CT scan of dural arteriovenous fistulas

Summary CT was performed on ten cases of dural intracranial arteriovenous fistulas. There were 3 fistulas of the transverse sinus draining directly into the homolateral jugular vein; 2 fistulas of the sinus with distal occlusion of the sinus and back flow into the cortical veins (one was on the transverse sinus, the other on the sagittal sinus); 2 fistulas of the middle fossa; 3 fistulas with direct venous drainage into the cortical veins, one of these forming a tumor process in the posterior fossa. Osseous abnormalities were seen in only one case. Cerebral CT abnormalities, such as patchy or vermicular enhancement, were seen in all the cases with fistulas draining into the cerebral veins. Cerebral CT was normal in cases of fistulas of the sinus without back flow into the cerebral veins.     

Is there a dural wall between the cavernous sinus and the pituitary fossa? Anatomical and MRI findings

We compared MRI studies of the sellar area and embryological and adult histological studies of the cavernous sinuses and pituitary fossa. MRI studies were performed in 50 normal subjects with coronal sections using a fast inversion-recovery sequence to demonstrate the dural walls of the cavernous sinus and pituitary fossa. With this sequence, dura mater appears as a high-signal linear structure. The lateral and superior walls of the cavernous sinus was easily identified on all studies, but demonstration of a dural wall separating the cavernous sinus from the pituitary fossa was not possible. These results correlated well with embryological and adult histological studies obtained from 14 specimens. The absence of a strong separation between the pituitary fossa and the cavernous sinus explains the high incidence of extension of pituitary tumours to the cavernous sinuses and vice versa. Received: 5 January 1998 Accepted: 14 February 1998     

Follow-up MRI in dural arteriovenous malformations involving the cavernous sinus: emphasis on detection of venous thrombosis

Summary Six patients with a dural arteriovenous malformation (dural AVM) involving the cavernous sinus were followed up with magnetic resonance imaging in order to assess change in the lesions. Spin-echo (SE) imaging of three patients in whom the AVM appeared to have closed at least 1 month earlier (two of them spontaneously, and one after external carotid artery embolization) showed neither apparent flow void in the involved cavernous sinus nor evidence of venous thrombosis. SE images of the other three patients who had not been cured by external carotid artery embolization (two of whom were examined within a week of treatment), detected persisting arteriovenous shunts, including high-flow cortical venous drainage, seen as flow void. Two-dimensional time-of-flight MR angiography (2D TOF MRA) was performed simultaneously in three patients. Whereas shunting blood and the normal cavernous sinus were of high intensity, presumed thrombosed cavernous sinuses were isointense with stationary brain tissue. SE imaging can confirm the resolution of arteriovenous shunts, but poorly delineates ver acute and chronic thrombosis of the draining veins. In contrast, 2D TOF MRA directly demonstrates flowing blood, permitting the diagnosis of venous thrombosis; it should be included in follow-up of a dural AVM involving the cavernous sinus when venous thrombosis is suspected.     

Cerebral vascular malformations: applications of magentic resonance imaging to differential diagnosis

Summary Twelve patients with cerebral vascular malformations (5 cavernous angiomas, 1 thrombosed arteriovenous malformation, and 6 venous angiomas) were studied with magnetic resonance (MR) imaging. All lesions were clearly depicted. Characteristic MR findings were obtained mainly on T2-weighted images: a markedly low intensity area was always seen. The margins of arteriovenous malformation (AVM) and venous angioma were irregular while those of cavernous angioma were smooth in all planes on T2-weighted images. Gradient-echo (GrE) pulse sequences were more sensitive than T2-weighted spin echo (SE) in lesion detection. MR imaging could play an important role in the differential diagnosis of cerebral vascular malformations.     

Acute subdural hematoma due to arteriovenous malformation primarily in dura mater: a case report

We report a 42-year-old female with alcohol addiction who suddenly died of subdural hematoma (SDH) caused by dural arteriovenous malformation (AVM). In autopsy, there was seen a massive SDH with a total weight of 181 g that covered an entire part of the left cerebral hemisphere, although either serious external injuries of the head or any visible internal injuries of the brain were observed. SDH subsequently resulted in the tonsillar, transtentorial and subfalcial herniations with a right-sided shift of the left-lateral and third ventricles, and the left thalamus as well. Histopathological examination on the serial sections cut from the falx cerebri revealed abnormal distribution of arteries and veins with various sizes, which were comprehensively highlighted by immunohistochemical stainings with alpha-SMA and CD31. Although a very point of bleeding was not identified even by careful histological observation, we concluded that dural AVM could be critical for acute SDH in the present case. The value of ethanol concentration examined in the samples from SDH supported that the lesion could be not chronic, but acute.     

