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Depression discrimination using fMRI and DTI data by wavelet based fusion scheme 被引量:1
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作者 赵竟 罗国平 +1 位作者 姚志剑 卢青 《Journal of Southeast University(English Edition)》 EI CAS 2012年第1期25-28,共4页
Both functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) can provide different information of the human brain, so using the wavelet transform method can achieve a fusion of these two ty... Both functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) can provide different information of the human brain, so using the wavelet transform method can achieve a fusion of these two types of image data and can effectively improve the depression recognition accuracy. Multi-resolution wavelet decomposition is used to transform each type of images to the frequency domain in order to obtain the frequency components of the images. To each subject, decomposition components of two images are then added up separately according to their frequencies. The inverse discrete wavelet transform is used to reconstruct the fused images. After that, principal component analysis (PCA) is applied to reduce the dimension and obtain the features of the fusion data before classification. Based on the features of the fused images, an accuracy rate of 80. 95 % for depression recognition is achieved using a leave-one-out cross-validation test. It can be concluded that this wavelet fusion scheme has the ability to improve the current diagnosis of depression. 展开更多
关键词 classification functional magnetic resonanceimaging (fMRI) diffusion tensor imaging (DTI) medicalimage fusion DEPRESSION
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Sonography of the small intestine 被引量:10
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作者 Kim Nylund Svein Фdegaard +5 位作者 Trygve Hausken Geir Folvik Gülen Arslan Lied Ivan Viola Helwig Hauser Odd-Helge Gilja 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第11期1319-1330,共12页
In the last two decades, there has been substantial development in the diagnostic possibilities for examining the small intestine. Compared with computerized tomography, magnetic resonance imaging, capsule endoscopy a... In the last two decades, there has been substantial development in the diagnostic possibilities for examining the small intestine. Compared with computerized tomography, magnetic resonance imaging, capsule endoscopy and double-balloon endoscopy, ultrasonography has the advantage of being cheap, portable, flexible and user-and patient-friendly, while at the same time providing the clinician with image data of high temporal and spatial resolution. The method has limitations with penetration in obesity and with intestinal air impairing image quality. The flexibility ultrasonography offers the examiner also implies that a systematic approach during scanning is needed. This paper reviews the basic scanning techniques and new modalities such as contrast-enhanced ultrasound, elastography, strain rate imaging, hydrosonography, allergosonography, endoscopic sonography and nutritional imaging, and the literature on disease-specific findings in the small intestine. Some of these methods have shown clinical benefit, while others are under research and development to establish their role in the diagnostic repertoire. However, along with improved overall image quality of new ultrasound scanners, these methodshave enabled more anatomical and physiological changes in the small intestine to be observed. Accordingly, ultrasound of the small intestine is an attractive clinical tool to study patients with a range of diseases. 展开更多
关键词 Contrast-enhanced ultrasound Crohn'sdisease Endoscopic sonography ENDOSONOGRAPHY ENTEROCLYSIS Hydrosonography Magnetic resonanceimaging ULTRASONOGRAPHY Virtual endoscopy Visualization
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Four-dimensional flow magnetic resonance imaging incirrhosis 被引量:7
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作者 Zoran Stankovic 《World Journal of Gastroenterology》 SCIE CAS 2016年第1期89-102,共14页
Since its introduction in the 1970’s,magnetic resonance imaging(MRI)has become a standard imaging modality.With its broad and standardized application,it is firmly established in the clinical routine and an essential... Since its introduction in the 1970’s,magnetic resonance imaging(MRI)has become a standard imaging modality.With its broad and standardized application,it is firmly established in the clinical routine and an essential element in cardiovascular and abdominal imaging.In addition to sonography and computer tomography,MRI is a valuable tool for diagnosing cardiovascular and abdominal diseases,for determining disease severity,and for assessing therapeutic success.MRI techniques have improved over the last few decades,revealing not just morphologic information,but functional information about perfusion,diffusion and hemodynamics as well.Four-dimensional(4D)flow MRI,a time-resolved phase contrast-MRI with three-dimensional(3D)anatomic coverage and velocity encoding along all three flow directions has been used to comprehensively assess complex cardiovascular hemodynamics in multiple regions of the body.The technique enables visualization of 3D blood flow patterns and retrospective quantification of blood flow parameters in a region of interest.Over the last few years,4D flow MRI has been increasingly performed in the abdominal region.By applying different acceleration techniques,taking 4D flow MRI measurements has dropped to a reasonable scanning time of 8 to 12 min.These new developments have encouraged a growing number of patient studies in the literature validating the technique’s potential for enhanced evaluation of blood flow parameters within the liver’s complex vascular system.The purpose of this review article is to broaden our understanding of 4D flow MRI for the assessment of liver hemodynamics by providing insights into acquisition,data analysis,visualization and quantification.Furthermore,in this article we highlight its development,focussing on the clinical application of the technique. 展开更多
