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.     

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。     

Posterior cranial fossa dural arteriovenous malformation with a varix mimicking a thrombosed aneurysm: case report

Summary Dural arteriovenous malformations (AVMs) in the posterior cranial fossa are relatively infrequent. Intradural haemorrhage is one of their specific complications. Angiographic demonstration of varices or aneurysmal structures is one of the hallmarks of severe cases. We report a patient with posterior cranial fossa dural AVM associated with a varix mimicking a thrombosed aneurysm on CT and MRI. Internal carotid and vertebral angiography failed to demonstrate an aneurysm, but external carotid injection revealed a dural AVM affecting the sigmoid sinus, and a varix. The AVM was completely eliminated by embolization. When a dural AVM is suspected clinically selctive angiography should be performed to confirm the diagnosis even when CT or MRI do not show dilated vessels.     

Dural arteriovenous malformation in a child with Bannayan-Riley-Ruvalcaba Syndrome

Intracranial arteriovenous malformations (AVM) are a rare feature of Bannayan-Riley-Ruvalcaba syndrome (BRRS). Palencia et al reported a case of intracranial arteriovenous malformation in a child with BRRS in a Spanish journal in 1986. However, the occurrence of dural AVM in a patient with BRRS has not since been addressed in the literature. Advancements in imaging and therapeutic embolization, and the ability now to screen for phosphatase and tensin homologue (PTEN) mutations allow us to detect and manage these patients sooner. Early detection of intracranial AVMs is necessary because of the risk for progression to venous ischemia and resultant neurologic damage. We present the case of a child with headaches and periorbital venous congestion due to a dural AVM with bilateral venous outflow occlusion who was treated with multiple embolizations, now with interval remission of headache symptoms.     

Endovascular venous approach in the treatment of ruptured intra-cerebral arterio-venous malformation

Trans-venous approach has been described for endovascular treatment of many vascular lesions namely the intracranial dural, cavernous and intra-orbital malformations. A patient with a ruptured left deep parietal arteriovenous malformation (AVM) treated with primary transvenous Onyx 18 embolization is reported. Trans-arterial approaches were unsuccessful because of the tiny tortuous feeding arteries and hence a transvenous approach was used for embolization. Follow-up angiography at 3 month revealed persistent angiographic cure of the AVM. Our case illustrates that in patients with ruptured small AVM having a single draining vein, transvenous treatment can be utilized to achieve occlusion resulting in AVM cure.     

Digital intravenous substraction angiography of intracranial arteriovenous malformations

Twenty-one intracranial arteriovenous malformations (17 pial, 3 dural, 1 mixed) have been studied by digital intravenous subtraction angiography (DIVA). A comparison with conventional arteriography has been performed. In this series DIVA was 100% diagnostic for AVM. However DIVA missed some small arterial pedicles (1 lenticulostriate, 1 thalamoperforating, 1 anterior choroidal artery and 2 pharyngeal arteries). Sectorial analysis of AVM needs selective arteriography. DIVA is a good method for screening and follow-up of intracranial AVM, but selective arteriography is often still necessary to complete the pre-operative evaluation.     

脊髓血管畸形的血管内栓塞治疗：附九例报告

作者报道了９例经数字减影血管造影（ＤＳＡ）确诊后同时进行血管内栓塞治疗的脊髓血管畸形（ＡＶＭ）病例。根据ＤＳＡ显示的异常血管的部位、形态、分布和供血动脉及引流静脉情况将其分为两型：硬膜动静脉瘘（ＡＶＦ）型和硬膜内ＡＶＭ型，然后经导管注入栓塞物质进行栓塞治疗。栓塞后造影显示ＡＶＭ大部或完全消失，６例栓塞程度达１００％，平均９２．２％。在２个月至３年的随访期内，７例肢体肌力增加，症状明显改善。栓塞后反     

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.     

硬脊膜动静脉瘘的诊断和治疗进展

硬脊膜动静脉瘘(Spinal dural arteriovenous fistulaSDAVF)是一种常见的脊髓血管畸形,多发于50~60岁的男性,是不明原因的获得性病变[1]。其预后取决于就诊时的神经功能缺失情况[2]。由于本病的临床表现常不具有特异性,所以部分病例的诊断相当困难,早期认识本病非常重要。现就本病的病理、诊断及治疗进展进行综述。一、病理及病理生理SDAVF的瘘口常位于椎间孔处脊神经后根的硬脊膜袖口处,可单发或多发,引流静脉增粗并可返流入脊髓表面静脉或静脉丛。供血动脉为根软膜动脉。椎间孔硬脊膜袖口处的动静脉交通使正常的向心引流模式发生逆转…     

