《中枢神经系统影像》PPT课件.ppt

中枢神经系统影像学表现 Neuroimaging of the Central Nervous System,学习内容：颅脑、脊髓、血管,1. 不同成像技术的特点和临床应用,2. 正常影像学表现,3. 基本病变影像学表现,4. 影像新技术,不同成像技术的特点和临床应用,1. X线图像的特点,2. CT图像的特点,3. MR图像的特点,4. DSA检查,中枢神经系统正常影像学表现 Anatomy of the Central Nervous System with Neuroimaging,正常影像学表现,颅脑,头颅X线平片,颅骨最基本的影像学检查方法 显示颅骨骨质改变，是诊断颅骨骨折 和骨缝分离的有效方法,特点,局限性,仅提示病变存在，但不能确诊 临床表现明显但无异常发现,计算机体层摄影（CT）,CT图像的特点,局限性,断层图像不利于器官结构和病灶的整体显示 CT检查对疾病的定性诊断仍有一定限度 CT检查使用X线，具有辐射性损伤,是目前常用的影像学检查方法 常规CT图像采用横断层图像，克服了普通X线检 查各种组织结构重叠干扰的影响 分辨率高，对比度强,CT定位像,扫描基线： 采用眦耳线（即眼外眦与外耳道中心的联线），层厚8-10mm，共9-12层,大脑： 额叶 颞叶 顶叶 枕叶 基底节 丘脑,幕上,小脑：半球、蚓部 脑干：中脑 延髓 桥脑,幕下,脑实质,双侧脑室 第三脑室 第四脑室,脑室系统,鞍上池 环池 桥小脑池 枕大池 外侧裂池 大脑纵裂池,脑池系统,脑室脑池系统,磁共振成像（MRI）,优势： 组织分辨率高 任意平面成像 多种参数、序列成像,缺点： 扫描时间长 MRI对钙化不敏感 个别患者有幽闭恐惧症， MRI检查有禁忌症,中枢神经系统基本病变 Common Presentation of Neurological Disease,XPlain,颅高压征：颅缝增宽，脑回压迹增深 颅骨：破坏，增生 蝶鞍：扩大、吸收、变形 钙化：,DSA,颅内占位使血管移位 脑血管形态改变,计算机体层摄影（CT）,密度异常: 低密度、等密度、高密度、混杂密度 增强特征: 不强化、轻中度强化、明显强化 脑结构改变: 占位效应 脑萎缩 脑水肿、脑积水 颅骨改变： 骨质破坏、增生、吸收、 骨折,计算机体层摄影（CT）,常规CT通过密度 的变化反应信息,0,-1000,+1000,-10,-20,-30,-40,-60,-50,-70,-80,-990,-980,10,20,30,40,50,60,70,990,980,970,960,水,空气,骨,-90,脂肪,软组织,1）低密度病变：,脑水肿 脑梗塞 、脑软化 脑肿瘤 炎性病变 慢性血肿,颅内疾病的平扫基本CT征象,2）等密度病变：,脑肿瘤 脑梗塞的等密度期 颅内血肿的等密度期 (亚急性出血),颅内疾病的平扫基本CT征象,3)高密度病变,颅内血肿 钙化 肿瘤 炎性肉芽肿,颅内疾病的平扫基本CT征象,4) 混杂密度病变,脑肿瘤（颅咽管瘤、恶性胶质瘤、畸胎瘤） 出血性脑梗塞 炎性病变,颅内疾病的平扫基本CT征象,磁共振成像（MRI）,MRI通过磁共振信号的变化反应信息,人体不同器官的正常组织与病理组织的 T1和T2是相对恒定的，而且它们之间有一定的差别，这种组织间驰豫时间上的差别，是MRI成像基础,基本病变信号特征,目的:,病灶强化方式: 明显强化、中度强化、 轻度强化、不强化,显示平扫未发现病灶；了解病灶血供情况；区别肿瘤和瘤周水 肿；有利诊断和鉴别诊断,增强检查,增强检查,CT: 对比剂:含碘非离子型造影剂 剂量:50-100ml 注射速率：1-2ml/sec 注射方式:人工手推或高压器注射,MRI: 对比剂:顺磁性造影剂：Gd-DTPA 剂量:15-30ml 注射速率： 1-2 ml/sec 注射方式:人工手推或高压器注射,脊髓和椎管内病变,Spine Common imaging method,* Plain film (平片) * Myelography（脊髓造影） * Spinal angiography （脊髓血管造影） * Computed tomography * Magnetic resonance imaging,SPINE,脊髓 MRI,检查方法 以矢状面为主，辅以横断面和冠状面，确定病变的三维关系，方法有平扫和增强 影像观察和分析 正常脊髓灰质、白质及脑脊液信号特点与颅内脑质及脑脊液一致,脊髓,检查方法 以矢状面为主，辅以横断面和冠状面，确定病变的三维关系，方法有平扫和增强扫描 影像观察与分析 正常脊髓灰质、白质与脑脊液信号特点与颅内脑实质与脑脊液信号一致,脊髓基本病变,脊髓外形异常：脊髓增粗、萎缩 脊髓密度（信号）异常：局限性、弥漫性 蛛网膜下腔形态异常：,可分为出血性和非出血性损伤，MRI可直观地显示脊髓损伤的部位、范围、类型和程度 脊髓水肿：T1WI等、低信号，T2WI高信号 出血：T1WI和T2WI均为高信号 脊髓软化、囊变、空洞： T1WI低信号，T2WI高信号 脊髓萎缩：脊髓变细,脊髓损伤,脑血管成像 (Cerebral vascular angiography),DSA(digital substraction angiography) CTA(computed tomography angiography) MRA(magnetic resonance angiography),DSA (数字减影血管造影),颈内动脉、椎动脉、颈外动脉血管显示 Vertebrobasilar artery (VA) 椎基动脉 Internal carotid artery (ICA) 颈内动脉 Extenal corotid artery (ECA) 颈外动脉 Willis环: 大脑前动脉, 大脑后动脉, 前后交动脉, 颈内动脉末端 诊断动脉瘤、动静脉畸形、肿瘤血供,Vertebrobasilar artery (VA) 椎基动脉 Internal carotid artery (ICA) 颈内动脉 Extenal corotid artery (ECA) 颈外动脉 Willis环: 大脑前动脉, 大脑后动脉,前后交通动脉, 颈内动脉末端,Advantage of 64 slice VCT：CTA,Diseases of CNS,Vascular diseases 血管病变：hemorrhage, infarct (ischemic infarct, hemorrhagic infarct, lacunar infarct) Infectious diseases 感染性病变 Vascular Malformality 血管畸形,Vascular diseases 血管疾病,Acute Intracerebral Hemorrhage 急性脑出血,临床表现 Clinical findings: Hypertension,Vascular malformation, Aneurysm, Hematopathy,Tumor 影像学表现 Imaging findings CT: Location, Density, Secondary signs MR: Location, Signal, Secondary signs 鉴别诊断 Differential Diagnosis,Evolution of Hematoma on CT 血肿在CT上的演变,Acute hematoma: 4 hrs after ictus 急性脑血肿：发病后4小时,4 days after ictus 发病后4天,3 months after initial CT 首次CT后3个月,Evolution of Hematoma on CT 血肿在CT上的演变,10,40,50,60,70,80,20,30,1,2,3,4,5,6,7,8,9,10,11,12,13,14,ISODENSE,HYPERDENSE,HYPODENSE,Decreasing Density of Hematoma血肿密度的下降,Density Compared to Cortex,Time in Days,Intracerebral Hemorrhage Imaging findings,CT: 1)Location: 高血压性脑出血基底节区多见 2) Density: 急性期高密度，随时间推移密度渐减低 3) Secondary signs：占位效应明显，可破入脑室、蛛网膜下腔，继发阻塞性脑积水 MRI：不同的出血时间信号不同，反映血肿内血红蛋白、氧合血红蛋白、脱氧血红蛋白、正铁血红蛋白、含铁血黄素的演变过程 超急性期（6h) : 氧合血红蛋白（T1WI等，T2WI高信号） 急性期（7-72h）：脱氧血红蛋白（T1WI等或略低，T2WI低信号） 亚急性期（3 d-2W）: 正铁血经蛋白（T1WI高信号，T2WI高信号） 慢性期（2W后）：含铁血黄素（ T1WI低，T2WI低信号）,Blood Products 血肿,Acute hematoma well seen on CT 急性血肿宜用CT观察,Subacute and chronic hematoma better evaluated on MRI 亚急性和慢性血肿宜用MRI观察,Primary (hypertensive) bleeds occur in the basal ganglia; for bleeds at other locations, hunt for a cause 高血压出血常在基底节；其它部位的话要寻找病因,Brain Infarction 脑梗塞,临床表现 Clinical findings: Thrombosis, Embolism, Hypotension , High pour-point state 影像学表现 Imaging findings CT MR: Ischemic infarct ;Hemorrhagic infarct; Lacunar infarct 鉴别诊断 Differential Diagnosis,左侧大脑前动脉闭塞致左侧额上回脑梗塞：CT平扫示左侧额上回长条状低密度区（），边界较清，轻度占位表现,左侧枕叶大脑后动脉梗塞 ：CT平扫示左侧枕叶低密度区，未见明显占位表现,左侧大脑中动脉梗塞：CT平扫示左颞顶叶大片低密度区，边界清晰，密度与脑脊液相似，左侧脑室扩大，中线结构无移位。,右侧额后顶前出血性脑梗塞：CT平扫示右额顶叶大片低密度区内散在不规则高密度出血灶,Fogging effect 模糊效应: 缺血性脑梗塞2-3周时病灶变为等密度而不可见 Lacunar brain infarction 腔隙性脑梗塞：深部髓质小动脉闭塞所致，大小约10-15mm，好发于基底节、丘脑、小脑和脑干。 Hemorrhagic transformation after infarction 出血性脑梗塞：CT示在低密度脑梗塞灶内，出现不规则斑点、片状高密度出血灶。,Cerebral infarction imaging findings,CT: 24h内，CT可无阳性发现，或显示脑沟回模糊；动脉致密征；岛带征。 24h后，与闭塞血管供血区一致，同时累及皮层和髓质，呈底在外的三角形或楔形低密度，边缘不清，常并发脑水肿，病灶大时可出现轻度占位效应。 4-6周，边缘清楚、近于脑脊液密度的囊腔, 1个月后可出现脑萎缩。 出血性脑梗塞：扇形低密度梗塞区内出现不规则高密度出血斑。 腔隙性梗塞：好发于基底节区，因小的终末动脉闭塞所致，表现为直径小于15mm低密度灶，边缘清楚。 