Objective To review the current status of magnetic resonance imaging (MRI) techniques in the evaluation of hepatic fibrosis. Methods The application and recent advances of various kinds of MRI techniques in evaluating hepatic fibrosis were summarized by literature review. Results The state-of-the-art of MRI evaluating of hepatic fibrosis included common contrast-enhanced MRI, double contrast-enhanced MRI, and various functional MRI techniques. Common contrast-enhanced MRI could detect morphological changes of the liver, but little value in phasing. Double contrast-enhanced MRI markedly increased the contrast to noise ratio. Except diagnosis liver fibrosis, functional MRI also could phase it by its serverity. Conclusion MRI techniques, especially those functional MRI techniques, are advancing very fast and have very great potentiality in both the diagnosis and severity assessment of hepatic fibrosis.
Nowadays, an increasing number of researches have shown that epilepsy, as a kind of neural network disease, not only affects the brain region of seizure onset, but also remote regions at which the brain network structures are damaged or dysfunctional. These changes are associated with abnormal network of epilepsy. Resting-state network is closely related to human cognitive function and plays an important role in cognitive process. Cognitive dysfunction, a common comorbidity of epilepsy, has adverse impacts on life quality of patients with epilepsy. The mechanism of cognitive dysfunction in epileptic patients is still incomprehensible, but the change of resting-state brain network may be associated with their cognitive impairment. In order to further understand the changes of resting-state network associated with the cognitive function and explore the brain network mechanism of the occurrence of cognitive dysfunction in patients with epilepsy, we review the related researches in recent years.
This study aimed to characterize and magnetic resonance imaging (MRI) track the mesenchymal stem cells labeled with polylysine-coated superparamagnetic iron oxide (PLL-SPIO). Rat bone marrow derived mesenchymal stem cells (rMSCs) were labeled with 25, 50 and 100 μg/mL PLL-SPIO for 24 hours. The labeling efficiency was assessed by iron content, Prussian blue staining, electron microscopy and in vitro MR imaging. The labeled cells were also analyzed for cytotoxicity and differentiation potential. Electron microscopic observations and Prussian blue staining revealed that 75%-100% of cells were labeled with iron particles. PLL-SPIO did not show any cytotoxicity up to 100 μg/mL concentration. Both 25 μg/mL and 50 μg/mL PLL-SPIO labeled stem cells did not exhibit any significant alterations in the adipo/osteo/chondrogenic differentiation potential compared to unlabeled control cells. The lower concentration of 25 μg/mL iron labeled cells emitted an obvious dark signal in T1W, T2WI and T2*WI MR image. The novel PLL-SPIO enables to label and track rMSCs for in vitro MRI without cellular alteration. Therefore PLL-SPIO may potentially become a better MR contrast agent especially in tracking the transplanted stem cells and other cells without compromising cell functional quality.
摘要:目的: 探討臂叢神經磁共振成像的技術方法及其可行性。 方法 :對15例正常志愿者行雙側臂叢神經成像:包括常規快速自旋回波序列T1加權(T1W/TSE)、快速自旋回波序列T2加權(T2W/TSE)、快速自旋回波序列T2加權加SPIR脂肪抑制(T2W/SPIR)冠狀位掃描以及彌散加權背景抑制成像序列(DWIBS)軸位掃描。 結果 :T1W/TSE、T2W/TSE、及T2W/SPIR對臂叢節后神經同層顯示率分別為533%、567%和833%;DWIBS MIP重建圖像對臂叢神經的全貌顯示較為完整、清晰、直觀;T1W/TSE、T2W/TSE、T2W/SPIR及DWIBS MIP重建圖像的對比噪聲比分別為109±09、107±13、185±68和299±133,T2W/SPIR序列和DWIBS MIP重建圖像的對比噪聲比明顯高于T1W/TSE和T2W/TSE序列。 結論 :T2W/SPIR序列對臂叢神經的同層顯示率及圖像的對比噪聲比明顯高于常規T1W/TSE、T2W/TSE序列, DWIBS MIP重建圖像能夠顯示臂叢神經的全貌,兩者為臂叢神經成像較為有效的技術方法,對于臂叢神經病變的診斷即具有十分重要的意義。Abstract: Objective: To determine the optimal sequences of brachial plexus with MRI. Methods : Fifteen volunteers were underwent MRI on 15T scanner, the Sequences of T1W/TSE/COR, T2W/TSE/COR, T2W/SPIR/COR and Diffusionweighted imaging with background body signal suppression were performed. Results : The display rates of brachial plexus postganglionic segment nerve showing at the same slice were 533%, 567% and 833% on T1W/TSE/COR, T2W/TSE/COR, T2W/SPIR/COR. Brachial plexus on DWIBS MIP were clear and complete. Contrastnoise ratio of four sequences was 109±09, 107±13, 185±68 and 299±133,respectively. Contrastnoise ratio of T2W/SPIR/COR and DWIBS MIP was significantly higher than that of the other two sequences. Conclusion : Display rate of brachial plexus and contrastnoise ratio of images on T2W/SPIR/COR were higher than those of routine sequences. Image of DWIBS MIP can show the outline of brachial plexus clearly. The two sequences were reliable and effetive techoniquic in diagnosis of brachial plexus lesion.
