腦疝分類及影像學(xué)表現(xiàn)圖解ppt課件

1、圖解腦疝,1,腦疝,是指在顱內(nèi)壓增高的情況下，腦組織通過某些腦池向壓力相對較低的部位移位的結(jié)果，即腦組織由其原來正常的位置而進(jìn)入了一個(gè)異常的位置。,2,腦疝的類型：,a.大腦鐮疝 ： 一側(cè)大腦半球占位病變可使同側(cè)扣帶回經(jīng)大腦鐮下緣疝入對側(cè)，胼胝體受壓下移。 小腦幕切跡疝 b.前疝：也稱顳葉溝回疝，是顳葉溝回疝于腳間池及環(huán)池的前部；②后疝：顳葉內(nèi)側(cè)部疝于四疊體池及環(huán)池的后部；f.小腦幕切跡上疝：后顱凹占位病變時(shí)，小腦上蚓部可向上疝入小

2、腦幕切跡的四疊體池。c.中心疝：幕上壓力增高，致使大腦深部結(jié)構(gòu)及腦干縱軸牽張移位。 d.顱外疝： 腦組織通過顱外缺損疝出。e.枕骨大孔疝 ： 后顱凹占位病變時(shí)，可致小腦扁桃體疝入枕骨大孔。g.蝶骨嵴疝：顱前凹和顱中凹的占位病變，由于病變部壓力相對高一些，則額眶回可越過蝶骨嵴進(jìn)入顱中凹，可顳葉前部擠向顱前凹。,3,示意圖,a) subfalcial (cingulate) herniation ;鐮下疝b) uncal hern

3、iation ; 鉤疝c) downward (central, transtentorial) herniation ; 下行性小腦幕疝d) external herniation ; 顱外疝e) tonsillar herniation.扁桃體疝f) ascending transtentorial herniation (reversed tentorial)上行性小腦幕疝g) sphenoid herniation蝶骨

4、嵴疝,4,類型,5,示意圖,6,解剖關(guān)系,7,解剖關(guān)系,8,解剖關(guān)系,9,The suprasellar cistern & the quadrigeminal cistern,The left and center images show the suprasellar cistern. Its anterior borders are formed by the frontal lobes (F). Its lateral

5、borders are formed by the uncus (U) of the temporal lobes. The left image shows the 5-pointed star appearance of the suprasellar cistern where the posterior border is formed by the pons (Po). The black arrow points to th

6、e fourth ventricle. The center image shows a higher cut where the suprasellar cistern has a 6-pointed star appearance since the posterior border is formed by the cerebral peduncles (P) which have a central cleft. The ri

7、ght image shows the quadrigeminal cistern (black arrow). Note the "baby's bottom" appearance of its anterior border. When ICP is increased, the quadrigeminal cistern space is compressed or obliterated.,10,T

8、he suprasellar cistern& the quadrigeminal cistern.,The midline sagittal MRI scan shows the levels of the axial diagrams. The quadrigeminal cistern is located above (anterior to) the "Q" in the highest cut

9、shown (number 9). The anterior border of the quadrigeminal cistern is formed by the superior colliculi (c). Image 8 (lower cut) also shows the quadrigeminal cistern. In this case, its anterior border is formed by the inf

10、erior colliculi (c). This gives the anterior border of the quadrigeminal cistern the appearance of a "baby's bottom". The quadrigeminal plate is comprised of the superior and inferior colliculi. The quadrig

11、eminal cistern is posterior to this quadrigeminal plate, thus its anterior border may be formed by the inferior or superior colliculi.,11,鐮下疝,12,Subfalcine herniation (cingulate herniation)Transtentorial herniation,The

12、suprasellar cistern (left image) is obliterated. The quadrigeminal cistern is very compressed and pushed posteriorly (center image). A subdural hematoma with a midline shift is noted. There is central transtentorial a

13、nd subfalcine herniation.,13,ACA供血區(qū)梗塞,14,Uncal herniation,15,鞍上池缺角,16,冠狀位CT與MRI,17,海馬旁回褶皺,18,對側(cè)顳角增寬,19,同側(cè)橋前池增寬,20,同側(cè)環(huán)池增寬,21,Uncal herniation,22,Uncal herniation,obliteration of the suprasellar cistern (red arrow) and t