MRI：较早发现病变,Subcortical arteriosclerotic encephalopathy Bingswangers disease 皮层下动脉硬化性脑病,临床表现 Clinical findings 影像学表现 Imaging findings CT MR 鉴别诊断 Differential Diagnosis,Infectious diseases 感染性疾病,Pathogens : Bacterium , Virus , Fungi , Parasite Pathology : Meningitis , Encephalitis , Vein inflammation,Brain abscess 脑脓肿,临床表现 Clinical findings: Otogenic , Blood-borne , Traumatic , Cryptogenic 影像学表现 Imaging findings CT MR 鉴别诊断 Differential Diagnosis,Brain abscess Imaging finding on CT,CT 1、急性炎症期：平扫大片低密度灶，边界模糊，伴占位效应，增强无强化 2、化脓坏死期：平扫低密度区内出现更低密度坏死灶，增强呈不均匀强化 3、脓肿形成期：平扫见等密度环，内为低密度脓肿并可有气泡影；增强呈环形强化，其壁完整、光滑、均匀，或多房分隔,Brain abscess Imaging finding on MR,MR 1、脓腔呈长T1和长T2异常信号 2、增强呈薄壁环形强化，内外壁光滑,Tuberculosis, CNS,临床表现 Clinical findings 影像学表现 Imaging findings CT MR 鉴别诊断 Differential Diagnosis,Tuberculous meningistis and encephalitis Imaging findings,CT 平扫： 1、早期无异常发现 2、脑底池炎性渗出表现为脑底池密度升高 3、脑内结核：脑内以基底节区多见呈低或等密度灶 4、脑积水 增强：脑膜增厚强化，结核球呈结节状或环形强化,Tuberculous meningistis and encephalitis Imaging findings,MR 平扫： 1、脑底池T1WI信号升高，T2WI信号更高，抑水T2WI显示病灶更清楚，高信号 2、脑内结核球T1WI呈略低信号，T2WI呈低、等或略高混杂信号，周围水肿轻 3、脑积水 增强：脑膜明显增厚强化，结核球呈结节状强化或环状强化,cerebral cysticercosis imaging finding,分型：脑实质型；脑室型、脑膜型、混合型 CT：脑内多发低密度小囊，囊腔内可见致密小点状囊虫头节，囊虫死亡后呈高密度点状钙化 MR：脑内多发小囊，小囊主体呈长T1长T2信号，其内偏心结节呈短T1和长T2信号 增强：囊壁与头节可轻度强化,Vascular Deformality 血管畸形,Aneurysm 血管瘤,临床表现 Clinical findings: headache 影像学表现 Imaging findings CT: 1)Direct signs: no thrombosis ; part of thrombosis ; totally thrombosis 2) Secondary signs: subarachnoid hemorrhage, hematoma, hydrocephalus , encephaledema , infarct MR: DSA 鉴别诊断 Differential Diagnosis,Brain Arteriovenous Malformations 脑动静脉畸形,临床表现 Clinical findings 影像学表现 Imaging findings CT MR DSA 鉴别诊断 Differential Diagnosis,Traumatic Brain Injury- CT,Traumatic Brain Injury- Clinical Features,Signs and Symptoms of head injury can include any combination of the following: lose consciousness Vomiting Seizure Weakness Headache Inability to speak Amnesia 健忘症 ,CNS trauma Clinical Features - consciousness,No Loss of consciousness(L.O.C) (SDH， EDH?， Not DAI 弥漫性轴索损伤) Awake at the scene， Delayed LOC (SDH，EDH， Swelling， Not DAI) Transient LOC-Wake-up-Delayed LOC (“Classic” lucid interval for EDH) Continuous LOC Following Impact (“Classic” shearing / Diffuse Axonal injury DAI弥漫性轴索损伤),Immediate unenhanced head CT scan is the procedure of choice for diagnosis head injury Computed tomography (CT)： it is quick, accurate, and widely available Head CT scan can show location, volume, effect of the lesions of intracranial injuries.,Classification of Head Injury： - centripetal approach ouside to inside,Extracerebral injury: Scalp-hematoma 头皮血肿 Calvarium-skull fracture 颅骨骨折 Epidural hematoma (EDH) 硬膜外血肿 Subdural hematoma (SDH) 硬膜下血肿 