Accuracy of quantitative diffusion-weighted imaging for differentiating benign and malignant pancreatic lesions: a systematic review and meta-analysis.

BACKGROUND: A variety of imaging techniques can be used to evaluate diffusion characteristics to differentiate malignant and benign pancreatic lesions. The diagnostic performance of diffusion parameters has not been systematic assessed. PURPOSE: We aimed to investigate the diagnostic efficacy of quantitative diffusion-weighted imaging (DWI) for pancreatic lesions. METHODS: A literature search was conducted using the PubMed, Embase, and Cochrane Library databases for studies from inception to March 30, 2020, which involves the quantitative diagnostic performance of diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM) in the pancreas. Studies were reviewed according to inclusion and exclusion criteria. The quality of articles was evaluated by the Quality Assessment of Diagnostic Accuracy Studies-2 (QUATAS-2). A bivariate random-effects model was used to evaluate pooled sensitivities and specificities. Univariable meta-regression analysis was used to test the effects of factors that contributed to the heterogeneity. RESULTS: A total of 31 studies involving 1558 patients were ultimately eligible for data extraction. The lowest heterogeneity was found in specificity of perfusion fraction (f) with the I2 value was 17.97% and Cochran p value was 0.28. However, high heterogeneities were found for the other parameters (all I2 > 50%). There was no publication bias found in funnel plot (p = 0.30) for the apparent diffusion coefficient (ADC) parameter. The pooled sensitivities for ADC, f, pure diffusion coefficient (D), and pseudo diffusivity coefficient (D*) were 83%, 81%, 76%, and 84%, respectively. The pooled specificities for ADC, f, D, and D* were 87%, 83%, 69%, and 81% respectively. The areas under the curves for ADC, f, D, and D* were 0.92, 0.87, 0.79, and 0.87 respectively. CONCLUSION: Quantitative DWI and IVIM have a good diagnostic performance for differentiating malignant and benign pancreatic lesions. KEY POINTS: • IVIM has high sensitivity and specificity (84% and 83%, respectively) for differential diagnosis of pancreatic lesions, which is comparable to that of the ADC (83% and 87%, respectively). • The ADC has an excellent diagnostic performance for differentiating malignant from benign IPMNs (sensitivity, 0.83; specificity, 0.92); the f has the best diagnostic performance for differentiating pancreatic carcinoma from PNET (sensitivity, 0.85; specificity, 0.85). • For the ADC, using a maximal b value < 800 s/mm2 has a higher diagnostic accuracy than ≥ 800 s/mm2; performing in a high field strength (3.0 T) system has a higher diagnostic accuracy than a low field strength (1.5 T) for pancreatic lesions.

DWI and T2-Weighted MRI Volumetry in Resectable Rectal Cancer: Correlation With Lymphovascular Invasion and Lymph Node Metastases.

OBJECTIVE. The purpose of this study was to assess whether MR volumetric data on DW and T2-weighted MR images are correlated with lymphovascular invasion and lymph node metastases in resectable rectal cancer. MATERIALS AND METHODS. This retrospective study consisted of 50 consecutive patients with rectal cancer who underwent radical surgery within 1 week of MRI. The gross tumor volume was determined on both diffusion-weighted and T2-weighted MR images and correlated with pathologic lymphovascular invasion and lymph node metastases using univariate, multivariate, and ROC curve analyses. RESULTS. Both gross tumor volume values showed correlations with lymphovascular invasion (r = 0.750 vs r = 0.710; p < 0.0001) and lymph node metastases (r = 0.780 vs r = 0.755; p < 0.0001). Both values were associated with lymphovascular invasion and lymph node metastases in univariate analysis (all p < 0.0001), whereas only the DWI-based value was an independent risk factor for lymphovascular invasion (odds ratio = 1.207; p = 0.005) and lymph node metastases (odds ratio = 1.420; p = 0.005) in multivariate analysis. Both values could distinguish between N0 and N1, N0 and N1-N2, and N0-N1 and N2 disease (all p < 0.0001) in the Mann-Whitney U test. The area under the ROC curve was higher for the DWI-based value in lymphovascular invasion (0.899 vs 0.877), N0 vs N1 (0.865 vs 0.827), N0 vs N1-N2 (0.934 vs 0.911), and N0-N1 vs N2 (0.932 vs 0.927). CONCLUSION. Tumor volumetry data correlated with both lymphovascular invasion and lymph node metastases in resectable rectal cancer. In particular, the DWI-based gross tumor volume showed the most potential for noninvasive preoperative evaluation of lymphovascular invasion and lymph node metastases.

[Clinical value of MRI united-sequences examination in diagnosis and differentiation of morphological sub-type of hilar and extrahepatic big bile duct cholangiocarcinoma].