关键词 Four-dimensional FLOW MAGNETIC resonanceimaging Phase contrast-magnetic resonance IMAGING Liver CIRRHOSIS IMAGING technique HEMODYNAMICS Bloodflow Visualization Quantification TIPS SPLANCHNIC system
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Focal liver lesions:Practical magnetic resonance imaging approach 被引量:7
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作者 António P Matos Fernanda Velloni +3 位作者 Miguel Ramalho Mamdoh AlObaidy Aruna Rajapaksha Richard C Semelka 《World Journal of Hepatology》 CAS 2015年第16期1987-2008,共22页
With the widespread of cross-sectional imaging, a growth of incidentally detected focal liver lesions(FLL) has been observed. A reliable detection and characterization of FLL is critical for optimal patient management... With the widespread of cross-sectional imaging, a growth of incidentally detected focal liver lesions(FLL) has been observed. A reliable detection and characterization of FLL is critical for optimal patient management. Maximizing accuracy of imaging in the context of FLL is paramount in avoiding unnecessary biopsies, which may result in post-procedural complications. A tremendous development of new imaging techniques has taken place during these last years. Nowadays, Magnetic resonance imaging(MRI) plays a key role in management of liver lesions, using a radiation-free technique and a safe contrast agent profile. MRI plays a key role in the non-invasive correct characterization of FLL. MRI is capable of providing comprehensive and highly accurate diagnostic information, with the additional advantage of lack of harmful ionizing radiation. These properties make MRI the mainstay for the noninvasive evaluation of focal liver lesions. In this paper we review the state-of-the-art MRI liver protocol, briefly discussing different sequence types, the unique characteristics of imaging non-cooperative patients and discuss the role of hepatocyte-specific contrast agents. A review of the imaging features of the most common benign and malignant FLL is presented, supplemented by a schematic representation of a simplistic practical approach on MRI. 展开更多
关键词 MALIGNANT BENIGN Magnetic resonanceimaging FOCAL liver LESIONS HEPATOBILIARY contrastagents
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Assessment of stricturing Crohn's disease:Current clinicalpractice and future avenues 被引量:4
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作者 Dominik Bettenworth Tobias M Nowacki +2 位作者 Friederike Cordes Boris Buerke Frank Lenze 《World Journal of Gastroenterology》 SCIE CAS 2016年第3期1008-1016,共9页
Crohn's disease(CD) is a chronic remittent idiopathic disease. Although the early phase of the disease is commonly characterized by inflammation-driven symptoms, such as diarrhea, the frequency of fibrostenotic co... Crohn's disease(CD) is a chronic remittent idiopathic disease. Although the early phase of the disease is commonly characterized by inflammation-driven symptoms, such as diarrhea, the frequency of fibrostenotic complications in patients with CD increases over the long-term course of the disease. This review presents the current diagnostic options for assessing CD-associated strictures. In addition to the endoscopic evaluation of CD strictures, this review summarizes the currently available imaging modalities, including ultrasound and cross-sectional imaging techniques. In addition to stricture detection, differentiating between the primarily inflammatory strictures and the predominantly fibrotic ones is essential for selecting the appropriate treatment strategy(anti-inflammatory medical treatment vs endoscopical or surgical approaches). Therefore, recent imaging advances, such as contrast-enhanced ultrasound and ultrasound elastography, contribute to the development of noninvasive non-radiating imaging of CD-associated strictures. Finally, novel magnetic resonance imaging techniques, such as diffusion-weighted, motility and magnetization transfer imaging, as well as 18F-FDG PET/CT, molecular imaging approaches and biomarkers, are critically reviewed with regard to their potential role in assessing stricturing CD. 展开更多
关键词 Crohn's DISEASE Inflammatory bowel DISEASE Intestinal STRICTURE Endoscopy Magnetic resonanceimaging Ultrasound Computed tomography 18F-FDGPET/CT CEUS Elastography
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Changes in brain functional network connectivity after stroke 被引量:3
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作者 Wei Li Yapeng Li +1 位作者 Wenzhen Zhu Xi Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第1期51-60,共10页
