Nomogram based on multimodal magnetic resonance combined with B7-H3mRNA for preoperative lymph node prediction in esophagus cancer

Accurate preoperative prediction of lymph node metastasis(LNM)in esophageal cancer(EC)patients is of crucial clinical significance for treatment planning and prognosis.AIM To develop a clinical radiomics nomogram that can predict the preoperative lymph node(LN)status in EC patients.METHODS A total of 32 EC patients confirmed by clinical pathology(who underwent surgical treatment)were included.Real-time fluorescent quantitative reverse transcription-polymerase chain reaction was used to detect the expression of B7-H3 mRNA in EC tissue obtained during preoperative gastroscopy,and its correlation with LNM was analyzed.Radiomics features were extracted from multi-modal magnetic resonance imaging of EC using Pyradiomics in Python.Feature extraction,data dimensionality reduction,and feature selection were performed using XGBoost model and leave-one-out cross-validation.Multivariable logistic regression analysis was used to establish the prediction model,which included radiomics features,LN status from computed tomography(CT)reports,and B7-H3 mRNA expression,represented by a radiomics nomogram.Receiver operating characteristic area under the curve(AUC)and decision curve analysis(DCA)were used to evaluate the predictive performance and clinical application value of the model.RESULTS The relative expression of B7-H3 mRNA in EC patients with LNM was higher than in those without metastasis,and the difference was statistically significant(P<0.05).The AUC value in the receiver operating characteristic(ROC)curve was 0.718(95%CI:0.528-0.907),with a sensitivity of 0.733 and specificity of 0.706,indicating good diagnostic performance.The individualized clinical prediction nomogram included radiomics features,LN status from CT reports,and B7-H3 mRNA expression.The ROC curve demonstrated good diagnostic value,with an AUC value of 0.765(95%CI:0.598-0.931),sensitivity of 0.800,and specificity of 0.706.DCA indicated the practical value of the radiomics nomogram in clinical practice.CONCLUSION This study developed a radiomics nomogram that includes radiomics features,LN status from CT reports,and B7-H3 mRNA expression,enabling convenient preoperative individualized prediction of LNM in EC patients.

Does sevoflurane sedation in pediatric patients lead to“pseudo”leptomeningeal enhancement in the brain on 3 Tesla magnetic resonance imaging?

BACKGROUND Prominent leptomeningeal contrast enhancement(LMCE)in the brain is observed in some pediatric patients during sedation for imaging.However,based on clinical history and cerebrospinal fluid analysis,the patients are not acutely ill and do not exhibit meningeal signs.Our study determined whether sevoflurane inhalation in pediatric patients led to this pattern of‘pseudo’LMCE(pLMCE)on 3 Tesla magnetic resonance imaging(MRI).AIM To highlight the significance of pLMCE in pediatric patients undergoing enhanced brain MRI under sedation to avoid misinterpretation in reports.METHODS A retrospective cross-sectional evaluation of pediatric patients between 0-8 years of age was conducted.The patients underwent enhanced brain MRI under inhaled sevoflurane.The LMCE grade was determined by two radiologists,and interobserver variability of the grade was calculated using Cohen’s kappa.The LMCE grade was correlated with duration of sedation,age and weight using the Spearman rho rank correlation.RESULTS A total of 63 patients were included.Fourteen(22.2%)cases showed mild LMCE,48(76.1%)cases showed moderate LMCE,and 1 case(1.6%)showed severe LMCE.We found substantial agreement between the two radiologists in detection of pLMCE on post-contrast T1 imaging(kappa value=0.61;P<0.001).Additionally,we found statistically significant inverse and moderate correlations between patient weight and age.There was no correlation between duration of sedation and pLMCE.CONCLUSION pLMCE is relatively common on post-contrast spin echo T1-weighted MRI of pediatric patients sedated by sevoflurane due to their fragile and immature vasculature.It should not be misinterpreted for meningeal pathology.Knowing pertinent clinical history of the child is an essential prerequisite to avoid radiological overcalling and the subsequent burden of additional investigations.

