From strength to precision: A systematic review exploring the clinical utility of 7-Tesla magnetic resonance imaging in abdominal imaging

BACKGROUND After approval for clinical use in 2017 early investigations of ultra-high-field abdominal magnetic resonance imaging(MRI)have demonstrated the feasibility as well as diagnostic capabilities of liver,kidney,and prostate MRI at 7-Tesla.However,the elevation of the field strength to 7-Tesla not only brought advantages to abdominal MRI but also presented considerable challenges and drawbacks,primarily stemming from heightened artifacts and limitations in Specific Absorption Rate,etc.Furthermore,evidence in the literature is relatively scarce concerning human studies in comparison to phantom/animal studies which necessitates an investigation into the evidence so far in humans and summarizing all relevant evidence.AIM To offer a comprehensive overview of current literature on clinical abdominal 7T MRI that emphasizes current trends,details relevant challenges,and provides a concise set of potential solutions.METHODS This systematic review adheres to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.A PubMed search,utilizing Medical Subject Headings terms such as"7-Tesla"and organ-specific terms,was conducted for articles published between January 1,1985,and July 25,2023.Eligibility criteria included studies exploring 7T MRI for imaging human abdominal organs,encompassing various study types(in-vivo/ex-vivo,method development,reviews/meta-analyses).Exclusion criteria involved animal studies and those lacking extractable data.Study selection involved initial identification via title/abstract,followed by a full-text review by two researchers,with discrepancies resolved through discussion.Data extraction covered publication details,study design,population,sample size,7T MRI protocol,image characteristics,endpoints,and conclusions.RESULTS The systematic review included a total of 21 studies.The distribution of clinical 7T abdominal imaging studies revealed a predominant focus on the prostate(n=8),followed by the kidney(n=6)and the hepatobiliary system(n=5).Studies on these organs,and in the pancreas,demonstrated clear advantages at 7T.However,small bowel studies showed no significant improvements compared to traditional MRI at 1.5T.The majority of studies evaluated originated from Germany(n=10),followed by the Netherlands(n=5),the United States(n=5),Austria(n=2),the United Kingdom(n=1),and Italy(n=1).CONCLUSION Further increase of abdominal clinical MRI field strength to 7T demonstrated high imaging potential,yet also limitations mainly due to the inhomogeneous radiofrequency(RF)excitation field relative to lower field strengths.Hence,further optimization of dedicated RF coil elements and pulse sequences are expected to better optimize clinical imaging at high magnetic field strength.

Magnetic resonance imaging and multi-detector computed tomography assessment of extracellular compartment in ischemic and non-ischemic myocardial pathologies

Myocardial pathologies are major causes of morbidity and mortality worldwide. Early detection of loss of cellular integrity and expansion in extracellular volume(ECV) in myocardium is critical to initiate effective treatment. The three compartments in healthy myocardium are: intravascular(approximately 10% of tissue volume), interstitium(approximately 15%) and intracellular(approximately 75%). Myocardial cells, fibroblasts and vascular endothelial/smooth muscle cells represent intracellular compartment and the main proteins in the interstitium are types Ⅰ/Ⅲ collagens. Microscopic studies have shown that expansion of ECV is an important feature of diffuse physiologic fibrosis(e.g., aging and obesity) and pathologic fibrosis [heart failure, aortic valve disease, hypertrophic cardiomyopathy, myocarditis, dilated cardiomyopathy, amyloidosis, congenital heart disease, aortic stenosis, restrictive cardiomyopathy(hypereosinophilic and idiopathic types), arrythmogenic right ventricular dysplasia and hypertension]. This review addresses recent advances in measuring of ECV in ischemic and non-ischemic myocardial pathologies. Magnetic resonance imaging(MRI) has the ability to characterize tissue proton relaxation times(T1, T2, and T2*). Proton relaxation times reflect the physical and chemical environments of water protons in myocardium. Delayed contrast enhanced-MRI(DE-MRI) and multi-detector computed tomography(DE-MDCT) demonstrated hyper-enhanced infarct, hypo-enhanced microvascular obstruction zone and moderately enhanced peri-infarct zone, but are limited for visualizing diffuse fibrosis and patchy microinfarct despite the increase in ECV. ECV can be measured on equilibrium contrast enhanced MRI/MDCT and MRI longitudinal relaxation time mapping. Equilibrium contrast enhanced MRI/MDCT and MRI T1 mapping is currently used, but at a lower scale, as an alternative to invasive sub-endomyocardial biopsies to eliminate the need for anesthesia, coronary catheterization and possibility of tissue sampling error. Similar to delayed contrast enhancement, equilibrium contrast enhanced MRI/MDCT and T1 mapping is completely noninvasive and may play a specialized role in diagnosis of subclinical and other myocardial pathologies. DE-MRI and when T1-mapping demonstrated sub-epicardium, sub-endocardial and patchy mid-myocardial enhancement in myocarditis, Behcet's disease and sarcoidosis, respectively. Furthermore, recent studies showed that the combined technique of cine, T2-weighted and DE-MRI technique has high diagnostic accuracy for detecting myocarditis. When the tomographic techniques are coupled with myocardial perfusion and left ventricular function they can provide valuable information on the progression of myocardial pathologies and effectiveness of new therapies.

