Crohn disease is a chronic inflammatory bowel disease and characterized by many complicated complications and diverse imaging manifestations.At present,in regards of diagnosis and treatment,a key issue is to find a non-invasive,fast and accurate examination method.In recent years,a variety of imaging techniques such as computed tomography enterography,spectral CT,magnetic resonance enterography and magnetic resonance functional imaging have shown promising application prospects in evaluating of disease severity and therapeutic effect of Crohn disease.The research progress of CT and MRI for evaluation of Crohn disease were reviewed in this article,in order to provide imaging reference for the clinical diagnosis and treatment of Crohn disease.

Objective To establish and validate a machine learning model integrating abdominal contrast-enhanced CT radiomics features and clinical characteristics,and to construct a predictive model for the efficacy of anticoagulant treatment in portal vein thrombosis(PVT).Methods A retrospective selection was conducted on 94 PVT patients who received anticoagulant treatment.Patients were divided into effective and ineffective treatment groups based on the follow-up results.Clinical information was collected,and imaging features were evaluated.Univariate and multivariate logistic regression were performed to select clinical information and imaging fea-tures for constructing a clinical-imaging model.On CT venous phase images,the PVT mask was delineated and radiomics features were extracted,and the radiomics model was screened and established.A combined model was further developed using features from both the clinical-imaging and radiomics models.Receiver operating characteristic(ROC)curves were used to evaluate the predictive efficacy of different models.Results The area under the curve(AUC)for the clinical-imaging model,radiomics model,and com-bined model were 0.594,0.794,and 0.776,respectively.The radiomics and combined models demonstrated superior predictive efficacy for anticoagulant treatment in PVT compared to the clinical-imaging model.No significant difference in performance was observed between radiomics and combined models.Conclusion The radiomics model and combined model based on abdominal contrast-enhanced CT can effectively predict the efficacy of anticoagulant treatment for PVT.

Objective To establish a predictive model for hepatic sinusoidal obstruction syndrome(HSOS)and Budd-Chiari syn-drome(BCS),and to evaluate the performance of the model.Methods From April 2016 to February 2024,20 patients with HSOS and 40 patients with BCS who were first discharged from the Beijing Friendship Hospital Affiliated to Capital Medical University hospital infor-mation system(HIS)system were retrospectively collected.The clinical data of all patients were extracted,and the independent risk fac-tors for HSOS were screened by multi-factor Logistic regression method,and the differential diagnosis model was established accordingly,and then the efficacy was evaluated by receiver operating characteristic(ROC)curve.Results Multivariate Logistic regression analysis showed that hepatic vein stenosis or unclear display(OR=39.441,95％CI:5.928-262.429)was an independent risk factor for HSOS,and paravertebral vein opening was an independent protective factor for HSOS(OR=0.026,95％CI:0.002-0.285).Based on the above two parameters,a prediction model for HSOS in patients with hepatic venous outlet tract obstruction was established.The ROC curve showed that the area under the curve(AUC)of the model was 0.922(95％CI:0.864-0.991),with the sensitivity of 85.0％and the specificity of 92.5％.Conclusion Hepatic vein stenosis or unclear display is an independent risk factor for HSOS in patients with hepatic vein outflow tract obstruction during hospitalization,and the model constructed can predict the risk of HSOS.

Objective:To evaluate the relationship between transverse sinus stenosis (TSS) and cerebral blood flow in normal adults based on four-dimensional flow (4D Flow) MRI.Methods:The study was a cross-sectional study. Totally 81 normal volunteers who underwent magnetic resonance venography (MRV) and 4D Flow MRI were prospectively enrolled at Beijing Friendship Hospital, Capital Medical University from January 2020 to December 2022. Based on MRV evaluation of transverse sinus dysplasia, the volunteers were divided into a dysplasia group (26 cases) and a non-dysplasia group (55 cases); The area of the stenosis and the normal transverse sinus at the distal end were measured. The degree of TSS and the bilateral average transverse sinus stenosis (BA-TSS) were calculated. TSS was determined using TSS levels of 1/3, 1/2, and 2/3 as thresholds, and was divided into three groups: no TSS group, unilateral TSS group, and bilateral TSS group, with 28, 39, and 14 cases, 37, 37, and 7 cases, and 43, 36, and 2 cases, respectively. Based on 4D Flow MRI, the blood flow of the internal carotid artery, vertebral artery, superior sagittal sinus, straight sinus, and transverse sinus distal and proximal ends were measured. The cerebral blood flow (bilateral internal carotid artery blood flow+bilateral vertebral artery blood flow), venous sinus return blood flow 1 (superior sagittal sinus blood flow+straight sinus blood flow), return blood flow 2 (sum of bilateral transverse sinus distal end blood flow), return blood flow 3 (sum of bilateral transverse sinus proximal end blood flow), and the ratio of return blood flow to cerebral blood flow were calculated. Independent sample t-test was used to compare the differences between the group with and without transverse sinus dysplasia; Single factor analysis of variance was used to compare the differences between the TSS free group, unilateral TSS group, and bilateral TSS group. Based on single factor linear regression, the relationships between BA-TSS and blood flow parameters were analyzed.Results:There was no statistically significant difference in various blood flow parameters between the group with and without transverse sinus dysplasia (all P>0.05). When using 1/3, 1/2, and 2/3 as thresholds, there was no statistically significant difference in various blood flow parameters between the non TSS group, unilateral TSS group, and bilateral TSS group (all P>0.05). BA-TSS was linearly positively correlated with cerebral blood flow (β=0.986, 95% CI 0.108-1.865, P=0.028), but not linearly correlated with return blood flow 1, 2, and 3 (all P>0.05). The degree of BA-TSS was linearly negatively correlated with return blood flow 1/cerebral blood flow (β=-0.001, 95% CI -0.002-0, P=0.009) and return blood flow 2/cerebral blood flow (β=-0.001, 95% CI -0.002-0, P=0.018), but not with return blood flow 3/cerebral blood flow ( P=0.076). Conclusion:The BA-TSS degree in normal adults is positively correlated with cerebral blood inflow and negatively correlated with the proportion of venous sinus outflow.

