中枢神经系统影像学诊断课件.pptx

1、 l脑脑l脊髓脊髓lECT，emission computed tomographySPECT,single photon emission computed tomographyPET,positron emission tomographyl脑血管造影脑血管造影,cerebral angiographyl经颅经颅Doppler,transcranial doppler，TCD l头颅平片头颅平片,plain film，Magnetic Resonance Imaging,Computed Tomography 软组织分辨率最高 任意面成像，有利于观察解剖关系 检查序列多 T1WI,T2WI

2、,PDWI等 钙化、骨化、早期出血灶显示不如CT 价格贵l是最常用的检查方法 显示骨和钙化一般比MRI好 显示早期出血比MRI好 对脑组织的分辨率不如MRIlDSA，digital substractive angiography magnetic resonance angiography computed tomography angiography transcranial DopplerCT angiography,diffusion weighted imaging,perfusion weighted imaging,emission computed tomographyAbso

3、lute CBF(A)D=time for the lower edge of the bolus to reach the tissue(B)A patient with right carotid occlusion and small right side infarction(arrow)lSPECTlPET tracer most common is 18FDG，analogue of glucoselMRIl定位像(topography，scout image)T1WIaxialT2WIaxialT1WIcoronalT2WIsagital颅骨破坏颅板增厚颅板变薄骨折线depres

4、sed skull fracture skull destructionThinningz tableThickness of skull tablel平扫密度改变 density changes占位效应 mass effect,space occupying effect脑水肿 brain edema,cerebral edema脑积水 hydrocephalus脑萎缩 brain atrophy,cerebral atrophy病灶的强化表现 features after contrast inject平扫密度改变l高密度灶：钙化（肿瘤、血管畸形）、出血 出血的演变l低密度灶：坏死、水肿、

5、液体、气体和脂类l等密度灶：肿瘤、出血某一阶段l混杂密度灶：多种成分病变，多见l钙化：正常生理钙化、血管畸形、少枝胶质瘤等等密度isodensity低密度水肿Low density占位效应高密度High density占位效应混杂密度 mixed density钙化 calcificationspace occupying effect,mass effectCommon diseasel肿瘤 tumorl出血 bleedingl显著肿胀 edemamanifestationl中线结构移位 displacement of midline structuresl脑室与脑池移位变形l脑室、脑池扩大

6、 enlargement of ventricle and cisternl脑沟变化 fucil脑体积的改变 enlargement of brain volumel炎症性水肿 inflammatory swelling感染 infection出血 bleeding挫伤 contusion等l血脑通透性增加increasing permeability of BBB肿瘤 tumor感染 infection等l原因 etiology脑积液产生和吸收失衡脑脊液循环通路障碍所致脑室系统异常扩大l类型 type交通性脑积水communicative hydrocephalus阻塞性脑积水 obstru

7、ctive hydrocephalus代偿性脑积水 compensatory hydrocephalus梗阻性脑积水 正常脑压性脑积水Normal pressure hydrocephalusl描述 description各种原因引起脑组织减少而继发的脑室和蛛网膜下腔扩大l分类 type广泛性 diffuse局限性 local 皮质 cortex白质 white matterl机制 mechanism血脑屏障通透性增加异常血管增生引起血流量增加l常见类型 common type均一强化：脑膜瘤、生殖细胞瘤等环状强化：脑脓肿、脑转移瘤、星形细胞瘤等斑状强化：血管畸形、炎症等不规则强化：恶性胶质瘤

8、等等等密度，均匀强化Isodensity,homogeneous enhancement环形强化Ring-rim enhancementl增厚thicknessl变薄 thinl破坏 destructionl增生 proliferationgiant cell reparative granulomatrauma颅骨破坏l与CT类似的表现 the similar sign as to CT占位效应脑积水脑萎缩l信号改变复杂，与CT密度改变不同长T1、长T2信号：肿瘤、脑梗死、炎症等脑脊液信号：囊性变、囊肿（FLAIR序列变黑）短T1、长T2信号：脂肪、黑色素瘤等无信号：钙化、晚期疤痕组织血管流