Magnetic resonance imaging characterization of circumferential and longitudinal strain under various coronary interventions in swine

AIM:To compare the acute changes in circumferential and longitudinal strain after exposing a coronary artery to various interventions in swine.METHODS:Percutaneous balloon angioplasty catheter was guided to location aid device(LAD)under X-ray fluoroscopy to create different patterns of ischemic insults.Pigs(n=32)were equally divided into 4 groups:controls,90 min LAD occlusion/reperfusion,LAD microembolization,and combined LAD occlusion/microembolization/reperfusion.Three days after interventions,cine,tagged and viability magnetic resonance imaging(MRI)were acquired to measure and compare left and right circumferential strain,longitudinal strain and myocardial viability,respectively.Measurements were obtained using HARP and semi-automated threshold method and statistically analyzed using unpaired t-test.Myocardial and vascular damage was characterized microscopically.RESULTS:Coronary microemboli caused greater impairment in l left ventricular(LV)circumferential strain and dyssynchrony than LAD occlusion/reperfusion despite the significant difference in the extent of myocardial damage.Microemboli also caused significant decrease in peak systolic strain rate of remote myocardium and LV dyssynchrony.Cine MRI demonstrated the interaction between LV and right ventricular(RV)at 3 d after interventions.Compensatory increase in RV free wall longitudinal strain was seen in response to all interventions.Viability MRI,histochemical staining and microscopy revealed different patterns of myocardial damage and microvascular obstruction.CONCLUSION:Cine MRI revealed subtle changes in LV strain caused by various ischemic insults.It also demonstrated the interaction between the right and left ventricles after coronary interventions.Coronary microemboli with and without acute myocardial infarction(AMI)cause complex myocardial injury and ventricular dysfunction that is not replicated in solely AMI.

Hepatocellular carcinoma Liver Imaging Reporting and Data Systems treatment response assessment: Lessons learned and future directions

Hepatocellular carcinoma(HCC)is a leading cause of morbidity and mortality worldwide,with rising clinical and economic burden as incidence increases.There are a multitude of evolving treatment options,including locoregional therapies which can be used alone,in combination with each other,or in combination with systemic therapy.These treatment options have shown to be effective in achieving remission,controlling tumor progression,improving disease free and overall survival in patients who cannot undergo resection and providing a bridge to transplant by debulking tumor burden to downstage patients.Following locoregional therapy(LRT),it is crucial to provide treatment response assessment to guide management and liver transplant candidacy.Therefore,Liver Imaging Reporting and Data Systems(LI-RADS)Treatment Response Algorithm(TRA)was created to provide a standardized assessment of HCC following LRT.LIRADS TRA provides a step by step approach to evaluate each lesion independently for accurate tumor assessment.In this review,we provide an overview of different locoregional therapies for HCC,describe the expected post treatment imaging appearance following treatment,and review the LI-RADS TRA with guidance for its application in clinical practice.Unique to other publications,we will also review emerging literature supporting the use of LI-RADS for assessment of HCC treatment response after LRT.

Renal ablation using magnetic resonance-guided high intensity focused ultrasound: Magnetic resonance imaging and histopathology assessment

