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1、脑血管病HEMATOMA IN CT 血肿的CT表现,Inatially,high attenuation.higher attenuation than brain but less than bone(35-80 Hu).Over several days to weeks,gradual decrease in attenuation.Hypodensity to cystic cavity.,ACUTE HEMATOMA急性血肿mild edema轻度水肿,SUBACUTE HEMATOMA亚急性血肿,CHRONIC HEMATOMA慢性血肿,HEMATOMA IN MRI,Acute
2、(deoxyhemoglobin)急性期（脱氧血红蛋白）T1WI:Isointensity to mild hypointense 等到低信号 T2WI:Very high hypointense高信号Early subacute(intracellular methemoglobin)亚急性早期（细胞内高铁血红蛋白）TIWI:Increasing hyper-intensity T2WI:Hypo-intensity initially,changing to isointense,HEMATOMA IN MRI,Late subacute(Extracellular methemoglob
3、in)亚急性晚期（细胞外高铁血红蛋白）T1WI:Hyper-intensity T1WI高信号 T2WI:Hyper-intensity centrally T2WI中心高信号 Chronic(Hemosiderin-laden macrophages remain)慢性期（含铁血黄素）A thin,hypointense rim appears TIWI:Hypo-intensity decreases over time T2WI:Rim of hypo-intensity increases,central hyperintensity decrease,leaving only a l
4、ow signal intensity scar,ACUTE HEMOTOMA:DEOXYHEMOGLOBIN,ACUTE HEMATOMA,SUBACUTE HEMOTOMA,CHRONIC HEMATOMAHEMOSIDERIN慢性期（含铁血黄素）,CEREBRAL INFARCTION脑梗塞,The most common etiology of cerebral ischemia or infarction in the adult is occlusion of an artery resulting from either thrombus formation or embolis
5、m,with atherosclerosis the most common underlying cause在成人，脑缺血或脑梗塞最常见病因是动脉闭塞，通常是血栓或动脉粥样硬化。Carotid artery disease is especially common颈动脉疾病尤其常见。,CEREBRAL INFARCTION,ISCHEMIC INFARCTION缺血梗死HEMORRHAGIC INFARCTION 出血性梗死形成LACUNAR INFARCTION腔隙梗塞,Imaging appearance,CT is often normal in the first few hours
6、 of infarction or ischemia,sometimes for up to 24 hours.在梗死或缺血的最初几个小时，CT上通常表现为正常，有时甚至至24小时。Subtle effacement of sulci may be an important early clue to infarction.脑沟的细微消失可能是梗死的重要征象。,Imaging appearance,Some of the very earliest signs of MCA or internal carotid artery infarction on CT.A.Loss of the in
7、sular strip of gray matter(loss of gray-white matter distinction)B.Low attenuation in the ipsilateral caudate head if the perforating arteries are also affectedC.A high attenuation MCA,representing clot within the artery,Imaging appearance,With time,there is increasingly well-defined low attenuation
8、 in an area of infarction because of cytotoxic and vasogenic edema.Mass effect 占位效应Thrombotic infarctions often involve a large vascular distribution,embolic infarctions usually involve only a portion of a major arterial territory.The typical vascular distribution,often wedge-shaped and extending to
9、 the cortex.,Imaging appearance,MRI is more sensitive than CT for early changes of infarction,but in the first few hours after vascular occlusion,MRI also may appear normal.DWI,PWI may provide earlier evidence of infarction.对梗死的早期变化MRI较CT敏感，但是在血管闭塞最初的几个小时，MRI也可是正常的。DWI，PWI能提供更早的梗死证据。T1WI-low signal
10、intensity低信号强度 T2WI-high signal intensity高信号强度 FLAIR-high signal intensity高信号强度,Loss of the insular strip of gray matter,Subtle effacement of sulci脑沟的微小消失,ACUTE INFARCTIONLOW DESITY and MASS EFFECT低密度和占位效应,SUBACUTE INFARCTIONLOW DENSUTY AND GYRIFORM ENHANCEMENT,CHRONIC INFARCTIONLOW DENSUTY and ATRO
11、PHY,ACUTE INFARCTION LONG T1、LONG T2 and MASS EFFECT,T1WI T2WI,Flow-void effect 流空效应,CHRONIC INFARCTION,GYRIFORM ENHANCEMEMT,HEMORRHAGIC INFARCTION出血性梗死形成,LACUNAR INFACTION腔隙性梗死,hyperacute infarction梗死的超急性期,Acute infarction shows decreased diffusion,chronic infarction showing increased diffusion.,Cl
12、inical DWI can identify acute ischemic lesions that are not apparent on T2-Weighted MR images.DWI能分辨出无法在T2上显示的急性缺血部分,INTRACRANIAL INFECTION颅内感染,The key diagnostic evidence in suspected meningitis comes from cerebrospinal fluid analysis and culture,imaging has an adjunctive role only.脑膜炎的主要诊断依据是脑脊液分析
13、和培养，图像仅仅是从属地位。Imaging may detect processes such as abscess and encephalitis,may localized focal conditions,and may help demonstrate the progress or resolution of infection图像可以显示脓肿和脑炎的征象，可帮助确定炎症的进展或消退。,INTRACRANIAL INFECTION,Bacterial meningitis is common and is associated with serious morbidity.细菌性脑
14、膜炎是常见的，有较高的死亡率。Inflammatory exudates may obscure the subarachnoid cisterns on noncontrasted CT,whereas meningeal enhancement may be observed on CT or MRI following intravenous contrast material administration.(meninges thickening)在非对比的CT上炎性渗出物可以使蛛网膜下腔模糊，而给予静脉造影剂后脑膜增强就可以在CT或MRI上观察到（脑膜变厚）Lack of visib
15、le contrast enhancement does not exclude meningitis.缺少可见的对比增强不能排除脑膜炎。,INTRACRANIAL INFECTION,Imaging is important for evaluating complications of meningitis.影像学评估脑膜炎的并发症是重要的 Communicating hydrocephalus交通性脑积水 Vasculitis or vasospasm血管炎或血管痉挛 Ischemia or infarction缺血或梗死 Subdural fluid collection硬膜下积液 S
16、pread of infection(e.g.ventriculitis)感染扩散（脑室炎）,ABSCESS 脑脓肿,Abscess of the brain usually begins as cerebritis.Cerebritis is initially detected as an area of low attenuation edema on CT or of high signal intensity on T2WI and low signal intensity on T1WI MRI.With time cerebritis progresses to abscess.
