中枢神经系统影像诊断 一 Examinationmethods 1 X rayplainfilm Thismethodisverysimpleandcheap Somelesionscanbefoundbyit Usuallywecannotreachtoanexactdiagnosisonlybythisexamination 2 Tomography Exactdiagnosisstillcannotobtained Themethodcanmanifestedsomeosseousdestructionwhichcannotbeshownbyplainfilm Enhancement 3 CT Todisplaytumors hemorrhage infarction infectionandabnormality Toshowtheabnormalisodensitywhichcannotfoundbytheplainscan Toconfirmthequalityofthelesion Differentialdiagnosisoftumorandedema Plainscan Thecharactersofthelesionincludingsize appearance number position anatomyrelation andsooncanbeshownbyit 4 Magneticresonanceimaging Plainscan Enhancement Toshowtheabnormalisodensitywhichcannotfoundbytheplainscan Toconfirmthequalityofthelesion Differentialdiagnosisoftumorandedema MRA Toshowthevascularlesionssuchasaneurysmandarterialvenousmalformation Todisplaytumors hemorrhage infarction infectionandabnormality Thecharactersofthelesionincludingsize appearance number position anatomyrelation andsooncanbeshownbyit 5 DSA Toshowthevascularlesionssuchasaneurysm arterialvenousmalformation bloodsupplyofneoplasm 6 Myelography Toshowwhethertherearetumorsandobstructioninspinalcanal Itisalsohelpfultoensurethepositionanddegreeofobstruction 一 Normalmanifestation 一 Plainfilm 1 Cranium Theinnerandouterplatearedenseandthediploeisspongy 2 Skullsuture Allofthesuturesareshownassawtoothshadow 3 Convolutionalimpressions Multipleroundlowdensityinplainfilm 4 Theimpressionofthemiddlemeningealartery Theimpresstionofthemiddlemeningealarteryispresentedasstreaksshadowandgooutfromwidetonarrow 5 Impressionofdiploicvein 7 TheSella 6 Impressionofpacchioniangranulation 8 Internalauditorymeatus About6mmwide symmetricalcanal Thefrontalparietalirregularhypodensitynearthemidline Thediploicvein simpressappearsasnetlikehypodensityintheparietalregion 7 16mmlong 7 14mmwideand8 20mmdeep 10 calcificationoffalxcerebri 9 Calcificationofpinealbody 11 Calcificationofchoroidplexus 12Calcificationofpetro clinoidligament Itispresentedasnodularhyperdensityonthelateralskullradiograph Thefrontalviewshowthenormalpositionarepresentedthezonarydenseimageonthemidline Calcificationofchoroidplexusarepresentedtheanomalisticdenseimageandlateraltomidline Thedenseshadowbetweenintheanteriorandposteriorclinoidprocess 1 Whitematter ishypodensetograymatter CTvaluesis20 30Hu 2 Graymatter ishyperdensetowhitematter CTvaluesis30 40Hu 3 Ventricleandcistern arehypodense CTvaluesis0 10Hu 4 Skull ishyperdense CTvalues 250Hu 5 Physiologicalcalcification Spotorpatchdenseshadow CTvalues 60Hu 二 CTmanifestation 三 MRImanifestation 1 Morphologicalmanifestation Axial coronal sagittalMRIcanclearlyshowtheshapeofbrainandspinalcord suchaswhitematter greymatter ventricle cerebralfissure brainstem cerebralvessel pituitarybody etal Theefficiencyisclosetogrossspecimen MRIsignalintensity Frontallobe Pituitarybody Centralsulcus Pituitarystalk Opticchiasm Genuofcorpuscallosum Medullaoblongata Clivus Sphenoidsinus Parietallobe Thalamus Occipitallobe Mamillarybody Quadrigeminalbody Straightsimus 4thventricle Cerebellartonsil Genuofcorpuscallosum Frontallobe Spleniumofcorpuscollosum 3rdventricle Thalamus Headofcaudatenucleus Globuspallidus Occipitallobe Opticradiations Septumpellucidum Posteriorhornoflateralventricle Anteriorhornoflateralventricle Interventricularforamen Parietooccipitalsulcus Thalamus Headofcaudatenucleus Globuspallidus Occipitallobe Opticradiations Anteriorhornoflateralventricle Interventricularforamen 3rdventricle Genuofcorpuscallosum Septumpellucidum Spleniumofcorpuscollosum Posteriorhornoflateralventricle Posteriorlimbofinternalcapsule Genuofinternalcapsule Anteriorlimbofinternalcapsule Parietooccipitalsulcus Parietallobe Superiortemporalgyrus Middletemporalgyrus Pons Medullaoblongata Cerebralpeduncle Centrumsemiovale 3rdventricle Inferiortemporalgyrus Petrousridgeoftemporalbone Parahippocampalgyrus Anteriorhornoflateralventricle Lateralfissure Suprasellarcistern Pituitarybody Temporallobe Inerhemispericfissurecistern Corpuscallosum caudatenucleus globuspallidus putamen Opticchiasm Pituitarystalk Cavernoussinus DSAmanifestation Normalcerebralartery anteriorandmiddlecerebralartery graduallytaperoffwithsymmetricbranchesandsmoothmargin Thearterieshaveinvariablelocationandcorrespondingbraintissue Imageologicdiagnosisofthecommondisease 一 Braintumors havecommoncharacteristicinimageologicmanifestion Glioma astrocytoma Meningioma Pituitarytumor Acousticneuroma Metastasistumor 1 X raymanifestation Increaseofintracranialpressure Increaseanddeepeningofconvolutionalimpressions separationofsutures thinningofbones Tumorlocationsign Destructionofskull enlargementofthesellar displacementofcalcification dilationofInternalauditorymeatus pathologiccacification 2 CTmanifestation Densityabnormality Thetumorsareslightlyhypodensetoisodenseonplainscan Masseffect Displacementofmidline compressionandobstructionofventricle hydrocephalus Edema Hypodensityaroundtumor moresevereinmalignanttumor physiologicalcalcification