Haemorrhage in intracerebral arteriovenous malformations: detection with MRI and comparison with clinical history

Fifty-one patients with 59 angiographically proven cerebral arteriovenous malformations (AVMs) were examinded by high-field MRI to detect blood breakdown products. Results were correlated with the history of intracranial bleeding. Evidence of previous episodes of haemorrhage was seen in 10 of 12 patients (83.3%) with verified bleeding, in 4 of 9 patients (44.4%) with symptoms which could suggest bleeding and in 6 of 30 patients (20%) with negative histories. Because of the known rebleeding rate and the increased risk of associated complications, identification of the subgroup who had had haemorrhage and should therefore be considered for surgery may be beneficial. MRI can make a contribution to management by demonstrating prior haemorrhage in patients with an inadequate clinical history.     

The role of time-resolved 3D contrast-enhanced MR angiography in the assessment and grading of cerebral arteriovenous malformations

Purpose

To assess the role of three-dimensional (3D) contrast-enhanced, time-resolved MR angiography (CE TR MRA) in patients with intracranial arteriovenous malformations (AVMs).

Methods

We studied 12 patient with intracranial AVMs on a 3.0 T MR imaging system (Magentom TIM Trio, Siemens Medical Solutions, Erlangen, Germany) using 3D CE TR MRA with autocalibrating partially parallel acquisitions and echo sharing schemes, which provided temporal resolution of 0.58 or 1.7 s and near isotropic voxels. We qualitatively assessed image quality of the 3D CE TR MRA and compared the grading of the AVMs based on modified Spetzler-Martin system for 3D CE TR MRA and catheter digital subtraction angiography (DSA).

Results

CE TR MRA provided good quality images in the 3 standard orthogonal planes, and good arterial-venous separation in all cases. All AVMs were correctly graded by CE TR MRA when compared with DSA.3D CE TR MRA provides a non-invasive alternative to DSA for the evaluation of cerebral AVMs.     

Recovery of opthalmoplegia associated with cavernous sinus dural arteriovenous fistulas after transvenous cavernous sinus packing

Background

We report the recovery of ophthalmoplegia in 11 patients with cavernous sinus dural arteriovenous fistula (CSDAVF) after sinus packing at follow-up.

Methods

Of 18 patients with CSDAVF treated with transvenous cavernous sinus packing between August 2002 and December 2007 at Beijing Tiantan Hospital, there were 9 patients with initial CNIII or CNVI dysfunction and 2 patients with CNVI dysfunction immediately after cavernous sinus packing selected and reevaluated.

Results

Of 11 patients with CNIII or CNVI palsy, recovery was complete in 10. In 1 patient, complete CNVI palsy was unchanged because the CSDAVF was not cured. There were 6 men and 5 women with a mean age of 52.9 years. In 5 patients, CNVI palsy was associated with chemosis, proptosis and pulsatile tinnitus. Timing of treatment after onset of symptoms was from 4 to 35 days in 9 patients. All CSDAVFs were Barrow type D. Mean follow-up after treatment was 17.7 months (range, 2-54 months).

Conclusion

CSDAVF-induced CNIII or CNVI palsies can be cured after cavernous sinus packing transvenously in most patients.     

MR 3D-CISS序列对脊髓AVM的诊断价值

目的：评价MR 3D稳态构成干扰序列(constructive interference in steady state，CISS)对脊髓AVM的诊断价值。方法：回顾性分析26例脊髓动静脉畸形(arteriovenous malformations，AVM)患者的3D-CISS成像表现，并与DSA结果进行对照。结果：DSA显示16例脊髓AVM表现为脊髓背侧一条稍粗大的畸形血管干和分布于硬脊膜内许多高度迁曲的细小分支，呈蚯蚓状、匐行状迂曲血管影，脊髓表面纹理被穿透；7例则显示为一条扩张的引流静脉；3例表现为球状局限性血管丛。23例3D-CISS表现与DSA结果基本一致，3例DSA证实为胸段AVM，而3D-CISS发现为全段脊髓AVM。根据手术病理和最终诊断结果，3D-CISS序列诊断脊髓AVM的敏感性和特异性分别为92％、98％。结论：3D．CISS序列对疑为脊髓AVM病人有很好的筛选作用，其敏感性较高。     

Delayed angiography in the investigation of intracerebral hematomas caused by small arteriovenous malformations

We reviewed the clinical and radiological features of ten patients with small arteriovenous malformations that caused intracerebral hematomas. In six patients, angiography showed a small nidus (less than 1 cm in diameter) with a shunt at the site of the hematoma, and in four only an early-filling vein was evident. Six patients had only delayed angiography (4 weeks or more after the ictus). In three, angiography within 2 days of the ictus failed to reveal the cause of the bleed, but repeat angiography showed an early-filling vein in two, and a nidus with shunting in one. In only one patient did early angiography reveal the malformation. MRI was obtained in eight patients, and in two prominent vessels were evident in the wall of the hematoma cavity. In investigation of an unexplained intracerebral hematoma, MRI may be useful to exclude a neoplasm or cavernoma, although the latter may be not be evident in the presence of a recent hematoma. We suggest early MRI and angiography for investigation of an unexplained, nonhypertensive intracerebral bleed, with follow-up MRI and delayed angiography if the initial studies fail to reveal the cause.     