OBJECTIVE: To investigate MRI features and associated histological and pathological changes of hilar and extrahepatic big bile duct cholangiocarcinoma with different morphological sub-types, and its value in differentiating between nodular cholangiocarcinoma (NCC) and intraductal growing cholangiocarcinoma (IDCC). METHODS: Imaging data of 152 patients with pathologically confirmed hilar and extrahepatic big bile duct cholangiocarcinoma were reviewed, which included 86 periductal infiltrating cholangiocarcinoma (PDCC), 55 NCC, and 11 IDCC. Imaging features of the three morphological sub-types were compared. RESULTS: Each of the subtypes demonstrated its unique imaging features. Significant differences (P < 0.05) were found between NCC and IDCC in tumor shape, dynamic enhanced pattern, enhancement degree during equilibrium phase, multiplicity or singleness of tumor, changes in wall and lumen of bile duct at the tumor-bearing segment, dilatation of tumor upstream or downstream bile duct, and invasion of adjacent organs. CONCLUSION: Imaging features reveal tumor growth patterns of hilar and extrahepatic big bile duct cholangiocarcinoma. MRI united-sequences examination can accurately describe those imaging features for differentiation diagnosis.

[Clinical value of dual-source CT angiography in the diagnosis of postoperative aortic intramural hematoma in patients with endovascular stent-graft exclusion surgery].

OBJECTIVE: To determine the clinical value of dual-source CT angiography (DSCTA) in the diagnosis of postoperative aortic intramural hematoma (AIMH) in patients with endovascular stent-graft exclusion (EVE) surgery. METHODS: Between Oct 2008 and May 2013, thirty-six patients were diagnosed with AIMH by DSCTA, and 12 of these patients with type B underwent EVE. The 12 patients were followed up with DSCTA, which included imaging reconstruction (multi-plane reconstruction, MPR), maximum intensity projection (MIP) and volume rendering technique (VRT). The extent and type of AIMH, aortic ulcers and the outcomes and complications of AIMH were observed. RESULTS: The 36 cases of AIMH included 11 Stanford type A and 25 type B. No tearing intimal flap or contrast materials within the hematoma were observed. The maximum aortic diameter of the hematoma areas varied from 3.8 to 5.4 cm (average 4.3 cm) and the maximum thickness of the hematoma ranged from 0.5 cm to 1.3 cm (average 0.9 cm). The ratio between the minimum and the maximum diameter of the aortic lumen in the hematoma areas ranged from 0. 74 to 0. 98 (average 0.85). Aortic ulcers were revealed in 3 patients with type A AIMH and 8 patients with type B AIMH. Intimal tearing of distal abdominal aorta was found in 3 patients with type B AIMH. In the 12 patients underwent EVE surgery, hematoma shrank in all cases with 4 cases almost resolving and aortic ulcers in the area of stent-graft exclusion disappeared in 3 cases. The form of stent-graft appeared normal in 9 cases and slightly abnormal in 3 cases. Fluent main branches of aortic arch and none existence of stent endoleaking were observed. CONCLUSION: DSCTA with handy, effective and non-invasive advantages is one of the important imaging methods in the diagnosis of AIMH in patients with EVE surgery.

Three-Dimensional Feature Tracking Study of Healthy Chinese Ventricle by Cardiac Magnetic Resonance.

PURPOSE: Myocardial strain, as a crucial quantitative indicator of myocardial deformation, can detect the changes of cardiac function earlier than parameters such as ejection fraction (EF). It has reported that cardiac magnetic resonance(CMR) and post-processing software possess the ability to obtain the stability and repeatability strain values. Recently, the normal strain values range of people are debatable, especially in the Chinese population. Therefore, we aim to explore the ventricular characteristics and the myocardial strain values of the Chinese people by using the cardiac magnetic resonance feature tracking (CMR-FT). Additionally, we attempted to use the myocardial and chordae tendineae contours to calculate the ventricular volumes by the CMR-FT. This study may provide valuable insights into the application of CMR-FT in tracking the ventricular characteristics and myocardial strain for Chinese population, especially in suggesting an referable myocardial strain parameters of the Chinese. METHODS: A total of 109 healthy Chinese individuals (age range: 18 to 58 years; 52 males and 57 females) underwent 3.0T CMR to acquire the cardiac images. The commercial post-processing software was employed to analyse the image sequence by semi-automatic processing, then the biventricular morphology (End-Diastolic Volume, EDV; EDV/Body Surface Area, EDV/BSA), function(EF; Cardiac Output, CO; Cardiac Index, CI) and strain(Radial Strain, RS; Circumferential Strain, CS; Longitudinal Strain, LS) values were obtained.The biventricular myocardial strain values were stratified according to the age and gender. The Left Ventricular( LV base, mid, apex) and myocardial strain values of three coronary artery areas were calculated based on the the strain value of LV American Heart Association(AHA) 16 segments. RESULTS: It was shown that the females had larger LV globe strain values compared with the males (LVGPRS: 42.0 ± 8.5 versus 33.6 ± 6.2%, P < 0.001; LVGPCS: -21.2 ± 2.1 versus - 19.7 ± 2.3%, P < 0.001; LVGPLS: -16.4 ± 2.6 versus - 14.6 ± 2.2%, P < 0.001;). Moreover, the differences in RS, CS, and LS among the LV myocardium 16 segments were obvious. However, the right ventricle (RV) strain values showed non-normal distribution in the volunteers of this research. CONCLUSIONS: Here, we successfully tracked the characteristics of bilateral ventricles in healthy Chinese populations through using the 3.0T CMR. We confirmed that there was a gender difference in LV Globe Strain values. In addition, we obtained strain values for each myocardial segment of the LV and different coronary artery regions based on the AHA 16 segments method, Our results also showed that the RV strain values with a non-normal distribution, and RV global strain values were not related to the gender and age. Furthermore, LVGPRS, LVGPLS, and RVGPRS were significantly correlated with BMI, CO, CI, and EDV in the Chinese population.