Reduced Imaging Time and Improved Image Quality of 3D Isotropic T2-Weighted Magnetic Resonance Imaging with Compressed Sensing for the Female Pelvis

This study is to compare three-dimensional(3D)isotropic T2-weighted magnetic resonance imaging(MRI)with compressed sensing-sampling perfection with application optimized contrast(CS-SPACE)and the conventional image(3D-SPACE)sequence in terms of image quality,estimated signal-to-noise ratio(SNR),relative contrast-to-noise ratio(CNR),and the lesions’conspicuous of the female pelvis.Thirty-six females(age:51,28-73)with cervical carcinoma(n=20),rectal carcinoma(n=7),or uterine fibroid(n=9)were included.Patients underwent magnetic resonance(MR)imaging at a 3T scanner with the sequences of 3D-SPACE,CS-SPACE,and twodimensional(2D)T2-weighted turbo-spin echo(TSE).Quantitative analyses of estimated SNR and relative CNR between tumors and other tissues,image quality,and tissue conspicuity were performed.Two radiologists assessed the difference in diagnostic findings for carcinoma.Quantitative values and qualitative scores were analyzed,respectively.The estimated SNR and the relative CNR of tumor-to-muscle obturator internus,tumor-to-myometrium,and myometrium-to-muscle obturator internus was comparable between 3D-SPACE and CS-SPACE.The overall image quality and the conspicuity of the lesion scores of the CS-SPACE were higher than that of the 3D-SPACE(P<0.01).The CS-SPACE sequence offers shorter scan time,fewer artifacts,and comparable SNR and CNR to conventional 3D-SPACE,and has the potential to improve the performance of T2-weighted images.

A Rare Case of Concordant Atrioventricular Connection to L-Looped Ventricles in Situs Solitus:4-Dimensional Magnetic Resonance Imaging and 3D Printing

An infant male presented with the rare anatomy consisting of situs solitus,concordant atrioventricular connections to L-looped ventricles,double outlet right ventricle(DORV),and hypoplastic aortic arch.6 months after neonatal aortic arch repair,the morphologic right ventricle function deteriorated,and surgical evaluation was undertaken to determine if either biventricular repair with a systemic morphologic left ventricle or right ventricular exclusion was possible.After initial echocardiography,magnetic resonance imaging(MRI)was used to create detailed axial and 4-dimensional(4D)images and 3-dimensional(3D)printed models.The detailed anatomy of this rare,complex case and its use in pre-surgical planning is presented.

Diffusion-weighted magnetic resonance imaging reflects activation of signal transducer and activator of transcription 3 during focal cerebral ischemia/reperfusion

Signal transducer and activator of transcription（STAT）is a unique protein family that binds to DNA,coupled with tyrosine phosphorylation signaling pathways,acting as a transcriptional regulator to mediate a variety of biological effects.Cerebral ischemia and reperfusion can activate STATs signaling pathway,but no studies have confirmed whether STAT activation can be verified by diffusion-weighted magnetic resonance imaging（DWI）in rats after cerebral ischemia/reperfusion.Here,we established a rat model of focal cerebral ischemia injury using the modified Longa method.DWI revealed hyperintensity in parts of the left hemisphere before reperfusion and a low apparent diffusion coefficient.STAT3 protein expression showed no significant change after reperfusion,but phosphorylated STAT3 expression began to increase after 30 minutes of reperfusion and peaked at 24 hours.Pearson correlation analysis showed that STAT3 activation was correlated positively with the relative apparent diffusion coefficient and negatively with the DWI abnormal signal area.These results indicate that DWI is a reliable representation of the infarct area and reflects STAT phosphorylation in rat brain following focal cerebral ischemia/reperfusion.

Femoroacetabular impingement with chronic acetabular rim fracture- 3D computed tomography, 3D magnetic resonance imaging and arthroscopic correlation

Femoroacetabular impingement is uncommonly associated with a large rim fragment of bone along the superolateral acetabulum. We report an unusual case of femoroacetabular impingement(FAI) with chronic acetabular rim fracture. Radiographic, 3D computed tomography, 3D magnetic resonance imaging and arthroscopy correlation is presented with discussion of relative advantages and disadvantages of various modalities in the context of FAI.