Studies have shown that functional network connection models can be used to study brain net- work changes in patients with schizophrenia. In this study, we inferred that these models could also be used to explore func... Studies have shown that functional network connection models can be used to study brain net- work changes in patients with schizophrenia. In this study, we inferred that these models could also be used to explore functional network connectivity changes in stroke patients. We used independent component analysis to find the motor areas of stroke patients, which is a novel way to determine these areas. In this study, we collected functional magnetic resonance imaging datasets from healthy controls and right-handed stroke patients following their first ever stroke. Using independent component analysis, six spatially independent components highly correlat- ed to the experimental paradigm were extracted. Then, the functional network connectivity of both patients and controls was established to observe the differences between them. The results showed that there were 11 connections in the model in the stroke patients, while there were only four connections in the healthy controls. Further analysis found that some damaged connections may be compensated for by new indirect connections or circuits produced after stroke. These connections may have a direct correlation with the degree of stroke rehabilitation. Our findings suggest that functional network connectivity in stroke patients is more complex than that in hea- lthy controls, and that there is a compensation loop in the functional network following stroke. This implies that functional network reorganization plays a very important role in the process of rehabilitation after stroke. 展开更多
关键词 nerve regeneration brain injury STROKE motor areas functional magnetic resonanceimaging brain network independent component analysis functional network connectivity neuralplasticity NSFC grant neural regeneration
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Apparent diffusion coefficient evaluation for secondary changes in the cerebellum of rats after middle cerebral artery occlusion 被引量:3
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作者 Yunjun Yang Lingyun Gao +5 位作者 Jun Fu Jun Zhang Yuxin Li Bo Yin Weijian Chen Daoying Geng 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第31期2942-2950,共9页
Supratentorial cerebral infarction can cause functional inhibition of remote regions such as the cerebellum, which may be relevant to diaschisis. This phenomenon is often analyzed using positron emission tomography an... Supratentorial cerebral infarction can cause functional inhibition of remote regions such as the cerebellum, which may be relevant to diaschisis. This phenomenon is often analyzed using positron emission tomography and single photon emission CT. However, these methods are expensive and radioactive. Thus, the present study quantified the changes of infarction core and remote regions after unilateral middle cerebral artery occlusion using apparent diffusion coefficient values. Diffu- sion-weighted imaging showed that the area of infarction core gradually increased to involve the cerebral cortex with increasing infarction time. Diffusion weighted imaging signals were initially in- creased and then stabilized by 24 hours. With increasing infarction time, the apparent diffusion co- efficient value in the infarction core and remote bilateral cerebellum both gradually decreased, and then slightly increased 3-24 hours after infarction. Apparent diffusion coefficient values at remote regions (cerebellum) varied along with the change of supratentorial infarction core, suggesting that the phenomenon of diaschisis existed at the remote regions. Thus, apparent diffusion coefficient values and diffusion weighted imaging can be used to detect early diaschisis. 展开更多
关键词 neural regeneration brain injury cerebral ischemia cerebral infarction magnetic resonanceimaging apparent diffusion coefficient middle cerebral artery occlusion diffusion weighted imaging infarction core remote regions DIASCHISIS grants-supported paper NEUROREGENERATION
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Liver fat deposition and mitochondrial dysfunction in morbid obesity:An approach combining metabolomics with liver imaging and histology 被引量:2
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作者 Nahum Calvo Raúl Beltrán-Debón +14 位作者 Esther Rodríguez-Gallego Anna Hernández-Aguilera Maria Guirro Roger Mariné-Casadó Lidón Millá Josep M Alegret Fàtima Sabench Daniel del Castillo María Vinaixa Miguelàngel Rodríguez Xavier Correig Roberto García-álvarez Javier A Menendez Jordi Camps Jorge Joven 《World Journal of Gastroenterology》 SCIE CAS 2015年第24期7529-7544,共16页
AIM: To explore the usefulness of magnetic resonance imaging(MRI) and spectroscopy(MRS) for assessment of non-alcoholic fat liver disease(NAFLD) as compared with liver histological and metabolomics findings. METHODS: ... AIM: To explore the usefulness of magnetic resonance imaging(MRI) and spectroscopy(MRS) for assessment of non-alcoholic fat liver disease(NAFLD) as compared with liver histological and metabolomics findings. METHODS: Patients undergoing bariatric surgery following procedures involved in laparoscopic sleeve gastrectomy were recruited as a model of obesityinduced NAFLD in an observational, prospective, singlesite, cross-sectional study with a pre-set duration of 1 year. Relevant data were obtained prospectively and surrogates for inflammation, oxidative stress and lipid and glucose metabolism were obtained through standard laboratory measurements. To provide reliable data