MRI changes mostly involved the cortex and subcortical white matter.Four cases had abnormal spinal cord MRI.(4)Treatment and prognosis: intravenous methylprednone (IVMP) combined with intravenous immunoglobulin (IVIG) were administrated in acute stage.Rituximab (2/10 cases), mycophenolate mofetil (4/10 cases), IVIG (2/10 cases) monthly and low dose prednisone orally (2/10 cases) were given respectively in maintains stage.ARRs decreased from 1.4 to 0 and EDSS score improved significantly after these treatments above.Seven cases had residual neurological dysfunction with 3 cases of NMOSD, 3 cases of MDEM and 1 case of ADEM-ON, including motor dysfunction, learning disability and inattention, symptomatic epilepsy and visual impairment. Conclusions ADEM is the most common form of RDD associated with MOG abs in children.Those with high serum MOG abs titer on the first episode are prone to have ON or long segment myelitis.Immunomodification therapy is effective in the relapsed patients, residual neurological sequelae were related to the type of repeated demyelination.

Objective To develop and validate one optimal MR radiomics model for lymph node (LN) re-evaluation of locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotheray (NCRT). Methods Four hundred and seven patients with clinicopathologically confirmed LARC in Beijing Cancer Hospital were included in this study from July 2010 to June 2015. All patients received NCRT before surgery,and underwent T2WI and DWI before and after NCRT.These patients were chronologically divided in the primary cohort(300 patients)and independent validation cohort(107 patients).The predicting model was trained and validated using postoperative pathological findings as truth values. By using radiomics method, we extracted the features of the tumor and the largest LN before and after neoadjuvant therapy, combined different features of the tumor and/or the largest LN before and/or after neoadjuvant therapy,and constructed 4 different prediction models,compared the performance of four predicting models.The optimal model with the highest accuracy was validated in the independent cohort. Decision curve analysis was conducted to determine the clinical usefulness of the radiomics nomograms by quantifying the net benefits at different threshold probabilities in the validation dataset. Results In the primary cohort, the radiomics signatures from 4 models provided an AUC of 0.637, 0.709, 0.753, 0.835, respectively in LN re-evaluation after chemoradiotheray. The diagnostic efficacy of model 4 was much better than that of 1, 2 and 3 model. In the validation cohort, the radiomics signatures provided an AUC of 0.795 for LN re-evaluation after chemoradiotheray. The sensitivity, specificity, positive predictive value, negative predictive value were 0.813, 0.693, 0.531, 0.897, respectively (95% CI: 0.694 to 0.896, 0.647 to 0.911, 0.582 to 0.786, 0.361 to 0.621, 0.792 to 0.952). While the probability of predicting N+ ranges from 17% to 80%, using the proposed radiomics model to predict N+ shows a greater advantage than either the scheme in which all patients were assumed to N+ or the scheme in which all patients are N-. Decision curve analysis demonstrated that the radiomics nomograms were clinically useful. Conclusion With a systematic analysis and comparison of both pre-and post-NCRT MRI data, we constructed an optimal individualized LN re-evaluation model based on MR radiomics, combing primary tumor and the largest LN features, compared with other models (only with pre/post tumor or pre/post largest LN features).

Purpose To evaluate parameter changes of pelvic floor muscles in patients with female pelvic organ prolapse (POP) through diffusion tensor imaging (DTI).Materials and Methods Fifty female patients with POP at Ⅲ or ⅣV degree (research group) and fifty healthy women volunteers (control group) were collected to make prospective research.The axial DTI sequence was performed in subjects,with b=500 s/mm2,at 15 directions.DTI original images were imported into the post-processing software,and the corresponding DTI mappings were formed.In the original images,pelvic floor muscles were sketched out layer by layer,and various DTI parameters,including fractional anisotrophy (FA),mean diffusivity (MD),λl,λ2,λ3,linear anisotropy (CL),planar anisotropy (CP) and spherical anisotropy (CS),were calculated.Six kinds of pelvic floor muscles,including anal sphincter,superficial transverse perineal muscle,pubic visceral muscle,puborectal muscle and iliococcygeal muscle were measured,and five of them were measured on both sides.The difference of DTI parameters between right and left side of each muscle,and the difference of DTI parameters between research and control group were compared.Results Between the right and left side of five kinds of pelvic floor muscles in control group,significant difference was only found in FA,λ3,CP,CS value of internal obturator muscle (P＜0.01,P＜0.001).There were significant differences in FA,λ3,CL,CP and CS values of the left and right muscles in the study group (P＜0.05,P＜0.001).Compared with control group,FA value and CS value of superficial transverse perineal muscle,CL value of left pubic visceral muscle,FA,λ3,CL,CS and CP value of right pubic visceral muscle,λ1 and λ3 value of left iliococcygeal muscle of research group were significantly different (P＜0.01,P＜0.05).Conclusion DTI for observation of female pelvic floor muscle is technically feasible,and it can detect the injury of pelvic floor muscle in POP patients,and may be helpful to reveal the pathogenesis of POP.

