神经影像与腰穿教学.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,基础篇,临床常用的神经影像技术,计算机断层成像（,CT,）,：,普通,CT,+C,CTA,CTP.,磁共振成像（,MRI,）,:,T,1,WI,T,2,WI,+C,Flair,MRA,MRV,DWI,PWI,DTI,SWI,BOLD.,头颅和脊柱,X,线片,数字减影血管造影（,DSA,）,Head CT,Hounsfield Unit(HU)CT值,Different substances have different relative densities and thus,different Hounsfield units,不同组织有不同的相对密度，不同的,CT,值,Air:-1000 HU,Fat:-50 HU,Water:0 HU,Soft tissue:+40 HU,Blood:+40-80 HU,Stones:+100 to+400 HU,Bone:+1000 HU,Therefore,if youre not sure what youre looking at,measure its Hounsfield Unit!,当难以明确组织成分时，可以通过测量,CT,值来帮助,Windowing,The human eye can only perceive 16 shades of gray,The CT scanner records levels of gray far beyond what the eye can see,Therefore,to interpret images,we have to limit the number of Hounsfield units shown(windowing),The computer then converts this set range of HU into shades of gray we can see,Windows&levels 窗宽/窗位,Window width:,The range of HU of all tissues of interest,Tissues in this range will be displayed in various shades of gray,Tissues with HU outside the range are displayed as black or white,Window level:,The central HU of all the numbers in the window width,Windowing,+400,+300,+200,+100,0,-100,-200,-300,-400,Wide Window,Narrow Window,Hounsfield Units,Window examples,BRAIN window,W:80 L:40,BONE window,W:2500 L:480,SUBDURAL window,W:350 L:90,In head CT,3 windows are commonly used,Previous studies,以往的检查结果,Always check for any previous scans for comparison,Findings can be very subtle,A good way to spot them is to look for changes between the current and previous scans,Even old chest and abdominal films can give you clues to possible brain pathology,ie.Brain mets from lung cancer,Regions to inspect,采用固定的阅片顺序：由内向外,Midline structures&symmetry,中线结构,/,结构对称,Ventricles,脑室,Cisterns,脑池,Brain parenchyma,脑实质,Sulci,脑沟,Sinuses,鼻窦,Bones,骨,Skin/soft tissue,皮肤,/,软组织,1.Midline structures,Identify:,(,click,on the names to see their location),Falx Cerebri,大脑镰,Pineal gland,松果体,(,常常表现为钙化,),Great vein of Galen,Galen,大静脉,Fornix,穹窿,Midline shift 中线移位,Evaluate for midline shift:,Find a slice where the 2 lateral ventricles are prominent,Draw a vertical line down the middle joining the falx cerebri anteriorly&posteriorly,The septum between the lateral ventricles,偏移不应该超过,5mm,Midline shift examples,A right-sided abscess is causing a midline shift to the left,A left-sided tumor is causing a midline shift to the right,L,L,R,R,Click me,to see shift,Click me,to,see,shift,2.Ventricles 脑室,Third ventricle,第三脑室,Fourth ventricle,第四脑室,Identify:,(,click,on the names to see their location),Lateral ventricles x 2,侧脑室,Cerebral aqueduct,导水管,Ventricles 脑室,Evaluate for any changes in,Symmetry,对称性,Size,大小,Shape,形状,Density,密度,A displaced ventricle is often the product of mass effect or atrophy,Common pathology:,(,click,on name to see an example),Hydrocephalus,脑积水,Intra-ventricular Hemorrhage,脑室内出血,Mass effect,占位效应,Atrophy,萎缩,Ventricles,3.,Cisterns,Identify:,(,click,on the names to see their location),Suprasellar cistern,鞍上池,Ambient cistern,环池,Prepontine cistern,桥前池,Cisterna magna,枕大池,Cisterns,Evaluate for any changes in,Symmetry,对称性,Size,形状,Density,密度,Cisterns often contain,blood,with subarachnoid hemorrhage,Cisterns can fill with,pus,（脓）,in the setting of meningitis,4.Brain parenchyma 脑叶,First,identify the major lobes:,(,click,on names to see their location),Temporal lobe,Occipital lobe,Frontal lobe,Parietal lobe,Brain Parenchyma-Brainstem,Then identify:,(,click,on the names to see their location),Pons,Cerebellum,Midbrain,Medulla,Brain parenchyma Deep structures,Lastly,identify