Clinically Available and Reproducible Prediction Models for IDH and CDKN2A/B Gene Status in Adult-type Diffuse Gliomas.

PURPOSE: Isocitrate dehydrogenase (IDH) and cyclin-dependent kinase inhibitor (CDKN) 2A/B status holds important prognostic value in diffuse gliomas. We aimed to construct prediction models using clinically available and reproducible characteristics for predicting IDH-mutant and CDKN2A/B homozygous deletion in adult-type diffuse glioma patients. MATERIALS AND METHODS: This retrospective, two-center study analysed 272 patients with adult-type diffuse glioma (230 for primary cohort and 42 for external validation cohort). Two radiologists independently assessed the patients' images according to the Visually AcceSAble Rembrandt Images (VASARI) feature set. Least absolute shrinkage and selection operator (LASSO) regression analysis was used to optimise variable selection. Multivariable logistic regression analysis was used to develop the prediction models. Calibration plots, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA) were used to validate the models. Nomograms were developed visually based on the prediction models. RESULTS: The interobserver agreement between the two radiologists for VASARI features was excellent (κ range, 0.813-1). For the IDH-mutant prediction model, the area under the curves (AUCs) was 0.88-0.96 in the internal and external validation sets, For the CDKN2A/B homozygous deletion model, the AUCs were 0.80-0.86 in the internal and external validation sets. The decision curves show that both prediction models had good net benefits. CONCLUSION: The prediction models which basing on VASARI and clinical features provided a reliable and clinically meaningful preoperative prediction for IDH and CDKN2A/B status in diffuse glioma patients. These findings provide a foundation for precise preoperative non-invasive diagnosis and personalised treatment approaches for adult-type diffuse glioma patients.

T2WI-based MRI radiomics for the prediction of preoperative extranodal extension and prognosis in resectable rectal cancer.

OBJECTIVE: To investigate whether T2-weighted imaging (T2WI)-based intratumoral and peritumoral radiomics can predict extranodal extension (ENE) and prognosis in patients with resectable rectal cancer. METHODS: One hundred sixty-seven patients with resectable rectal cancer including T3T4N + cases were prospectively included. Radiomics features were extracted from intratumoral, peritumoral 3 mm, and peritumoral-mesorectal fat on T2WI images. Least absolute shrinkage and selection operator regression were used for feature selection. A radiomics signature score (Radscore) was built with logistic regression analysis. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of each Radscore. A clinical-radiomics nomogram was constructed by the most predictive radiomics signature and clinical risk factors. A prognostic model was constructed by Cox regression analysis to identify 3-year recurrence-free survival (RFS). RESULTS: Age, cT stage, and lymph node-irregular border and/or adjacent fat invasion were identified as independent clinical risk factors to construct a clinical model. The nomogram incorporating intratumoral and peritumoral 3 mm Radscore and independent clinical risk factors achieved a better AUC than the clinical model in the training (0.799 vs. 0.736) and validation cohorts (0.723 vs. 0.667). Nomogram-based ENE (hazard ratio [HR] = 2.625, 95% CI = 1.233-5.586, p = 0.012) and extramural vascular invasion (EMVI) (HR = 2.523, 95% CI = 1.247-5.106, p = 0.010) were independent risk factors for predicting 3-year RFS. The prognostic model constructed by these two indicators showed good performance for predicting 3-year RFS in the training (AUC = 0.761) and validation cohorts (AUC = 0.710). CONCLUSION: The nomogram incorporating intratumoral and peritumoral 3 mm Radscore and clinical risk factors could predict preoperative ENE. Combining nomogram-based ENE and MRI-reported EMVI may be useful in predicting 3-year RFS. CRITICAL RELEVANCE STATEMENT: A clinical-radiomics nomogram could help preoperative predict ENE, and a prognostic model constructed by the nomogram-based ENE and MRI-reported EMVI could predict 3-year RFS in patients with resectable rectal cancer. KEY POINTS: • Intratumoral and peritumoral 3 mm Radscore showed the most capability for predicting ENE. • Clinical-radiomics nomogram achieved the best predictive performance for predicting ENE. • Combining clinical-radiomics based-ENE and EMVI showed good performance for 3-year RFS.

