简介：AbstractParkinson disease (PD) is the second-most common neurodegenerative disorder. Its main pathological mechanism is the selective degeneration and deletion of dopaminergic neurons in the dense part of the substantia nigra and the damage of dopaminergic neurons caused by the abnormal deposition of a Lewy body, leading to a decreased dopamine level. Positron emission computed tomography (PET)/single photon emission computed tomography (SPECT) is a molecular imaging technology that can directly or indirectly reflect changes in molecular levels by using a specific tracer. With the research and development on the tracers of related enzymes for labeling dopamine transporter and dopamine receptor and for being involved in dopamine formation, this imaging technology has been applied to all aspects of PD research. It not only contributes to clinical work but also provides an important theoretical basis for exploring the pathological mechanism of PD at a molecular level. Therefore, this review discusses the application value of PET/SPECT in PD in terms of early diagnosis, disease severity evaluation, clinical manifestations, differential diagnosis, and pathological mechanism.

简介：Ｅｌｅｃｔｒｏｍａｇｎｅｔｉｃｔｏｍｏｇｒａｐｈｙ：ｃｏｎｓｉｓｔｅｎｃｙｏｆｉｍａｇｅｓａｎｄｇｒｏｕｎｄｗａｔｅｒｐｒｏｓｐｅｃｔｉｎｇＲＵＩＦＥＮＧ１）（冯锐）ＫＵＩＸＩＡＮＧＭＡ２）（马奎祥）ＨＯＮＧＧＵＯ３）（郭鸿）ＣＨＡＮＧＱＵＡＮ...

简介：Eightsetsofcoastalacoustictomography(CAT)systemsweredeployedduringNovember29toDecember10,2002atthecoastsonbothsidesofTokyoBaytomeasuretidalcurrentstructuresat15-mininterval.SoundtransmissionacrosstheTokyoBay(betweenYokohamaandChiba)wassuccessfullytraced,evenundersevereinterferencefromshipgeneratedwakesandbubbles.Tidalcurrentfieldschangingfromnorthwardtosouthwardflowarewellreconstructedbytheinverseanalysisoftravel-timedifferencedataforaperiodwiththebestsoundtransmissioncondition.ItissuggestedthattheCATisthemostpowerfultooltocontinuouslymaptidalcurrentfieldsinthecoastalseaswithheavyshippingtrafficandfisheriesactivity.

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简介：Basedonthethermaltomographytechnology,thisthesistriestocalculatequantityanddistributionofheatsourceinvivofrombodysurfacetemperature.AsuperpositiontemperatureimageofanumberofpointheatsourcesissurfacefittedtogettheQofheatsources(informationofcancercells)quantitatively.Theresultcanreflectthediseaseareainformationbecausecancercell'sQvalueismuchhigherthanthatofnormalcell.Thisapplicationisanewtryinthediagnosisofbreastcancer,whichhasanimportantvalueontheearlydetectionanddiagnosisofdiseasesource.

简介：Anoveltechniquetermednonredundantarrayscanningholographybasedontheprincipleofopticalheterodynescanningholographyandthetomographictechniqueofcodedapertureimagingisproposed.Thesystemdesignedintermsofthistechniquecodesanobjectopticallyanddecodesitscodedimagedigitally.Itcanrealizeopticaltomogramsofthree-dimensionalobjects.Italsohaspotentiallypracticalvalueduetoitscompactstructure.Thecomputersimulationspresenttheprincipleofthetechnique.Someexperimentsattheproof-principlelevelareperformedtotesttheprinciple.

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简介：Crossholeultrasonictomographyisreferredtoraytracingbygridingmethodandimagereconstructionbycombiningthesuccessivelylinearizediterationwithdampingleast-squaresQRdecomposition,withwhichtheresulthasbetterprecisionthanthatwithcrossholeseismictomographybyusingthesameinversionmethodinengineeringgeologicalinvestigation.Ithasbeenprovedinpracticethattheinvestigationwithcrossholeultrasonictomographycanclearlyshowthelocationandshapeoftheabnormalgeologicalunitwiththevolumemorethan60cmwhenthecrossholedistanceexceeds30m.Theresultofinvestigationhasbeenconfirmedbythedrilling.Thecrossholeultrasonictomographymethodwillbeextensivelyusedintheengineeringgeologicalinvestigation.