AIM: To use magnetic resonance-guided high intensity focused ultrasound(MRg-HIFU), magnetic resonance imaging(MRI) and histopathology for noninvasively ablating, quantifying and characterizing ablated renal tissue. METHODS: Six anesthetized/mechanically-ventilated pigs underwent single/double renal sonication(n = 24) using a 3T-MRg-HIFU(1.1 MHz frequency and 3000J-4400 J energies). T2-weighted fast spin echo(T2-W), perfusion saturation recovery gradient echo and contrast enhanced(CE) T1-weighted(T1-W) sequences were used for treatment planning, temperature monitoring, lesion visualization, characterization and quantification, respectively. Histopathology was conducted in excised kidneys to quantify and characterize cellular and vascular changes. Paired Student's t-test was used and a P-value < 0.05 was considered statistically significant.RESULTS: Ablated renal parenchyma could not be differentiated from normal parenchyma on T2-W or nonCE T1-W sequences. Ablated renal lesions were visible as hypoenhanced regions on perfusion and CE T1-W MRI sequences, suggesting perfusion deficits and necrosis. Volumes of ablated parenchyma on CE T1-W images invivo(0.12-0.36 cm3 for single sonication 3000 J, 0.50-0.84 cm3, for double 3000 J, 0.75-0.78 cm3 for single 4400 J and 0.12-2.65 cm3 for double 4400J) and at postmortem(0.23-0.52 cm3, 0.25-0.82 cm3, 0.45-0.68 cm3 and 0.29-1.80 cm3, respectively) were comparable. The ablated volumes on 3000 J and 4400 J double sonication were significantly larger than single(P < 0.01), thus, the volume and depth of ablated tissue depends on the applied energy and number of sonication. Macroscopic and microscopic examinations confirmed the locations and presence of coagulation necrosis, vascular damage and interstitial hemorrhage, respectively.CONCLUSION: Contrast enhanced MRI provides assessment of MRg-HIFU renal ablation. Histopathology demonstrated coagulation necrosis, vascular damage and confirmed the volume of damage seen on MRI.

Reperfusion injury components and manifestations determined by cardiovascular MR and MDCT imaging

Advances in magnetic resonance(MR) and computed tomography(CT) imaging have improved visualization of acute and scar infarct.Over the past decade,there have been and continues to be many significant technical advancements in cardiac MR and multi-detector computed tomography(MDCT) technologies.The strength of MR imaging relies on a variety of pulse sequences and the ability to noninvasively provide information on myocardial structure,function and perfusion in a single imaging session.The recent technical developments may also allow CT technologies to rise to the forefront for evaluating clinical ischemic heart disease.Components of reperfusion injury including myocardial edema,hemorrhage,calcium deposition and microvascular obstruction(MO) have been demonstrated using MR and CT technologies.MR imaging can be used serially and noninvasively in assessing acute and chronic consequences of reperfusion injury because there is no radiation exposure or administration of radioactive materials.MDCT is better suited for assessing coronary artery stenosis and as an alternative technique for as-sessing viability in patients where MR imaging is contraindicated.Changes in left ventricular(LV) volumes and function measured on cine MR are directly related to infarct size measured on delayed contrast enhanced images.Recent MR studies found that transmural infarct,MO and peri-infarct zone are excellent predictors of poor post-infarct recovery and mortality.Recent MR studies provided ample evidence that growth factor genes and stem cells delivered locally have beneficial effects on myocardial viability,perfusion and function.The significance of deposited calcium in acute infarct detected on MDCT requires further studies.Cardiac MR and MDCT imaging have the potential for assessing reperfusion injury components and manifestations.

Coronary Embolization and Myocardial Microinfarction: MR Imaging and Histopathologic Characterization

Magnetic resonance imaging (MRI) has been proven to reliably assess regional perfusion and left ventricular (LV) function of microembolized myocardium. The visibility of microinfarct on delayed enhancement MRI (DE-MRI) is limited and dependent on technical and biological issues. Furthermore, MRI underestimates total microinfarct size compared with microscopy. MRI studies revealed that the presence of microemboli in pre-existing acute infarct delays infarct healing and magnifies LV remodeling. Discrimination of acute from chronic microinfarct is based on presence of inflammatory cells, edema and scar tissue, respectively. These noninvasive findings highlight the importance of prognostic utility of MRI and warrant larger clinical studies or registries to evaluate the significance of presence of focal microinfarct. Serial microscopic studies revealed that intravascular microemboli migrate into the extravascular space and this migration process is a function of time. This phenomenon may limit the use of microemboli therapy in occluding hemorrhagic blood vessels or treating tumors. Despite current standard of care, existing methods and therapies do not prevent coronary embolization nor reverse their deleterious effects.