[Comparative analysis of dual resource computed tomography angiography and 3.0T magnetic resonance angiography in the diagnosis of intracranial aneurysms].

To comparatively study the diagnostic value of dual resource computed tomography angiography (DSCTA) and 3.0T magnetic resonance angiography (MRA) for intracranial aneurysm, we analyzed retrospectively radiographic data of DSCTA, 3.0T MRI and three dimensional digital subtraction angiography (3D DSA ) in cases suspected intracranial aneurysms during Jan. 2010 to Dec. 2011. With 3D DSA as "gold standard", the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of DSCTA and 3.0T MRA in diagnostic of intracranial aneurysms were analyzed, and the accuracy of both methods on evaluation of aneurysms size was compared as well. Totally fifty-three suspected cases were included, and forty-two intracranial aneurysms in thirty-five cases were identified by 3D DSA. For DSCTA, 37 aneurysms were detected in 32 patients, and 3 patients and 5 aneurysms were missed in all patients. However, for 3.0 T MRA, 33 aneurysms were detected in 33 patients, 5 patients and 8 aneurysms were missed, and 3 patients who did not have aneurysms were misdiagnosed as ones with intracranial aneurysms. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of DSCTA and 3.0T MRA were 91.4% vs. 85.7%, 100% vs. 83.3%, 100% vs. 90.9%, 85.7% vs. 75.0% and 94.3% vs. 84.9%,respectively. There was no significant difference in evaluation of aneurysms size between using the two methods. Data suggested that both DSCTA and 3.0T MRA had high accuracy for detection intracranial aneurysms and evaluation of aneurysms size, but as for detection of microaneurysms, DSCTA was superior to 3.0T MRA.

The Diagnostic Performance of Tumor Stage on MRI for Predicting Prostate Cancer-Positive Surgical Margins: A Systematic Review and Meta-Analysis.

PURPOSE: Surgical margin status in radical prostatectomy (RP) specimens is an established predictive indicator for determining biochemical prostate cancer recurrence and disease progression. Predicting positive surgical margins (PSMs) is of utmost importance. We sought to perform a meta-analysis evaluating the diagnostic utility of a high clinical tumor stage (≥3) on magnetic resonance imaging (MRI) for predicting PSMs. METHOD: A systematic search of the PubMed, Embase databases, and Cochrane Library was performed, covering the interval from 1 January 2000 to 31 December 2022, to identify relevant studies. The Quality Assessment of Diagnostic Accuracy Studies 2 method was used to evaluate the studies' quality. A hierarchical summary receiver operating characteristic plot was created depicting sensitivity and specificity data. Analyses of subgroups and meta-regression were used to investigate heterogeneity. RESULTS: This meta-analysis comprised 13 studies with 3924 individuals in total. The pooled sensitivity and specificity values were 0.40 (95% CI, 0.32-0.49) and 0.75 (95% CI, 0.69-0.80), respectively, with an area under the receiver operating characteristic curve of 0.63 (95% CI, 0.59-0.67). The Higgins I2 statistics indicated moderate heterogeneity in sensitivity (I2 = 75.59%) and substantial heterogeneity in specificity (I2 = 86.77%). Area, prevalence of high Gleason scores (≥7), laparoscopic or robot-assisted techniques, field strength, functional technology, endorectal coil usage, and number of radiologists were significant factors responsible for heterogeneity (p ≤ 0.01). CONCLUSIONS: T stage on MRI has moderate diagnostic accuracy for predicting PSMs. When determining the treatment modality, clinicians should consider the factors contributing to heterogeneity for this purpose.

Diagnostic performance of prediction models for extraprostatic extension in prostate cancer: a systematic review and meta-analysis.