Subarachnoid hemorrhage (SAH) 蛛网膜下腔出血 Intracerebral injury: Brain contusion (edema, hemorrhage) 脑挫伤 Intraventricular-hemorrhage（脑室出血）, 1. Skull fracture 2. Epidural hematoma 3. Epidural Hematoma 4. Subdural Effusion 5. Subarachnoid hemorrhage 6. Cerebral Cortical Contusion 7. Diffuse axonal injury 8. Sequelae of Head Injury,闭合性脑损伤的机制,冲 击 伤,作用力 接触力 惯性力,原因 直接碰撞 减速或 加速运动,脑损伤范围 局部 多处 弥散性,受伤时头部状态 固定不动 运动中,对 冲 伤,1. Skull fracture 骨折,部位 形态 与外界关系,颅盖骨折 颅底骨折 线性骨折 凹陷性骨折 粉碎性骨折 开放性骨折 闭合性骨折,分类,Linear fracture 线型骨折： Axial CT is not good for linear fracture Should carefully to identify the fracture line Depression fracture 凹陷型骨折： A more serious fracture Downward displacement of the skull bones presses directly on brain tissue and caused the injury CT is important for the fracture and other associated intracranial lesions Bone window to evaluate fracture,Skull fracture 骨折,CT,骨窗观察,线形骨折的临床表现,累及眶顶和筛骨：鼻出血眶周广泛淤血斑， “熊猫眼”征广泛球结膜下淤血斑、 脑膜、骨膜均破裂：脑脊液鼻漏 筛板或视神经管骨折：嗅神经或视神经损伤,累及蝶骨：鼻出血，脑脊液鼻漏 累及颞骨岩部：脑脊液耳漏、VII/VIII脑神经损伤 蝶骨、颞骨内侧部损伤：垂体/II-VI脑神经损伤 累及颈内动脉海绵窦部：颈内动脉海绵窦瘘 累及破裂孔或颈内动脉管：致命性鼻出血、耳出血,累及颞骨岩部后外侧：Battle征，乳突部皮下淤血 累及枕骨基底部：枕下肿胀、皮下淤血斑 枕骨大孔或岩尖后缘附近骨折：IX-XII脑神经损伤,颅底部线形骨折,颅盖部发生率高,颅前窝骨折 累及眶顶和筛骨，可伴有鼻出血、眶周广泛淤血(称“眼镜”征或“熊猫眼”征)以及广泛球结膜下淤血。如硬脑膜及骨膜均破裂，则伴有脑脊液鼻漏，脑脊液经额窦或筛窦由鼻孔流出。若骨折线通过筛板或视神经管，可合并嗅神经或视神经损伤。 颅中窝骨折 颅底骨折发生在颅中窝，如累及蝶骨，可有鼻出血或合并脑脊液鼻漏，脑脊液经蝶窦由鼻孔流出。如累及颞骨岩部，硬脑膜、骨膜及鼓膜均破裂时，则合并脑脊液耳漏，脑脊液经中耳由外耳道流出；如鼓膜完整，脑脊液则经咽鼓管流向鼻咽部而被误认为鼻漏。骨折时常合并有第、脑神经损伤。如骨折线通过蝶骨和颞骨的内侧面，尚能伤及垂体或第、V、脑神经。如骨折伤及颈动脉海绵窦段，可因颈内动脉海绵窦瘘的形成而出现搏动性突眼及颅内杂音。破裂孔或颈内动脉管处的破裂，可发生致命性鼻出血或耳出血。 颅后窝骨折 骨折线通过颞骨岩部后外侧时，多在伤后数小时至2日内出现乳突部皮下淤血(称Battle征巴特耳征)。骨折线通过枕骨鳞部和基底部，可在伤后数小时出现枕下部头皮肿胀，骨折线尚可经过颞骨岩部向前达颅中窝底。骨折线累及斜坡时，可于咽后壁出现黏膜下淤血。枕骨大孔或岩骨后部骨折，可合并后组脑神经()损伤症状。,What is Epidural hematoma？ 硬膜外血肿 EDH is a traumatic accumulation of blood between the inner table of the skull and the stripped-off dural membrane. What is Subdural hematoma？ 硬膜下血肿 SDH is a form of traumatic brain injury in which blood gathers within the inner meningeal layer of the dura.,dura,2 Epidural hematoma (硬膜外血肿),Direct trauma to cranium Fracture(90%) -Laceration （撕裂） of Meningeal A. and V. Location is 66% temporo-parietal（颞顶部） Temporal Bone (70-80%) lucid interval（中间清醒期 40%pts） Mortality （死亡率）of 15-30% 硬脑膜外血肿病人意识变化的典型特征是:昏迷一清醒一再昏迷,即意识障碍有“中间清醒期“,伤后有短暂的原发性昏迷,在血肿位形成前意识恢复,当血肿形成增大,颅内压增高可出现再次昏迷,硬膜外血肿（EDH）：颅内血肿积聚于 颅骨与硬膜之间,Epidural hematoma -CT,1 . Smoothly marginated, lenticular 透镜状, or biconvex 双凸homogenous hyperdense 高密度lesion 2. Rarely crosses the suture line because the dura is attached more firmly to the skull at sutures （缝）. 