Development and in vitro study of a bi-specific magnetic resonance imaging molecular probe for hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)ranks second in terms of cancer mortality worldwide.Molecular magnetic resonance imaging(MRI)targeting HCC biomarkers such as alpha-fetoprotein(AFP)or glypican-3(GPC3)offers new strategies to enhance specificity and help early diagnosis of HCC.However,the existing iron oxide nanoparticle-based MR molecular probes singly target AFP or GPC3,which may hinder their efficiency to detect heterogeneous micro malignant HCC tumors<1 cm(MHCC).We hypothesized that the strategy of double antibody-conjugated iron oxide nanoparticles which simultaneously target AFP and GPC3 antigens may potentially be used to overcome the tumor heterogeneity and enhance the detection rate for MRI-based MHCC diagnosis.AIM To synthesize an AFP/GPC3 double antibody-labeled iron oxide MRI molecular probe and to assess its impact on MRI specificity and sensitivity at the cellular level.METHODS A double antigen-targeted MRI probe for MHCC anti-AFP-USPIO-anti-GPC3(UAG)was developed by simultaneously conjugating AFP andGPC3 antibodies to a 5 nm ultra-small superparamagnetic iron oxide nanoparticle(USPIO).At the same time,the singly labeled probes of anti-AFP-USPIO(UA)and anti-GPC3-USPIO(UG)and non-targeted USPIO(U)were also prepared for comparison.The physical characterization including morphology(transmission electron microscopy),hydrodynamic size,and zeta potential(dynamic light scattering)was conducted for each of the probes.The antigen targeting and MRI ability for these four kinds of USPIO probes were studied in the GPC3-expressing murine hepatoma cell line Hepa1-6/GPC3.First,AFP and GPC3 antigen expression in Hepa1-6/GPC3 cells was confirmed by flow cytometry and immunocytochemistry.Then,the cellular uptake of USPIO probes was investigated by Prussian blue staining assay and in vitro MRI(T2-weighted and T2-map)with a 3.0 Tesla clinical MR scanner.RESULTS Our data showed that the double antibody-conjugated probe UAG had the best specificity in targeting Hepa1-6/GPC3 cells expressing AFP and GPC3 antigens compared with single antibody-conjugated and unconjugated USPIO probes.The iron Prussian blue staining and quantitative T2-map MRI analysis showed that,compared with UA,UG,and U,the uptake of double antigen-targeted UAG probe demonstrated a 23.3%(vs UA),15.4%(vs UG),and 57.3%(vs U)increased Prussian stained cell percentage and a 14.93%(vs UA),9.38%(vs UG),and 15.3%(vs U)reduction of T2 relaxation time,respectively.Such bi-specific probe might have the potential to overcome tumor heterogeneity.Meanwhile,the coupling of two antibodies did not influence the magnetic performance of USPIO,and the relatively small hydrodynamic size(59.60±1.87 nm)of double antibodyconjugated USPIO probe makes it a viable candidate for use in MHCC MRI in vivo,as they are slowly phagocytosed by macrophages.CONCLUSION The bi-specific probe presents enhanced targeting efficiency and MRI sensitivity to HCC cells than singly-or non-targeted USPIO,paving the way for in vivo translation to further evaluate its clinical potential.

Imaging plaque inflammation in asymptomatic cocaine addicted individuals with simultaneous positron emission tomography/magnetic resonance imaging

BACKGROUND Chronic cocaine use is associated with stroke, coronary artery disease and myocardial infarction, resulting in severe impairments or sudden mortality. In the absence of clear cardiovascular symptoms, individuals with cocaine use disorder (iCUD) seeking addiction treatment receive mostly psychotherapy and psychiatric pharmacotherapy, with no attention to vascular disease (i.e., atherosclerosis). Little is known about the pre-clinical signs of cardiovascular risk in iCUD and early signs of vascular disease are undetected in this underserved population. AIM To assess inflammation, plaque burden and plaque composition in iCUD aiming to detect markers of atherosclerosis and vascular disease. METHODS The bilateral carotid arteries were imaged with positron emission tomography/magnetic resonance imaging (PET/MRI) in iCUD asymptomatic for cardiovascular disease, healthy controls, and individuals with cardiovascular risk. PET with 18F-fluorodeoxyglucose (18F-FDG) evaluated vascular inflammation and 3-D dark-blood MRI assessed plaque burden including wall area and thickness. Drug use and severity of addiction were assessed with standardized instruments. RESULTS The majority of iCUD and controls had carotid FDG-PET signal greater than 1.6 but lower than 3, indicating the presence of mild to moderate inflammation. However, the MRI measure of wall structure was thicker in iCUD as compared to the controls and cardiovascular risk group, indicating greater carotid plaque burden. iCUD had larger wall area as compared to the healthy controls but not as compared to the cardiovascular risk group, indicating structural wall similarities between the non-control study groups. In iCUD, wall area correlated with greater cocaine withdrawal and craving. CONCLUSION These preliminary results show markers of carotid artery disease burden in cardiovascular disease-asymptomatic iCUD. Broader trials are warranted to develop protocols for early detection of cardiovascular risk and preventive intervention in iCUD.