PURPOSE: In recent decades, diverse nomograms have been proposed to predict extraprostatic extension (EPE) in prostate cancer (PCa). We aimed to systematically evaluate the accuracy of MRI-inclusive nomograms and traditional clinical nomograms in predicting EPE in PCa. The purpose of this meta-analysis is to provide baseline summative and comparative estimates for future study designs. MATERIALS AND METHODS: The PubMed, Embase, and Cochrane databases were searched up to May 17, 2023, to identify studies on prediction nomograms for EPE of PCa. The risk of bias in studies was assessed by using the Prediction model Risk Of Bias ASsessment Tool (PROBAST). Summary estimates of sensitivity and specificity were obtained with bivariate random-effects model. Heterogeneity was investigated through meta-regression and subgroup analysis. RESULTS: Forty-eight studies with a total of 57 contingency tables and 20,395 patients were included. No significant publication bias was observed for either the MRI-inclusive nomograms or clinical nomograms. For MRI-inclusive nomograms predicting EPE, the pooled AUC of validation cohorts was 0.80 (95% CI: 0.76, 0.83). For traditional clinical nomograms predicting EPE, the pooled AUCs of the Partin table and Memorial Sloan Kettering Cancer Center (MSKCC) nomogram were 0.72 (95% CI: 0.68, 0.76) and 0.79 (95% CI: 0.75, 0.82), respectively. CONCLUSION: Preoperative risk stratification is essential for PCa patients; both MRI-inclusive nomograms and traditional clinical nomograms had moderate diagnostic performance for predicting EPE in PCa. This study provides baseline comparative values for EPE prediction for future studies which is useful for evaluating preoperative risk stratification in PCa patients. CRITICAL RELEVANCE STATEMENT: This meta-analysis firstly evaluated the diagnostic performance of preoperative MRI-inclusive nomograms and clinical nomograms for predicting extraprostatic extension (EPE) in prostate cancer (PCa) (moderate AUCs: 0.72-0.80). We provide baseline estimates for EPE prediction, these findings will be useful in assessing preoperative risk stratification of PCa patients. KEY POINTS: • MRI-inclusive nomograms and traditional clinical nomograms had moderate AUCs (0.72-0.80) for predicting EPE. • MRI combined clinical nomogram may improve diagnostic accuracy of MRI alone for EPE prediction. • MSKCC nomogram had a higher specificity than Partin table for predicting EPE. • This meta-analysis provided baseline and comparative estimates of nomograms for EPE prediction for future studies.

Longitudinal course of hyperintensity on diffusion weighted imaging in adult-onset neuronal intranuclear inclusion disease patients.

Background: High signals on diffusion weighted imaging along the corticomedullary junction (CMJ) have demonstrated excellent diagnostic values for adult-onset neuronal intranuclear inclusion disease (NIID). However, the longitudinal course of diffusion weighted imaging high intensities in adult-onset NIID patients has rarely been investigated. Methods: We described four NIID cases that had been discovered using skin biopsy and NOTCH2NLC gene testing, after diffusion weighted imaging exhibiting the distinctive corticomedullary junction high signals. Then using complete MRI data from NIID patients, we analyzed the chronological diffusion weighted imaging alterations of those individuals that had been published in Pub Med. Results: We discussed 135 NIID cases with comprehensive MRI data, including our four cases, of whom 39 had follow-up outcomes. The following are the four primary diffusion weighted imaging dynamic change patterns: (1) high signal intensities in the corticomedullary junction were negative on diffusion weighted imaging even after an 11-year follow-up (7/39); (2) diffusion weighted imagings were initially negative but subsequently revealed typical findings (9/39); (3) high signal intensities vanished during follow-up (3/39); (4) diffusion weighted imagings were positive at first and developed in a step-by-step manner (20/39). We discovered that NIID lesions eventually damaged the deep white matter, which comprises the cerebral peduncles, brain stem, middle cerebellar peduncles, paravermal regions, and cerebellar white matter. Conclusion: The longitudinal dynamic changes in NIID of diffusion weighted imaging are highly complex. We find that there are four main patterns of dynamic changes on diffusion weighted imaging. Furthermore, as the disease progressed, NIID lesions eventually involved the deep white matter.

Computed tomography enterography-based multiregional radiomics model for differential diagnosis of Crohn's disease from intestinal tuberculosis.

PURPOSE: To build computed tomography enterography (CTE)-based multiregional radiomics model for distinguishing Crohn's disease (CD) from intestinal tuberculosis (ITB). MATERIALS AND METHODS: A total of 105 patients with CD and ITB who underwent CTE were retrospectively enrolled. Volume of interest segmentation were performed on CTE and radiomic features were obtained separately from the intestinal wall of lesion, the largest lymph node (LN), and region surrounding the lesion in the ileocecal region. The most valuable radiomic features was selected by the selection operator and least absolute shrinkage. We established nomogram combining clinical factors, endoscopy results, CTE features, and radiomic score through multivariate logistic regression analysis. Receiver operating characteristic (ROC) curves and decision curve analysis (DCA) were used to evaluate the prediction performance. DeLong test was applied to compare the performance of the models. RESULTS: The clinical-radiomic combined model comprised of four variables including one radiomic signature from intestinal wall, one radiomic signature from LN, involved bowel segments on CTE, and longitudinal ulcer on endoscopy. The combined model showed good diagnostic performance with an area under the ROC curve (AUC) of 0.975 (95% CI 0.953-0.998) in the training cohort and 0.958 (95% CI 0.925-0.991) in the validation cohort. The combined model showed higher AUC than that of the clinical model in cross-validation set (0.958 vs. 0.878, P = 0.004). The DCA showed the highest benefit for the combined model. CONCLUSION: Clinical-radiomic combined model constructed by combining CTE-based radiomics from the intestinal wall of lesion and LN, endoscopy results, and CTE features can accurately distinguish CD from ITB.

Multiparameter Magnetic Resonance Quantitative Evaluation of Pancreatic Cancer with Vascular Invasion.