椎管内动静脉血管畸形的MRI诊断

目的 评价MRI对椎管内动静脉血管畸形的诊断价值。方法 回顾性分析手术及DSA证实的12例椎管内动静脉畸形（AVM）的MRI资料。结果 椎管内AVM根据部位分为髓内AVM，硬膜内髓周AVM及硬脊膜动静脉瘘（AVF），MRI表现为脊髓增粗，髓内或髓周密集的血管流空影，同时可显示出血及脊髓内的软化或水肿。结论 MRI是评价椎管内AVM十分敏感和有效的方法。     

Intraarterial digital subtraction angiography of spinal arteriovenous malformations

Intraarterial digital subtraction angiography (DSA) in two patients with spinal dural arteriovenous fistulas demonstrated the major feeding arteries and the venous drainage of the respective malformations. However, the dural component of the malformations--which distinguishes them from intradural malformations--could not be recognized, nor was normal cord vasculature demonstrated. In a patient with an intradural arteriovenous malformation (AVM), only major arterial feeders were demonstrated. Intraarterial DSA provides essential anatomic information with an increased margin of safety in spinal AVMs, but supplemental selective arteriography, conventional or digital, also is currently required.     

硬膜窦血栓形成的MRI表现(附6例分析)

目的：探讨硬膜窦血栓形成的ＭＲＩ表现。方法：６例硬膜窦血栓形成，均做了ＭＲＩ检查，其中２例用了ＳＴＩＲ，１例用了ＦＬＡＩＲ序列，３例作了增强检查（Ｇｄ－ＤＴＰＡ），５例作了ＭＲＶ。结果：右横窦栓塞２例，左横窦１例，上矢状窦３例，脑肿胀５例，静脉性脑栓塞２例，脑血肿１例。增强检查，脑皮质及皮质静脉增强１例。结论：ＭＲＩ对硬膜窦血栓形成的诊断有独特的价值。硬膜窦流空信号消失和硬膜窦狭窄、闭塞是直接征像。脑肿胀、静脉性脑梗塞、脑血肿是间接征像     

Angiographic follow-up of large cerebral AVMs incompletely embolized with isobutyl-2-cyanoacrylate

This study evaluated the long-term angiographic results in large cerebral arteriovenous malformations (AVMs) partially embolized with isobutyl-2-cyanoacrylate. Preembolization, immediate postembolization, and long-term follow-up angiograms were performed in 30 large, partially embolized brain AVMs. Particular attention was paid to the relative size of the residual AVM nidus and the embolized arterial feeders, to recruitment of new feeders, to the size of residual draining veins, and to the speed of arteriovenous shunt. Nine cases with less than 50% AVM nidus obliteration showed no significant morphologic changes. In 18 cases with 50-75% obliteration of the AVM nidus, 11 (61.1%) showed no significant changes, six (33.3%) showed enlargement of the AVM nidus, and one (5.5%) evolved to complete angiographic obliteration. In three cases with 75-99% AVM nidus obliteration, one remained unchanged, one showed an increase in the size of the AVM nidus, and one evolved to complete obliteration. Evaluation by plain film, CT, and cerebral angiography of the isobutyl-2-cyanoacrylate deposits showed that when the polymer was positioned predominantly in arterial feeders there was invariably reconstitution of the AVM nidus through leptomeningeal, deep medullary, and/or dural collaterals. This phenomenon did not occur when the isobutyl-2-cyanoacrylate was deposited mainly in the AVM nidus.     

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     

脊髓血管畸形的影像学诊断和血管内栓塞治疗

复杂的脊髓血管解剖，包括脊髓多来源的供养动脉和多去路的引流静脉，导致脊髓血管畸形的影像学诊断变得困难。脊髓血管畸形大致分为三类：髓内动静脉畸形、髓周动静脉瘘和硬脊膜动静脉瘘。髓内动静脉畸形的畸形团位于或大部分位于脊髓实质内。其供血动脉为脊髓前动脉及其分支，脊髓后动脉也经常同时参与供血。其引流静脉常同时向脊髓前、后静脉引流。最典型的临床症状为畸形团破裂出血。其治疗以分次血管内栓塞治疗为主。手术切除弊大于利，一般不采用。治疗的目的是改善症状而非解剖治愈。髓周动静脉瘘是脊髓外的软膜动脉与静脉的直接交通，常常是脊髓前动脉或脊髓后动脉与相应的静脉直接沟通。主要临床症状亦多为出血，亦可源于脊髓缺血或水肿。治疗方法和原则类似髓内动静脉畸形，但流速缓慢的位于圆锥和终丝部位的髓周动静脉瘘多手术切除。硬脊膜动静脉瘘几乎占所有脊髓血管畸形的80%。男女比例7:1,40岁以上多发。其瘘口位于硬脊膜内和硬脊膜内、外层之间，常靠近椎间孔的神经根，是根动脉的硬脊硬支与根髓静脉之间的直接交通。主要临床症状源于脊髓静脉高压引起的脊髓水肿和坏死。应用稀胶栓塞治疗成功率可达90%。胶一定要在瘘口和引流静脉起始端形成良好的铸型方能避免复发。手术夹闭瘘口简单，效果好，但创伤较大。     

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.     

