神经模块-脑外伤新.ppt

HEAD TRAUMA Radiology,The Second Affiliated Hospital,Shantou University,Medical College 郑文斌 CNS trauma Clinical Features No Loss of consciousness(L.O.C)(SDH,EDH?,Not DAI)Awake at the scene,Delayed LOC(SDH,EDH,Swelling,Not DAI)Transient LOC-Wake-up-Delayed LOC)(“Classic”lucid interval for EDH)Continous LOC Following Impact (“Classic”shearing/Diffuse Axonal injury)Centripetal approach ouside to inside Scalp-hematoma Calvarium-skull fracture Epidural-hematoma Subdural-hematoma Subarachnoid-hemorrhage Intraparenchymal-,contusion,edema,hemorrhage Intraventricular-hemorrhage Calvarium-skull fracture Linear Stellate Depressed Basilar Eggshell EPIDURAL HEMATOMA EPIDURAL HEMATOMA Scoure of blood Menigeal Vessels-A,V Dural sinus lucid interval（40%pts）Bi-convex,Hyperdense -limited by sutures EPIDURAL HEMATOMA Direct trauma to cranium Fracture(90%)-Laceration of Meningeal A.and V.Location is 66%temporo-parietal Temporal Bone(70-80%)Mortality of 15-30%EPIDURAL HEMATOMA-CT Biconvex or lens-shaped homogeneous,heterogeneous,indicating active bleeding rarely crosses sutures fracture line SUBDURAL HEMATOMA SUBDURAL HEMATOMA Scoure of blood Laceration of Cortical A A.and V V.(Direct:penetrating injury)Large Contusions(Direct/indirect:Pulped Brain Bridging(Cortical)Veins SUBDURAL HEMATOMA 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,tentorial margins brain injury in 50%;Complex Injury(DAI)skull fracture in only 1%SUBDURAL HEMATOMA-CT Crescentic in shape Extends beyond calvarial sutures Acute SDH -Hyperdense Subacute SDH-Isodense(1-2 weeks)Chronic SDH -Hypordense Enhancement of veins may be useful in identifying isodense subdurals SUBDURAL HEMATOMA-MRI May be better for detection in the subacute stage,and at estimating age of subdural hematoma Can allow differentiation of epidural/subdural because of direct visualization of the dura,especially on coronal imaging Subarachnoid hemorrhage 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,interpeduncular cistern,pontine cistern,cistern of the lateral fissure）by plain CT scan Computed tomography(CT)is the method of choice to detect acute subarachnoid hemorrhage(SAH).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)CEREBRAL CORTICAL CONTUSION Scoure of blood Traumatic/Mechanical Disruption of small(capillary)Vessels Admixture of blood mixed with Native Tissue(Petechial hemorrage)Mottle/Speckled Density(“Salt and pepper”on CT)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%CEREBRAL CORTICAL CONTUSION-CT Ill-defined mixed hypodense and hyperdense lesions-hemorrhage and edema May coalesce 1-2 days after trauma Edema and mass effect related to contusion CEREBRAL CORTICAL CONTUSION-MRI More sensitive than CT in identifying nonhemorrhagic lesions Multiple areas superficial T2 hyperintensity indicating edema Heterogeneous T1/T2 signal intensity dependent upon age of hemorrhagic foci DIFFUSE AXONAL SHEARING INJURY（弥漫性轴索损伤）DIFFUSE AXONAL SHEARING INJURY 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 SHEARING INJURY-CT 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 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 SHEARING INJURY-MRI QUESTIONS All of the following are related to the pathogenesis of epidural hematoma EXCEPT:A.Disruption of bridging veins +This is the etiology of a subdural hematoma B.Laceration of the middle meningeal artery -That statement is true C.Disruption of the dural venous sinuses -That statement is true D.Frequent incidence of associated skull fracture -That statement is true SUBDURAL HEMATOMA-Which of the following sta