Multidetector CT angiography in diagnosing type I and type IVA spinal vascular malformations

Multidetector CT (MDCT) angiography is an imaging technique that can provide high-resolution and high-contrast images; however, published reports of MDCT angiography in the evaluation of spinal vascular malformations are limited. We present 2 cases in which MDCT angiography led to diagnosis of a type I (spinal dural arteriovenous fistula) in one and type IVA (perimedullary spinal cord simple arteriovenous fistula fed by a single arterial feeder) spinal vascular malformation, both confirmed by conventional angiography. MDCT angiography can localize the feeding vessel and the fistula, thus greatly reducing the amount of time required for conventional angiography.     

Spinal vascular malformations: MR angiography after treatment

PURPOSE: To evaluate the role of magnetic resonance (MR) angiography in the assessment of spinal vascular malformation therapy. MATERIALS AND METHODS: Thirty-four patients with spinal vascular malformations (30 dural arteriovenous fistulas, two perimedullary arteriovenous fistulas, and two intramedullary arteriovenous malformations) underwent MR angiography and MR imaging before and after endovascular or surgical treatment. RESULTS: MR angiography showed residual flow in perimedullary vessels in seven patients with dural fistula after embolization with liquid adhesive. In all seven, treatment failure was confirmed with arteriography. Long-lasting disappearance of flow in perimedullary vessels was demonstrated at MR angiography in 22 patients with dural fistula. MR imaging demonstrated normalization of spinal cord volume in 16 of 22 patients and signal intensity on T2-weighted images in three patients. Disappearance of cord enhancement was observed in five of 21 patients and of perimedullary enhanced vessels in six of 13 patients. In one additional patient with dural fistula treated with embolization, early posttreatment MR angiography showed disappearance of flow in perimedullary vessels, which reappeared at follow-up and was consistent with reopening of a small residual fistula. Posttreatment MR angiography demonstrated transient reduction of flow in the nidus in two patients with intramedullary malformations treated with embolization. Permanent disappearance of flow in the perimedullary vessel was seen after endovascular treatment in two patients with perimedullary fistula. CONCLUSION: MR angiography is more sensitive than MR imaging in depicting residual or recurrent flow in peri- or intramedullary vessels, which indicates patency of the vascular malformation.     

The so-called transcerebral veins: appearance in three different cases.

The radiologic findings in three patients with dilated transcerebral (medullary) veins detected on routine computed tomography and/or magnetic resonance imaging were reviewed. Sectional imaging showed the dilatation of transcerebral veins as well as the dilated superior ophthalmic veins in all patients. It also demonstrated the primary pathology: vein of Galen aneurysmal malformation; dural sinus fistula with varix; and dural arteriovenous fistula. All three patients had both arteriovenous fistula and sinovenous occlusion. We concluded that the dilated transcerebral veins developing secondary to elevation of the cerebral venous pressure, might be the useful radiologic finding of some dural vascular pathologies on sectional imaging.     

搏动性耳鸣的CT和DSA

目的：采用CT和DSA探讨疗效显著的搏动性耳鸣的病因,总结针对搏动性耳鸣患者的最佳影像学检查方法。方法：回顾性分析102例经手术或介入治疗后搏动性耳鸣消失或明显减轻患者的CT和DSA资料,患者均行颅面部双期增强CT扫描和DSA检查。结果：102例引起搏动性耳鸣的病变包括颈内动脉海绵窦瘘（CCF）41例,海绵窦区及横窦、乙状窦区硬脑膜动静脉瘘25例,乙状窦憩室15例,颈静脉球体瘤12例,鼓室球瘤5例,颅外动静脉畸形3例,面颊部动静脉瘘1例。CT显示CCF39例,显示率为95.1%;硬脑膜动静脉瘘18例,显示率为72%;颅外动静脉畸形2例,显示率为66.7%;对乙状窦憩室、颈静脉球体瘤及鼓室球瘤的显示率为100%。DSA对所有病变均能显示,DSA显示血管畸形的能力明显优于CT（P=0.004）,CT对CCF的显示率明显高于对血管畸形的显示率（P=0.006）。结论：疗效显著的搏动性耳鸣常见病因是CCF和硬脑膜动静脉瘘,双期CT增强扫描和DSA是寻找病原因的重要方法,CT可取代DSA作为筛选方法。     

MR angiography of spinal vascular malformations.

