包尚聯(lián)ICMIP-全體會(huì)議的發(fā)言

1、Present and Future of Medical Imaging Physics包尚聯(lián)Shanglian Bao北京大學(xué)醫(yī)學(xué)物理和工程北京市重點(diǎn)實(shí)驗(yàn)室Beijing Key Lab of Medical Physics & Engineering北京大學(xué)腫瘤物理診療技術(shù)研究中心The Research Center of Tumor Diagnosis and Therapeutical Physicsbao 2022/8/281ICMIP-2013 沈陽(yáng)南京Basic disciplines of health protectionPhysics，Chemistry & infor

2、matics Safeguard human healthSolve problem from original requirementGoal: get enough Vivo state information by Non-invasive medical imaging means including molecular，cell，organ and system for morphological, physiological and psychological information in precise, accuracy2022/8/282ICMIP-2009 沈陽(yáng)Physic

3、s & Engineering of Medical Imaging Medical Imaging PhysicsPrinciple and prototype deviceMedical Imaging EngineeringIndustry device and productionBoth do application in clinical disease Diagnosisdisease therapeuticsData treatment and analysisVerification and guarantee 2022/8/283ICMIP-2013 沈陽(yáng)南京4 Major

4、 ModalitiesX-ray Imaging (animal & human imaging)Planer: DR, CRTomography: spiral CT, Cone Bean CT NMI (animal & human imaging)SPECT: combining with CTPET: combining with CTMRI (animal & human imaging)Middle，high & Extra high field system;Ultrasound I3D, 4D imagingGeneral and special2022/8/284ICMIP-

5、2013 沈陽(yáng)Essential TaskAll places & times need to extend the human eye capability，Accompanying human developmentAfter Macroscopic information，Microscopic information more important； After morphology，physiology more important；After eye visible information, eye invisible information is more important, i

6、ncluding physiology and psychology.2022/8/285ICMIP-2013 沈陽(yáng)南京Front Direction: Molecular ImagingPermanent topic：New genetic material and proteinsAccompanying the progress of mankindRevealing essential pathological reasonVery earlier (sufficient time to adjust and treatment)2022/8/286ICMIP-2013 沈陽(yáng)南京mRN

7、ADNARNA酶的合成和活性調(diào)控物轉(zhuǎn)運(yùn)蛋白 RNA結(jié)合物報(bào)告探針報(bào)告基因DNAAATglut 4代謝產(chǎn)物MAb激素配體縮氨酸DNA合成物+ other moleculesAll in dynamical and 3D distribution2022/8/287ICMIP-2013 沈陽(yáng)南京Two most important moleculesNew genetic materialHuman evolution faster than before (natural and artificial)Nature：changes on biodiversity, climatic condit

8、ions, food chain, speed of mixed race geneArtificial：New genetic modification of plants and animals，even humanProteinsHuman Progress rely on proteins and new proteins 2022/8/288ICMIP-20139 沈陽(yáng)Gene MutationGood gene mutationPromoting human progressBad gene mutationCause diseases, such as cancerVarious

9、 diseases, e.g. cancer，cardiovascular & brain diseases increasing Every Individual：progressive disease，which is genetically determined 2022/8/289ICMIP-2013 沈陽(yáng)南京突變, 超量表達(dá)基因, 抗原產(chǎn)生抗體生物標(biāo)志物 遺傳 病毒感染 化學(xué)致癌物 輻射致癌物 老化 其他血液中相應(yīng)抗體Cancer genetic material encoding the protein markers用載體克隆基因克隆表達(dá), 基因和載體蛋白克隆篩選得到癌癥相關(guān)克隆

10、Other MoleculesSuch as Metabolites，Hormones，NeurotransmittersMainly determined by acquired environmentalWhich were worse than before in China, which dependence on health carenew challenges for health workersMedical physicists & physiciansEngineers and others2022/8/2811ICMIP-2013 沈陽(yáng)南京Complexity & hug