Objective To investigate the diagnostic value of dynamic MRI with coupling agent filled vaginal and rectumin the display of vaginal vault prolapse and rectocele. Methods Thirty three female patients, who were diagnosed with pelvic organ prolapse with Ⅲ degrees and above by gynecologic outpatient clinic and prepared to be treated with surgery were prospectively collected. All of them underwent two types of dynamic MRI, one was routine dynamic MRI (Group A) and the other was dynamic MRI with vaginal and rectum filled with coupling agent (Group B). Two radiologists evaluated and scored the display of vaginal vault and rectocele on these two groups of dynamic MRI images. According to the joint result of two radiologists, two gynecologists made surgical planning. Kappa test was used to compare the consistency of scores performedby two radiologists, and Fisher exact test was used to compare the differentiation fromboth groups, as well as the differentiation of probability of high uterosacral ligament suspension.Results The Kappa value of both groups was 0.65 and 1.00 respectively, where the consistency of Group B was superior than Group A. There were significant differences between the two groups(P<0.01), where Group B was better than Group A. Based on the imaging results of Group A, 7 patients (21.2%, 7/33) were decided to make high uterosacral ligament suspension. Based on the imaging results of Group B, 20 patients (60.6%, 20/33) were decided to make high uterosacral ligament suspension, and differences were statistical significance between the two groups(P<0.05). Conclusions Fo purpose of the displaying vaginal vault and rectocele, the dynamic MR imaging with vaginal and rectum filled with coupling agent was better than routine method. The proposed method can provide important information and reference for the establishment of surgical planning.

Objective To evaluate the correlations between the cerebral hemodynamic changes of severe acute encephalopathy with the clinical features from emergency periods to stable periods and the value of transcranial Doppler ultrasonography( TCD)in cerebral function assess. Methods Thirty patients with acute brain diseases by assisted mechanical ventilator from Jun 2014 to May 2015 in PICU were included and followed up to Nov 2015,then grouped by Glasgow Coma Scale( GCS),MRI,prognosis( mental sequelae after half a year). Each subject was examined through the temporal bone window by TCD at emergency peri-ods and stable periods. The systolic cerebral blood flow velocity( sCBFV),and pulsatility index( PI)of bilat-eral middle cerebral artery( MCA),anterior cerebral artery,posterior cerebral artery were analyzed. Multivari-ant analysis of variance,repeated measures analysis of variance was conducted to compare sCBFV and PI of MCA among groups in different clinical periods. The variants included sex,disease diagnosis,prognosis, MRI,GCS,and the first abnormal TCD. The variation within groups was tested via a Hotelling T2 test. All sCBFV and PI of each artery and the D-value of sCBFV between the different periods were compared accord-ing to the prognosis groups. Results (1)Five patients could be lateralized,and their lateralization of MRI focus was consistent with the abnormal sides of sCBFV in the stable periods.(2)The D-value of sCBFV in left MCA between the different periods in the poor prognosis group was significantly higher than that in the good prognosis group[(71. 93 ± 58. 21)cm/s vs.(33. 20 ± 30. 23)cm/s,t = -2. 287,P =0. 033].(3) Multivariant analysis of variance showed that GCS classification and disease diagnosis were significantly cor-related with the cerebral hemodynamic changes respectively(P =0. 042,0. 005,respectively).(4)sCBFV and PI of left MCA reduced significantly in the stable periods than those in the emergency periods( P =0. 002,0. 003,respectivly). Conclusion The cerebral hemodynamic changes by TCD from emergency peri-ods to stable periods are consistent with the clinical status,dynamic evaluation by TCD may facilitate the evaluation of brain dysfunction in the severe acute encephalopathy.