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简介：AbstractPurpose:Pelvic fracture evaluation with abdominopelvic computed tomography (CT) and formal CT cystography for rule out of urine bladder injury have been commonly employed in pediatric trauma patients. The additional delayed imaging required to obtain optimal CT cystography is, however, associated with increased doses of ionizing radiation to pelvic organs and represent a significant risk in the pediatric population for future carcinogenic risk. We hypothesized that avoidance of routine CT cystography among pediatric pelvic fracture victims would not result in an appreciable rate of missed bladder injuries and would aid in mitigating the radiation exposure risk associated with these additional images.Methods:A retrospective cohort study involving blunt trauma pelvic fractures among pediatric trauma patients (age<14) between the years 1997 and 2016 was conducted utilizing the Israeli National Trauma Registry. Statistical analysis was performed using SAS statistical software version 9.4 via the tests of Chisquare test and two-sided Fisher's exact test. A p value of less than 0.05 was considered statistically significant.Results:A total of 1072 children were identified from the registry for inclusion. Mean age of patients was 7.7 years (range 0-14) and 713 (66.5%) were male. Overall mortality in this population was 4.1% (44/1072). Only 2.1% (23) of pediatric patients with pelvic fractures had bladder injury identified, with just 9 children having intraperitoneal bladder rupture (0.8% of all the patients).Conclusion:The vast majority of blunt pediatric trauma victims with pelvic fractures do not have urine bladder injuries. Based on our study results we do not recommend the routine utilization of CT cystography in this unique population.

简介：这篇论文涉及源于分子的成像的区域的一个提出病的问题并且作为BLT被知道问题。用Tikhonov规则化技术，一个二次的优化问题能被提出。我们为调整优化问题的有限元素近似提供改进错误估计。一些数字例子被举表明我们的理论结果。

简介：一个精确的宏速度模型的评价在地震成像和模型参数倒置起一个重要作用。完整的波形倒置(FWI)是古典数据域倒置方法。然而，FWI的不合身的衣服功能是高度非线性的，并且本地优化不能向本地最小阻止不合身的衣服功能的集中。收敛到全球最小，FWI需要一个好起始的模型或可靠低频率部件和长偏移量数据。在这篇文章，我们在场一个wave-equation-based思考traveltime断层摄影术(WERTT)方法，它能为FWI提供一个好背景模型(起始的模型)并且(最少平方)预先叠深度移植(LS-PSDM)。首先，速度模型被分解成一个low-wavenumber部件(背景速度)和一个high-wavenumber部件(反射率)。第二，主要思考波浪被波浪方程demigration预言，并且思考traveltime由一个自动的拣方法是计算的。最后，思考traveltime剩余的l2标准的不合身的衣服功能被一个基于坡度的方法最小化。建议方法能转换的数字测试表演一个好背景模型，它能为LS-PSDM或FWI被用作一个起始的模型。

简介：在这份报纸，我们以可变健全速度在photoacoustic断层摄影术调查伴随方程，并且建议三个变化反复的算法。这些算法的基本想法是反复地计算原来的方程和伴随方程。我们现在的数字例子和表演这些变化反复的算法的井表演。[从作者抽象]

简介：Recentdevelopmentsinthenovelimagingtechnologyofcardiaccomputedtomography(CT)notonlypermitdetailedassessmentofcardiacanatomybutalsoprovideinsightintocardiovascularphysiology.Foremost,coronaryCTangiography(CCTA)enablesdirectnoninvasiveexaminationofbothcoronaryarterystenosesandatheroscleroticplaquecharacteristics.CalculationofcomputationalfluiddynamicsbycardiacCTallowsthenoninvasiveestimationoffractionalflowreserve,whichincreasesthediagnosticaccuracyfordetectionofhemodynamicallysignificantcoronaryarterydisease.Inaddition,acombinationofmyocardialCTperfusionandCCTAcanprovidesimultaneousanatomicalandfunctionalassessmentofcoronaryarterydisease.Finally,detailedanatomicalevaluationofatrial,ventricular,andvalvularanatomyprovidesdiagnosticinformationandguidanceforproceduralplanning,suchasfortranscatheteraorticvalvereplacement.TheclinicalapplicationsofcardiacCTwillbeextendedwiththedevelopmentofthesenovelmodalities.