How to use magnetic resonance imaging following neoadjuvant chemotherapy in locally advanced breast cancer

Magnetic resonance imaging(MRI) is highly sensitive in identifying residual breast cancer following neoadjuvant chemotherapy(NAC), and consequently is a commonly used imaging modality in locally advanced breast cancer patients. In these patients, tumor response is an important prognostic indicator. However, discrepancies between MRI findings and surgical pathology are well documented. Overestimation of residual disease by MRI may result in greater surgery than is actually required while underestimation may result in insufficient surgery. Thus, it is important to understand when MRI findings are reliable and when they are less accurate. MRI most accurately predicts pathology in triple negative, Her2 positive and hormone receptor negative tumors, especially if they are of a solid imaging phenotype. In these cases, post-NAC MRI is highly reliable for surgical planning. Hormone receptor positive cancers and those demonstrating non mass enhancement show lower concordance with surgical pathology, making surgical guidance more nebulous in these cases. Radiologists and surgeons must assess MRI response to NAC in the context of tumor subtype. Indiscriminate interpretations will prevent MRI from achieving its maximum potential in the pre-operative setting.

Radiology education in Europe: Analysis of results from 22 European countries

AIM To assess the state of radiology education across Europe by means of a survey study.METHODS A comprehensive 23-item radiology survey was distributed via email to the International Society of Radiology members, national radiological societies, radiologists and medical physicists. Reminders to complete the survey were sent and the results were analyzed over a period of 4 mo(Jan-April 2016). Survey questions include length of medical school and residency training; availabilityof fellowship and subspecialty training; number of residency programs in each country; accreditation pathways; research training; and medical physics education. Descriptive statistics were used to analyze and summarize data.RESULTS Radiology residency training ranges from 2-6 years with a median of 5 years, and follows 1 year of internship training in 55%(12 out of 22) European countries. Subspecialty fellowship training is offered in 55%(12 out of 22) European countries. Availability for specialization training by national societies is limited to eight countries. For nearly all respondents, less than fifty percent of radiologists travel abroad for specialization. Nine of 22(41%) European countries have research requirements during residency. The types of certifying exam show variation where 64%(14 out of 22) European countries require both written and oral boards, 23%(5 out of 22) require oral examinations only, and 5%(1 out of 22) require written examinations only. A degree in medical physics is offered in 59%(13 out of 22) European countries and is predominantly taught by medical physicists. Nearly all respondents report that formal examinations in medical physics are required.CONCLUSION Comparative learning experiences across the continent will help guide the development of comprehensive yet pragmatic infrastructures for radiology education and collaborations in radiology education worldwide.

Monitoring the Sequelae of Coronary Microembolization on Myocardium Using Noninvasive Imaging (Review)

Acute myocardial infarction (AMI) is a leading cause of death worldwide. It has been clinically classified into 1) ischemic from a primary coronary event (e.g., plaque rupture or thrombotic occlusion), 2) ischemic from a supply-and-demand mismatch and c) ischemic from a percutaneous coronary interventions (PCI). Catheter-based PCI has been frequently used as an alternative to conventional bypass surgery for patients at high risk. However, this method of treatment is associated with microvascular obstruction (MVO) by dislodged microemboli that results in left ventricular (LV) dysfunction/remodeling, perfusion deficits, microinfarction and arrhythmia. The contributions of microemboli after revascularization of AMI have been acknowledged by major cardiac and interventional societies. Recent studies showed that Emboli Detection and Classification (EDAC) Quantifier offers increased sensitivity and capability for detecting dislodged coronary microemboli during PCI. Coronary microembolization can be detected directly by monitoring intra-myocardial contrast opacification on contrast echocardiography, increasing F-18 fluorodeoxyglucose (FDG) uptake on positron emission tomography, loss/diminution of signal on first pass perfusion and hypoenhanced zone on contrast enhanced magnetic resonance imaging (MRI) and multidetector computed tomography (MDCT) and indirectly by ST-segment elevation on electro-cardiography (ECG). The relations between volumes/sizes of microemboli, visibility of microinfarct, myocardial perfusion and LV function are still under intensive discussions. Non-invasive imaging can play important role in assessing these parameters. This review shed the light on the techniques used for detecting coronary microemboli, microvascular obstruction and microinfarct and the short- and long-term effects of microemboli on LV function, structure and perfusion.