PURPOSETo determine the potential and limitations of MR angiography in the evaluation of spinal vascular malformations.METHODSEleven consecutive patients with spinal vascular malformations proved with spinal selective arteriography underwent two-dimensional phase-contrast MR angiography.RESULTSAbnormal vessels within the spinal canal were identified with MR angiography in 10 patients. In 1 patient with a dural arteriovenous fistula no definite vascular abnormality was seen with MR angiography. Correlation of MR angiography with spinal selective arteriography showed that the former allowed identification of the arterial feeder in 3 patients with intramedullary arteriovenous malformations and 2 with perimedullary arteriovenous fistula, whereas the source of intradural draining vein was seen in only 2 of 6 patients with dural arteriovenous fistula.CONCLUSIONMR angiography is a promising complementary tool to MR imaging for detection and characterization of spinal vascular malformations.     

Intracranial dural arteriovenous fistulas: evaluation with combined 3D time-of-flight MR angiography and MR digital subtraction angiography

OBJECTIVE: The purpose of this study was to compare the diagnostic utility of 3D time-of-flight (TOF) MR angiography and MR digital subtraction angiography in patients with angiographically proven moderate- to high-flow intracranial dural arteriovenous fistula. MATERIALS AND METHODS: Two neuroradiologists, unaware of patients' histories and angiographic findings, retrospectively reviewed 17 MR angiograms with 3D TOF MR angiography and MR digital subtraction angiography in 15 patients with dural arteriovenous fistula and also reviewed 35 MR angiograms in control patients without findings of dural arteriovenous fistula on angiography. Disagreements were resolved by consensus. RESULTS: In patients with dural arteriovenous fistula, source images of 3D TOF MR angiography showed two abnormal findings: multiple high-intensity curvilinear or nodular structures adjacent to the sinus wall and high-intensity areas in the venous sinus. Findings of multiple high-intensity structures adjacent to the sinus wall were observed in all cases of dural arteriovenous fistula. Findings of high-intensity areas in the venous sinus were observed in 13 of 17 cases of dural arteriovenous fistula. Findings of multiple high-intensity structures adjacent to the sinus wall were not observed in any control subjects. Findings of high-intensity areas within the venous sinus were observed in five of 35 control subjects. Findings of MR digital subtraction angiography showed early filling of the venous sinus, suggestive of dural arteriovenous fistula, in 13 of 15 patients with dural arteriovenous fistula. Sensitivity and specificity of multiple high-intensity structures adjacent to the sinus wall, high-intensity areas in the venous sinus, and early filling of the venous sinus were 100% and 100%, 76% and 86%, and 87% and 100%, respectively. Although 3D TOF MR angiography failed to show the findings of retrograde cortical venous drainage and venous sinus occlusion, MR digital subtraction angiography clearly showed both findings in all five subjects. CONCLUSION: A protocol including both 3D TOF MR angiography (source images) and MR digital subtraction angiography allowed the diagnosis of moderate- to high-flow dural arteriovenous fistula. In addition, cortical venous drainage was reliably noted in a small subset of patients.     

Preangiographic evaluation of spinal dural arteriovenous fistulas with elliptic centric contrast-enhanced MR Angiography and effect on radiation dose and volume of iodinated contrast material

BACKGROUND AND PURPOSE: The detection and localization of spinal dural arteriovenous fistulas (AVFs) remain diagnostic challenges. This study tested the hypothesis that elliptic centric contrast-enhanced MR angiography (MRA) can be used to detect spinal dural AVFs, predict the level of fistulas, and reduce the radiation dose and volume of iodinated contrast material associated with conventional angiography. METHODS: We examined 31 patients who presented with suspected spinal dural AVF between December 2000 and March 2004. All patients underwent MRA and conventional angiography. The effect of MRA on subsequent conventional angiography was assessed by analyzing total fluoroscopy time and volume of iodinated contrast material used. RESULTS: At angiography, spinal dural AVFs were diagnosed in 22 of 31 patients, and MRA depicted an AVF in 20 of the 22 patients. MRA findings correctly predicted a negative angiogram in seven of nine cases. Of the 20 true-positive MRA results, the level of the fistula was included in the imaging volume in 14. In 13 of these 14 cases, MRA results correctly predicted the side and the level of the fistula to within one vertebral level. Fluoroscopy time and the volume of contrast agent was reduced by more than 50% in the 13 patients with a spinal dural AVF in whom MRA prospectively indicated the correct level. CONCLUSION: Contrast-enhanced MRA can be used to detect spinal dural AVFs, predict the level of fistulas, and substantially reduce the radiation dose and volume of contrast agent associated with catheter spinal angiography.     