Endovascular treatment of dural fistulas with the venous outflow of laterocavernous sinus

Objective

To report our findings concerning the laterocavernous sinus (LCS) drainage of dural fistulas, focusing our attention on the important implications in treatment of the LCS, which is one of the principal drainage pathways of the superficial middle cerebral vein (SMCV).

Methods

Consecutive 32 patients with dural fistulas treated endovascularly between 2005 and 2008 were reviewed. Seven patients had angiographic features such as dural fistulas draining with SMCV via LCS. Clinical records for these 7 patients were focused to determine their presenting symptoms, angiographic features, endovascular treatments, and clinical outcomes.

Results

Over 3 years, 7 patients had 7 dural fistulas drained with SMCV via LCS were treated. Six-vessel angiography confirmed the presence of the dural fistulas. All fistulas were Cognard Type III featured by leptomeningeal veins drainage. One fistula involving the lesser sphenoid wing and 6 fistulas involving CS were supplied by external carotid artery branches with or without dural branches of the internal carotid artery. LCS was identified as a contiguous to SMCV drainage in these cases. One patient was treated with transvenous coil embolization alone, two with transvenous a combination of Onyx and coil embolization, and 4 with transarterial embolization. An angiographic obliteration and clinical cure was achieved in all patients. Complication was local hair loss due to X-ray radiation in one patient.

Conclusion

It is very important to diagnose the presence of LCS in dural fistulas during the diagnostic angiography. It is believed that the knowledge of LCS might be relevant for the understanding and treatment of dural fistulas involving the LCS.     

Origin of spinal arteriovenous malformation and normal cord vasculature from a common segmental artery: angiographic and therapeutic considerations

The dural type of spinal arteriovenous malformation (AVM) can be cured by excision or by embolization of the nidus. The common origin of the blood supply to the malformation and to the cord from the same segmental artery would profoundly affect therapeutic choices. This anatomic situation was encountered in two of nine such lesions. The angiographic appearance and the importance of recognizing this common origin is discussed.     

Application of Time-Resolved 3D Digital Subtraction Angiography to Plan Cerebral Arteriovenous Malformation Radiosurgery

BACKGROUND AND PURPOSE:Time-resolved 3D-DSA (4D-DSA) enables viewing vasculature from any desired angle and time frame. We investigated whether these advantages may facilitate treatment planning and the feasibility of using 4D-DSA as a single imaging technique in AVM/dural arteriovenous fistula radiosurgery.MATERIALS AND METHODS:Twenty consecutive patients (8 dural arteriovenous fistulas and 12 AVMs; 13 men and 7 women; mean age, 45 years; range, 18–64 years) who were scheduled for gamma knife radiosurgery were recruited (November 2014 to October 2015). An optimal volume of reconstructed time-resolved 3D volumes that defines the AVM nidus/dural arteriovenous fistula was sliced into 2D-CT-like images. The original radiosurgery treatment plan was overlaid retrospectively. The registration errors of stereotactic 4D-DSA were compared with those of integrated stereotactic imaging. AVM/dural arteriovenous fistula volumes were contoured, and disjoint and conjoint components were identified. The Wilcoxon signed rank test and the Wilcoxon rank sum test were adopted to evaluate registration errors and contoured volumes of stereotactic 4D-DSA and integration of stereotactic MR imaging and stereotactic 2D-DSA.RESULTS:Sixteen of 20 patients were successfully registered in Advanced Leksell GammaPlan Program. The registration error of stereotactic 4D-DSA was smaller than that of integrated stereotactic imaging (P = .0009). The contoured AVM volume of 4D-DSA was smaller than that contoured on the integration of MR imaging and 2D-DSA, while major inconsistencies existed in cases of dural arteriovenous fistula (P = .042 and 0.039, respectively, for measurements conducted by 2 authors).CONCLUSIONS:Implementation of stereotactic 4D-DSA data for gamma knife radiosurgery for brain AVM/dural arteriovenous fistula is feasible. The ability of 4D-DSA to demonstrate vascular morphology and hemodynamics in 4 dimensions potentially reduces the target volumes of irradiation in vascular radiosurgery.