14、he quadrigeminal cistern (green arrow),23,Uncal herniation,The ipsilateral ventricle, sulci, fissures are compressed and obliterated, isappeared.,obliteration of the suprasellar cistern(s) and quadrigeminal cistern(q),

15、24,Uncal herniation,Acute infarction1st day,Acute infarction 4th day,25,Uncal herniation,Before surgery, a big GBM in the left temporal lobe with uncal herniation.After surgery, the GBM was removed, the suprasellar c

16、istern and quadrigeminal cisterns are normal.,26,Uncal herniation,Acute infarction of right posterior artery (PCA), this is a complication of uncal/transtentorial herniation, because the PCA was compressed by brain herni

17、ation.,27,雙側(cè)大腦后動脈梗塞,28,雙側(cè)大腦后動脈梗塞,29,Durette hemorrhage,30,Durette hemorrhage,31,Kernohan’s notch顳葉疝壓跡,32,Uncal herniation,When mass effects within or adjacent to the temporal lobe occur, the medial portion of the tempora

18、l lobe (uncus) is forced medially and downward over the tentorium. There is ipsilateral pupillary dilation. The uncus is pushed medially into the suprasellar cistern. There is bilateral uncal herniation. The suprasellar

19、cistern is obliterated.,33,early uncal herniation,The right uncus is pushing into the suprasellar cistern; early right uncal herniation.,34,中心疝,35,中心疝,36,Superior vermian herniation ( ascending transtentorial herniation

20、),由于后顱凹的占位效應(yīng)，小腦蚓和小腦半球通過小腦幕切跡向上移動,37,陀螺狀外觀,38,雙側(cè)環(huán)池變窄,39,四疊體池充滿,40,不露齒的微笑,41,皺眉,42,第一天的四疊體池和環(huán)池,43,第二天，四疊體池和環(huán)池消失,44,腦積水,45,ascending transtentorial herniation,46,枕大孔疝,47,枕大孔疝,48,Tonsillar herniation,In tonsillar herniation

21、(rare), a mass effect in the posterior fossa causes the cerebellar tonsils to herniate inferiorly through the foramen magnum compressing the medulla and upper cervical spinal cord. Conscious patients complain of neck pa

22、in and vomiting. They may have nystagmus, pupillary dilatation, bradycardia, hypertension and respiratory depression. Early tonsillar herniation is difficult to recognize in an unconscious patient. It may not be evide

23、nt on CT scan since axial views cannot see the pathology well. It is best seen on sagittal MRI. Clinically changes in vital signs may be the only clinical clue in an unconscious patient.,49,Tonsillar herniation,50,a ma

24、le patient in his 30's who died of brain stem herniation after completing a marathon.,The CT shows (A) loss of the rostral cerebral sulci suggesting increase in ICP, (B) and (C) a large hydrocephalus with widening of

25、 both temporal horns. The grey matter can still be differentiated from the white matter, but all sulci are lost. This suggests that the brain oedema is of relative recent onset and massive tissue ischaemia has not yet oc

26、curred. (D) Compression of the fourth ventricle with dilatation of the third ventricle and the caudal aspect of both temporal horns. This is observed with considerable brain oedema and obstructive hydrocephalus. (E) Hern

27、iation of the medulla and pons into the foramen magnum. (F) The tonsils are located at the level of the dens which is a good indicator for foramen magnum herniation.,51,,(A) The disc shows florid hemorrhages with relativ

28、ely little swelling, indicating a rapid, dramatic increase in CSF pressure. Progressive changes of optic disc oedema are seen in a patient with an intracranial tumour who declined treatment (B-D). (B) Early nerve fiber d

29、ilatation is seen particularly superiorly, inferiorly and nasally. (C) This increases and venous engorgement develops. (D) Temporal nerve fiber dilatation and swelling of the disc increases and hemorrhages appear. (E) In

30、 gross chronic disc oedema the normal retinal vasculature is masked and dilated superficial capillaries are observed. (F) In atrophic optic disc oedema nerve fibers are eventually destroyed and the optic disc without via

31、ble nerve fibers does not swell. This patient had longstanding benign intracranial hypertension. Retinochoroidal venous collaterals are present (black arrowhead).,52,顱外疝,53,核磁選擇,1. Subfalcine herniation. This is best see

32、n on coronal MR images.2. Descending transtentorial herniation (uncal herniation, hippocampal herniation). best seen on coronal images, but the compression of the brainstem is best observed on axial T2-WI.3. Ascendin