from MRI and MRS, novel procedures were designed to limit sampling variability and other sources of error using a 1.5T Signa HDx scanner and protocols acquired from the 3D or 2D Fat SAT FIESTA prescription manager. We used our previously described 1H NMRbased metabolomics assays. Data were obtained immediately before surgery and after a 12-mo period including histology of the liver and measurement of metabolites. Values from 1H NMR spectra obtained after surgery were omitted due to technical limitations.RESULTS: MRI data showed excellent correlation with the concentration of liver triglycerides, other hepatic lipid components and the histological assessment, w h i c h e xc l u d e d t h e p r e s e n c e o f n o n-a l c o h o l i c steatohepatitis(NASH). MRI was sufficient to follow up NAFLD in obese patients undergoing bariatric surgery and data suggest usefulness in other clinical situations. The information provided by MRS replicated that obtained by MRI using the-CH3 peak(0.9 ppm), the-CH2- peak(1.3 ppm, mostly triglyceride) and the-CH=CH- peak(2.2 ppm). No patient depicted NASH. After surgery all patients significantly decreased their body weight and steatosis was virtually absent even in patients with previous severe disease. Improvement was also observed in the serum concentrations of selected variables. The most relevant findings using metabolomics indicate increased levels of triglyceride and monounsaturated fatty acids in severe steatosis but those results were accompanied by a significant depletion of diglycerides, polyunsaturated fatty acids, glucose-6-phosphate and the ATP/AMP ratio. Combined data indicated the coordinated action on mitochondrial fat oxidation and glucose transport activity and may support the consideration of NAFLD as a likely mitochondrial disease. This concept may helpto explain the dissociation between excess lipid storage in adipose tissue and NAFLD and may direct the search for plasma biomarkers and novel therapeutic strategies. A limitation of our study is that data were obtained in a relatively low number of patients.CONCLUSION: MRI is sufficient to stage NAFLD in obese patients and to assess the improvement after bariatric surgery. Other data were superfluous for this purpose. 展开更多
关键词 FATTY LIVER DISEASE MAGNETIC resonanceimaging Lipids MAGNETIC resonance spectroscopy Metabolomics Mitochondrial function Morbid obesity Non-alcoholic FATTY LIVER DISEASE Non-alcoholic steatohepatitis
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A rapid micro-magnetic resonance imaging scanning for three-dimensional reconstruction of peripheral nerve fascicles 被引量:2
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作者 Zhi Yao Li-Wei Yan +7 位作者 Tao Wang Shuai Qiu Tao Lin Fu-Lin He Ru-Heng Yuan Xiao-Lin Liu Jian Qi Qing-Tang Zhu 《Neural Regeneration Research》 SCIE CAS CSCD 2018年第11期1953-1960,共8页
The most common methods for three-dimensional reconstruction of peripheral nerve fascicles include histological and radiology techniques. Histological techniques have many drawbacks including an enormous manual worklo... The most common methods for three-dimensional reconstruction of peripheral nerve fascicles include histological and radiology techniques. Histological techniques have many drawbacks including an enormous manual workload and poor image registration. Micro-magnetic resonance imaging(Micro-MRI), an emerging radiology technique, has been used to report results in the brain, liver and tumor tissues. However, micro-MRI usage for obtaining intraneural structures has not been reported. The aim of this study was to present a new imaging method for three-dimensional reconstruction of peripheral nerve fascicles by ~1T micro-MRI. Freshly harvested sciatic nerve samples from an amputated limb were divided into four groups. Two different scanning conditions(Mannerist Solution/GD-DTPA contrast agent, distilled water) were selected, and both T1 and T2 phases programmed for each scanning condition. Three clinical surgeons evaluated the quality of the images via a standardized scale. Moreover, to analyze deformation of the two-dimensional image, the nerve diameter and total area of the micro-MRI images were compared after hematoxylin-eosin staining. The results show that rapid micro-MRI imaging method can be used for three-dimensional reconstruction of the fascicle structure. Nerve sample immersed in contrast agent(Mannerist Solution/GD-DTPA) and scanned in the T1 phase was the best. Moreover, the nerve sample was scanned freshly and can be recycled for other procedures. MRI images show better stability and smaller deformation compared with histological images. In conclusion, micro-MRI provides a feasible and rapid method for three-dimensional reconstruction of peripheral nerve fascicles, which can clearly show the internal structure of the peripheral nerve. 展开更多
关键词 nerve regeneration peripheral nerve fascicular three-dimensional reconstruction fascicular topography micro-magnetic resonanceimaging rapid acquired images contrast agent Mannerist Solution histological techniques deformation analysis peripheral nerve injury neural regeneration
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Ectopic pancreaticobiliary drainage accompanied by proximal jejunal adenoma:A case report 被引量:1