Urokinase plasminogen activator receptor (uPAR) is a membrane protein which is attached to the cellular external membrane. The uPAR expression can be observed both in tumor cells and in tumor-associated stromal cells. Thus, in the present study, the human amino-terminal fragment (hATF), as a targeting element to uPAR, is used to conjugate to the surface of superparamagnetic iron nanoparticle (SPIO). Flowcytometry was used to examine the uPAR expression in different tumor cell lines. The specificity of hATF-SPIO was verified by Prussian blue stain and cell phantom test. The imaging properties of hATF-SPIO were confirmed in vivo magnetic resonance imaging (MRI) of uPAR-elevated colon tumor. Finally, the distribution of hATF-SPIO in tumor tissue was confirmed by pathological staining. Results showed that the three cells in which we screened, presented different expression characteristics, i.e., Hela cells strongly expressed uPAR, HT29 cells moderately expressed uPAR, but Lovo cells didn't express uPAR. In vitro, after incubating with Hela cells, hATF-SPIO could specifically combined to and be subsequently internalized by uPAR positive cells, which could be observed via Prussian blue staining. Meanwhile T2WI signal intensity of Hela cells, after incubation with targeted probe, significantly decreased, and otherwise no obvious changes in Lovo cells both by Prussian blue staining and MRI scans. In vivo, hATF-SPIO could be systematically delivered to HT29 xenograft and accumulated in the tumor tissue which was confirmed by Prussian Blue stain compared to Lovo xenografts. Twenty-four hours after injection of targeting probe, the signal intensity of HT29 xenografts was lower than Lovo ones which was statistically significant. This targeting nanoparticles enabled not only in vitro specifically combining to uPAR positive cells but also in vivo imaging of uPAR moderately elevated colon cancer lesions.
Objective
To clarify relationship between signal heterogeneity on hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI and prognosis of hepatocellular carcinoma (HCC).
Methods
From January 2014 to January 2017 in the First Affiliated Hospital of Chongqing Medical University, a total of 77 patients with the pathologically proved HCC underwent Gd-EOB-DTPA-enhanced MRI prior to surgery were included in this study. On the basis of the signal heterogeneity in the hepatobiliary phase, the included patients were designed to homogeneous hypointensity group and heterogeneous hyperintensity group. The disease-free survival time were compared between the 2 groups and it’s influencing factors were analyzed.
Results
Seventy-seven patients with HCC were included, including 45 cases of homogeneous hypointensity and 32 cases of heterogeneous hyperintensity. There were no significant differences in the age, gender, etiology, liver function, alpha-fetoprotein, differentiated degree, Child-Pugh grade, lesion diameter, lesion border, and number of lesions between the 2 groups (P>0.05). However, the HCC patients with heterogeneous hyperintensity had a later BCLC staging (P=0.001). The disease-free survival time of the patients with homogeneous hypointensity and heterogeneous hyperintensity was (17.0±9.8) months and (12.4±10.4)months, respectively. The Kaplan-Meier survival curve showed that the disease-free survival time in the patients with homogeneous hypointensity was significantly better than that in the patients with heterogeneous hyperintensity (P=0.020). The results of univariate analysis showed that the other confounding factors had no effect on the disease-free survival time of patients with hepatocellular carcinoma (P>0.05) except for the signal of hepatobiliary phase (P<0.05). Furthermore, the hepatobiliary phase signal, BCLC stage, and degree of differentiation, which might be clinically considered as potentially influencing for the prognosis of patients with HCC, were included in the Cox multivariate proportional hazard regression model and found that the heterogeneous hyperintensity was still the risk factor of the disease-free survival rate in patients with HCC (P=0.047).
Conclusion
Signal heterogeneity on hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI is related to prognosis of patients with HCC, heterogeneous hyperintensity may indicate a lower disease-free survival rate.
White matter lesion (WML) of presumed vascular origin is one of the common imaging manifestations of cerebral small vessel diseases, which is the main reason of cognitive impairment and even vascular dementia in the elderly. However, there is a lack of early and effective diagnostic methods currently. In recent years, studies of diffusion tensor imaging (DTI) and resting-state functional magnetic resonance imaging (rs-fMRI) have shown that cognitive impairment in patients with WMLs is associated with disrupted white matter microstructural and brain network connectivity. Therefore, it’s speculated that DTI and rs-fMRI can be effective in early imaging diagnosis of WMLs-related cognitive impairment. This article reviews the role and significance of DTI and rs-fMRI in WMLs-related cognitive impairment.