3. Frequent incidence of associated skull fracture（90%）- fracture line,Acute Epidural Hematoma,The hematoma still contains uncoagulated blood,or still has active bleeding. 血肿包含不凝血或活动出血 Round,stream-like filling defects may be seen in the hemotoma 血肿内可见圆形密度减低影,.,3 Epidural Hematoma 硬膜下血肿,Scoure of blood Laceration （撕裂） of Cortical（脑皮层血管 ）A A. and V V. (Direct: penetrating injury)(直接穿透伤) Bridging (Cortical) Veins（桥静脉） Dural sinus （静脉窦） Large Contusions (Direct /indirect: Pulped Brain,硬膜下血肿（SDH）： 颅内出血积聚于硬脑膜和蛛网膜下腔之间,Subdural Hematoma 硬膜下血肿 Presentation,Significant head trauma, but chronic subdural - only minor or remote history of trauma Bilateral in 20% adults (common in elderly), 80-85% bilateral in infants Extension into interhemispheric fissure （纵裂）， tentorial （小脑幕）margins Brain injury in 50%; Complex Injury (DAI) Skull fracture in only 1%,Subdural Hematoma -CT,1. Sickle-shape (镰刀型) or new lunar shape (新月型) 2. Extends past the sutures 3. Acute SDH - Hyperdense Subacute SDH - Isodense (1-2 weeks) Chronic SDH Hypordense 4. Brain injury in 50%; Complex Injury (DAI) ; 5. Skull fracture in only 1%,Acute Subdural Hematoma 急性硬膜下血肿,The hematoma may extending into the subdural space of tentorial region. 血肿可以延伸到小脑幕区.,Acute Subdural Hematoma,The hematoma may extending into the interhemispheric fissure 血肿延伸至大脑镰部.,Chronic Subdural Hematoma 慢性硬膜下血肿,Shape： Semilunar， fusiform，Oval shape 外形：半月形、纺锤形、椭圆形. Density ：Hyperdense Isodense Hypodense Mixed density 密度：高密度、等密度、低密度、混杂密度,Isodense Chronic subdural hematoma,等密度 慢性硬膜下血肿.,Hyperintensity of chronic subdural hematoma高密度慢性硬膜下血肿 （T1/T2均为高信号）,.,等密度硬膜下血肿,双侧脑室对称变小，体部呈长条状 两侧侧脑室前角内聚，夹角变小，呈“兔耳征” 脑白质变窄塌陷 皮层脑沟消失,Membrane Hematoma,Epidural Acute Biconvex Unilateral Skull Fracture 90% Limited by sutures Direct trauma to cranium Laceration （撕裂） of Meningeal Artery lucid interval（中间清醒期 40%pts）,Subdural Acute to Chronic New lunar shape Bilateral Fracture +/- 1% Cross sutures Contre coup Injury对冲伤 Laceration （撕裂） of Bridging Veins（桥静脉）,4. Subdural Effusion 硬膜下积液,Subdural Effusion 硬膜下积液,Occurred in aged patient or infant 发生在老人及幼儿. Developed several days later after a head injury 外伤几天后形成 Often bilateral 常双侧 Spontaneously resorbed 自发吸收. Craniotomy, V-P shunt,meningitis also may cause subdural effusion 穿颅术、VP、脑膜炎也可发生.,5. Subarachnoid hemorrhage （蛛网膜下腔出血）,Subarachnoid hemorrhage,The sensitivity of CT has been reported to range from 85 to 100 %. High density lesion was demonstrated in cerebral cisterns（Subarachnoid space over cerebral convexity， Suprasella cistem（鞍上池）， interpeduncular cistern（脚间池），pontine