11、e numberMolecules in vivoHuge numbers：constructor body, keep stable running, maintain vitality of cells and humanComplexityMultiple Structures & multiple functionsDifferent roles in different processDynamical changes2022/8/2812ICMIP-2013 沈陽(yáng)南京New Tasks on Devices and ProbesDevicesCreative new measuri

12、ng imaging devices Multiple modality integrationComprehensive data analysis and processingProbesCovering all kind of moleculesMethodologies on Synthesis, labeling and testingProbes for new modalities，e.g. for MRI 2022/8/2813ICMIP-2013 沈陽(yáng)南京Molecular Nuclear Medical ImagingTraditional molecular imagin

13、gPET，SPECT & their combination with CT, MRIDeveloped a sufficient number of biological probesRoutine clinical diagnostic toolDisadvantage Poor space and time resolutionsTake them as anatomic source only using their WeaknessWhy no dynamical analysis in ChinaNo time to satisfy so many patientsNo speci

14、alist to do the analysisNo original creative research (including the drug D)2022/8/2814ICMIP-2013 沈陽(yáng)南京2001，first Inter. Conference in molecular imaging in Boston2002, May, Nature: Vasilis Ntziachristos et al: Fluorescence molecular tomography resolves protease activity in vivo2002, October Mr. Tang

15、Xiaowei hold the Xiangshan Science Symposium in Hang Zhou, Title: Molecular medical imaging.End of 2002，Based imaging measurements (including optical imaging) of the dynamics of molecular and cellular events Visualization, Science: One of the top ten breakthroughs2006, 973 subject on molecular iamgi

16、ng set up, Tian Jie, Bai Jing and Bao Shanglian 2011, continued 分子影像學(xué)國(guó)內(nèi)外研究現(xiàn)狀和發(fā)展趨勢(shì)綜述Diagnosis in earlier stage, distinguish Benign and malignant tumors；Develop new drugs：Pharmacology, toxicity, and in vivo stability, including the probesTesting the dynamical analysis modelQuantitative parameters in p

17、arameter imagingSignificant of Dynamical Molecular Imaging”input”output”Authentic tracerconcentrationavailable inarterial bloodConcentrationin tissuemeasured byPET scannerPerfusionEndothelial permeabilityVascular volume fractionTransport across cell membranesSpecific binding to receptorsNon-specific

18、 bindingEnzyme activityPrinciple parametric image：Perfusion (mL blood)/(min x mL tissue)Glucose uptake rate (mol glucose) / (min x mL tissue)Binding potential (Bmax/Kd)BLOODorPLASMATACTISSUE TAC-sinogram or-image or-regionalRESULTS(model parameters)MODELModel TAC:時(shí)間活度曲線分類流出型平臺(tái)型流入型 parameters：time-to

19、-peakSlopeSERGlucoseGlucose-6-PhosphateGlucoseK1k3k2k418FFDG18FFDG -6-Phosphate18FFDGK*1k*3k*2k*4Lumped constant (LC) correctsfor the different affinities oftransporters and hexokinaseto glucose and FDGInflux rate constant:Linear & Non- Linear models，here FDG Three compartment modelPET 3D Dynamic Da

20、ta clustering results byK-means and hierarchical clustering combined使用LLS（第一行所示）和cLLS（第二行所示）方法分析3D PET FDG臨床動(dòng)態(tài)數(shù)據(jù)得到的第12層參數(shù)圖像結(jié)果 Parameter images of FDG PETMRI & fMRIAdvantagesOnly modality can simultaneously measure anatomical, physiological and psychological imaging data;Without radiation damage;disa

21、dvantages Complex and expensivefMRI dose not spread in clinical (re-training physicians, phyicists)FutureClinical regulation of Neurology & psychological Develop and practice more reliable analyzing softwareAdd more position in radiology Dept.2022/8/2823ICMIP-2013 沈陽(yáng)南京Condition is Ripe Whatever phys

22、iology or psychology，the application in clinical is Progressively ripeFacilities of MRI Improve faster； Physiological parameter measuring is accurate enough for clinical testSports, and ear, nose and eye-related functions are enough precisely measured in some degree2022/8/2824ICMIP-2013 沈陽(yáng)南京e.g. Qua