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作者 Dong-Sheng Wu,Wei-Xia Chen,Xiao-Peng Wang, Department of Radiology,West China Hospital of Sichuan University,Chengdu 610041,Sichuan Province,China Author contributions:Wu DS and Wang XP collected data and carried out the research Wu DS wrote the manuscript Chen WX revised the article. 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第35期4467-4470,共4页
A patient with obstructive jaundice was examined by multidetector row helical computed tomography (MDCT)and magnetic resonance imaging(MRI),and his common bile duct was observed to be leading into the distal portion o... A patient with obstructive jaundice was examined by multidetector row helical computed tomography (MDCT)and magnetic resonance imaging(MRI),and his common bile duct was observed to be leading into the distal portion of the horizontal duodenum with a pancreaticobiliary union outside the duodenal wall. A mass was also found in the proximal jejunum.All the above findings were confirmed by subsequent surgery,thus contrast-enhanced MDCT and MRI with appropriate image post-processing could provide non- invasive and accurate information regarding anatomy and lesions of the pancreaticobiliary duct and duodenal union,which may improve the feasibility of surgery and reduce postoperative complications. 展开更多
关键词 Ectopic drainage Pancreaticobiliary malju-nction Computed tomography Magnetic resonanceimaging
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Factors predicting aggressiveness of non-hypervascular hepatic nodules detected on hepatobiliary phase of gadolinium ethoxybenzyl diethylene-triamine-pentaacetic-acid magnetic resonance imaging
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作者 Tsutomu Kanefuji Toru Takano +11 位作者 Takeshi Suda Kouhei Akazawa Takeshi Yokoo Hiroteru Kamimura Kenya Kamimura Atsunori Tsuchiya Masaaki Takamura Hirokazu Kawai Satoshi Yamagiwa Hidefumi Aoyama Minoru Nomoto Shuji Terai 《World Journal of Gastroenterology》 SCIE CAS 2015年第15期4583-4591,共9页
AIM: To establish a prognostic formula that distinguishes non-hypervascular hepatic nodules(NHNs) with higher aggressiveness from less hazardous one. METHODS: Seventy-three NHNs were detected in gadolinium ethoxybenzy... AIM: To establish a prognostic formula that distinguishes non-hypervascular hepatic nodules(NHNs) with higher aggressiveness from less hazardous one. METHODS: Seventy-three NHNs were detected in gadolinium ethoxybenzyl diethylene-triamine-pentaaceticacid magnetic resonance imaging(Gd-EOB-DTPA-MRI) study and confirmed to change 2 mm or more in size and/or to gain hypervascularity. All images were interpreted independently by an experienced, board-certified abdominal radiologist and hepatologist; both knew thatthe patients were at risk for hepatocellular carcinoma development but were blinded to the clinical information. A formula predicting NHN destiny was developed using a generalized estimating equation model with thirteen explanatory variables: age, gender, background liver diseases, Child-Pugh class, NHN diameter, T1-weighted imaging/T2-weighted imaging detectability, fat deposition, lower signal intensity in arterial phase, lower signal intensity in equilibrium phase, α-fetoprotein, des-γ-carboxy prothrombin, α-fetoprotein-L3, and coexistence of classical hepatocellular carcinoma. The accuracy of the formula was validated in bootstrap samples that were created by resampling of 1000 iterations. RESULTS: During a median follow-up period of 504 d, 73 NHNs with a median diameter of 9 mm(interquartile range: 8-12 mm) grew or shrank by 68.5%(fifty nodules) or 20.5%(fifteen nodules), respectively, whereas hypervascularity developed in 38.4%(twenty eight nodules). In the fifteen shrank nodules, twelve nodules disappeared, while 11.0%(eight nodules) were stable in size but acquired vascularity. A generalized estimating equation analysis selected five explanatories from the thirteen variables as significant factors to predict NHN progression. The estimated regression coefficients were 0.36 for age, 6.51 for lower signal intensity in arterial phase, 8.70 or 6.03 for positivity of hepatitis B virus or hepatitis C virus, 9.37 for des-γ-carboxy prothrombin, and-4.05 for fat deposition. A formula incorporating the five coefficients revealed sensitivity, specificity, and accuracy of 88.0%, 86.7%, and 87.7% in the formulating cohort, whereas these of 87.2% ± 5.7%, 83.8% ± 13.6%, and 87.3% ± 4.5% in the bootstrap samples. CONCLUSION: These data suggest that the formula helps Gd-EOB-DTPA-MRI detect a trend toward hepatocyte transformation by predicting NHN destiny. 展开更多
关键词 Hepatocellular carcinoma Magnetic resonanceimaging Ethoxybenzyl MOIETY Non-hypervascular hepaticnodule Fate prediction
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Decreased frontal lobe function in people with Internet addiction disorder
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作者 Jun Liu Fatema Esmail +7 位作者 Lingjiang Li Zhifeng Kou Weihui Li Xueping Gao Zhiyuan Wang Changlian Tan Yan Zhang Shunke Zhou 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第34期3225-3232,共8页
In our previous studies, we showed that frontal lobe and brainstem functions were abnormal in online game addicts. In this study, 14 students with Internet addiction disorder and 14 matched healthy controls underwent ... In our previous studies, we showed that frontal lobe and brainstem functions were abnormal in online game addicts. In this study, 14 students with Internet addiction disorder and 14 matched healthy controls underwent proton-magnetic resonance spectroscopy to measure cerebral function. Results demonstrated that the ratio of N-acetylaspartate to creatine decreased, but the ratio of cho- line-containing compounds to creatine increased in the bilateral frontal lobe white matter in people with Internet addiction disorder. However, these ratios were mostly unaltered in the brainstem, suggesting that frontal lobe function decreases in people with Internet addiction disorder. 展开更多