Objective: To analyze the value of multiparameter magnetic resonance (mpMRI) in the diagnosis of pancreatic cancer with vascular invasion from two aspects: morphology and function, so as to provide a reliable diagnostic basis for preparing the clinical treatment plans. Methods: Totally 31 case data of pancreatic cancer patients diagnosed in our hospital from January 2020 to March 2021 were enrolled in this study. All patients underwent multiparameter magnetic resonance imaging (T1WI, T2WI, DKI, and DCE-MRI) before surgery, and then all patients underwent pancreatic cancer surgery. Two experienced radiologists analyzed these obtained images according to the image reports and combined them with the pathological results. Taking pathological results as gold standard, the sensitivity, specificity, and accuracy of quantitative parameters derived from T2WI, DKI, DCE, T2WI + DKI, T2WI + DCE, and T2WI + DKI + DCE for the diagnostic capabilities of pancreatic cancer vascular invasion were calculated using diagnostic laboratory methods. Kappa consistency test was used to estimate the consistency of two radiologists' diagnosis and analysis. The images obtained by DKI sequence were input into the postprocessing software MITK-Diffusion v2014.10.02, The images obtained from DCE sequence were processed by the Tissue 4D software on the Siemens syngo via workstation to calculate and analyze each tumor ROI's MD, MK values from DKI, and K trans, K ep, V e values from DCE. Independent samples t-test was used to compare the parameters of pancreatic cancer with vascular invasion group (16 cases) and nonvascular invasion group (15 cases). ROC curve was used to analyze the efficacy of each parameter in diagnosing pancreatic cancer vascular invasion. Results: The sensitivity, specificity, and accuracy of T2WI were 62.5%, 53.5%, and 58.1%; those of DKI were 56.3%, 60.0%, and 58.1%; those of DCE were 68.8%, 60.0%, and 64.5%; those of T2WI + DKI were 68.8%, 66.7%, and 67.7%; those of T2WI + DCE were 75.0%, 66.7%, and 71.1%; those of T2WI + DKI + DCE were 81.2%, 73.3%, and 77.4%, respectively. These two diagnostic radiologists analyzed image data with good consistency, Kappa = 0.834. MD, MK, K trans, K ep, and V e were significantly different between the vascular invasion group and the nonvascular invasion group (p < 0.05). Each parameter's AUC of ROC curve was 0.773, 0.829, 0.794, 0.802, and 0.846 (p < 0.05). Take MD = 2.285 × 10-3 mm/s2, MK = 0.72, K trans = 0.103, K ep = 0.337, and V e = 0.353 as thresholds; the sensitivity of these parameters to diagnose vascular invasion of pancreatic cancer was 73.33%, 75%, 87.5%, 68.8%, and 68.8%. The specificity of them was 75%, 80%, 60%, 86.7%, and 86.7%, respectively. Conclusion: The combined analysis of T2WI + DKI + DCE can improve the specificity and accuracy of diagnostic efficiency of vascular invasion of pancreatic cancer and provide an important diagnostic basis for pancreatic cancer's preoperative treatment.

Study on the Application Value of PBL Combined with Situational Simulation Teaching Method in Clinical Practice Teaching of Radiology Department.

Objective: To study the application value of PBL (Problem-Based Learning) combined with a situational simulation teaching method in clinical practice teaching of radiology. Methods: 120 interns who practiced in the radiology department of our hospital from 2020 to 2021 were randomly divided into a study group and a control group. The research group used PBL combined with the scenario simulation teaching method to carry out clinical practice teaching activities. The control group was carried out according to the conventional teaching plan. After 3 months, the teaching effect and satisfaction of the two groups were compared. Results: The imaging report quality control score, intravenous contrast agent score, and practice test score in the study group were higher than those in the control group. The scores of the small class and special class in the research group were higher than those in the control group, and the difference was statistically significant (P < 0.05). The scores of job competency questionnaire in the research group were higher than those in the control group (P < 0.05). The occupational self-efficacy questionnaire score of the research group was higher than that of the control group (P < 0.05). The nursing practice satisfaction score of the research group was higher than that of the control group (P < 0.05). Conclusion: The value of PBL combined with the scenario simulation teaching method in the teaching of radiology clinical practice is significant, which can improve the work ability of interns and make them more satisfied.

Study on the Application Effect of the Case Teaching Method Based on Primary Teaching Principle in Clinical Teaching of Radiology.