简介：Thechangesintheiridocornealanglestructureduringaccommodationareassessedbymeansofanteriorsegmentopticalcoherencetomography.Thirteenrighteyeswereincludedinthestudy.ThedeviceusedforthemeasurementwastheVisante?omnisystem.Thestimuliweresetupatdifferentvergences(0.0D,-1.5D,and-3.0D).Theangleopeningdistance500and750,thetrabecularirisspacearea500and750,andthescleralspurangleparameterswereassessedatthenasalandtemporalregions.Theresultsintheiridotrabecularanglecomparingthethreeaccommodativestatesoftheeyedidnotyieldanystatisticallysignificantdifferenceatnasalortemporalanglesections.Inlightofourresultsandintheconditionsofourstudy,thestructuresoftheiridocornealanglearenotsignificantlychangedwithaccommodation.

简介：这份报纸为用BDS(BeiDou航行卫星系统)估计湿折射度地的精确论述一条新奇途径模拟仅仅，为深圳和香港GNSS的GPS，和BDS+GPS联网。模拟被把人工的噪音加到真实观察数据集执行。，而不是使用，从观点计算的d和s参数在以前的研究弄湿延期，我们采用偏爱和RMS参数，从全部的voxels的断层摄影术结果计算了，回答决心以便获得折射度的精确的更直接、全面的评估。结果显示出那：(1)湿折射度估计了独自使用BDS的tropospheric(仅仅使用的9颗卫星)的精确基本上比得上GPS的；(2)BDS+GPS(当前的操作)不能显著地改进数据为折射度断层摄影术的应用程序的空间密度；并且(3)特别地在更低的空气，折射度断层摄影术的精确的任何细微增加在中国运作的气象学的服务上为任何应用依赖者忍受大意义。

简介：多尺度的策略在基于波形的速度倒置的成功的申请是很重要的。策略顺序preceeds从长当模特儿突然速度可伸缩，很好在完整的波形倒置(FWI)被开发了解决本地mininum问题。相反，它的不好在图象域波形断层摄影术(IWT)理解，哪个幕後放映的影像普通图象的支离破碎的波形部件聚在一起进速度更改。IWT对本地最小的问题不太敏感，但是趋于与低分辨率造长规模的模型。以便由IWT造长规模、短规模的模型，我们讨论在图象域限制的几多尺度的策略。策略包括模型reparameterization，客观功能切换和重新可伸缩的坡度。Marmsousi模型和真实数据上的数字测试证明我们的建议多尺度的IWT在有宽wavenumber光谱的buidling速度模型是有效的。

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简介：AbstractBackground:Certain hemophilia patients are unable to cooperate with or afford magnetic resonance imaging (MRI) examinations. The purpose of our study was to explore the value of multislice spiral computed tomography (MSCT) in evaluating hemophilic arthropathy (HA).Methods:Thirty-eight patients with 73 joints of HA were consecutively selected from January 2016 to May 2018 for this prospective study. All 73 joints were examined by X-ray, CT, and MRI within 2 days. The MRI scores of the joints were determined by the International Prophylaxis Study Group (IPSG) standard. The CT findings were quantified according to the IPSG standard, except for cartilage injury, which was quantified by joint space narrowing using the X-ray Pettersson score. The CT and MRI scores were compared by the paired Wilcoxon signed-rank test. The correlations between the CT score of joint space narrowing and MRI score of cartilage injury and the total CT and MRI scores were analyzed by Spearman rank correlation. The kappa test was used to compare the consistency of CT and MRI scores.Results:MRI was superior to CT based on the scores for small amount of effusion (P < 0.05), synovial hypertrophy and hemosiderin deposition in the mild groups (P < 0.05). The CT and MRI scores were not significantly different for moderate and massive effusion, synovial hypertrophy, and hemosiderin deposition in the moderate and severe groups, bone erosion or cystic changes (P > 0.05), and there was a high degree of consistency between the two scores (kappa > 0.81). The consistency between the Pettersson scores of joint space narrowing on CT and the IPSG scores of cartilage injury on MRI was high (kappa = 0. 774, P < 0.05).Conclusion:The image scores of MSCT are generally consistent with MRI except for mild synovitis, which can be used as an alternative for the evaluation of HA.