关键词 neural regeneration Internet addiction disorder internet gaming addiction magnetic resonanceimaging magnetic resonance spectroscopy N-ACETYLASPARTATE choline-containing compounds CREATINE grants-supported paper NEUROREGENERATION
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Hollow iron oxide nanoparticles as multidrug resistant drug delivery and imaging vehicles 被引量:11
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作者 Ruijun Xing Ashwinkumar A. Bhirde +4 位作者 Shouju Wang Xiaolian Sun Gang Liu Yanglong Hou Xiaoyuan Chen 《Nano Research》 SCIE EI CAS CSCD 2013年第1期1-9,共9页
Magnetic nanopartides have been used as drug delivery vehicles against a number of cancer cells. Most of these theranostic formulations have used solid iron oxide nanoparticles (SIONPs) loaded with chemotherapeutics... Magnetic nanopartides have been used as drug delivery vehicles against a number of cancer cells. Most of these theranostic formulations have used solid iron oxide nanoparticles (SIONPs) loaded with chemotherapeutics as nano-carrier formulation for both magnetic resonance imaging (MRI) and cancer therapy. In this study, we applied the dopamine-plus-human serum albumin (HSA) method to modify hollow iron oxide nanoparticles (HIONPs) and encapsuated doxorubicin (DOX) within the hollow porous structure of the nano-carrier. The new delivery system can load more drug than solid iron oxide nanoparticles of the same core size using the same coating strategy. The HIONPs-DOX formulation also has a pH-dependent drug release behaviour. Compared with free DOX, the HIONPs-DOX were more effectively uptaken by the multidrug resistant OVCAR8- ADR cells and consequently more potent in killing drug resistant cancer cells. MRI phantom and cell studies also showed that the HIONPs-DOX can decrease the T2 MRI signal intensity and can be used as a MR/contrast agent while acting as a drug delivery vehicle. For the first time, the dual application of chemo drug transport and MR imaging using the HIONPs-DOX formulation was achieved against both DOX-sensitive and DOX-resistant cancer cells. 展开更多
关键词 drug resistance hollow nanoparticles DOXORUBICIN magnetic resonanceimaging (MRI) drug delivery
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Facile synthesis of magnetic-plasmonic nanocomposites as T1 MRI contrast enhancing and photothermal therapeutic agents 被引量:6
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作者 Zhongzhen Yang Xianguang Ding Jiang Jiang 《Nano Research》 SCIE EI CAS CSCD 2016年第3期787-799,共13页
Nanocomposites combining magnetic and plasmonic components have received widespread attention in recent years due to their potential applications in biomedical research. Herein, we describe a facile method for growing... Nanocomposites combining magnetic and plasmonic components have received widespread attention in recent years due to their potential applications in biomedical research. Herein, we describe a facile method for growing small iron oxide nanoparticles on various plasmonic core materials with different shapes and surfaces by utilizing a polypyrrole interlayer. By focusing on Au nanorod@polypyrrole@iron oxide (Au NR@PPy@FexO) nanocomposites, we show that these systems exhibit a low r2/rl ratio of 4.8, making them efficient T1 positive contrast-enhancing agents for magnetic resonance imaging (MRI). Moreover, we show that the nanocomposites are excellent photothermal agents in the second near infrared region, with high photothermal conversion efficiency, reaching up to 46%. In addition, the Au NR@PPy@FexO nanocomposites show very low cytotoxicity. In summary, the present results highlight the great potential of the synthetic method and the nanocomposites developed in this study for T~ MRI and/or infrared thermal imaging-guided photothermal cancer therapeutic applications. 展开更多
关键词 PLASMONICS iron oxide PHOTOTHERMAL T1 magnetic resonanceimaging (MRI) THERANOSTICS
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Catalase-imprinted Fe3O4/Fe@fibrous SiO2/polydopamine nanoparticles: An integrated nanoplatform of magnetic targeting, magnetic resonance imaging, and dual-mode cancer therapy 被引量:5
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作者 Jinxing Chen Shan Lei +3 位作者 Kun Zeng Mozhen Wang Anila Asif Xuewu Ge 《Nano Research》 SCIE EI CAS CSCD 2017年第7期2351-2363,共13页