23、ntitative DEC-MRIMethodology TAC Characterization analysisAnalysis of hemodynamic parametersDWI to determine ADC valueslower in tumor areaEnhanced morphological tumor areaEasy to be used by radilogists TAC:時(shí)間活度曲線分類流出型平臺(tái)型流入型 parameters：time-to-peakSlopeSERDCE-MRI 藥代分析評(píng)估化療效果的研究病人化療前情況 （左乳）浸潤(rùn)性導(dǎo)管癌，部分呈導(dǎo)管

24、內(nèi)癌，局灶區(qū)域見淋巴細(xì)胞聚集（invasive ductal carcinoma with ductal carcinoma in situ and lymphocytes aggregation病人化療后情況 化療后乳腺改良根治標(biāo)本：乳腺浸潤(rùn)性導(dǎo)管癌（invasive ductal carcinoma），腫瘤組織伴壞死、退變及鈣化，肉眼未見明確腫塊，鏡下可見腫瘤浸潤(rùn)范圍約2x2cm。余乳腺組織內(nèi)可見纖維腺瘤形成。乳頭、基底及切緣凈。淋巴結(jié)：腋窩3/8可見癌轉(zhuǎn)移；另送（腋窩）0/3未見癌轉(zhuǎn)移。化療前 Ktrans 三維分布Typical output curvesEvaluation afte

25、r Chemotherapy for G4OverviewBREAST IMAGING REPORTING AND DATA SYSTEM: BI RADS American College of Radiology. Illustrated Breast Imaging Reporting and Data System (BI-RADS), 3rd ed. Reston, VA: American College of Radiology, 1998Fig 57-year-old woman with lesion variably termed focal asymmetric dens

26、ity versus indistinct mass. Bilateral routine craniocaudal (A) and mediolateral oblique (B) mammograms show focal normal variant asymmetric parenchyma (arrows) that was unchanged for 5 years.THE SHORTAGE OF CHARACTERISTIC KINETIC CURVE (CKC)Katja C. Siegmann, Markus Mller-Schimpfle, Fritz Schick, Ch

27、ristopher T. Remy et al, “MR ImagingDetected Breast Lesions: Histopathologic Correlation of Lesion Characteristics and Signal Intensity Data,” AJR. 178, 14031409 (2002).Neoadjuvant chemotherapy for locally advanced breast cancerTWO-COMPARTMENT REFERENCE REGION PHARMACOKINETIC ANALYSISKtrans (volume

28、transfer constant) Ve (extravascular extracellular volume).The Ktrans is always believed to correlated to angiogenesis and Ve may increase in the case of edema or necrosis. Ktrans 與血管生成有關(guān)Ve 與水腫或壞死有關(guān)TRADITIONAL QUANTITATIVE TWO-COMPARTMENT REFERENCE REGION PHARMACOKINETIC ANALYSISChallenge 1: 3D T1 m

29、ap of the whole imaging volume With gradient echo multi-angle approach used, it take more than ten minutes for the measurement.Challenge 2: AIF (Artery input function: the concentration of contrast agent in the vascular) It is difficult to get AIF through direct measurement.Traditional solution Popu

30、lation-based (cause significant errors in the calculation)More than conventional DCE-MRI 3D dataset acquisitions Our solutionFixed T1 value for contrast agent concentration deriving.Reference region model instead of conventionalA empirical formula and fuzzy-cluster are adopted for conventional DCE-M

31、RI data points deficiency.results a slice of breast 3D DCE-MRI dataset, the tumor in the left is selected for segmented and further3D Ktrans maps show the proliferation area in the periphery with the increased Ktrans value in this area.For 3D Ve map, the malignant area (defined by the Ktrans map) st

32、ill has increased values in the rim where tumor locates. In the center of the tumor, the Ve value is still relatively low.a benign example (one slice of the 3D DCE-MRI dataset)the 3D Ktrans map of the tumor, some relative high voxel of the Ktrans map may be caused by the exchange between the normal