Objective:To investigate the role of a modified positioning device in improving image quality and diagnostic efficacy for thyroid cancer in contrast-enhanced neck CT imaging.Methods:This prospective cross-sectional study included 137 patients with pathologically confirmed thyroid lesions who underwent contrast-enhanced neck CT at Zhangzhou Affiliated Hospital of Fujian Medical University from January to April 2024. Patients scanned in January and February (modified positioning group, n=62) underwent scanning using the modified positioning device, whereas those scanned in March and April (traditional positioning group, n=75) underwent scanning with conventional positioning. The estimated volume CT dose index (CTDI vol) in the thyroid region was recorded. Subjective image quality for thyroid and neck regions was evaluated using a 5-point Likert scale. Diagnostic assessments for thyroid cancer, capsule invasion, and lymph node metastasis were independently conducted by one junior radiologist and one senior radiologist using a 5-point scoring system, with scores≥3 considered positive diagnoses. The differences of CTDI vol and image quality scores between the 2 groups were compared using Mann-Whitney U test. The diagnostic performance was evaluated by the receiver operating characteristic curve analysis. Results:The estimated CTDI vol values for the thyroid region were significantly lower in the modified positioning group compared to the traditional positioning group [11.20 (8.37, 13.56) vs. 12.46 (10.10, 19.43) mGy, Z=1.99, P=0.026]. Subjective image quality scores for thyroid and neck regions were significantly higher in the modified positioning group than in the traditional positioning group (all P<0.001). For thyroid cancer diagnosis by the senior radiologist, the modified positioning group had a significantly higher area under the curve (AUC) of 0.842 (95% CI 0.728-0.956) compared to the traditional positioning group (AUC=0.666,95% CI 0.554-0.777, Z=2.17, P=0.031). No significant differences were observed in diagnostic performance between the junior and senior radiologists for thyroid cancer, capsule invasion, and lymph node metastasis in other subgroup comparisons (all P>0.05). Conclusion:The modified positioning device using in contrast-enhanced neck CT imaging can improve image quality and diagnostic efficacy for thyroid cancer while reducing radiation exposure to the thyroid gland.

Objective To investigate the imaging features and causes of missed diagnosis of colorectal cancer(CRC)in routine abdomi-nopelvic CT examinations.Methods A retrospective analysis was conducted on the clinical and imaging data of 38 patients with CRC which were initially overlooked in routine abdominopelvic CT examinations.The imaging features and causes of missed diagnosis were analyzed.Results Distribution of lesions:ten cases(26.3％)located in the caecum-ascending colon,6 cases(15.8％)located in the transverse colon,1 case(2.6％)located in the descending colon,18 cases(47.4％)located in the sigmoid colon and 3 cases(7.9％)located in the rectum.The mean length of diseased bowel was(2.8±1.3)cm.Pericolic fat stranding was found in 16 cases,locore-gional adenopathy was found in 19 cases,and focal pericolic neovascularity was found in 12 cases.The four reasons for missed diagno-sis included:(1)comprehensive assessment of colorectal conditions was not routinely performed;(2)small lesion size;(3)unfamiliar with the subtle secondary signs of CRC;(4)image-related reasons.Conclusion Radiologists should conduct conventional and com-prehensive assessment of the colorectum in routine abdominopelvic CT examinations.With the accumulation of diagnostic experience,it will be beneficial to reduce the missed diagnosis rate of CRC.