Recent advances in the research on the molecular mechanism of cell death and methods for preparation of nanomaterials make the integration of various therapeutic approaches, targeting, and imaging modes into a single ... Recent advances in the research on the molecular mechanism of cell death and methods for preparation of nanomaterials make the integration of various therapeutic approaches, targeting, and imaging modes into a single nanoscale complex a new trend for the development of future nanotherapeutics. Hence, a novel ellipsoidal composite nanoplatform composed of a magnetic Fe3O4/Fe nanorod core (-120 nm) enwrapped by a catalase (CAT)-imprinted fibrous SiO2/ polydopamine (F-SiO2/PDA) shell with thickness 70 nm was prepared in this work. In vitro experiments showed that the Fe3O4/Fe@F-SiO2/PDA nanoparticles can selectively inhibit the bioactivity of CAT in tumor cells by the molecular imprinting technique. As a result, the H2O2 level in tumor cells was elevated dramatically. At the same time, the Fe304FFe core released Fe ions to catalyze the conversion of H2O2 to *OH in tumor cells. Eventually, the concentration of *OH in tumor cells rapidly rose to a lethal level thus triggering apoptosis. Combined with the remarkable near-infrared light (NIR) photothermal effect of the CAT- imprinted PDA layer, the Fe3O4/Fe@F-SiO2/PDA nanoparticles can effectively kill MCF-7, HeLa, and 293T tumor cells but are not toxic to nontumor cells. Furthermore, these nanoparticles show good capacity for magnetic targeting and suitability for magnetic resonance imaging (MRI). Therefore, the integrated multifunctional nanoplatform opens up new possibilities for high-efficiency visual targeted nonchemo therapy for cancer. 展开更多
关键词 molecular imprintednanoparticles reactive oxygen species NIR photothermal therapy magnetic targeting magnetic resonanceimaging (MRI)
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Intravascular contrast agents in diagnostic applications: Use of red blood cells to improve the lifespan and efficacy of blood pool contrast agents 被引量:5
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作者 Antonella Antonelli Carla Sfara Mauro Magnani 《Nano Research》 SCIE EI CAS CSCD 2017年第3期731-766,共36页
In medicine, discrimination between pathologies and normal areas is of great importance, and in most cases, such discrimination is made possible by novel imaging technologies. Numerous modalities have been developed t... In medicine, discrimination between pathologies and normal areas is of great importance, and in most cases, such discrimination is made possible by novel imaging technologies. Numerous modalities have been developed to visualize tissue vascularization in cardiovascular diseases or during angiogenic and vasculogenic processes. Here, we report the recent advances in vasculature imaging, providing an overview of the current non-invasive approaches in biomedical diagnostics and potential future strategies for prognostic assessment of vessel diseases, such as aneurysms and coronary artery occlusion leading to myocardial infarction. There are several contrast agents (CAs) available to improve the visibility of specific tissues at the early stage of diseases, allowing for rapid treatment. However, CAs are also hampered by numerous limitations, including rapid diffusion from blood vessels into the interstitial space, toxicity, and low sensitivity. Extravasation from blood vessels leads to a rapid loss of the image. If the contrast medium can fully be confined to the vascular space, high-resolution structural and functional vascular imaging could be obtained. Many scientists have contributed new materials and/or new carrier systems. For example, the use of red blood cells (RBCs) as CA-delivery systems appears to provide a scalable alternative to current procedures that allows adequate vascular imaging. Recognition and removal of CAs from the circulation can be prevented and/or delayed by using RBCs as biomimetic CA-carriers, and this technology should be clinically validated. 展开更多
关键词 diagnostic applications magnetic resonanceimaging (MRI) vascular contrast agents red blood cells medical imaging new tomography
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Abnormal functional connectivity with mood regulating circuit in unmedicated individual with major depression: a resting-state functional magnetic resonance study 被引量:12
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作者 PENG Dai-hui SHEN Ting +6 位作者 ZHANG Jie HUANG Jia LIU Jun LIU Shu-yong JIANG Kai-da XU Yi-feng FANG Yi-ru 《Chinese Medical Journal》 SCIE CAS CSCD 2012年第20期3701-3706,共6页
Background Reports on mood regulating circuit (MRC) indicated different activities between depressed patients and healthy controls. The functional networks based on MRC have not been described in major depression di... Background Reports on mood regulating circuit (MRC) indicated different activities between depressed patients and healthy controls. The functional networks based on MRC have not been described in major depression disorder (MDD). Both the anterior cingulate cortex (ACC) and thalamus are all the key regions of MRC. This study was to investigate the two functional networks related to ACC and thalamus in MDD. Methods Sixteen patients with MDD on first episode which never got any medication and sixteen matched health controls were scanned by 3.0 T functional magnetic resonance imaging (fMRI) during resting-state. The pregenual anterior cingulate cortex (pgACC) was used as seed region to construct the functional network by cortex section. The thalamus was used as seed region to construct the functional network by limbic section. Paired-t tests between-groups were performed for the seed-target correlations based on the individual fisher z-transformed correlation maps by SPM2. Results Depressed subjects exhibited significantly great functional connectivity (FC) between pgACC and the parahippocampus gyrus in one cluster (size 923) including left parahippocampus gyrus (-21, -49,7), left parietal lobe (-3, -46, 52) and left frontal lobe (-27, -46, 28). The one cluster (size 962) of increased FC on thalamus network overlapped the precuneus near to right parietal lobe (9, -52,46) and right cingulate gyrus (15, -43, 43) in health controls. Conclusions Abnormal functional networks exist in earlier manifestation of MDD related to MRC by both cortex and limbic sections. The increased functional connectivity of pgACC and decreased functional connectivity of thalamus is mainly involved in bias mood processing and cognition. 展开更多