Transvenous embolization of a dural arteriovenous fistula of the cavernous sinus through the contralateral pterygoid plexus

We report a new transvenous endovascular route for treatment of dural arteriovenous fistulas of the cavernous sinus. The cavernous sinus was approached from the contralateral pterygoid plexus and embolization of a dural fistula was performed successfully with Guglielmi detachable coils. Received: 16 June 1997 Accepted: 6 August 1997     

Pelvic arteriovenous malformations: gadolinium-enhanced three-dimensional MR angiography findings

Pelvic arteriovenous malformations (PAVMs) are rare disorders traditionally diagnosed by conventional angiography. Breath-hold three-dimensional gadolinium-enhanced MR angiography (3D-Gd-MRA) is a state-of-the-art alternative for vascular imaging. We describe the 3D-Gd-MRA findings in two patients with PAVMs. The 3D-Gd-MRA approach provides a noninvasive and versatile method for evaluation of PAVMs that enables both angiographic assessment of the malformations and evaluation of visceral involvement, which can preclude surgical intervention. Received: 15 September 1999; Revised: 27 December 1999; Accepted: 27 December 1999     

Idiopathic dural herniation of the thoracic spinal cord

Symptomatic anterior or anterolateral dural herniation of the spinal cord is rare, and not uncommonly misdiagnosed, both clinically and radiologically. We present four patients with a radiological diagnosis of herniation of the thoracic spinal cord, and review the current literature. All affected patients have been adults, typically presenting with long-standing, unexplained sensory symptoms and eventually developing a Brown-Séquard syndrome, with or without motor changes. Herniation occurs in the upper or midthoracic region, between the T2 and T8 levels.     

Enhanced cervical MRI in identifying intracranial dural arteriovenous fistulae with spinal perimedullary venous drainage

Diagnosis of an intracranial dural arteriovenous fistula (DAVF) with spinal perimedullary venous drainage is challenging because the presenting symptoms are usually related to dysfunction of the spine, not of the brain. Repeated spinal angiograms are usually performed before the diagnosis is finally made by cerebral angiography. We report two cases of intracranial DAVFs with spinal perimedullary venous drainage. In both cases contrast-enhanced cervical MRI demonstrated dilated lower brainstem and upper spinal veins, which, we believe, is a good indicator of the existence of such drainage. We suggest that, in cases with perimedullary serpentine enhancement on thoracic or lumbar MR images, additional Gd-enhanced cervical spinal MR imaging should be performed. The simple process of tracing the veins upwards may avoid a lot of unnecessary examinations and delay in the diagnosis. Received: 3 July 1997 Accepted: 6 August 1997     

磁共振成像对硬脊膜动静脉瘘的诊断及随访价值

目的：讨论MRI对硬脊膜动静脉瘘（SDAVF）的初步诊断及随访价值。方法：回顾性分析资料完整的13例SDAVF患者的手术前后或栓塞前后MRI资料。结果：13例患者中手术前或栓塞前诊断为椎间盘突出7例,脊髓炎3例,神经根炎1例,正确诊断2例,误诊率高。分析MRI片提示病灶区脊髓呈现平均连续5个椎体节段长T2信号,T1、T2加权像髓外硬膜下可见密集的血管流空影。10例患者在T1增强中见到迂曲扩张的冠状静脉丛,术后或栓塞后3－6个月复查MRI,长T2信号及血管流空影消失。结论：MRI对硬脊膜动静脉瘘（SDAVF）的诊断治疗具有较可靠的初诊及随访意义,脊髓长T2信号及血管流空影对诊断有意义。     