the deep structures:,(,click,on the names to see their location),Thalamus,Lentiform Nucleus,Caudate,Corpus Callosum,Internal capsule,External capsule,Look for mass lesions,(,click,on the names to see example),Abscess,脓肿,Neoplasm,肿瘤,Parenchymal masses,Note how the tumor becomes bright with contrast,Also note the surrounding dark area of edema,Note the ring enhancing lesion consistent with that of an abscess,Acute Infarct,The middle cerebral artery(MCA),becomes,hyperdense,due to occlusion,The usual border between grey and white matter is,lost,due to vasogenic edema,Hyperdense,MCA sign,急性梗死的早期征象,Loss of gray-white differentiation,Click me,to see,Click me,to,see,Chronic Infarct,Then,look for signs of,chronic infarction,:,Mild midline shift to the right due to atrophy,Retractment of parenchyma from skull due to atrophy,Focal area of hypodensity,Acute Infarct,急性脑梗死,3 hours after onset,4 days later,Intracranial artery territories,Microangiopathic,change,微血管改变,You may encounter the term“microangiopathic change”in reports and wonder what it is,Microangiopathic change refers to age-related white matter ischemia due to microvessel disease,Very commonly seen in the elderly,Its clinical significance is still not known,Microangiopathic change,Normal,Types of Hematoma,Look for evidence of a bleed:,Subdural Hematoma,Due to tear of bridging veins,Look for,crescentic shape,along brain surface,Crosses suture lines,Epidural Hematoma,Due to rupture of middle meningeal artery,Associated with skull fractures,Look for,biconvex,lenticular,shape,Does not cross suture lines,Subdural vs.Epidural,SUBDURAL,EPIDURAL,Note the cresentic shape,Note the lenticular shape,Click me,to see shape,Click me,to see shape,Subarachnoid Hemorrhage,Blood in subarachnoid space,Blood in sulci,Blood in ventricle,Look for a subarachnoid hemorrhage,Due to aneurysm rupture,trauma,or AVM,Blood in the,subarachnoid space,and/or,ventricles,Blood can often first be seen in the inter-peduncular cistern,(Normal),Intraparenchymal Hemorrhage,Look for intraparenchymal hemorrhage:,blood(acute,subacute,or chronic)located in brain parenchyma,surrounding area of edema may also be seen,Usually caused by hypertension,Hemorrhage timeline,If you see a bleed,try to assess if its new or old:,ACUTE bleed(3 days),Hyperdense,(80-100 HU)relative to brain,Caused by protein-Hb component,Can be hard to spot if hemoglobin is low(2 weeks),Hypodense,(40 HU),relative to brain,Density of blood over time in a subdural hematoma,Acute,(14 days),Hyperdense blood,Isodense blood,Hypodense blood,5.Sulci(脑沟),Central sulcus,Precentral sulcus,Sulci,Sylvian fissures,外侧裂,Postcentral sulcus,Identify:,Sulci,Remember that sulci will become deeper and more prominent with age,Look for,blood,in the sulci&Sylvian Fissure which are indications of a,subarachnoid bleed,Acute blood in Sylvian fissure,Acute blood in sulci,6.Sinuses,Switch to,Bone Window,to better evaluate the sinuses,Identify:,(,click,on the names to see their location),Ethmoid Sinus,Sphenoid Sinus,Superior Saggital Sinus,Frontal Sinus,Maxillary Sinus,Sinuses,Evaluate for any sinusitis:,fluid in sinuses,(notice the air/fluid level),normal,sinusitis,Sinuses,Also look for any:,Mucosal thickening,Blood in sinuses,(especially with history of trauma),Polyps or mucous retention cysts,7.Bone,Stay on the,Bone Window,and look at the bones now,Identify:,(,click,on the names to see their location),Skull,Sutures,Mastoid air cells,Bone,Evaluate for any:,Fractures,Surgical changes,(ie.craniotomies),8.Skin&Soft tissue,Evaluate for