Bi-specific T1 positive-contrast-enhanced magnetic resonance imaging molecular probe for hepatocellular carcinoma in an orthotopic mouse model

BACKGROUND Hepatocellular carcinoma(HCC)is the second leading cause of cancer-related mortality.HCC-targeted magnetic resonance imaging(MRI)is an effective noninvasive diagnostic method that involves targeting clinically-related HCC biomarkers,such as alpha-fetoprotein(AFP)or glypican-3(GPC3),with iron oxide nanoparticles.However,in vivo studies of HCC-targeted MRI utilize single-target iron oxide nanoprobes as negative(T2)contrast agents,which might weaken their future clinical applications due to tumor heterogeneity and negative MRI contrast.Ultra-small superparamagnetic iron oxide(USPIO)nanoparticles(approximately 5 nm)are potential optimal positive(T1)contrast agents.We previously verified the efficiency of AFP/GPC3-double-antibody-labeled iron oxide MR molecular probe in vitro.AIM To validate the effectiveness of a bi-specific probe in vivo for enhancing T1-weighted positive contrast to diagnose the early-stage HCC.METHODS The single-and double-antibody-conjugated 5-nm USPIO probes,including antiAFP-USPIO(UA),anti-GPC3-USPIO(UG),and anti-AFP-USPIO-anti-GPC3(UAG),were synthesized.T1-and T2-weighted MRI were performed on day 10 after establishment of the orthotopic HCC mouse model.Following intravenous injection of U,UA,UG,and UAG probes,T1-and T2-weighted images were obtained at 12,12,and 32 h post-injection.At the end of scanning,mice were euthanized,and a histologic analysis was performed on tumor samples.RESULTS T1-and T2-weighted MRI showed that absolute tumor-to-background ratios in UAG-treated HCC mice peaked at 24 h post-injection,with the T1-and T2-weighted signals increasing by 46.7%and decreasing by 11.1%,respectively,relative to pre-injection levels.Additionally,T1-weighted contrast in the UAG-treated group at 24 h post-injection was enhanced 1.52-,2.64-,and 4.38-fold compared to those observed for single-targeted anti-GPC3-USPIO,anti-AFP-USPIO,and nontargeted USPIO probes,respectively.Comparison of U-,UA-,UG-,and UAG-treated tumor sections revealed that UAG-treated mice exhibited increased stained regions compared to those observed in UG-or UA-treated mice.CONCLUSION The bi-specific T1-positive contrast-enhanced MRI probe(UAG)for HCC demonstrated increased specificity and sensitivity to diagnose early-stage HCC irrespective of tumor size and/or heterogeneity.

Effect and cerebral mechanism of moxibustion at heat-sensitized Yaoyangguan(GV3)in patients with lumbar disc herniation and myofascial pain syndrome by resting-state functionality magnetic resonance imaging:protocol for an observational study

We want to explore the analgesic brain effect of the moxibustion at heat-sensitized Yaoyangguan(GV3)in patients with lumbar disc herniation(LDH)and myofascial pain syndrome(MPS).In an assessor-blinded observational study,we will include 15 LDH and 15 MPS.They will accept same treatment of heat-sensitive moxibustion at Yaoyangguan(GV3).The resting-state functionality magnetic resonance imaging image data of brain activities before and after treatment will be analyzed by mean fractional amplitude of low-frequency fluctuation,regional homogeneity analysis and brain functional connection.We select seed of first sensory cortex,second sensory cortex,insula cortex,periaqueductal gray and anterior cingulate cortex as the regions of interest to analyse the relationship between brain functional connectivity of pain-related networks and clinical data.Our study could disclose key brain targets and central response characteristics of the analgesic brain effect and the brain functional connection of heat-sensitive moxibustion.

