中枢神经系统影像诊断CNS.ppt

中枢神经系统影像诊断 协和医院放射科孔祥泉 一、Examination methods 1. X-ray plain film This method is very simple and cheap. Some lesions can be found by it. Usually we cannot reach to an exact diagnosis only by this examination 2. Tomography2. Tomography Exact diagnosis still cannot obtained The method can manifested some osseous The method can manifested some osseous destruction which cannot be shown by plain film. destruction which cannot be shown by plain film. EnhancementEnhancement: : 3. CT To display tumors, hemorrhage, infarction, infection and abnormality.To display tumors, hemorrhage, infarction, infection and abnormality. To show the abnormal To show the abnormal isodensityisodensity which cannot found by the plain scan. which cannot found by the plain scan. To confirm the quality of the lesion.To confirm the quality of the lesion. Differential diagnosis of tumor and edema .Differential diagnosis of tumor and edema . Plain scanPlain scan: : The characters of the lesion including size, appearance, The characters of the lesion including size, appearance, number, number, position , anatomy relation ,and so on can be shown by it. position , anatomy relation ,and so on can be shown by it. 4. Magnetic resonance imaging Plain scanPlain scan: : EnhancementEnhancement: : To show the abnormal To show the abnormal isodensityisodensity which cannot found by the plain scan. which cannot found by the plain scan. To confirm the quality of the lesion.To confirm the quality of the lesion. Differential diagnosis of tumor and edema .Differential diagnosis of tumor and edema . MRA: To show the vascular lesions such as aneurysm and arterial venous malformation. To display tumors, hemorrhage, infarction, infection and abnormality.To display tumors, hemorrhage, infarction, infection and abnormality. The characters of the lesion including size, appearance, The characters of the lesion including size, appearance, number, number, position , anatomy relation ,and so on can be shown by it. position , anatomy relation ,and so on can be shown by it. 5. DSA To show the vascular lesions such as aneurysm, arterial venous malformation.,blood supply of neoplasm 6. Myelography To show whether there are tumors and obstruction in spinal canal. It is also helpful to ensure the position and degree of obstruction. 一、 Normal manifestation （一）、（一）、Plain filmPlain film 1.Cranium1.Cranium The inner and outer plate are dense and the The inner and outer plate are dense and the diploediploe is spongy. is spongy. 2. 2.Skull sutureSkull suture All of the sutures are shown as All of the sutures are shown as sawtoothsawtooth shadow shadow 3.Convolutional impressions Multiple round low density in plain film.Multiple round low density in plain film. 4.The impression of the middle 4.The impression of the middle meningealmeningeal artery artery The The impresstionimpresstion of the middle of the middle meningealmeningeal artery is presented as artery is presented as streaks shadow and go out from wide to narrow streaks shadow and go out from wide to narrow 5. 5. ImpressionImpression of of d diploiciploic vein vein 7. 7. The The SellaSella : : 6. 6. Impression of Impression of pacchionianpacchionian granulation granulation 8. Internal auditory 8. Internal auditory meatusmeatus: : About 6mm wide ,symmetrical canalAbout 6mm wide ,symmetrical canal The frontal parietal irregular The frontal parietal irregular hypodensityhypodensity near the midline. near the midline. The The diploicdiploic veins impress appears as netlike veins impress appears as netlike hypodensityhypodensity in the in the parietal region .parietal region . 716mm long, 714mm wide and 820mm deep.716mm long, 714mm wide and 820mm deep. 10.calcification of 10.calcification of falxfalx cerebricerebri : : 9. 9. Calcification of Calcification of pineal body :pineal body : 11.Calcification of 11.Calcification of choroidchoroid plexus plexus 12 Calcification of 12 Calcification of petro-clinoidpetro-clinoid ligament : ligament : It is presented as nodular It is presented as nodular hyperdensityhyperdensity on the lateral skull radiograph. on the lateral skull radiograph. The frontal view show the normal position are presented the The frontal view show the normal position are presented the zonaryzonary dense image on the midline . dense image on the midline . Calcification of Calcification of choroidchoroid plexus are presented the anomalistic dense plexus are presented the anomalistic dense image and lateral to midline.image and lateral to midline. The dense shadow between in the anterior and posterior The dense shadow between in the anterior and posterior clinoidclinoid process. process. 