利用大脑^(18)F-FDG PET的深度学习模型预测阿尔茨海默病的诊断

目的开发并验证一种深度学习算法,该算法可以基于脑部18F-FDG PET来预测阿尔茨海默病(AD)、轻度认知障碍或并非两者的诊断结果,并与放射阅片者的识别能力进行比较。

将一种新的人肝细胞生长因子质粒——VM202转载入猪心肌缺血模型的心肌内,用MRI评估心肌灌注、活力及功能

目的将新构建的人肝细胞生长因子质粒VM202转载入梗死后的心肌内,对这种以避免左心室(LV)重构而达到保护目的的治疗方法进行评价。

在指导图象的身体干预的先生对比媒介的价值

In the past few years,there have been multiple advances in magnetic resonance (MR) instrumentation,in vivo devices,real-time imaging sequences and interventional procedures with new therapies.More recently,interventionists have started to use minimally invasive image-guided procedures and local therapies,which reduce the pain from conventional surgery and increase drug effectiveness,respectively.Local therapy also reduces the systemic dose and eliminates the toxic side effects of some drugs to other organs.The success of MR-guided procedures depends on visualization of the targets in 3D and precise deployment of ablation catheters,local therapies and devices.MR contrast media provide a wealth of tissue contrast and allows 3D and 4D image acquisitions.After the development of fast imaging sequences,the clinical applications of MR contrast media have been substantially expanded to include pre-during-and post-interventions.Prior to intervention,MR contrast media have the potential to localize and delineate pathologic tissues of vital organs,such as the brain,heart,breast,kidney,prostate,liver and uterus.They also offer other options such as labeling therapeutic agents or cells.During intervention,these agents have the capability to map blood vessels and enhance the contrast between the endovascular guidewire/catheters/devices,blood and tissues as well as direct therapies to the target.Furthermore,labeling therapeutic agents or cells aids in visualizing their delivery sites and tracking their tissue distribution.After intervention,MR contrast media have been used for assessing the efficacy of ablation and therapies.It should be noted that most image-guided procedures are under preclinical research and development.It can be concluded that MR contrast media have great value in preclinical and some clinical interventional procedures.Future applications of MR contrast media in image-guided procedures depend on their safety,tolerability,tissue specificity and effectiveness in demonstrating success of the interventions and therapies.

Experimental validation of material discrimination ability of muon scattering tomography at the TUMUTY facility

Muon scattering tomography is believed to be a promising technique for cargo container inspection, owing to the ability of natural muons to penetrate into dense materials and the absence of artificial radiation. In this work, the material discrimination ability of muon scattering tomography is evaluated based on experiments at the Tsinghua University cosmic ray muon tomography facility,with four materials: flour(as drugs substitute), aluminum,steel, and lead. The features of the different materials could be discriminated with cluster analysis and classifiers based on support vector machine. The overall discrimination precisions for these four materials could reach 70, 95, and 99% with 1-, 5-, and 10-min-long measurement,respectively.

De-novo hepatocellular carcinoma after pediatric living donor liver transplantation

De-novo malignancies carry an incidence ranging between 3%-26% after transplant and account for the second highest cause of post-transplant mortality behind cardiovascular disease. While the majority of de-novo malignancies after transplant usually consist of skin cancers, there has been an increasing rate of solid tumor cancers over the last 15 years. Although, recurrence of hepatocellular carcinoma(HCC) is well understood among patients transplanted for HCC, there are increasing reports of de-novo HCC in those transplanted for a non-HCC indication. The proposed pathophysiology for these cases has been mainly connected to the presence of advanced graft fibrosis or cirrhosis and always associated with the presence of hepatitis B or C virus. We report the first known case of de-novo HCC in a recipient, 14 years after a pediatric living related donor liver transplantation for end-stage liver disease due to biliary atresia without the presence of hepatitis B or C virus before and after transplant. We present this case report to increase the awareness of this phenomenon and address on the utility for screening and surveillance of hepatocellular carcinoma among these individuals. One recommendation is to use similar guidelines for screening, diagnosis, and treatment for HCC as those used for primary HCC in the pre-transplant patient, focusing on those recipients who have advanced fibrosis in the allograft, regardless of etiology.

Real-time computerized video enhancement for minimally invasive fetoscopic surgery