海绵窦侵袭型垂体瘤磁共振诊断系统及其相关因素分析

目的：探讨MR对海绵窦侵袭型垂体瘤的诊断价值，寻求建立一套海绵窦侵袭型垂体瘤的MR诊断系统。方法：选取手术中已经确诊的39例海绵窦侵袭型垂体瘤，同期162例非侵袭型垂体瘤做对照，应用计算机分析冠状位MR上肿瘤与海绵窦的关系。包括海绵窦形态的改变、窦内间隙的改变以及肿瘤与颈内动脉海绵窦段的关系等。将相关的各个类型均做为拟诊标准分别计算各自的灵敏度(Se)、特异度(Sp)、阳性预告值(PV )、阴性预告值(PV-)。依据医学统计学原理中的判别分析法进一步系统分析MR图像对于是否海绵窦侵袭型垂体瘤的诊断意义。结果：肿瘤包绕颈内动脉≥70％确诊侵袭的意义最大(PV ，100％)，肿瘤超过颈内动脉外侧连线的诊断意义也较高(PV ，86．1％)；如果肿瘤包绕颈内动脉的角度不到20％、肿瘤未超过颈内动脉内侧连线以及海绵窦内侧间隙未出现肿瘤则可以排除海绵窦侵袭的存在。同时应用判别分析法建立了一个海绵窦侵袭型垂体瘤及非海绵窦侵袭型垂体瘤的统计学判别计量数值表。从而完善了海绵窦侵袭型垂体瘤MR图像诊断系统。结论：通过系统分析垂体瘤加RI的表现，能够比较准确的确立海绵窦侵袭型垂体瘤的诊断。     

Magnetic resonance imaging of cavernous sinus cavernous hemangiomas

Summary Radiological findings of surgically verified cavernous hemangiomas of the cavernous sinus are presented with special reference to the appearance in magnetic resonance imaging. Differences in radiological features of the cavernous sinus cavernous hemangiomas and intracerebral cavernous hemangiomas are discussed.     

Dynamic gadolinium-enhanced MRI in the detection of spinal arteriovenous malformations

Arteriovenous fistulae and malformations (AVFs and AVMs) of the spinal cord are rare, potentially treatable causes of progressive disability. Although a variety of MRI abnormalities has been described, the diagnosis rests on the findings on selective spinal angiography.Collecting T2^*-weighted MR images during the passage of a gadolinium bolus gives information about perfusion and blood volume. We carried out dynamic MRI in seven patients with vascular abnormalities (5 dural AVFs, 1 intramedullary AVM, 1 cryptic angioma) and in two patients without an AVM. High resolution T1- and T2-weighted sagittal images of the whole spinal cord were first obtained using a multiarray receiver coil. Sagittal radiofrequency spoilt gradient echo images (GE34/25, flip angle 10⁰) were then obtained during bolus injection of gadolinium-DTPA. Abnormalities were seen in all seven patients with AVFs or AVMs. In the patient with an intramedullary AVM and four of the five with dural AVFs transient signal reduction was seen within the perimedullary venous plexus during passage of the bolus. The findings correlated well with those from selective spinal angiography. We conclude that dynamic MRI offers a useful adjunct to angiography and may localise an arteriovenous shunt when conventional MRI fails to do so. In combination with high-resolution imaging of the entire spinal cord the technique may make myelography redundant; it is simple, well tolerated and can be carried out without significant time penalty.     

硬脊膜动静脉瘘的MRI和DSA影像学特点及栓塞治疗

目的 探讨硬脊膜动静脉瘘的MRI和DSA影像学特点及血管内栓塞治疗方法。方法 12例硬脊膜动静脉瘘患者均行MRI和脊髓血管造影检查,4例行栓塞治疗。分析其MRI和血管造影表现。结果 12例硬脊膜动静脉瘘中,MRI屉示脊髓内弥漫性长T2信号影11例,脊髓斑片状强化2例,脊髓背侧异常血管影6例。脊髓血管造影均能显示其瘘口和引流静脉,并反映其病变范围、供血状况及特征。4例行栓塞治疗患者其临床症状均有改善。结论 脊髓血管造影是诊断硬脊膜动静脉瘘的主要确诊方法。MRI对确定诊断具有重要作用。血管内栓塞是一种有效的治疗方法。     

MR动态减影血管造影在脑动静脉畸形治疗前后中的评价

目的评价MR动态减影血管造影（MR-DSA）在脑动静脉畸形（AVM）栓塞治疗前后的价值和限度。方法22例AVM患者，在栓塞前后均行MR—DSA、三维增强MR血管造影（3D—CEMRA）、MR质子加权成像（PWI）和DSA检查，同时由2名有经验的医生独立进行双盲对照研究。结果MR-DSA和DSA在22例AVM栓塞前后的瘤巢大小及分类上结果一致，MR—DSA能够显示AVM栓塞后的血液动力学改变，瘤巢及引流静脉显影推迟17例，瘤巢变小13例（其中完全消失4例），与DSA符合率为100％。与DSA相比，MR-DSA没有显示瘤巢内动脉瘤和栓塞后引流静脉及供血动脉直径变小各1例，而3D-CEMRA对此显示清晰。栓塞后的PWI与栓塞前相比，22例均可见不同程度的高信号。结论MR—DSA是1种快速、有效、无创的血管造影检查方法，能提供AVM栓塞前后的血流动力学信息，MR—DSA、3D-CEMRA和PWI应在AVM的随访中相互结合，综合运用。