1. 1. W White matter:hite matter: is is hypodensehypodense to gray matter. CT values is to gray matter. CT values is 20-30Hu20-30Hu 2. Gray matter: 2. Gray matter: is is hyperdensehyperdense to white matter . CT values is to white matter . CT values is 30-40Hu30-40Hu 3. Ventricle and cistern : 3. Ventricle and cistern : are are hypodensehypodense. CT values is . CT values is 0-10Hu0-10Hu 4. Skull : 4. Skull : is is hyperdensehyperdense. CT values . CT values 250Hu250Hu 5. Physiological calcification: 5. Physiological calcification: Spot or patch dense shadow. CT values60Hu 二、 CT manifestation 三、 MRI manifestation 1 . Morphological manifestation Axial, coronal,sagittal MRI can clearly show the shape of brain and spinal cord,such as white matter,grey matter,ventricle,cerebral fissure,brainstem,cerebral vessel,pituitary body,et al. The efficiency is close to gross specimen . T1WI T2WI WHITE MATTER HIGH LOW GREY MATTER LOW HIGH CSF LOW HIGH FAT HIGH MEDIUM SKULL TABLE LOW LOW DIPLOE HIGH LOW MENINGES LOW LOW VESSEL LOW LOW CALCIFICATION LOW LOW MRI signal intensity Frontal lobe Pituitary body Central sulcus Pituitary stalk Optic chiasm Genu of corpus callosum Medulla oblongata Clivus Sphenoid sinus Parietal lobe Thalamus Occipital lobe Mamillary body Quadrigeminal body Straight simus 4th ventricle Cerebellar tonsil Genu of corpus callosum Frontal lobe Splenium of corpus collosum 3rd ventricle Thalamus Head of caudate nucleus Globus pallidus Occipital lobe Optic radiations Septum pellucidum Posterior horn of lateral ventricle Anterior horn of lateral ventricle Interventricular foramen Parietooccipital sulcus Thalamus Head of caudate nucleus Globus pallidus Occipital lobe Optic radiations Anterior horn of lateral ventricle Interventricular foramen 3rd ventricle Genu of corpus callosum Septum pellucidum Splenium of corpus collosum Posterior horn of lateral ventricle Posterior limb of internal capsule Genu of internal capsule Anterior limb of internal capsule Parietooccipital sulcus Parietal lobe Superior temporal gyrus Middle temporal gyrus Pons Medulla oblongata Cerebral peduncle Centrum semiovale 3rd ventricle Inferior temporal gyrus Petrous ridge of temporal bone Parahippocampal gyrus Anterior horn of lateral ventricle Lateral fissure Suprasellar cistern Pituitary body Temporal lobe Inerhemisperic fissure cistern Corpus callosum caudate nucleus globus pallidus, putamen Optic chiasm Pituitary stalk Cavernous sinus DSA manifestation Normal cerebral artery (anterior and middle cerebral artery) gradually taper off with symmetric branches and smooth margin. The arteries have invariable location and corresponding brain tissue. Imageologic diagnosis of the common disease （一） Brain tumors have common characteristic in imageologic manifestion Glioma,astrocytomaGlioma,astrocytoma MeningiomaMeningioma Pituitary tumorPituitary tumor Acoustic Acoustic neuromaneuroma Metastasis tumorMetastasis tumor 1、X-ray manifestation 、Increase of intracranial pressure Increase and deepening of convolutional impressions, separation of sutures,thinning of bones. 、Tumor location sign Destruction of skull,enlargement of the sellar,displacement of calcification,dilation of Internal auditory Internal auditory meatusmeatus, pathologic , pathologic cacificationcacification 2、CT manifestation 、Density abnormality The tumors are slightly The tumors are slightly hypodensehypodense to to isodenseisodense on plain scan. on plain scan. 、Mass effect Displacement of midline, compression and obstruction of ventricle, hydrocephalus. 、Edema Hypodensity around tumor, more severe in malignant tumor. 、physiological calcification:physiological calcification: egeg: Irregular calcification can been seen in : Irregular calcification can been seen in OligodendrogliomaOligodendroglioma 、Destruction of bone Defect of bone, decreased denstiy,eg: acoustic neuroma 、Enhancement Increase of tumor density, there is no enhancement in the area of necrosis and edema MRI manifestation 、Signal abnormality The tumors are slightly The tumors are slightly hypointensityhypointensity to to isointensityisointensity on plain scan on plain scan 、Mass effect Displacement of midline, compression and obstruction of ventricle, hydrocephalus 、Edema Edema is around tumor with long T1 and T2 relaxing times. 