脑静脉血栓形成影像学(1).pptx

Cerebral Venous Thrombosis,Barbara Simons,Geert Lycklama a Nijeholt and Robin Smithuis Radiology department of the Medical Centre Haaglanden in the Hague and the Rijnland hospital in Leiderdorp,the Netherlands,脑静脉性栓塞形成,Introduction When to think of venous thrombosis Dense clot sign Empty delta sign Absence of normal flow void on MR Venous infarction Imaging in suspected thrombosis CT-venography MR-venography DSA Pitfalls in CT Arachnoid Granulations Mimick of dense clot sign Pseudo empty delta sign Wrong bolus timing Pitfalls in MRI Hypoplastic transverse sinus Low signal intensity in thrombus Flow void on contrast-enhanced MR Chronic dural sinus thrombosis and related syndromes DAVF Thrombosis and increased CSF pressure Venous territories,Publicationdate October 21,2010 Cerebral venous thrombosis is an important cause of stroke especially in children and young adults.It is more common than previously thought and frequently missed on initial imaging.It is a difficult diagnosis because of its nonspecific clinical presentation and subtle imaging findings.In this article we will focus on:Findings on routine imaging that should make you think of unsuspected venous thrombosis.How to image patients in suspected venous thrombosis.Pitfalls.,此时应想到静脉栓塞可能致密斑块征空三角征MR上正常流空征消失静脉性脑梗塞疑似此病的成像方法CT静脉成像MR静脉成像DSACT陷阱蛛网膜颗粒酷似致密凝块征假性空三角征错误的团注时间MRI陷阱横窦发育不良血栓内低信号强度MR对比增强时的流空硬膜窦栓塞临床与相关综合征DAWF（硬膜动静脉瘘）栓塞和脑脊液压力增高静脉分布图,静脉性脑梗塞是中风的重要原因，尤其是在儿童或年轻人。它比以前更常见而且常常在最初的成像中漏诊,由于临床上缺少特征而且影像所见微妙，因而诊断困难,这里主要讨论的内容：*提示可疑静脉性脑梗塞的常规影像学表现*疑为静脉性脑梗塞如何进一步进行影像学检查*陷阱,Cerebral venous thrombosis is located in descending order in the following venous structures:Major dural sinuses:Superior sagittal sinus,transverse,straight and sigmoid sinuses.Cortical veins:Vein of Labbe,which drains the temporal lobe.Vein of Trolard,which is the largest cortical vein that drains into the superior sagittal sinus.Deep veins:Internal cerebral and thalamostriate veins.Cavernous sinus.Clinically patients with cerebral venous thrombosis present with variable symptoms ranging from headache to seizure and coma in severe cases.In neonates shock and dehydration is a common cause of venous thrombosis.In older children it is often local infection,such as mastoiditis,or coagulopathy.In adults,coagulopathies is the cause in 70%and infection is the cause in 10%of cases.In women,oral contraceptive use and pregnancy are strong risk factors.,重要的解剖与临床,脑静脉性栓塞多位于以下的静脉结构*主要静脉窦：上矢状窦、横窦、直窦和乙状窦。*皮质静脉：Labbe静脉，颞叶的引流静脉；Trolard 静脉，为最大的皮质静脉，汇入上矢状窦。*深静脉：大脑内静脉和丘脑纹状体静脉。*海绵窦。*临床上，脑静脉栓塞可有多种症状，严重病例如头痛、癫痫、昏迷。*新生儿休克或脱水是脑静脉栓塞常见的原因。*在儿童，局灶性的感染如中耳炎或凝血障碍。*成人中，70%的病因为凝血障碍；10%源自感染 女性，口服避孕药与妊娠也是其危险因素。,When to think of venous thrombosis,On a routine non-enhanced MR or CT you should think of the possibility of venous thrombosis when you see:Direct signs of a thrombusInfarction in a non-arterial location,especially if it is bilateral and hemorrhagicCortical or peripheral lobar hemorrhage Cortical edema,Venous thrombosis has a nonspecific presentation and therefore it is important to recognize subtle imaging findings and indirect signs that may indicate the presence of thrombosis.,Although these findings are often present on initial scans,they are frequently detected only in retrospect.Clinically patients with venous thrombosis often present with seizures,which is not a symptom in patients with an arterial infarction.,什么情况下考虑静脉窦栓塞呢？,在常规的CT或MR平扫图像若有下面的表现应该想到静脉性脑栓塞可能：*静脉血栓的直接征象*脑梗塞非动脉性的常见部位，尤其是为双侧性、出血性*皮质或周围脑叶的出血*脑皮质水肿,脑静脉血栓形成为非特异性的表现，因此，认识这些微妙的影像学的表现以及间接征象很重要，它可以指出血栓形成之存在。,静脉血栓形成的病人在临床上常表现癫痫，但这不是动脉性脑梗塞病人出现的症状。,尽管这些表现经常地出现在最初的扫描中，但却经常只是在回顾中发现这些异常。,11、透明隔静脉12、丘脑纹状体静脉13、大脑内静脉14、大脑大静脉15、基底静脉24、直窦25、蝶顶窦26、海绵窦27、海绵间窦29、岩上窦30、岩下窦,1、上矢状窦2、下矢状窦3、窦汇4、横窦5、乙状窦6、颈静脉球7、颈内静脉8、浅表皮层静脉9、静脉10、大脑中浅静脉,Trolard静脉,Labbe静脉,Rosenthal基底静脉,附加：正常解剖图与静脉栓塞的病理解剖示意图,正常脑静脉窦示意图,上矢状窦及脑静脉栓塞伴发的脑肿胀及损伤,损伤的脑组织出血,Dense clot sign（1）Direct visualization of a clot in the cerebral veins on a non enhanced CT scan is known as the dense clot sign.It is seen in only one third of cases.Normally veins are slightly denser than brain tissue and in some cases it is difficult to say whether the vein is normal or too dense(see pitfalls).In these cases a contrast enhanced scan is necessary to solve this problem.,*致密凝块征（1）：CT平扫见到的脑静脉血栓的直接表 现，出现率为1/3.*正常的脑静脉表现为密度较脑组织轻度高，但有些 病例的正常与否判断确有困难（参见陷阱）。*CT增强扫描可准确地解决该问题。,Dense clot sign(2)Visualization of a thrombosed cortical vein that is seen as a linear or cord-like density,is also known as the cord sign.Another term that is frequently used,is the dense vessel sign.,Dense clot sign(3)On the left images of a patient with a hemorrhagic infarction in the temporal lobe(red arrow).Notice the dense transverse sinus due to thrombosis(blue arrows).,*致密凝块征（2）：CT平扫见到的脑皮质静脉血栓的表 现，呈线样或绳索样高密度影，即所谓绳索征（上图 红箭）。也有称其为致密血管征。,*致密凝块征（3）：CT平扫显示颞叶出血性梗 塞（红箭）。*注意因血栓导致的左侧横窦高密度（蓝箭）。,Two cases of empty delta sign due to thrombosis of the superior sagittal sinus.,Empty delta sign（1）The empty delta sign is a finding that is seen on a contrast enhanced CT(CECT)and was first