17、脑脓肿通常起始于脑炎。脑炎被最早发现是在CT上是低密度的水肿区或在MRI上T2高信号影，T1低信号影。随时间推移，脑炎可发展为脑脓肿。,ABSCESS,Abscess wall is usually fairly thin and uniform,high density on CT,low signal intensity on MRI脓肿壁在CT上通常较薄，厚薄不甚不一致，呈高密度，在MRI上则呈低信号。Surrounding edema周围水肿Central fluid attenuation or signal intensity 中心液化区呈水样信号强度Well-defined ri
18、ng-like pattern of enhancement 边界清楚的环状强化,ABSCESS,Abscess wall is usually fairly thin and uniform,high density on CT.,ABSCESS,Abscess wall is usually fairly thin and uniformlow signal intensity on MRI,The differential diagnosis between cerebral abscess and cystic tumor脑脓肿和囊性瘤的鉴别诊断,Multiform glioblast
19、oma多形恶性胶质细胞瘤,Abscess脓肿,Bulk phase容积相,Hydration layer水,TUBERCULOUS MENINGITIS结核性脑膜炎,TUBERCULOUS MENINGITIS结核性脑膜炎,meninges thickening脑膜增厚并强化,Cranial Trauma,Skull颅骨 Penetrating injury穿透性损伤 Closed head injury闭合性头部损伤Hemorrhage出血Mass effect占位效应Shift of intracranial structure颅内结构的移位Secondary effects:继发效应 i
20、nfarction,hydrocephalus梗死，脑水肿,脑挫裂伤Gunshot枪弹伤,2.Intracranial hemorrhage颅内出血,Extra-axial hematoma Subdural hematoma硬膜下血肿 Epidural hematoma硬膜外血肿 subarachnoid hemorrhage蛛网膜下腔血肿Intraventricular hemorrhage脑室内血肿Intra-axial hematoma,Hematoma血肿,Acute hemorrhage is usually dense(bright)on CT.急性出血通常在CT上是高密度（亮的
21、）On MRI,the signal of hematoma is depended.而在MRI上，血肿信号是不确定的,3.Epidural Hematoma硬膜外血肿,Usually result from arterial bleeding,often from laceration of the middle meningeal artery by a squamosal temporal bone fracture.However,venous or mixed sources also may cause epidural hematoma.通常来自动脉出血，常见的是颞骨鳞部骨折导致
22、的脑膜中动脉破裂。但是静脉或者混合来源的也可以导致硬膜外血肿。,Epidural Hematoma硬膜外血肿,Extra-axialDo not cross sutures不越过颅骨缝Usually with convex margins or a lentiform shape通常是凸面的或者是透镜状Mass effect占位效应Fracture骨折,EPIDURAL HEMATOMA硬膜外血肿,lentiform shape凸透镜状,EPIDURAL HEMATOMAS,Pneumatosis积气症,4.Subdural Hematoma硬膜下血肿,Usually result from
23、venous bleeding 通常来自静脉出血The most common location is over the cerebral convexities 最常见的位置是脑的凸面,Subdural Hematoma硬膜下血肿,Extra-axialMay cross sutures可以越过颅骨缝Usually extending widely across the convexity and appear crescentic(new moon,luniform)通常越过凸面，显示为新月形Mass effect占位效应Skull fracture(sometimes)颅骨骨折（有时）,
24、SUBDURAL HEMATOMA,extending widely across the convexity横跨脑的凸面,SUBDURAL HEMATOMA,SUBADURAL HEMATOMA,先天发育畸形DISPLASIA OF CORPUS CALLOSUM胼胝体发育不良,May be an isolated anomaly or part of a more extensive malformation complex.May be partial or complete agenesis.分为部分性或完全性The interhemispheric lipomas are often
25、 bulky in the absence of the corpus callosum.,DISPLASIA OF CORPUS CALLOSUM,Lateral ventricles have a more parallel configuration,with crescent-shaped frontal horns.Occipital white matter is undeveloped.Dilatation of the atria and occipital horns.The third ventricle is usually dilated with upward her
26、niation to the interhemispheric fissureAbsence of corpus callosun.,DISPLASIA OF CORPUS COLLUSUM,Lateral ventricles have a more parallel configuration,with crescent-shaped frontal horns侧脑室平行，新月形前角,DISPLASIA OF CORPUS COLLUSUM,Absence of corpus callosun,课后复习题：1、脑梗塞的影像学特点有哪些？2、脑出血的影像学特点有哪些？3、颅内感染的影像学特征。,