Objective To compare the ability of single-phase,dual-phase,and triphasic models in forecasting postoperative pancreatic fistula(POPF)after pancreaticoduodenectomy(PD)using radiomics based on triphasic enhanced CT.Methods A total of 181 patients who underwent multi-phase enhanced CT prior to PD were retrospectively selected,and the collection phase included non-contrast,arterial phase(AP),and equilibrium phase(EP).3D Slicer software was utilized to segment the region of interest(ROI)for the postoperative pancreatic remnant on each phase.Radiomics feature extraction was performed using R software,followed by feature selection through least absolute shrinkage and selection operator(LASSO)regression with five-fold cross-validation to prevent model overfitting.The effective features selected were combined in a weighted linear manner to obtain a Radiomics score(Radscore).The patients were divided into training set and test set in a 7︰3 ratio.Logistic regression was employed to construct seven POPF prediction models(three single-phase,three dual-phase,and one triphasic models)based on different phase combinations.The diagnostic performance of the models was evaluated using the area under the curve(AUC)of receiver operating characteristic(ROC)curve,accuracy(ACC),sensitivity(SEN),and specificity(SPE).The DeLong test was applied to compare the differences in AUC among different models.Results After LASSO regression,24 effective features associated with POPF were selected from different phases.In the test set,the triphasic model exhibited the highest AUC and ACC(AUC=0.76,ACC=0.808).The calibration curve demonstrated the strongest agreement between the estimated probabilities and observed probabilities for the triphasic model.The decision curve analysis(DCA)curve indicated that the triphasic model had the largest threshold range with a higher net benefit.Conclusion Compared with single-phase and dual-phase models,the triphasic model based on enhanced CT provides better prediction of POPF after PD,aiding clinical decision-making and improve prognosis.

Purpose To compare the MRI features of hepatic sinusoidal obstruction syndrome(HSOS)and Budd-Chiari syndrome(BCS).Materials and Methods A total of 12 cases of HSOS and 12 cases of BCS diagnosed with liver biopsy or liver transplantation disease or digital subtraction angiography were retrospectively collected from April 2016 to November 2023 in Beijing Friendship Hospital,Capital Medical University.The clinical and MRI features of the two groups were analyzed,and the characteristic clinical and MRI features were summarized.Results The glutamic-oxaloacetic transaminase,total bilirubin and direct bilirubin in HSOS patients were significantly higher than those in BCS group,while albumin was significantly lower than that in BCS group,the difference was statistically significant(Z=-3.407,-2.078,-2.425,-2.252,all P<0.05).Of the 12 HSOS patients,ten patients with HSOS had a history of taking hebel medicine(gynura segetum),six patients with HSOS showed the second portal of liver characteristic trifolium-like enhancement,BCS features did not appear.Of the 12 BCS patients,ten had main portal vein widening,ten spleen enlargement,ten accessory hepatic vein,eight transverse hepatic vein,eleven perihepatic lateral branch and seven paravertebral varicose veins.In HSOS and BCS patients,the uneven proportion of liver parenchymal signals was identified by MRI plain scan(12 cases,10 cases,respectively),and the proportion of liver parenchymal signal mottle-like enhancement was also demonstrated in portal and delayed phases(12 cases,12 cases,respectively).Conclusion The characteristic MRI signs are helpful for the diagnosis of HSOS and BCS,and the history of taking hebel medicine(gynura segetum)is helpful for the differentiation of the two diseases.

Objective:To dynamically assess liver fibrosis using magnetic resonance elastography (MRE) and explore factors associated with fibrosis reversal in patients with metabolic dysfunction-associated steatohepatitis (MASH).Methods:This study included data from patients diagnosed with MASH by liver biopsy who underwent at least two MRE examinations. Patients were divided into a fibrosis reversal group and a non-reversal group according to whether MRE values decreased by 20% during follow-up. Differences in clinical data between the groups were compared using analysis of variance, the Kruskal-Wallis test, and the chi-square test. Univariate and multivariate logistic regression analyses were used to explore independent risk factors for fibrosis reversal in MASH.Results:A total of 46 cases were included in this study (mean age 50.1±12.3 years, BMI 26.1±3.1 kg/m2). Among them, the reversal group accounted for 26.1%. The rate of decrease in MRI proton density fat fraction (PDFF) was significantly higher in the reversal group (-50.0% vs. -8.1%, P=0.001) than in the non-reversal group between the two MRE examinations. The reversal group showed a more significant change rate of decreases in fasting insulin (-37.3% vs. -3.6%, P=0.011), insulin resistance index (-38.6% vs. -6.5%, P=0.044), and ALP (-24.9% vs. 0, P=0.004). Multivariate logistic regression analysis indicated that the rate of change in MRI PDFF was an independent predictor of fibrosis reversal ( OR=0.96, 95% CI: 0.92-1.00, P=0.046). Conclusion:A decrease in MRI proton density fat fraction levels is independently associated with liver fibrosis reversal in MASH, suggesting that intervention targeting liver fat content may be an effective treatment strategy.