关键词 DEPRESSION anterior cingulate cortex thalamus functional connectivity functional magnetic resonanceimaging
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Precise synthesis of discrete and dispersible carbon- protected magnetic nanoparticles for efficient magnetic resonance imaging and photothermal therapy 被引量:3
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作者 An-Hui Lu Xiang-Qian Zhang +4 位作者 Qiang Sun Yan Zhang Qingwei Song Ferdi Schuth Fang Cheng 《Nano Research》 SCIE EI CAS CSCD 2016年第5期1460-1469,共10页
Carbon-protected magnetic nanoparticles exhibit long-term stability in acid or alkaline medium, good biocompatibility, and high saturation magnetization. As a result, they hold great promise for magnetic resonance ima... Carbon-protected magnetic nanoparticles exhibit long-term stability in acid or alkaline medium, good biocompatibility, and high saturation magnetization. As a result, they hold great promise for magnetic resonance imaging, photothermal therapy, etc. However, since pyrolysis, which is often required to convert the carbon precursors to carbon, typically leads to coalescence of the nanoparticles, the obtained carbon-protected magnetic nanoparticles are usually sintered as a non-dispersible aggregation. We have successfully synthesized discrete, dispersible, and uniform carbon-protected magnetic nanoparticles via a precise surface/interface nano-engineering approach. Remarkably, the nanoparticles possess excellent water-dispersibility, biocompatibility, a high T2 relaxivity coefficient (384 mM^-1·s^-1), and a high photothermal heating effect. Furthermore, they can be used as multifunctional core components suited for future extended investigation in early diagnosis, detection and therapy, catalysis, separation, and magnetism. 展开更多
关键词 magnetic nanoparticles CARBON FE3O4 magnetic resonanceimaging (MRI) colloidal suspensions photothermal therapy
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Novel carbon nanohybrids as highly efficient magnetic resonance imaging contrast agents 被引量:3
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作者 Rongli Cui Juan Li Huan Huang Mingyi Zhang Xihong Guo Yanan Chang Min Li Jinquan Dong Baoyun Sun Gengmei Xing 《Nano Research》 SCIE EI CAS CSCD 2015年第4期1259-1268,共10页
Novel carbon nanohybrids based on unmodified metallofullerenes have been successfully fabricated for use as a new magnetic resonance imaging (MRI) contrast agent. The nanohybrids showed higher R1 relaxivity and bett... Novel carbon nanohybrids based on unmodified metallofullerenes have been successfully fabricated for use as a new magnetic resonance imaging (MRI) contrast agent. The nanohybrids showed higher R1 relaxivity and better brightening effect than Gd@C82(OH)x, in Tl-weighted MR images in vivo. This is a result of the proton relaxivity from the original gadofullerenes, which retained a perfect carbon cage structure and so might completely avoid the release of Gd^3+ ions. A "secondary spin-electron transfer" relaxation mechanism was proposed to explain how the encaged Gd^3+ ions of carbon nanohybrids interact with the surrounding water molecules. This approach opens new opportunities for developing highly efficient and low toxicity MRI contrast agents. 展开更多
关键词 graphene oxide METALLOFULLERENE magnetic resonanceimaging (MRI) NANOHYBRIDS
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Single ultrasmall Mn2+-doped NaNdF4 nanocrystals as multimodal nanoprobes for magnetic resonance and second near-infrared fluorescence imaging 被引量:3
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《Nano Research》 SCIE EI CAS CSCD 2018年第2期1069-1081,共13页
Multimodal imaging probes have attracted wide attention and have potential to diagnose diseases accurately because of the complementary advantages of multiple imaging modalities. However, intractable issues remain wit... Multimodal imaging probes have attracted wide attention and have potential to diagnose diseases accurately because of the complementary advantages of multiple imaging modalities. However, intractable issues remain with regard to their complicated multi-step fabrication for hybrid nanostructure and interference of different modal imaging. In the present stud we present, for the first time, T1 and T2-weighted magnetic resonance imaging (MRI) of ultrasmaU Mn2+-doped NaNdF4 nanocrystals (NCs), which can also be used simultaneously for second near infrared (NIR-U) fluorescence and computed tomography (CT) imaging, thus enabling high-performance multimodal MRI/NIR-II/CT imaging of single NaNdF4:Mn NCs. The NaNdF4:Mn was demonstrated as a nanoprobe for in vitro and in vivo multimodal MRI and NIR-II fluorescence imaging of human mesenchymal stem cells. The results provide a new strategy to simplify the nanostructure and preparation of probes, based on the features of NaNdF4:Mn NCs, which offer highly efficient multimodal MRI/NIR-II/CT imaging. 展开更多
关键词 NaNdF4:Mn ultrasmall nanoprobe magnetic resonanceimaging (MRI) second near infrared(NIR-II) fluorescence multimodal imaging
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