9、空信号：多为无信号l水肿 edema T1WI为低信号 low signalT2WI为略高信号 slightly high intensityl出血 bleeding信号变化复杂 the change of signal is complex长T1、长T2病灶，肿瘤水肿 edema钙化无信号囊性病灶 cystic T2WI高信号l增强环状均匀不均匀脑回状 acute stage 1周l高密度 hyperdensityl周围水肿 surrounding edema absorption stage 2周2个月l始于37天，密度逐渐减低 cystic change stage 2个月l水样低密度

10、water-like density（Hyperacute hematoma）6小时小时lT1WI等信号，T2WI为等信号（Acute hematoma）7小时小时3天天lT1WI呈等信号，血肿内缘可见低信号强度的硬膜，T2WI呈低信号（Subacute hematoma）3天天4周周l高信号(metahemoglobin)（Remote hematoma）4周周l液体信号l周围有低信号（hemosiderin)CT T1WI T2WICTT2WISubacute to chronic hematomaAcute hematomaGRET1WI trauma of brain cerebrao

11、vascular disease脑梗死 cerebral infarction脑出血 cerebral hemorrhage cerebral tumor显示骨折、早期出血好方便快速多螺旋可快速形全身检查CT检查阴性亚急性期慢性期CT未普及的地区 cerebral contusion intracerebral hematoma subdural hematoma epidural hematoma subarachnoid hemorrhage cerebral contusion 脑内散在出血灶，静脉淤血、脑血肿和肿胀laceration of brain 伴有脑膜、脑或血管撕裂l发病部位

12、发病部位 location着力点附近 coup site着力点对冲部位 contrecoupl病理病理 pathology脑水肿 坏死液化散在小出血点 低密度病灶内散在斑点状高密度出血灶边缘模糊 ill-defined rim占位效应 mass effect脑水肿lT1WI呈低或等信号lT2WI高信号出血bleedingl表现与血肿期龄有关There is a focal area of haemorrhagic contusion in the right frontal lobe,with surrounding low density due to infarction or oedem

13、a.This is a frequent location for a contrecoup injury following a blow to the back of the head.l其他名称其他名称 synonymy剪切伤 shear injuryl机制机制 mechanism头受到旋转暴力致大脑绕中轴发生旋转运动 白质、灰白质交界区、胼胝体、脑干及小脑等受到剪切力损伤 弥漫性轴索断裂、点片状出血和水肿l临床临床 clinical features伤后意识立即丧失，多数立即死亡部分持续昏迷，后果严重This image demonstrates a small petechial h

14、aemorrhage in a typical location at the grey-white matter interface(arrow).As is often the case,there were multiple such lesions on other slices硬脑膜与蛛网膜之间颅脑外伤的56急性硬膜下血肿l多与脑挫裂伤同时存在l症状重慢性硬膜下血肿l轻微头痛l有或无明确外伤史Epidural spacesubidural spaceDural matterl颅骨下方新月形高密度影l占位效应等密度硬膜下血肿低密度硬膜下血肿epidural hematoma颅骨与硬膜之

15、间占颅脑外伤的23急性：85亚急性：12慢性:少见颅板下梭形或半圆形高密度影多位于骨折附近不跨越颅缝l颅内血管破裂进入蛛网膜下腔l病因 etiology外伤 trauma 自发性 spontaneouslyl动脉瘤 51l高血压动脉硬化 15l动静脉畸形 6%l临床 clinical features好发年龄：3040岁三联征l剧烈头痛l脑膜刺激征l血性脑脊液intracerebral hemorrhageinfarct of brainaneurysmvascular malformation脑出血脑出血 intracranial hemorrhagel病因病因 etiology高血压高血压

16、 hypertensive intracerebral hemorrhage 占占40动脉瘤破裂动脉瘤破裂脑血管畸形出血脑血管畸形出血出血性脑梗死出血性脑梗死外伤外伤脑肿瘤脑肿瘤血液病血液病 等等l机制机制微小动脉瘤破裂脑血管玻璃样变基底节、丘脑、脑桥和大脑半球白质内易破溃入脑室脑水肿脑组织受压坏死脑出血脑出血 intracranial hemorrhagel脑内血肿脑内血肿破入脑室破入蛛网膜下腔脑积水 thrombosis embolic low blood pressurel发病率发病率 incidence为脑血管病首位 ischemic infarction hemorrhage inf