、Physiological calcification:Physiological calcification: 、Destruction of bone 、Enhancement Increase of tumor density, there is no enhancement in the area of necrosis and edema T1 and T2 prolongation of bone area can been near tumors Hypointensity in the tumor on T1WI and T2 WI DSA manifestation 、Mass effect Vessels displacement ,separation,gathering,bending, straightening 、Tumor dyeing Tumors with sufficient blood supply can been seen 1. X-RAY PLAIN FILM manifestation （二）Craniocerebral injury To find the presence or absence of skull fracture and to access the location and type of fracture(linear fracture,comminuted fracture,depressed fracture) Intracranial injury cannot been observed CT manifestation 、Epidural Epidural hematomahematoma 、SubduralSubdural hematomahematoma 、IntracerebralIntracerebral hematomahematoma 、Cerebral contusionCerebral contusion shows a localized biconvex high density under the inner table Generalized peripheral high density under the inner table Round or irregular hyperdensity Haemorrhage and edema are intercurrent,producing motley density MRI manifestation 、Chronic epidural Chronic epidural hematomahematoma Shows a localized biconvex high intensity under the inner table 、Chronic Chronic subduralsubdural hematomahematoma Generalized peripheral high intensity under the inner table 、Chronic Chronic intracerebralintracerebral hematomahematoma Chronic hematoma producing irregular hyperintensity with ring sign. （三） Vascular diseases 1 1、Intracranial aneurysmIntracranial aneurysm DSA CT MRI Demonstrate rounded high density link to relative artery with irregular size and smooth margin Shows rounded flow void with smooth margin on T1WI and T2WI Displays isodensity on plain scan and rounded hyperdensity on CECT 2、Intracranial vascular malformation （Arteriovenous malformation） DSA CT MRI Vein early emerging,malformed nidus, narrowing of feeding artery,dilated draining vein. Malformed vascular nidus producing racemose flow void with narrowing of feeding artery,dilated draining vein. Displays isodensity on plain scan and rounded hyperdense malformed vascular nidus on CECT 3、cerebral infarction MRI Ischemic infarction producing sector or irregular shape with T1 and T2 prolongation. Mass effect can been seen in extensive cases. cerebral lacuna have been identified as infarctions less than 1 cm. CT Ischemic infarction producing sector or irregular hypodensity with blurred margin. cerebral lacunas are not easy to find. 四、Infectious diseases Suppurative infection: Tuberculous infection： Viral infection： Patasitic infection： Encephalitis, Brain abscess, Meningitis Meningitis, Tuberculoma Encephalitis, Meningitis Cysticercosis, Schistosomiasis 1、Brain abscess CT: Plain scan shows round hypodensity with ringlike peripheral isodensity and edema. There is ring enhancement of the uniform thick abscess wall . The central hyodense area in the cavity dose not change in enhancement. MRI： The abscess have long T1 and T2 relaxation times with surrounding edema. There is ring enhancement of the uniform thick abscess wall . The abscess cavity have not enhancement. 2、cerebral cysticercosis Larval of Taenia solium parasitize in brain. Cerebral larval infestation is characterized by a fluid-filled cyst with a mural soft-tissue nodule.the disease can been classified as larval living stage, larval death stage, calcification stage. Multiple Multiple spotlikespotlike high-density with similar size in brain. high-density with similar size in brain. CT:CT: MRI:MRI: Accompanied by edema, the multiple cysts with Accompanied by edema, the multiple cysts with long T1 and T2 signal are no more than 1 cm in long T1 and T2 signal are no more than 1 cm in diameter, diameter, larval living stage:larval living stage: The low-density cysts occur in groups with The low-density cysts occur in groups with spotlikespotlike mural nodule .mural nodule . Calcification stage:Calcification stage: 二. Normal manifestation Examination of spinal cord 一、Examination method MRI CTCTMyelographyMyelographyX-rayX-ray spinal canal: 11mm long,16mm wide, Spinal cord: columniform,smooth margin,homogeneous 三、三、IntramedullaryIntramedullary tumor are predominantly tumor are predominantly ependymomaependymoma and and astrocytoma.(aboutastrocytoma.(about 90% of all 90% of all intraspinalintraspinal tumors) tumors) The outline of MRI diagnosis 1. the spinal cord is enlarged and the lesion is extensive 2. The subarachnoid space around the spinal cord is narrowed or blocked 3.secondary syringohydromyelia 4. The tumors are slightly hypointense on T1 and slightly hyperintense on T2. Enhancement can been seen. 4 4、ExtramedullaryExtramedullary intraduralintradural t