《head CT.ppt》由会员分享，可在线阅读，更多相关《head CT.ppt（20页珍藏版）》请在三一文库上搜索。
1、How to read a head CT,yan chen,KEY WORDS,emergency medicine 急诊医学；应急医学 mass effect 占位效应 intracranial lesions ,ntrkrenl 颅内病变 crescent-shaped kresnt 新月形的；逐渐增加的 lenticular/biconvex lentkjl/ baknveks 两面凸的 the dense bone 致密骨 cranium kreinjm 颅；头盖 cross-sectional anatomy ntm 断层解剖 CSF（Cerebrospinal Fluid ）,s
2、erbr()span()lflud paranasal sinusitis ,prneizl ,sansats 鼻窦炎 orbits 眼眶,KEY WORDS,basal cisterns sstn 基底池 cortical sulci/fissures k:tikl 皮质沟/裂 cerebral convexity knvekst 大脑凸面 neurological deficit defst; di- 神经功能缺损 slit-like slit 裂隙状 petechial ptikl 瘀点的；瘀斑的 lateral skull topogram tprm 头颅侧位定位相 frontal l
3、obe frntl 大脑额叶 temporal lobe tmprl 颞叶 occipital lobe ksipitl 枕叶 parietal lobe prat()l 顶叶,KEY WORDS,epidural hematoma(EDH)硬脑膜外血肿 subdural hematoma(SDH)硬脑膜下血肿 traumatic subarachnoid hemorrhage(SAH) ,sbrknid intracerebral hematomas ,intrsiri:brl大脑内血肿 diffuse axonal injury ksnl(DAI)弥漫性轴索损伤 tentorial SDH
4、 幕的 pneumocephalus 颅腔积气 hydrocephalus 脑积水 linear skull fracture lini skl颅骨线性骨折 depressed skull fracture 颅骨凹陷性骨折 cerebral venous sinuses thrombosis 脑静脉窦血栓形成,Computed tomography (CT) is the most useful neuroimaging study in emergency medicine practice because it readily detects acute blood collections
5、 and intracranial lesions causing mass effect. These are the most important immediate considerations in patients presenting with head trauma, headache, or stroke.,CRANIAL CT TECHNIQUE,Head CT slices are oriented obliquely, parallel to the base of the skull, and not in a true axial plane . This reduc
6、es the number of slices that are degraded by artifacts caused by the dense bone at the base of the skull.,THREE DISPLAY WINDOWS,(A) On the brain window image, the crescent-shaped subdural hematoma has the same white appearance as the skull. (level +30, width 80) (B) On the subdural window image, the
7、 blood collection is readily distinguished from skull.(level +25, width 250),Many intracranial lesions produce CT findings that can be identified ,if we have enough knowledge of normal CT anatomy as well as the CT manifestations of various intracranial disorders. The disorders can be epidural hemato
8、ma,subdural h-ematoma,traumatic subarachnoid hemorrhage,intracere-bral hematomas,diffuse axonal injury,tentorial SDH,linear skull fracture,depressed skull fracture ,etc.,A systematic approach A targeted approach,A SYSTEMATIC APPROACH,SymmetryCompare left and right sides of the cranium MidlineLook fo
9、r midline shift Cross-sectional anatomyReview anatomical landmarks for each slice Brain tissueGray matter, white matter, intracerebral lesions Skull and soft tissuesScalp swelling, fractures, sinuses, orbits CSF spacesVentricles, basal cisterns, cortical sulci, and fissures Subdural windowsLook for
10、blood collections adjacent to the skull Bone windowsSkull, orbits and sinuses, intracranial air,A TARGETED APPROACH,HeadacheBlood in the basilar cisterns (SAH), masses,hydrocephalus, cerebral venous sinuses thrombosis, paranasal sinusitis,StrokeExamine region of neurological deficit for blood, edema
11、, or masses,TraumaBlood (extra-axial, intraparenchymal), cerebral edema,fractures, pneumocephalus, scalp swelling, coup, and contra-coup injuries,EASILY MISSED INJURIES,Subdural hematoma（Tentorial SDH） Diffuse axonal injury Depressed skull fracture Etc.,Subdural hematoma,Crescent shape due to blood
12、overlying the cerebral convexity,The right side of the tentorial membrane has a higher atte- nuation due to overlying blood (arrow). This is sometimes called “pseudoenhancement”,True enhancement, however,is symmetrical.,Tentorial SDH,Diffuse axonal injury,Slit-like lateral ventricles due to diffuse
13、cerebral edema.A small (petechial) hemorrhage is caused by shear forces at the gray /white interface when the brain is subjected to a forceful impact.,Depressed skull fracture,A depressed skull fracture at the most superior aspect of the skull is more easily seen on the scout lateral skull topogram than on the axial CT images because the fracture is in the plane of the CT slices.,Thank you for your attention,