33、vessel and tissue.the 3D Ktrans map of the tumor regionClinical available softwareAfter several PhD thesisIt has been developed as clinical usable softwareBut, been introduced to Top Grade company, but not been approve by CFDA2022/8/2844ICMIP-2013 沈陽(yáng)南京New Requirements Need put is into a special desi

34、gned MRI facilityTest for more tumors Further improve the accuracy Practice in wide clinical application2022/8/2845ICMIP-2013 沈陽(yáng)南京Brain imaging & Its ApplicationUSA, Europe start the new projects on brain imaging and more challenge research goal Main task is Connections between individual nerve fibe

35、rs, too difficult non-invasivelyHuman has about 1.5 X 1012 neuronsEach neuron has about 103-105 SynapsesUSA going on plan：HCPNIH：2010-2015;Derive the connection between main brain region to reveal the difference at 1mm space resolutionUndertakerUniversity of Washington, $ 30 million;Harvard Universi

36、ty and the Massachusetts General Hospital and other institutions, $ 8.5 million TasksScan 1200 brain of health adults（including 300 pairs of twins) compare their difference of connectivity, Cognitive and behavioral，Eventually all depict the human brain neural connectionsThey published the results by

37、 MGH firstThe previous results are at 2-3 mm space resulutionEuropean Brain ProjectFeb of 2013，CEC JRC declared: HumanBrainProject in 1 billion euros in 10 years to simulate whole brainFirst step is also 1mm space resolution simulation with real time requirement, This is an Infinite, no end plan bot

38、h of USA and EuropeAbout the applications Create an artificial brain, know how to improve the connectivity to increase the efficiencyUnderstand how the disease is formed and the onset via comparison with patients such as Schizophrenia, clinical depression or autism (精神分裂癥、臨床抑郁癥或自閉癥)Human can do it a

39、t different space resolution level and at Different stages of the process北大正在開展的研究簡(jiǎn)介北京大學(xué)高家紅教授來(lái)了之后，正在組建一個(gè)有3臺(tái)3T和1臺(tái)9.4T動(dòng)物成像系統(tǒng)的MRI中心在神經(jīng)科學(xué)中的應(yīng)用是高家紅教授的專長(zhǎng)直接測(cè)量神經(jīng)元的電磁活動(dòng)產(chǎn)生的信號(hào)并成像動(dòng)態(tài)連接度的研究基于解剖學(xué)結(jié)構(gòu)，尤其是纖維束的連接基于功能的虛擬的連接靜息態(tài)的連接問題MRI設(shè)備的關(guān)鍵技術(shù)研究開發(fā)0.7T C型超導(dǎo)MRI系統(tǒng)，實(shí)現(xiàn)產(chǎn)業(yè)化梯度線圈、屏蔽線圈和勻場(chǎng)線圈的設(shè)計(jì)；RF線圈的設(shè)計(jì)和制造譜儀的研發(fā)系統(tǒng)軟件的開發(fā)我的研究小組正在開展立體視覺方面的

40、工作三維立體視覺fMRI研究適應(yīng)三維立體影視節(jié)目觀看、顯示器的立體化以及其他三維、四維影視節(jié)目的增加三維立體視覺盲的存在，基于雙眼視覺差的三維立體視覺功能測(cè)量立體視覺盲的鑒別觀看三維立體視覺舒適度問題的研究V1-V4解剖學(xué)結(jié)構(gòu)成像和定位研究人腦視覺皮層區(qū)域特性分析視網(wǎng)膜映射腦功能實(shí)驗(yàn)第二部分解剖圖像信息處理 & 可視化 第一部分 第三部分解剖圖像信息處理 & 可視化 第一部分notice針對(duì)人類大腦皮層數(shù)據(jù)的二維平面化分析方法，能夠提高解剖學(xué)信息的縱向?qū)Ρ确治瞿芰途?(Anticevic et al., 2008; Van Essen et al., 1998) ，提高功能數(shù)據(jù)分析結(jié)果的顯