Fe_(3)O_(4)-rhodamine 6G nanoparticles:An iron enhanced pH sensitive multimodal probe for fluorescence and magnetic resonance imaging of tumor cell

The accurate diagnosis of tumor at the early stage depends on efficient medical imaging methods using probes with high sensitivity to the environment of tumor cells.For this purpose,we design the Fe_(3)O_(4)-rhodamine 6 G(Rh6G)nanoparticles(NPs)as a kind of dual-mode probe for fluorescence and magnetic resonance imaging(MRI).The Fe_(3)O_(4)-Rh6G NPs are demonstrated to be Fe^(3+)enhanced and pH-sensitive fluorescent agents,and the strongest fluorescence performance occurs under the pH value of 3.Cyto-toxicity assessment in HeLa cells proves the good biocompatibility and low toxicity of the Fe_(3)O_(4)-Rh6G NPs.The consequent fluorescence experiments in tumor cells show good imaging contrast,which is con-tributed by both the Fe^(3+)released from Fe_(3)O_(4)and the acid environment of tumor cells.Moreover,the Fe_(3)O_(4)-Rh6G NPs are superparamagnetic and have a strong MRI T 2 contrast effect.According to the per-formance in fluorescence and MRI tests,the Fe_(3)O_(4)-Rh6G NPs are potential dual-mode probes for MRI contrast agents and fluorescence probes with high biocompatibility for early-stage tumor detection.

Three-dimensional arterial spin labeling and diffusion kurtosis imaging in evaluating perfusion and infarct area size in acute cerebral ischemia

BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is important.AIM To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral ischemia.METHODS Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were included.All patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own software.The apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were compared.The correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was analyzed.RESULTS The DKI parameters of focal and control areas in the study subjects were compared.The ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control area.The MK,RK,and AK values in the lesion area were significantly higher than those in the control area.The MK/MD value in the infarct lesions was used to determine the matching situation.MK/MD<5 mm was considered matching and MK/MD≥5 mm was considered mismatching.PLD1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly different.PLD1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control areas.The MK and MD maps showed a lesion area of 20.08±5.74 cm^(2) and 22.09±5.58 cm^(2),respectively.T2WI showed a lesion area of 19.76±5.02 cm^(2).There were no significant differences in the cerebral infarction lesion areas measured using the three methods.MK,MD,and T2WI showed a good correlation.CONCLUSION DKI parameters showed significant difference between the focal and control areas in patients with acute ischemic cerebral infarction.3DASL can effectively determine the changes in perfusion levels in the lesion area.There was a high correlation between the area of the infarct lesions diagnosed by DKI and T2WI.

胎盘体积结合葡萄糖转运蛋白3对胎儿生长受限的预测价值

目的探讨胎盘体积联合血清中葡萄糖转运蛋白3(GLUT3)对胎儿生长受限的预测价值。方法以我院2018年12月—2020年5月行MRI检查的100例胎儿生长受限的孕妇作为观察组,孕检正常的100例孕妇作为对照组。根据MRI检查获取受试者胎盘体积,并检测受试者血清GLUT3的水平;采用logistics回归模型构建胎盘体积与血清GLUT3联合诊断模型,应用ROC曲线下面积(AUC)评判胎盘体积和血清GLUT3独立或两者联合应用对胎儿生长受限的预测价值。结果两组孕妇胎盘体积和血清GLUT3水平比较差异均具有显著性(t=13.380、54.173,P<0.05)。以胎盘体积联合血清GLUT3预测胎儿生长受限的模型为Logit(P)=-0.647×胎盘体积+0.598×GLUT+0.431;胎盘体积联合血清GLUT3预测胎儿生长受限的灵敏度、特异度及AUC均明显高于单个指标(P<0.05)。结论胎盘体积联合血清GLUT3对胎儿生长受限具有一定的预测价值。