Objective: A case-control study explored the application of case-based teaching methods in the clinical teaching of radiology. Materials and Methods: 126 radiology interns of grade 2018 were selected by cluster sampling and randomly divided into the research group and the control group. The traditional teaching approach was used in the control group and the primary teaching principle was used in the research group. The teaching effects of the two groups were compared. Results: The interns' test scores, the research group's case summary multiple-choice questions, case-group multiple-choice questions, case analysis questions, theoretical total scores, and practical operation assessment scores were significantly higher than those of the control group, and the difference was statistically significant (P < 0.05). The total score of dimensions of the interns' critical thinking ability in the study group were significantly higher than those in the control group, and the difference was statistically significant (P < 0.05). The interns' perception of teachers, students' academic self-perception, students' perception of environment, students' social self-perception, and the total score of the DREEM scale in the study group were considerably greater than those in the control group, and the difference was statistically significant (P < 0.05). After teaching, the scores of systematic thinking ability and evidence-based thinking ability of the interns were significantly increased. The improvement in the study group was more significant than that in the control group, and the difference was statistically significant (P < 0.05). Following teaching, the scores of learning interest, self-management, plan implementation, and mutual cooperation of the interns in the two groups were significantly upregulated, and the difference was statistically significant (P < 0.05). Among them, the improvement of interns' abilities in the research group was significantly better than that in the control group, and the difference was statistically significant (P < 0.05). The scores of learning goal, learning process, learning effect, classroom environment construction, teaching strategy, and technology application in the research group were greater than those in the control group, and the difference was statistically significant (P < 0.05). The satisfaction rate of the study group was higher than that of the control group, and the difference was statistically significant (P < 0.05). Conclusion: The application of the case teaching method based on primary teaching principle in the radiology clinical teaching course is helpful to cultivate students' critical thinking ability and improve students' performance and classroom teaching effectiveness.

Peritumoral Imaging Manifestations on Gd-EOB-DTPA-Enhanced MRI for Preoperative Prediction of Microvascular Invasion in Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis.

Purpose: The aim was to investigate the association between microvascular invasion (MVI) and the peritumoral imaging features of gadolinium ethoxybenzyl DTPA-enhanced magnetic resonance imaging (Gd-EOB-DTPA-enhanced MRI) in hepatocellular carcinoma (HCC). Methods: Up until Feb 24, 2022, the PubMed, Embase, and Cochrane Library databases were carefully searched for relevant material. The software packages utilized for this meta-analysis were Review Manager 5.4.1, Meta-DiSc 1.4, and Stata16.0. Summary results are presented as sensitivity (SEN), specificity (SPE), diagnostic odds ratios (DORs), area under the receiver operating characteristic curve (AUC), and 95% confidence interval (CI). The sources of heterogeneity were investigated using subgroup analysis. Results: An aggregate of nineteen articles were remembered for this meta-analysis: peritumoral enhancement on the arterial phase (AP) was described in 13 of these studies and peritumoral hypointensity on the hepatobiliary phase (HBP) in all 19 studies. The SEN, SPE, DOR, and AUC of the 13 investigations on peritumoral enhancement on AP were 0.59 (95% CI, 0.41-0.58), 0.80 (95% CI, 0.75-0.85), 4 (95% CI, 3-6), and 0.73 (95% CI, 0.69-0.77), respectively. The SEN, SPE, DOR, and AUC of 19 studies on peritumoral hypointensity on HBP were 0.55 (95% CI, 0.45-0.64), 0.87 (95% CI, 0.81-0.91), 8 (95% CI, 5-12), and 0.80 (95% CI, 0.76-0.83), respectively. The subgroup analysis of two imaging features identified ten and seven potential factors for heterogeneity, respectively. Conclusion: The results of peritumoral enhancement on the AP and peritumoral hypointensity on HBP showed high SPE but low SEN. This indicates that the peritumoral imaging features on Gd-EOB-DTPA-enhanced MRI can be used as a noninvasive, excluded diagnosis for predicting hepatic MVI in HCC preoperatively. Moreover, the results of this analysis should be updated when additional data become available. Additionally, in the future, how to improve its SEN will be a new research direction.

Cerebral Functional Manipulation of Repetitive Transcranial Magnetic Stimulation in Cognitive Impairment Patients After Stroke: An fMRI Study.

Objective: Recently, the area of repetitive transcranial magnetic stimulation (rTMS) targeting neurological rehabilitation has been advanced as a potential treatment for post-stroke cognitive impairment (PSCI). However, the underlying mechanisms remains to be elusived. This study aims to figure out cerebral functional manipulation of rTMS in patients with PSCI through using the resting-state functional magnetic resonance imaging (rs-fMRI). Methods: Thirty patients with PSCI were recruited and randomly allocated into two groups: the rTMS intervention group and control group. The rTMS intervention group was given 20 min of 5 Hz rTMS (or control) over left dorsolateral prefrontal cortex (DLPFC) besides routine cognitive intervention training for 3 consecutive weeks, five times per week, on weekdays. Cognition performance was assessed by the Minimum Mental State Examination (MMSE) and Montreal cognitive assessment (MoCA). Neural activity and functional connectivity (FC) changes were acquired by rs-fMRI with fractional amplitude of low-frequency fluctuation (fALFF) and seed-based correlation analysis. Results: Cognition improvements were observed both in rTMS intervention group and control group (P < 0.01), while the rTMS group got more significant improvent than control group (P < 0.05). To be specified, compared with the control group, the rTMS group got higher fALFF values in these brain regions including superior temporal gyrus, inferior frontal gyrus and parahippocampal gyrus, while lower fALFF values in middle temporal gyrus, middle frontal gyrus and fusiform gyrus. In addition, the rTMS group showed increased FC between LDPFC and toprecuneus, inferior temporal gyrus, middle and inferior frontal gyrus and marginal gyrus, while decreased FC between LDPFC and middle temporal gyrus and thalamus. Conclusion: The increase and decrease of neural activity and FC in cognition-related regions detected by rs-fMRI are good indicators to clarify the underlining mechanisms of rTMS on PSCI.