any:,Surgical changes,Sub-galeal hematoma,Foreign body,Recap,Begin with the basic identification,Remember to check for previous scans,Check the technique,Look at each region of the brain systematically,We started from the middle and worked out:,Midline structures,Ventricles,Cisterns,Brain parenchyma,Sulci,Sinuses,Bones,Skin/soft tissue,Recap,In each area,identify the major anatomy,Then look for findings,Below is a list of important things not to miss:,Midline,:,midline shift,Ventricles,:,blood,and,mass effect,Cisterns,:,blood,and,pus,Parenchyma,:signs of,ischemia,and/or,bleeding,Sulci,:for,blood,Sinuses,:signs of,sinusitis,Bones,:,fractures,Soft tissue,:,hematoma,CASES,Case#1,Ms.EW is an 80 y/o female presenting with:,Expressive aphasia/apraxia,表达性失语,/,失用,Mild right facial droop,轻度右侧口角下垂,Atrial fibrillation,房颤,A non-contrast CT scan of her brain was performed,R,L,Your analysis,What are your findings?,What is your impression?,What would be your top diagnosis?,Normal,R,L,Case#1-Answer,Mrs.EW had an infarction of her,Left Parietal Lobe,The location is consistent with,MCA,infarction,The cause was emboli related to her atrial fibrillation,Case#2,Ms.YM is an 45 y/o male presenting suddenly with,:,Expressive aphasia/apraxia,表达性失语,/,失用,Consciousness disorder:insomnolence,Right side hemiplegia,A non-contrast CT scan was performed at 3hs after onset,诊断：,Acute cerebral infaction,R,L,Treatment,Thrombolysis:rt-PA 0.9mg/kg(90mg),10%i.v.within 1 min,90%i.v.gtt.within 1 hour,Brain protection:,自由基清除剂,Another head CT scan was performed at 24hs after onset,R,L,Following treatment,Decreasing the ICP:dehydration,Neurosugical consultant,Operational therapy,Case#3,Mrs.Cui Jinshi is a 56 y/o female presenting with:,A sudden onset headache while eating,nausea&vomiting,恶心呕吐,No history of trauma,Otherwise well,PE:(-),A non-contrast CT scan of his brain is performed,诊断：,subarachnoid hemorrhage,R,L,CTA,R,L,R,L,R,L,Head MRI,正常脑结构MRI像,T1WI,T2WIFLAIR DWI,常用的序列,MR信号表现,脑,白,质,脑,灰,质,脑,脊,液,脂,肪,颅,板,板,障,脑,膜,血,管,钙,化,T,1,WI,高,中,低,高,低,高,低,低,低,T,2,WI,低,中,高,中,低,中,低,低,低,男,58,岁，急性头痛，言语不清,2,天。,1,年来反复发作；失语，伸舌偏右，右半身肌力差。,(1,2)T,1,左颞枕叶大片长,T,1,信号，左侧基底节点状长,T,1,信号；,信号；,(3,，,4,，,5)T,2,像上述病灶呈长,T,2,信号,；,诊断：左颞枕叶脑梗塞,(,陈旧性,),；左侧基底区腔隙性脑梗塞,(,病灶新,),。,急性脑梗死,4,天后,4,天后,MR,扫描,当天,T,1,T,2,T,2,脑梗死,脑出血MRI信号变化,T,1,WI,T,2,WI,超急性期,（,4,周）,低,高,(1)T1,右侧外囊区有一环状短,T1,信号，中心呈等,T1,，外周有稍长,T1,信号，占位性明显；,(2)T2,像上述病灶呈长,T2,信号，中心呈等,T2,，外周有水肿,；,(3,，,4,，,5),增强，血肿呈环状强化。,男,52,岁，急起头痛，口角歪斜，左侧肢体无力,2,天。伸舌偏右，左侧肢体肌力,IV,。,脑出血,男,24,岁，头晕伴视物成双,1,周余,。,(1),脑干片状高信号，界清，脑干不膨大，第四脑室顶受压；,(2)T2,像上述病灶呈长,T2,信号,；,(3,4),增扫病灶周边强化。,脑干出血,弥散加权成像（,DWI,）的优点,可以在梗死后数分钟内显示超急性期缺血病灶,能发现,T2,加权像无法识别的小的皮层梗死或脑干梗死,区别新旧梗死灶,能发现开展不同诊断性或治疗性措施后出现的无症状梗死灶,显示近半数临床表现为,TIA,患者的相关梗死灶,Case,Mr.Li J-Sh,a 56 ys male,presenting with:,视物不清,3,天，右侧肢体麻木,2,天，右侧肢体活动不灵伴言语不清,1,天,.,P.E.,神清，不完全运动性失语，双眼右侧同向性偏盲，右侧肢体肌力,3,级，右侧面部及右偏身痛觉减退，双侧病理征（,+,）,R,L,R,L,MRA:vertibrobasal a.system,左大脑后,A,未显影,基底动脉,右大脑后,A,R,L,提高篇,大脑的静脉系统,(CE-MRV),绿色：上矢状窦,浅蓝：下矢状窦,暗紫：直窦 橙色：窦汇,深蓝：横窦 黄色：乙状窦,淡紫：颈静脉及球部,不同颜色标注皮层引流静脉的引流区域,绿色：汇入上矢状窦,黄色：汇入基底硬脑膜窦,蓝色：汇入横窦,用不同的颜色标注深部静脉的引,流区域：,紫色：大脑内静脉、,Galen,静脉,蓝色：髓静脉,1,、丘脑纹状静脉,2,、透明隔静脉,3,、大脑内静脉,4,、基底静脉,5,、,Galen,静脉,深静脉系统,(CE-MRV),Questions,？,腰椎穿刺术,脑脊液生理,保护、支持、营养作用,总量,110-120ml,每天更新,3-4,次，病理状况下每日可分泌,5000-6000ml,血脑屏障,适应症,诊断性穿刺,中枢神经系统炎性病变，各种脑炎和脑膜炎,怀疑,SAH,而头,CT,不能证实或与脑膜炎鉴别困难,（脑出血、脑血栓）,脑膜癌瘤病的诊断,中枢神经系统血管炎、脱髓鞘、颅内转移瘤,脊髓病变、多发神经跟病变的诊断及鉴别,怀疑颅压异常,脊髓造影,治疗性穿刺：鞘内药物治疗,麻醉,禁忌症,颅内压升高伴明显的视乳头水肿,后颅窝占位,穿刺部位化脓性感染或脊椎结核,脊髓压迫症的脊髓功能已处于功能临界状态,血液疾病或药物导致有出血倾向者，血小板,5000/mm,3,开放性颅脑损伤,并发症,低颅压头痛：腰穿后48小时内发生率36.5%,脑疝：循环呼吸衰竭,穿刺部位疼痛,局部血肿、感染,脑脊液漏,麻药过敏,其他：如穿刺针折断,NEJM 腰穿视频,Questions,？,