磁共振SWI序列联合血清Id1、IGFBP-3对脑胶质瘤术前分级的评估价值

目的分析磁共振磁敏感加权成像(SWI)序列联合血清分化抑制因子1(Id1)、胰岛素样生长因子结合蛋白-3(IGFBP-3)对脑胶质瘤术前分级的评估价值。方法选取2019年12月至2022年6月我院收治的脑胶质瘤患者98例作为此次研究对象,根据恶化情况分为低级别组(世界卫生组织Ⅰ级和Ⅱ级)46例,高级别组(世界卫生组织Ⅲ级和Ⅳ级)52例;入选患者均进行磁共振SWI序列检查;采用酶联免疫吸附(ELISA)法检测血清Id1、IGFBP-3水平;采用Pearson法分析血清Id1、IGFBP-3水平的相关性;受试者工作特征(ROC)曲线分析Id1、IGFBP-3水平对脑胶质瘤术前分级的临界诊断点;采用四格表分析磁共振SWI序列联合血清Id1、IGFBP-3对脑胶质瘤术前高低级别的诊断价值。结果高级别组ITSS分级显著高于低级别组(P>0.05)。高级别组Id1、IGFBP-3水平均显著高于低级别组(P>0.05)。根据pearson相关性分析得知,脑胶质瘤患者血清Id1、IGFBP-3水平呈正相关(r=0.486,P<0.05)。根据ROC曲线得知,Id1、IGFBP-3诊断脑胶质瘤术前分级的曲线下面积(AUC)分别为0.837、0.861,二者联合诊断脑胶质瘤术前分级的AUC为0.908。磁共振SWI序列在脑胶质瘤术前分级诊断中准确度为83.67%,灵敏度为84.62%,特异度为82.61%;Id1在脑胶质瘤术前分级诊断中准确度为79.59%,灵敏度为80.77%,特异度为78.26%;IGFBP-3在脑胶质瘤术前分级诊断中准确度为81.63%,灵敏度为82.69%,特异度为80.43%;三者联合检测在脑胶质瘤术前分级诊断中准确度为91.84%,灵敏度为92.31%,特异度为91.30%。结论Id1、IGFBP-3在脑胶质瘤患者血清中显著升高,磁共振SWI序列联合血清Id1、IGFBP-3可以提高对脑胶质瘤术前分级的评估价值。

Fe_(3)O_(4)@Angelica sinensis polysaccharide nanoparticles as an ultralow-toxicity contrast agent for magnetic resonance imaging

Although iron oxide(Fe_(3)O_(4)) nanoparticles have broad application prospects as magnetic resonance imaging(MRI) contrast agent, their biocompatibility and biotoxicity still need to be improved. In this study, we prepared Fe_(3)O_(4)@Angelica sinensis polysaccharide nanoparticles(Fe_(3)O_(4)@ASP NPs) with a 9 nm Fe_(3)O_(4) core and ASP as the coating material. The Fe_(3)O_(4)@ASP NPs are superparamagnetic, can be taken up by liver and spleen macrophages in the circulatory system in vivo, and are a good-biocompatibility and low-toxicity transverse relaxation time(T_(2)) and T_(2)-star(T_(2)^(*)) magnetic resonance imaging(MRI) contrast agent for the liver. The cytotoxicity assessment using HeLa cells and the pathological tests in mice validate that Fe_(3)O_(4)@ASP NPs have low toxicity and good biocompatibility in vivo, which can be attributed to the ASP as a natural polysaccharide with good biocompatibility and its function of protecting the liver. Fe_(3)O_(4)@ASP NPs are a potential new MRI contrast agent with high signal intensity in vivo.

MRI与3D-DSA融合技术在脑动静脉畸形手术的应用研究

目的初步探讨磁共振成像(MRI)与三维数字减影血管造影(3D-DSA)图像融合技术在颅内动静脉畸形(AVM)手术中的应用价值。方法回顾分析南京军区南京总医院神经外科2015年1月至2015年4月诊断明确为AVM的6例患者,术前均行MRI与3D-DSA检查,并行MRI与3DDSA影像融合。根据MRI与3D-DSA融合图像进一步制定手术方案行显微直视手术切除。结果所有患者MRI与3D-DSA融合图像不仅可清楚的显示AVM与周围神经结构之间的空间关系,同时对部分合并微小动脉瘤或小血管畸形的患者可清晰的显示病变在血肿或脑组织之间的位置。所有患者行显微直视手术切除术后均恢复良好,复查脑血管造影未见明显畸形血管团残留。术后6例患者均行MRI随访,AVM均无复发,同时未有新发神经功能障碍及再出血。结论 MRI与3D-DSA融合图像可为显微外科手术切除AVM提供更多重要信息,有效的辅助AVM手术的术前规划。

Luminescence property and magnetic resonance imaging of Gd_(2)O_(3):Tb^(3+) nanocrystals doped with Zn^(2+),Li^(+)

Gd_(2)O_(3):Tb^(3+) nanocrystal co-doped with Zn^(2+)and Li^(+) was prepared by the combination of polyol and solid-phase methods.The synthesized nanoparticles were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),photoluminescence(PL)spectra and magnetic resonance imaging(MRI).The results revealed that both Gd_(2)O_(3):Tb^(3+)/Zn^(2+) and Gd_(2)O_(3):Tb^(3+)/Li^(+) had cubic unit structures with a spherical shape,and the fluorescence intensity of the nanoparticles reached a maximum at a doping concentration of0.050 mmol%for Zn^(2+) and 2 mol%for Li^(+),respectively.In addition,the T_(1)/T_(2)(longitudinal/transverse relaxation time)-weighted MRI signals got enhanced due to the increased longitudinal relaxivity(r1)and transverse relaxivity(r2)after the doping by metal ions.Therefore,the materials reported here can be used for fluorescence and MR bimodal imaging,as tracers and for fluorescence detections.

