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1、HEAD TRAUMA,Radiology,The Second Affiliated Hospital,Shantou University,Medical College郑文斌,CNS trauma Clinical Features,No Loss of)(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 Impa
2、ct(“Classic”shearing/Diffuse Axonal injury),Centripetal approach ouside to inside,Scalp-hematomaCalvarium-skull fractureEpidural-hematomaSubdural-hematomaSubarachnoid-hemorrhageIntraparenchymal-,contusion,edema,hemorrhageIntraventricular-hemorrhage,Calvarium-skull fracture,LinearStellateDepressedBas
3、ilarEggshell,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 craniumFracture(90%)-Laceration of Meningeal A.and V.Location is 66%temporo-parietalTemporal Bone(70-80%)
4、Mortality of 15-30%,EPIDURAL HEMATOMA-CT,Biconvex or lens-shaped homogeneous,heterogeneous,indicating active bleedingrarely crosses suturesfracture line,SUBDURAL HEMATOMA,SUBDURAL HEMATOMA,Scoure of bloodLaceration of Cortical A A.and V V.(Direct:penetrating injury)Large Contusions(Direct/indirect:P
5、ulped BrainBridging(Cortical)Veins,SUBDURAL HEMATOMA Presentation,significant head trauma,but chronic subdural-only minor or remote history of traumaBilateral in 20%adults(common in elderly),80-85%bilateral in infantsextension into interhemispheric fissure,tentorial marginsbrain injury in 50%;Comple
6、x Injury(DAI)skull fracture in only 1%,SUBDURAL HEMATOMA-CT,Crescentic in shape Extends beyond calvarial suturesAcute SDH-HyperdenseSubacute SDH-Isodense(1-2 weeks)Chronic SDH-HypordenseEnhancement of veins may be useful in identifying isodense subdurals,SUBDURAL HEMATOMA-MRI,May be better for detec
7、tion in the subacute stage,and at estimating age of subdural hematomaCan 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 10
8、0%.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
9、).,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.(hyperi
10、ntense on T1WI and T2WI),CEREBRAL CORTICAL CONTUSION,Scoure of blood,Traumatic/Mechanical Disruption of small(capillary)VesselsAdmixture of blood mixed with Native Tissue(Petechial hemorrage)Mottle/Speckled Density(“Salt and pepper”on CT),CEREBRAL CORTICAL CONTUSION,Presentation Loss of consciousnes
11、s,headache,mental status changeUsually in a superficial cortical location50%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 edemaMay coalesce 1-
12、2 days after trauma Edema and mass effect related to contusion,CEREBRAL CORTICAL CONTUSION-MRI,More sensitive than CT in identifying nonhemorrhagic lesionsMultiple areas superficial T2 hyperintensity indicating edemaHeterogeneous T1/T2 signal intensity dependent upon age of hemorrhagic foci,DIFFUSE
13、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 eventLocation of injuries are typically in areas of large numbers of parallel axons such as the corpus callosum,internal capsule,brain
14、 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 brainstemThe axonal injury itself is not visualized,but the associated micro(and macro)hemorrhages in the characteristi
15、c distribution are seen,detecting and characterizing brainstem lesions,specifically and predominately non-hemorrhagic contusionsAppearance depends on presence or absence of hemorrhage T1-weighted sequences often normal;multiple hyperintense foci at gray-white junctions and corpus callosum on T2WI,DI
16、FFUSE 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
17、sinuses-That statement is true D.Frequent incidence of associated skull fracture-That statement is true,SUBDURAL HEMATOMA-Which of the following statements is CORRECT,A.It is associated with underlying brain injury approximately 20%of the time-50%are associated with underlying brain injuryB.It is as
18、sociated with a lucent interval with regards to patient presentationNo,epidural hematoma is associated with a lucent intervalC.It is associated with a better overall prognosis than is an epidural hematomaThe prognosis of a subdural hematoma is generally worse than an epidural hematoma due to high ra
19、te of underlying brain injuries,All of the following concerning cortical contusions are true EXCEPT:,A.Occur most commonly in the frontal lobes+They occur more commonly in the temporal lobesB.Secondary to brain impacting against bone or dura after acceleration/deceleration injury-This statement is t
20、rueC.Ill-defined mixed hypodense and hyperdense lesions in cortical surface on CT-This statement is trueD.MRI is more sensitive than CT in identifying nonhemorrhagic lesions-This statement is true,颅脑外伤,总结,硬膜外血肿（Epidural Hematoma）,概述：颅脑外伤中，硬膜外血肿占3%，急性占86.%，亚急性占10.3%，慢性占3.5%，以脑膜中动脉出血最常见，小孩少见，可能与脑膜中动脉与
21、颅板尚未紧密靠拢有关。血肿部位，多见于颞、额顶。,硬膜外血肿CT表现：,平扫为颅板下双凸形高密度区，血肿密度多均匀，不均匀者，早期可能与血清溢出、脑脊液或气体进入有关。可伴有骨折血肿压迫邻近血管，可出现脑水肿或脑梗塞,硬膜下血肿（Subdural Hematoma）,概述：发生于硬脑膜与蛛网膜之间，占颅脑损伤的36%。急性小于3天，亚急性为4天-3周，慢性为大于3周，长者可达10年。硬膜下血肿常与脑挫裂伤同时存在，血肿多见于脑凸面。,CT表现,急性血肿：颅板下新月形 高密度 影，少数为等或低密度，可见于贫血。亚急性和慢性血肿：可表现为高、等、低密度。,脑挫裂伤（Cerebral Contusi
22、on）,概述：头部受暴力打击而使脑组织发生器质性损伤。早期为伤后数日内，脑组织以出血、水肿、坏死为主要表现.中期为伤后数天至数周，逐步出现修复性病理变化，坏死区组织液化，逐步由疤痕组织修复，大的病灶有肉芽组织修复。晚期经历数月至数年，小病灶由疤痕修复，大的可形成囊腔，邻近脑组织萎缩。,脑挫裂伤（Cerebral Contusion）-CT,损伤局部呈低密度改变：其大小可从几厘米至全脑，形态不一，边缘模糊，白质区明显，数天至数周后有的可以恢复为正常脑组织，有的可发展为脑软化以及脑内囊腔。散在点片状出血：位于低密度区内，形态不规则，有些可融化成较大血肿。,血肿MRI（磁场强度有关）,急性早期血肿（小于24h）：T1WI 等信号，T2WI等信号急性期（1-3d）:T1WI 等信号，T2WI低信号亚急性血肿（3d2周）：T1WI 高信号，T2WI高信号(中心部低信号)慢性早期血肿（2周-3周后）：T1WI高信号，T2WI高信号慢性期血肿(3周后):T1WI高信号，T2WI高信号（周边低信号环）-,THANKS,