41、著性和可信度 (Argall et al., 2006; Hagler et al., 2006; Jo et al., 2007; Van Essen, 2005).結(jié)合FreeSurfer和MW 投影的平面分析處理，引入大腦皮層的多層面劃分，對(duì)五種掃描的數(shù)據(jù)進(jìn)行了高分辨率重采樣、配準(zhǔn)和參數(shù)計(jì)算。掃描序列和參數(shù)計(jì)算得到多個(gè)參數(shù)掃描膨脹的球體空間& 2D 統(tǒng)一空間第四類 Mollweide 投影圖大腦皮層的多層細(xì)分研究?jī)?nèi)容 第一部分(A) 其中一個(gè)被試的鼓起的左半腦 (LH) 。(B) 球面坐標(biāo)系下，經(jīng)過(guò)配準(zhǔn)的左半腦。(C) Mollweide 投影平面圖。第四類 Mollweide 投影圖(

42、MW4)枕極 Occipital pole (黃色標(biāo)記點(diǎn)) 在投影平面圖中心. 根據(jù)投影平面中心的位置不同，還有另外三類顯示See also: /hcnlab/cortical-mapping/57大腦皮質(zhì)周圍多個(gè)層面Cortical surface S0: 白質(zhì)WM/灰質(zhì)GM交界面;Pial surface S1: 白質(zhì)GM/腦脊液CSF交界面; Surface S0.5: S0 and S1中間的一層面;Surfaces S-1 and S-2: S0向內(nèi)白質(zhì)中的1 mm and 2 mm 位置的層面. 58Scan:(1) 兩組高分辨率的MPRage T1加權(quán)像 (TR = 3000 m

43、s, TE = 1.62 ms, flip angle = 9o, voxel size 1 1 1 mm); (2) 高分辨率T2加權(quán)像 (TR = 2000 ms, TE = 409 ms, variable flip angle, voxel size 1 1 1 mm); (3) 兩組 DTI 掃描 (TR = 10700 ms, TE = 95 ms, flip angle = 15o, b = 1500 s/mm2, 30 個(gè)方向, voxel size 2 2 2 mm)， 其中第二次DTI掃描的擴(kuò)散梯度方向與第一次相反，以減少圖像平面內(nèi)的非仿射幾何失真 (Shen et al.

44、, 2004); (4) 兩組MT掃描，其中一組不加MT脈沖。 (TR = 2600 ms, TE = 13.3 ms, flip angle = 70o, voxels size 2 2 2 mm); (5) 四組EPI掃描，伴隨四組視覺刺激 (TR = 2510 ms, TE = 30 ms, flip angle = 90o, voxels size 3 3 4 mm). 數(shù)據(jù)采集參數(shù) 第一部分Parameters：FA: DTI中所使用的各向異性參數(shù)能夠很好的反映神經(jīng)纖維的組織結(jié)構(gòu)和完整性。 (Le Bihan, 2003).MTR: Magnetization Transfer Ra

45、tio ，磁化率轉(zhuǎn)移成像（MTI）使用MTR參數(shù)，表征細(xì)胞膜和髓磷脂的分布情況(Bastin et al., 2009; Schiavone et al., 2009; Vrenken et al., 2010). MTR = (Ms M0) / M0 x100%T1/T2: T1加權(quán)像 (我們使用的序列名稱為MPrage) 和T2加權(quán)像的比值也能從一定程度反映髓磷脂分布和大腦皮層區(qū)域的分界線 (Glasser and Van Essen, 2011). 圖像處理獲得的參數(shù) 第一部分視網(wǎng)膜映射腦功能實(shí)驗(yàn)第二部分 第三部分視網(wǎng)膜映射腦功能實(shí)驗(yàn)的流程第二部分旋轉(zhuǎn)楔形縮放圓環(huán)刺激圖01FFT 分析0