CXCR4 Peptide Conjugated Au-Fe2O3 Nanoparticles for Tumor-targeting Magnetic Resonance Imaging

Peptide-functionalized Au-Fe2O3 nanoparticles（termed as anti-CXCR4-Au-Fe2O3 NPs） have been constructed through conjugation of dumbbell-like Au-Fe203 NPs with C-X-C motif chemokine receptor 4（CXCR4） binding cyclic peptide. One dumbbelMike Au-Fe2O3NP composes an Au NP[（3.3±0.3） nm in diameter] for conjugating CXCR4 binding cyclic peptide through Au-S covalent bond and a Fe2O3 NP[（8.7±0.8） nm in diameter] for using as T2-weighted magnetic resonance imaging（MRI） contrast agent. The anti-CXCR4-Au-Fe2O3 NPs have reasonable biocompatibility and integration of T2-weighted MRI contrast and tumor-targeting functionalities. The anti- CXCR4-Au-Fe2O3 NPs exhibit strong interactions with two kinds of breast tumor cells, MCF-7 cells and MDA-MB-231 cells, and high negative contrast in MRI of MDA-MB-231 tumor bearing mouse with 62% decreasing of MRI signal, indicating that the anti-CXCR4-Au-Fe2O3 NPs can recognize tumor with high efficacy and specificity.

TbF3 nanoparticles as dual-mode contrast agents for ultrahigh field magnetic resonance imaging and X-ray computed tomography

Considering the development of magnetic resonance imaging （MRI） under ultrahigh magnetic field （〉3 T）, the exploration of novel contrast agents （CAs） for ultrahigh field MRI is urgently needed. Herein, we report polyethyleneimine （PEI）-coated TbF3 nanoparticles （NPs）, which were synthesized by a facile solvothermal method, as potential dual-mode CAs for ultrahigh field MRI and X-ray computed tomography （CT）. Owing to their strong paramagnetism, the TbF3 NPs showed excellent transverse relaxivity （395.77 mM-l.s-1） and negligible longitudinal relaxivity under an ultrahigh magnetic field （7 T） with a great potential as a T2-weighted MRI contrast agent. Furthermore, by comparison with the clinically used CT CAs （iohexol）, the TbF3 NPs showed superior X-ray attenuation ability. The practical application for T2-weighted MRI and CT imaging was demonstrated with an animal model. Moreover, cell cytotoxicity and in vivo toxicity assessments implied the low toxicity of TbF3 NPs. In summary the above results indicate that TbF3 NPs are promising candidates for ultrahigh field MRI and CT dual-mode imaging.

Myocardial fibrosis detection in arrhythmogenic right ventricular dysplasia/cardiomyopathy by 3. 0T magnetic resonance imaging

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is characterized by fibro-fatty replacement of the right ventricle.However,the feasibility and significance of myocardial fibrosis detec-ted by delayed enhancement (DE) using 3.0T magnetic resonance imaging (MRI) in.ARVD /C is seldomly studied.Methods Twenty-seven consecutive patients were prospectively evaluated for ARVD /C.Magnetic reso-nance imaging was performed on a 3.0T scanner.Ten minutes after intravenous administration of 0.2 mmol /kg of gadodiamide,DE-MRI was obtained.Diagnosis of ARVD /C was based upon the Task Force criteria and in-cluded MRI findings.Results Seventeen(59% ) of 27 patients met the Task Force criteria for ARVD /C.Right ven-tricle DE was found in all (100% ) ARVD /C patients compared with none (0%) of the 10 patients without ARVD /C (P <0.001) .Additional left ventricular DE was found in 8/17 ARVD/C patients while without left ventricular mor-phological and functional abnormalities detected by echocardiography or MRI.Conclusions DE using 3.0T MRI could effectively detect myocardial fibrosis in the right and left ventricular myocardium in ARVD /C patients.Detection of myocardial fibrosis may have an important clinical significance in ARVD/C diagnosis.Histological left ventricle in-volvement may be easily missed by echocardiography.