Breast cancer is a malignant tumor with the highest incidence and mortality rate among women worldwide. Early screening and standardized diagnosis and treatment of breast cancer are conducive to improving the survival rate of patients. Breast magnetic resonance imaging (MRI) plays a crucial role in the screening of high-risk populations, diagnosis, staging, and treatment efficacy evaluation. To improve the writing efficiency and diagnostic accuracy of breast MRI reports and promote standardized diagnosis and treatment of breast cancer, there is an urgent need for standardized imaging structured reports. We present the imaging structured report protocol of MRI for breast diseases utilized at West China Hospital of Sichuan university, which aims to promote standardized documentation of breast MRI reports.
Objective
To compare diagnosis values of computed tomography (CT) and magnetic resonance imaging (MRI) in preoperative staging of rectal carcinoma.
Methods
The imaging data of 81 patients with rectal carcinoma from January 2013 to January 2017 in the Hefei Second People’s Hospital were retrospectively analyzed. Based on the postoperative pathological results, the diagnostic accordance rates of CT and MRI on the T staging and N staging were calculated.
Results
The sensitivities of the CT and MRI on the preoperative T staging of rectal carcinoma were 69.1% (56/81) and 82.5% (52/63), the difference was not statistically significant (χ2=3.396, P=0.065), the Kappa values was 0.521 and 0.371, respectively, the MRI on the T staging was in a good agreement with the pathological diagnosis. The sensitivitie of the T1-2, T3, and T4 stagings with CT was 70.0%, 66.7%, and 72.0%, respectively, with MRI was 83.3%, 83.3%, and 81.0%, respectively, which had no significant difference respectively between the CT and the MRI. The areas under the receiver operating characteristic curve of the T1-2, T3, and T4 stagings with the CT and MRI were 0.809, 0.689, 0.798 and 0.897, 0.826, 0.869, respectively. The sensitivities of the CT and MRI on the preoperative N staging of rectal carcinoma were 59.3% (48/81) and 65.1% (41/63), the difference was not statistically significant (χ2=0.509, P=0.476), the Kappa values were 0.371 and 0.463, respectively. The sensitivities of the N0, N1, N2 stagings with CT were 64.7%, 45.5%, 64.0%, with MRI were 70.3%, 63.2%, 72.5%, which had no significant difference respectively between the CT and the MRI.
Conclusions
Results of in this study show that MRI is superior to CT for judgment of tumor infiltration. Neither CT nor MRI is able to provide satisfactory assessment of lymph node metastasis.
ObjectiveTo investigate the value of a predictive model for sentinel lymph node (SLN) metastasis after neoadjuvant therapy (NAT) based on the radiomic features from multi-modality magnetic resonance imaging (MRI) in combination with clinicopathologic data. MethodsThe clinical data and MRI images of breast cancer patients (initially diagnosed with cN0, all underwent NAT and surgical treatment) from two hospitals (Affiliated Hospital of Southwest Medical University and Suining Central Hospital) from January 2018 to September 2024, were retrospectively collected. The radiomic features from the multi-modality images, including T2-weighted short tau inversion recovery (T2STIR), diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE), were extracted and selected. The predictive models for SLN metastasis after NAT were constructed using four algorithms: LightGBM, XGBoost, support vector machine (SVM), and logistic regression (LR), in combination with clinicopathologic data. The models were evaluated for performance and interpretability using receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis, and Shapley additive explanation (SHAP) analysis. ResultsA total of 236 breast cancer patients were enrolled in this study. Among them, 216 patients from the Southwest Medical University were subdivided in an 8∶2 ratio into a training set (n=173) and internal validation set (n=43), while 20 patients from the Suining Central Hospital served as the external validation set. The multivariate logistic regression analysis showed that the lymphovascular invasion [OR (95%CI)=21.215 (4.404, 102.202), P ＜0.001] and perineural invasion [OR (95%CI)=25.867 (1.870, 357.790), P=0.002] were the risk factors, while high Ki-67 expression [OR (95%CI)=0.119 (0.035, 0.404), P＜0.001] was the protective factor of SLN metastasis after NAT. The predictive models utilizing multi-modality MRI and clinicopathologic data yielded area under the ROC curve values of the internal and external validation sets of 0.750 [95%CI=(0.395, 1.000)] / 0.625 [95%CI=(0.321, 0.926)] for LightGBM, 0.878 [95%CI=(0.707, 1.000)] / 0.778 [95%CI=(0.525, 0.986)] for XGBoost, 0.641 [95%CI=(0.488, 0.795)] / 0.681 [95%CI=(0.345, 1.000)] for SVM, and 0.667 [95%CI=(0.357, 0.945)] / 0.583 [95%CI=(0.196, 0.969)] for LR. The XGBoost demonstrated the best predictive performance. Further SHAP analysis revealed that the lymphovascular invasion, T2STAR-MRI_FIRSTORDER_Minimum, and platelet were the key features influencing the predictions of the models. ConclusionThe findings of this study suggest that XGBoost prediction model based on radiomic features derived from multi-modality MRI (T2STIR, DWI, and DCE) in combination with clinicopathologic data is able to predict SLN metastasis after NAT in patients with breast cancer.