Background:The only definitive treatment for twin-to-twin transfusion syndrome is minimally invasive fetoscopic surgery for the selective coagulation of placental blood vessels.Fetoscopic surgery is a technically challenging operation,mainly due to the poor visibility conditions in the uterine environment.We present the design of an algorithm for the computerized enhancement of fetoscopic video and show that the enhanced video increases the ability of human users to identify blood vessels within fetoscopic video rapidly and accurately.Methods:A computer algorithm for the enhancement of fetoscopic video frames was created.First,optical fiber artifacts were removed via a modification of unsharp masking.Second,image contrast was increased via Contrast Limited Adaptive Histogram Equalization(CLAHE).Third,the effect of contrast enhancements on stationary features was removed by normalizing to a windowed mean of the video frames.Fourth,color information was reincorporated by combining the mean-normalized result with the unnormalized contrast enhanced image using the soft light blending algorithm.Medical trainees(n?16)were recruited into a study to validate the algorithm.Subjects were shown enhanced or unenhanced fetoscopic video frames on a screen and were asked to identify whether a randomly placed marker fell on a blood vessel or on background.The accuracy of their responses was recorded.Results:On the subset of images where subjects had the lowest mean accuracy in identifying the placement of the marker,subjects performed better when viewing video frames enhanced by the computer(accuracy 74.27%;SE 0.97)than when viewing unenhanced video frames(accuracy 63.78%;SE 2.79).This result was statistically significant(p<0.01).Conclusion:Real-time computerized enhancement of fetoscopic video has the potential to ease the readability of video in poor lighting conditions,thus providing a benefit to the surgeon intraoperatively.

Discovery and development of brain-penetrant ^(18)F-labeled radioligands for neuroimaging of the sigma-2 receptors

We have discovered and synthesized a series of indole-based derivatives as novel sigma-2(σ_(2))receptor ligands.Two ligands with high σ_(2) receptor affinity and subtype selectivity were then radiolabeled with F-18 in good radiochemical yields and purities,and evaluated in rodents.In biodistribution studies in male ICR mice,radioligand[18F]9,or 1-(4-(5,6-dimethoxyisoindolin-2-yl)butyl)-4-(2-[18F]fluoroethoxy)-1H-indole,was found to display high brain uptake and high brain-to-blood ratio.Pretreatment of animals with the selective σ_(2) receptor ligand CM398 led to significant reductions in both brain uptake(29%-54%)and brain-to-blood ratio(60%-88%)of the radioligand in a dose-dependent manner,indicating high and saturable specific binding of[18F]9 to σ_(2) receptors in the brain.Further,ex vivo autoradiography in male ICR mice demonstrated regionally heterogeneous specific binding of[18F]9 in the brain that is consistent with the distribution pattern of σ_(2) receptors.Dynamic positron emission tomography imaging confirmed regionally distinct distribution and high levels of specific binding for[18F]9 in the rat brain,along with appropriate tissue kinetics.Taken together,results from our current study indicated the novel radioligand[18F]9 as the first highly specific and promising imaging agent for σ_(2) receptors in the brain.

Adaptive Binary Coding for Scene Classification Based on Convolutional Networks

With the rapid development of computer technology,millions of images are produced everyday by different sources.How to efficiently process these images and accurately discern the scene in them becomes an important but tough task.In this paper,we propose a novel supervised learning framework based on proposed adaptive binary coding for scene classification.Specifically,we first extract some high-level features of images under consideration based on available models trained on public datasets.Then,we further design a binary encoding method called one-hot encoding to make the feature representation more efficient.Benefiting from the proposed adaptive binary coding,our method is free of time to train or fine-tune the deep network and can effectively handle different applications.Experimental results on three public datasets,i.e.,UIUC sports event dataset,MIT Indoor dataset,and UC Merced dataset in terms of three different classifiers,demonstrate that our method is superior to the state-of-the-art methods with large margins.

犬永久性冠状动脉闭塞模型:磁共振心血管成像评估经皮穿刺心内膜基因植入技术及其疗效

目的 证明MRI引导下经心内膜植入血管内皮生长因子（VEGF）基因可以形成新生血管或改善梗死心肌的血供。材料和方法 动物研究的所有试验程序均获得机构委员会的批准。永久性冠状动脉闭塞犬成像2次：一次是冠状动脉阻塞后3d，评估急性心肌梗死：一次是冠状动脉阻塞后平均（50±3）d，评估慢性心肌梗死。治疗组动物（n=6）接受VEGF质粒与LacZ质粒混合物4个位置的植入。

RESTplus: an improved toolkit for resting-state functional magnetic resonance imaging data processing

Resting-state functional magnetic resonance imaging (RS-fMRI)[1,2] provides relatively high spatial and temporal resolution for mapping spontaneous brain activity non-invasively. It has been widely used in cognitive neuroscience and clinical studies. A number of comprehensive software packages have been developed for RS-fMRI data analysis, among which a MATLAB package named REST (RESing-state fMRI data analysis Toolkit, released in October 2008 at http://www.restfmri.net)[3] is the earliest one dedicated to RS-fMRI analysis. REST focuses on RS-fMRI postprocessing metrics.