cistern，cistern of the lateral fissure（侧裂池） by plain CT scan Computed tomography (CT) is the method of choice to detect acute subarachnoid hemorrhage (SAH).,Linear high density in the subarachnoid spaces (sulci， fissures，cistems) Often associates with other intracerebral or extracerebral lesions May cause hydrocephalus,Subarachnoid hemorrhage （SAH, 蛛网膜下腔出血）-CT,Subarachnoid hemorrhage- MRI,Magnetic resonance imaging (MRI) using FLAIR sequences shows a comparable sensitivity in acute SAH even be superior to CT. (hyperintense on T2 FLAIR ) In subacute SAH, starting from day 5 after the suspected hemorrhage, the sensitivity of MRI is clearly superior to CT. (hyperintense on T1WI and T2WI),纵裂池、脑沟SAH,SAH一引起交通性脑积水.,交通性脑积水.,2.6 Traumatic SAH in the sulci, interhemispheric fissure 9.10 Communicating hydrocephalus,6. Cerebral Cortical Contusion （脑挫伤）,Cerebral Cortical Contusion,Presentation Loss of consciousness，headache，mental status change Usually in a superficial cortical location 50% occur in temporal lobe 33% in frontal lobe (frontal pole and inferior surface) Delayed hemorrhage seen in 20%,7. Diffuse axonal injury （弥漫性轴索损伤）,Follows severe decelerating closed head trauma, patients are generally unconscious from the time of the event Location of injuries are typically in areas of large numbers of parallel axons such as the corpus callosum, internal capsule, brain stem, basal ganglia and subcortical white matter,Diffuse axonal injury （弥漫性轴索损伤）,Usually punctate hyperdensities are seen in the corpus callosum, gray white interfaces, and rostral brainstem The axonal injury itself is not visualized, but the associated micro (and macro) hemorrhages in the characteristic distribution are seen,Diffuse axonal injury -CT,Detecting and characterizing brainstem lesions, specifically and predominately non-hemorrhagic contusions Appearance depends on presence or absence of hemorrhage T1-weighted sequences often normal; multiple hyperintense foci at gray-white junctions and corpus callosum on T2WI,Diffuse Axonal Injury -MRI,0353骑摩托车与另一摩托车相撞，入院时为浅昏迷，GCS评分6分，20天后甚至转清，未能言语. 0366言语模糊，乱语，03616复查时对答正常 上图：伤后4天MRI检查 下图：伤后43天复查,Soon after head injury 8hour later,Delayed Hemorrhage 迟发血肿,Brain atrophy, due to brain contusion Communicating hydrocephalus,due to SAH，IVH Encephalomalacia or porencephalic cyst，due to brain contusion,脑挫裂伤所致的：脑萎缩.,交通性脑积水.,脑软化、脑穿通囊肿.,8. Sequelae of Head Injury 脑外伤后遗症,颅脑外伤的影像诊断注意点,1. 颅脑外伤首选CT检查，但病情与CT表现 不符时，要行MRI检查； 2 . 病情有变化时，随时复查CT。