Radiosurgery is an effective treatment alternative for cerebral arteriovenous malformations^1–4 and intracranial dural arteriovenous fistulas (DAVFs).^5–10 In AVM/DAVF radiosurgery, irradiation is delivered in a single fraction stereotactically to only the nidus of an AVM or fistula of a DAVF.Our current clinical practice of AVM/DAVF radiosurgery, integrated stereotactic imaging (MR imaging/MRA and x-ray digital subtraction angiography) is used for nidus/fistula delineation. The integrated multiple-stop stereotactic imaging is considered the reference imaging for AVM/DAVF radiosurgery. MR imaging is superior in delineating radiosurgical target in 3D, and DSA excels in defining the hemodynamics of AVM/AVF and differentiating the nidus/fistula from feeding arteries and draining veins of AVM/DAVF.¹¹ However, the role of DSA as a projective 2D representation of 3D structures in defining the nidus is limited, especially when the AVM is large and the nidus has an oblique long axis relative to the orthogonal DSA projections.¹² Moreover, for AVMs that undergo partial embolization before radiosurgery, the nidus may become intricate, and it may be difficult to define its morphology on 2D-DSA or MR imaging/MRA.¹³ Recently, it was shown that conebeam CT 3D angiography can generate images of a high spatial resolution that depict low-flow nidal compartments better than both DSA and MR imaging, though it lacks temporal information.¹⁴ While our current practice has achieved high tissue conformity in AVM radiosurgery and good therapeutic results,¹⁵ an alternative technique, if chosen, must be able to provide panoramic morphological and hemodynamic evaluation of nidi/fistulas in 1 stop.In contrast to 2D-DSA, fully time-resolved 3D-DSA, also known as 4D-DSA, provides a series of time-resolved 3D volumes that correspond to contrast dynamics with a C-arm-based imaging system.¹⁶ While the reconstruction of a 4D-DSA image from a single rotational image acquisition has some inherited technical difficulties, as mentioned by Royalty,¹⁷ the volumetric vascular morphology and bolus-arrival patterns reconstructed from 4D-DSA algorithms are validated.¹⁷ An animal study based on a canine model also demonstrated that 4D-DSA is capable of delineating vasculature effectively.¹⁸ Small-series studies also suggested that 4D-DSA enhances the ability to visualize the vascular anatomy of an AVM.^19,20 Accordingly, 4D-DSA enables evaluating feeding arteries, nidi, and draining veins in sequential imaging in 3D and eliminates the issue of overlapped vasculatures.In this study, we compare the registration errors of stereotactic 4D-DSA with those of integrated stereotactic imaging and the vascular anatomy of AVMs and DAVFs depicted by 4D-DSA volumes with the planned dose contours for each recruited patient and evaluate whether 4D-DSA may facilitate the planning of AVM/DAVF radiosurgery by minimizing the irradiation volume as 1-stop imaging.     

Retrograde flow in the dural sinuses detected by three-dimensional time-of-flight MR angiography

Introduction Retrograde flow in the left dural sinuses is sometimes detected by three-dimensional time-of-flight (3D-TOF) magnetic resonance (MR) angiography. The purpose of this study was to evaluate the incidence of this phenomenon and its characteristic features on 3D-TOF MR angiograms. Methods We retrospectively reviewed cranial MR angiography images of 1,078 patients examined at our institution. All images were obtained by the 3D-TOF technique with one of two 1.5-T scanners. Maximum intensity projection (MIP) images in the horizontal rotation view were displayed stereoscopically. We reviewed the source images, inferosuperior MIP images, and horizontal MIP images and identified retrograde flow in the dural sinuses. Results We found retrograde flow in the dural sinuses of 67 patients on the source images from 3D-TOF MR angiography; the incidence was 6.2%. In 47 of the 67 patients, retrograde flow was identified in the left inferior petrosal sinus, in 13, it was seen in the left sigmoid sinus, and in 6, it was seen in the left inferior petrosal and left sigmoid sinuses. The remaining patient had retrograde flow in the left inferior petrosal and left and right sigmoid sinuses. The mean age of the patients with retrograde flow was slightly greater than that of the patients without this phenomenon (70 years vs 63 years). Conclusion Retrograde flow in the dural sinuses frequently occurs on the left side in middle-aged and elderly patients during 3D-TOF MR angiography performed with the patient in the supine position. This phenomenon should not be misdiagnosed as a dural arteriovenous fistula. This article was presented as an electronic poster paper at the 31st Congress of the ESNR held in Geneva in September 2006.