17、arction lacunar infarctionl好发于基底节区、脑干、小脑等l病灶大小：515mm，其部位和范围与闭塞血管供血区一致，可有占位效应23周时可出现“（fogging effect）”增强：12个月形成边界清楚的 normal or subtle hypodensity sulca effacementMass effect(peak at 34 days)HypodensityContrast enhancementAtrophy DWI,PWI 6 hours 传统MRI，FLAIR 8 hourslMultiphasic perfusion CT obtained 3

18、hours after the sudden onset of right hemiparesis and aphasia in a 76-year-old woman.T1WIT2WIDWIMale,60years oldOnset 6 hoursl为胚胎期血管的发育异常，分为arteriovenous malformation,AVM静脉畸形 venous maformation毛细血管扩张症 capillary telangiectasia cavernous hemangioma 等不规则混杂密度灶钙化斑点或弧线形强化无水肿和占位效应Male,65yr扩张流空的畸形血管团邻近脑质：混杂

19、低信号（hemosiderin）Male,48 yrMale,48 yr海绵状血管瘤cavernous hemangiomaM，31yrl病因先天性 80后天性 20l常见年龄 predominated onset age3060 years oldlPredominated locationInternal carotid artery 90%Vertebral and basilar artery system 10%l蛛网膜下腔出血The white arrow on the black card marks the site of a ruptured berry aneurysm i

20、n the circle of WillisThe circle of Willis has been dissected,and three berry aneurysms are seen.l胶质瘤 glioma 4050l转移瘤 metastasis 3.1912.92%l脑膜瘤 meningioma 1520l垂体瘤 pituitary adenoma 10%l颅咽管瘤 craniopharyngiomal听神经瘤 acoustic neurinoma（glioma）星形细胞瘤 astrocytoma 40%少突胶质细胞瘤 oligodendroglioma 515%室管膜瘤 epen

21、dymoma 髓母细胞瘤 medulloblastoma 48%局灶性或全身性癫痫发作为最重要表现神经功能障碍颅内压增高l低密度灶，分界清楚，占位效应轻，无或轻度强化l高、低或混杂密度，可呈囊性l斑点钙化和瘤内出血l形态不规则，边界不清l占位效应和瘤周水肿明显l不规则环形伴壁结节强化，或不均匀强化稍低或混杂信号均匀或不均匀性高信号l恶性程度越高，其T1、T2值愈长，囊壁和壁结节强化越明显Male,43 yr蛛网膜粒帽细胞多居于，与硬脑膜粘连矢状窦旁、脑凸面、蝶骨嵴、嗅沟、桥小脑角、大脑镰或小脑幕等，与部位少数：脑室、眼眶肿瘤包膜完整，多由脑膜动脉供血，血运丰富，常有钙化，少数有出血、坏死和囊变

22、上皮型纤维型过渡型砂砾型血管瘤型l等15型lCTl等或略高密度l常见斑点状钙化l广基底与硬脑膜相连l边界清楚l可有瘤周水肿l颅板：增生或破坏l均匀性显著强化lT1WI等或稍低信号lT2WI等或高信号l边缘清楚l与正常脑组织间有时有脑脊液影l明显均匀强化l脑膜尾症 dural tail sign女 653月前出现反应迟钝，记忆力下降，左下肢无力CT plain scanT2WIT1WIT1WIenhancementFemal,61yr右下肢无力2年，加重2月脑膜瘤侵犯颅骨中老年人顶枕区皮髓质交界处lung,breast,prostate,kidney,and so on多发或单发结节 multi

23、pl or single nodule等或低密度 isodensity or low density出血时：高密度 hyperdensity瘤周水肿 surrounding edema结节或环形强化 nodular or ring enhancement长T1、长T2信号l泌乳素、生长激素、性激素和促肾上腺皮质激素瘤：直径10mml包膜完整l较大可坏死、囊变、出血，偶可钙化l向四周侵犯：l压迫症状:视力障碍、垂体功能低下、阳痿、头痛等l内分泌症状：泌乳素、生长激素、促肾上腺皮质激素等Pituitary gland tumorMale,41yr2006年年11月月1日日青岛青岛lThank You青岛八大关秋色Cranial Metastasis of Hepatocellular CarcinomaHydatid cyst of the brain