Assessment of histologic prognostic factors of resectable rectal cancer: comparison of diagnostic performance using various apparent diffusion coefficient parameters.

This study is to investigate optimum apparent diffusion coefficient (ADC) parameter for predicting lymphovascular invasion (LVI), lymph node metastasis (LNM) and histology type in resectable rectal cancer. 58 consecutive patients with resectable rectal cancer were retrospectively identified. The minimum, maximum, average ADC and ADC difference value were obtained on ADC maps. Maximum ADC and ADC difference value increased with the appearance of LVI (r = 0.501 and 0.495, P < 0.001, respectively) and development of N category (r = 0.615 and 0.695, P < 0.001, respectively). ADC difference value tended to rise with lower tumor differentiation (r = - 0.269, P = 0.041). ADC difference value was an independent risk factor for predicting LVI (odds ratio = 1.323; P = 0.005) and LNM (odds ratio = 1.526; P = 0.005). Maximum ADC and ADC difference value could distinguish N0 from N1 category, N0 from N1-N2, N0-N1 from N2 (all P < 0.001). Only ADC difference value could distinguish histology type (P = 0.041). ADC difference value had higher area under the receiver operating characteristic curve than maximum ADC in identifying LVI (0.828 vs 0.797), N0 from N1 category (0.947 vs 0.847), N0 from N1-N2 (0.935 vs 0.874), and N0-N1 from N2 (0.814 vs 0.770). ADC difference value may be superior to the other ADC value parameters to predict LVI, N category and histology type of resectable rectal cancer.

[The value of sixty-four slice spiral CT angiography in diagnosing and evaluating abdominal aortic aneurysm before operations].

OBJECTIVE: To assess the value of sixty-four slice spiral CT angiography (CTA) in diagnosing and evaluating abdominal aortic aneurysm (AAA) before operations. METHODS: Between Oct 2006 and Jan 2008, forty-three consecutive patients with suspected AAA underwent examinations by the sixty-four slice spiral CT angiography with 370 mg I/mL contrast material. Of these patients, 38 patients whose AAA imaging quality met the diagnostic criteria were enrolled in the study. Imaging reconstruction were made at the workstation, which included multi-plane reconstruction (MPR), maximum intensity projection (MIP) and volume rendering technique (VRT). The comprehensive observation and analysis focused on the type, location, size and extension of AAA. The classification of AAA was based on the relevant parameters that satisfied the requirement of endovascular stent-graft exclusion. RESULTS: (1) The aneurysms of all of the 38 patients were located at under the level of renal arteries, including six that were adjacent to renal arteries and 32 under renal arteries. (2) Among the 38 patients with AAA, 4 were type I , 3 were type II A, 4 were type II B, 21 were type II C, and 6 were type III. (3) The sixty-four slice spiral CT angiography clearly displayed the shape, locality and size of the aneurysms, the anatomic relations between the aneurismal bodies and the adjacent main branches of aorta, and the mural thrombus in all of the patients. Relevant parameters of AAA could be accurately measured by the CTA images. CONCLUSION: Sixty-four slice spiral CT angiography is a fast, non-invasive and effective instrument for diagnosing and evaluating AAA before operations.

[Preliminary study of tumor perfusion assessment with multidetector CT in carcinoma of esophagus and cardia].

OBJECTIVE: To investigate the clinical application of first-pass perfusion MDCT in the assessment of tumor angiogenesis in carcinoma of esophagus and cardia. METHODS: CT perfusion was performed with multi-detector row CT (MDCT) in 44 patients with carcinoma of esophagus and esophagogastric junction, who was diagnosed with pathological results and did not received any anti-tumor therapy. Twenty-one patients with peripheral lung cancer but normal esophagus were served as controls. Perfusion parameters were compared between normal and malignant esophagus, between adenocarcinoma and squamous cell carcinoma, as well as between tumors with metastases and those without metastases. RESULTS: Carcinoma of esophagus and esophagogastric junction showed higher blood flow, peak enhancement index, blood volume, and shorter time to peak compared with normal esophagus (P < 0.05). There were no statistically significant differences in perfusion parameters between adenocarcinoma and squamous cell carcinoma (P > 0.05), whereas tumors with metastases showed higher blood flow and shorter time to peak compared with those without metastases (P < 0.05). CONCLUSION: MDCT perfusion could assess tumor vascularity in carcinoma of esophagus and esophagogastric junction, and tumor vascularity or angiogenesis was not influenced by its histological type. However, high blood flow and short time-to-peak may be helpful to predict tumor metastases.