,答案: AADA,答案：CDDCB,答案：ECAE,颅内肿瘤/椎管内肿瘤影像诊断 Intracranial and intraspinal tumor radiology,脑肿瘤/椎管内肿瘤 Intracranial and intraspinal tumor,CT：With or without tumor，localization and qualitative diagnosis Advantages of MRI：No bone artifacts, multi-dimensional sections scanning, a variety of imaging parameters 。Therefore, a more accurate positioning and characterization of the tumor,Imaging signs of intracranial tumors,Direct signs ： 1）The site of tumor 2）The density (signal) of tumor 3） The number, size, shape and edge of tumor 4）The enhancement extent and morphology of tumor Indirect signs ： 1）Peritumoral edema 2）Changes in skull The expand and damage internal auditory canal can be seen in acoustic neuroma The skull corresponding shows thickening of meningiomas,星形细胞瘤（astrocytic tumors),Astrocytic tumors is the most common primary intracerebral tumours Astrocytoma in adults more common in Supratentorial, children more common in infratentorial cerebellar Astrocytoma mainly located in the white matter, grading - Tumor localization signs and symptoms of intracranial hypertension, Epilepsy,脑内肿瘤 直接征象 1）好发部位:白质 2）密度（信号）：级低密度，级高低混杂密度的囊性肿块，可有钙化与瘤内出血、坏死、囊变 3）数目、大小、形态和边缘： 级边界清楚， 级边界不清，形态不规则 4）增强的程度及形态： 级不强化， 级呈不规则环形伴壁结节强化 间接征象 1）瘤旁水肿：明显 2）颅骨变化：常无,星形细胞瘤 astrocytic tumors grade,脑膜瘤 Meningioma,Meningioma originated from arachnoid granulations cap cells, connected with the dura Most tumors occur outside the brain, some can occur even in ventricle A typical site followed by frequency of occurrence :,脑膜瘤影像特征总结,脑外肿瘤 直接征象 1）好发部位:矢状窦旁、脑凸面、蝶骨嵴、嗅沟、桥小脑角、大脑镰或小脑幕 2）密度（信号）：CT平扫等或略高密度、常见斑点状钙化 3）数目、大小、形态和边缘：类圆形，边界清，常以广基底与硬膜相连，表现成增厚强化的“脑膜尾征，脑组织受压形成”皮层扣压征“ 4）增强的程度及形态：均匀性显著强化,脑膜瘤影像特征总结,间接征象： 1）瘤旁水肿：轻或无，静脉或静脉窦受压时可出现中或重度水肿 2）颅骨变化：脑膜瘤可见相应颅骨增厚,Atypical Meningioma,1) 全瘤以囊性为主 2）肿瘤内密度不均匀 3）壁结节 4）瘤内有高密度出血 5）肿瘤完全钙化 6）全瘤密度低，并呈不均匀强化 7）环形强化 8）骨化性脑膜瘤 9）瘤周脑脊液样低密度区 10）酷似脑内的肿瘤 11）多发性脑膜瘤,Meningioma,Differential diagnosis Cerebral convexity and falx meningiomas：Metastases, malignant lymphoma, anaplastic astrocytoma Suprasellar region and the anterior cranial fossa meningioma Middle cranial fossa meningioma Posterior fossa meningioma Intraventricular meningioma,垂体腺瘤（pituitary adenoma),Clinical symptoms：Compression symptoms；Endocrine disorder Pathology: Outside the brain; Encapsulated,pituitary adenoma,pituitary microadenoma: 10mm, Limited to the intrasellar pituitary macroadenoma: 10mm,pituitary microadenoma,Direct signs ： Abnormal density（or signal ) within the pituitary After treatment, the tumor shrink, higher density Indirect signs 3) Pituitary height abnormaly 4) Bulge on the upper edge or collapse o