46、2響應(yīng)強(qiáng)度F-統(tǒng)計(jì)過(guò)濾相位編碼定位偽彩色標(biāo)記顯示視網(wǎng)膜映射03水平和垂直刺激對(duì)應(yīng)區(qū)域分界線參考前人研究成果04劃分區(qū)域激活信號(hào) 相位圖 確定邊界刺激圖及其條件第二部分signal信號(hào)時(shí)間序列( 上圖)頻譜分析(下圖)信號(hào)時(shí)序圖第二部分相位編碼視網(wǎng)膜映射定位圖結(jié)果.實(shí)驗(yàn)結(jié)果顯示第二部分上頁(yè)圖(A) and (B) 中的黃色矩形框區(qū)域放大圖.處理結(jié)果顯示(放大)第二部分依據(jù)多個(gè)被試平均結(jié)果所劃分的感興趣區(qū)域(ROI)，同時(shí)與白色線條顯示的Van Essen小組研究結(jié)果進(jìn)行對(duì)比印證. 視網(wǎng)膜映射腦功能實(shí)驗(yàn)第二部分人腦視覺皮層區(qū)域特性分析 第三部分不同ROI內(nèi)在五層平面上的EAR (左)FA (右)平

47、均值及其標(biāo)準(zhǔn)誤差各向異性的分布 第三部分不同ROI內(nèi)在五層平面上的MTR平均值及其標(biāo)準(zhǔn)誤差分層顯示MTR值 第三部分不同ROI內(nèi)在五層平面上的T1/T2平均值及其標(biāo)準(zhǔn)誤差顯示T1/T2平均值及其標(biāo)準(zhǔn)誤差結(jié)果的圖標(biāo)顯示 第三部分結(jié)論1對(duì)解剖學(xué)圖像的高精度配準(zhǔn)，能夠減少多個(gè)被試之間高階視覺區(qū)域(V2, V3 et al.)位置的差異.2多個(gè)解剖學(xué)參數(shù)在不同視覺功能區(qū)域內(nèi)都體現(xiàn)一定拓?fù)浞植家?guī)律.3白質(zhì)和灰質(zhì)內(nèi)不同的變化趨勢(shì).4ROI內(nèi)上述參數(shù)的左右大腦不對(duì)稱性.關(guān)于立體圖像中的雙眼視差引起的腦激活差異的功能磁共振研究立體圖像中的雙眼視差引起的腦激活差異。通過(guò)向觀察者展示消除了形狀因素差異的立體圖，幾

48、個(gè)與立體視覺相關(guān)的腦區(qū)被鑒別出來(lái)，它們主要分布在背側(cè)視覺通路上。在視差幅度和符號(hào)方面，信號(hào)強(qiáng)度和平面刺激相應(yīng)之間都表現(xiàn)出了明顯差異。.立體刺激片源的設(shè)計(jì)技術(shù)路線通常使用的隨機(jī)點(diǎn)立體圖這種立體圖在二維情況下是一群沒有意義的隨機(jī)點(diǎn)，而在三維情況下卻表現(xiàn)出了一定的形狀，因此三維與二維對(duì)比的差異不僅僅表現(xiàn)為平面與立體差異，還具有物體的形狀。立體片源的設(shè)計(jì)改進(jìn)后的隨機(jī)點(diǎn)立體圖采用黑白棋盤格布局的方式，使得二維和三維情況下具有相同的形狀特征，從而消除了形狀因素造成的對(duì)比差異，只存在立體差異。左右眼子圖融合后的紅藍(lán)立體圖二維和三維效果圖數(shù)據(jù)采集方法6種視差block（隨機(jī)展示）一個(gè)block群（8個(gè)bloc

49、k，每個(gè)block持續(xù)20s)Block實(shí)驗(yàn)設(shè)計(jì)方式，包含8種實(shí)驗(yàn)條件（1個(gè)控制條件，1個(gè)平面刺激條件，6個(gè)立體刺激條件）結(jié)果統(tǒng)計(jì)參數(shù)圖譜3對(duì)主要的區(qū)域得到了明顯的激活，它們分布在背側(cè)視覺通路（V2，V3A，hMT/V5)及頂葉(DIPSM, DIPSA)上。沒有明顯的腹側(cè)腦區(qū)被激活。而其他使用隨機(jī)點(diǎn)形成的立體圖的研究者在實(shí)驗(yàn)中卻發(fā)現(xiàn)了相關(guān)的腹側(cè)激活腦區(qū)。激活圖譜的說(shuō)明激活簇T得分峰值MNI 坐標(biāo)/mmBrodmann 腦區(qū)(體素?cái)?shù)目a)功能腦區(qū)19.04(-18, -90, 30)BA18(33), BA19(133)V2, V3A27.03(21, -93, 24)37.38(-39, -

50、81, 6)BA18(13), BA19(46), BA39(14)hMT/V545.63(39, -81, 3)55.58(-24, -57, 60)BA7(99)DIPSM, DIPSA66.74(24, -63, 66)a 體素?cái)?shù)目實(shí)質(zhì)包含在對(duì)應(yīng)Brodmann腦區(qū)內(nèi)的 激活體素?cái)?shù)目。體素大小為333mm。統(tǒng)計(jì)學(xué)直方圖分析結(jié)果3對(duì)激活簇的視差-激活圖所有背側(cè)通路腦區(qū)的激活強(qiáng)度都隨視差幅度增加而增加在相同視差幅度下，正視差（近視差）要比負(fù)視差（遠(yuǎn)視差）引起更強(qiáng)烈的腦激活結(jié)論使用靜態(tài)立體圖的實(shí)驗(yàn)發(fā)現(xiàn)了腹側(cè)區(qū)域的激活，而我們改進(jìn)后的圖片沒有引起腹側(cè)區(qū)域激活。因此我們推斷：背側(cè)視覺通路或許在立體

51、視覺處理中發(fā)揮著主要的作用，而腹側(cè)視覺通路僅僅抽取了立體圖中的形狀信息。我們的被試普遍反映正視差要比負(fù)視差的立體圖難感知，大視差要比小視差難感知。因此我們推斷：兩幅視網(wǎng)膜圖像越難以被感知，大腦激活區(qū)顯示出越強(qiáng)的響應(yīng)。觀察立體影視刺激的連接度問題通過(guò)比較不同腦區(qū)之間的神經(jīng)活動(dòng)的時(shí)間相關(guān)性，得到功能性腦網(wǎng)絡(luò)連接，而腦區(qū)之間的時(shí)間相關(guān)性強(qiáng)弱表示了腦功能區(qū)之間連接的強(qiáng)弱。通過(guò)解剖學(xué)結(jié)構(gòu)之間的連接(DTI和DSI)研究搞清楚神經(jīng)系統(tǒng)在連接過(guò)程中如何工作的。在很高空間分辨率條件下，兩種有可能一致。用fMRI開展的功能性連接采用fMRI手段獲得腦區(qū)的神經(jīng)活動(dòng)信號(hào)，相比其它方法它有更好的空間定位性。對(duì)于靜息狀

52、態(tài)和任務(wù)狀態(tài)下的BOLD信號(hào)的數(shù)據(jù)采集，都是通過(guò)EPI序列做連續(xù)掃描。然后構(gòu)建出不同腦區(qū)之間的功能連接。有兩種方法來(lái)分析功能數(shù)據(jù)1.用 Independent component analysis等統(tǒng)計(jì)學(xué)方法，在數(shù)據(jù)驅(qū)動(dòng)條件下分析時(shí)空信號(hào)，確定功能網(wǎng)絡(luò)。2. Seed-based/Region of interest 分析感興趣區(qū)和其它區(qū)域之間的關(guān)系，揭示這個(gè)功能區(qū)相關(guān)性質(zhì)。功能性連接和疾病的關(guān)系目前解決的只是粗連接上出問題的疾病，例如：老年癡呆癥：連接會(huì)減弱 Li, R (2012) AJNR Am J Neuroradiol.自閉癥：連接會(huì)增強(qiáng) Hulvershorn (2011) Brain Imaging Behav.精神分裂癥：連接網(wǎng)絡(luò)紊亂 Venkatara