Contrast-enhanced time-resolved MR angiography of spinal vascular malformations.

PURPOSE: The purpose of this work was to assess the potential and limitations of a contrast-enhanced time-resolved MR angiography technique for evaluation of spinal vascular malformations. METHOD: Two patients with intramedullary arteriovenous (AV) malformations and three patients with dural AV fistula underwent four serial acquisitions, every 17-20 s, of 20-32 coronal 1.5- to 2-mm-thick partitions with a fast 3D SPGR sequence after injection of 0.2-0.3 mmol/kg paramagnetic contrast agent. This was followed by coronal 3D and sagittal or coronal 2D phase contrast (PC) MR angiography. RESULTS: No spinal vessels were visualized in the first (baseline) series. In patients with intramedullary AV malformations, the arterial feeders, nidus, and perimedullary draining veins were visualized in the second (early) series. In the third (intermediate) series, the arterial feeder vanished, whereas the intercostal and lumbar veins appeared. In patients with dural AV fistula, abnormal intraspinal vessel appeared in the third series and persisted, although less conspicuous, in the fourth (late) series. Contrast-enhanced time-resolved MR angiography demonstrated the venous components of the lesion with better conspicuity than 3D PC MR angiography, whereas it was inferior for visualization of arterial feeders. Moreover, indirect identification of the level of the dural AV fistula was possible only on the phase display of the 2D PC MR angiography. CONCLUSION: Contrast-enhanced time-resolved MR angiography is a useful complement to PC MR angiography for the evaluation of spinal vascular malformation.     

Dynamic 3D MR angiography of intra- and extracranial vascular malformations at 3T: a technical note

Time-resolved, contrast-enhanced 3D MR angiography combined with parallel imaging at 3T was applied to an intracranial arteriovenous malformation, a dural arteriovenous fistula, and an extracranial facial arteriovenous malformation. The temporal resolution was one image every 1.5 seconds. Arterial feeders were depicted in all three cases. Early venous drainage was observed in the intracerebral arteriovenous malformation and the dural arteriovenous fistula, but not in the facial arteriovenous malformation. All findings were concordant with conventional angiography.     

Spinal dural arteriovenous fistula localization with a technique of first-pass gadolinium-enhanced MR angiography: initial experience

Nine patients with initial magnetic resonance (MR) imaging and clinical findings suggestive of spinal dural arteriovenous fistula (AVF) underwent spinal MR angiography with an autotriggered elliptic centric ordered three-dimensional gadolinium-enhanced technique (hereafter, this MR angiographic technique) before conventional intraarterial angiography. In all nine patients, findings with this MR angiographic technique correctly and precisely localized the spinal dural AVF. Observer error resulted in one case in which the site of the fistula was not prospectively reported but was easily identified retrospectively on the spinal MR angiogram.     

First-line investigation of acute intracerebral hemorrhage using dynamic magnetic resonance angiography

Purpose: To report the initial experience of magnetic resonance (MR) digital subtraction angiography (MR-DSA) in the dynamic assessment of the cerebral circulation in acute non-traumatic intracerebral hemorrhage (ICH).

Material and Methods: Twelve patients with acute ICH were investigated within 6 days of the ictus using a dynamic contrast-enhanced 2-D MR angiogram that produces subtracted images with a temporal resolution of 1-2 frame/s. The MR-DSA examinations were assessed for evidence of an intracranial vascular abnormality and were compared with (i) the routine MR sequences, (ii) non-dynamic time-of-flight MR angiography, and (iii) catheter angiogram performed during the same admission.

Results: All 12 MR-DSA examinations were considered to be technically satisfactory. MR-DSA detected an intracranial vascular abnormality in 7 patients (3 arteriovenous malformations, 2 aneurysms, 1 dural arteriovenous fistula, and 1 venous thrombosis). All abnormalities were confirmed by catheter angiography with the exception of one patient with venous sinus thrombosis found on MR imaging that did not undergo catheter angiography. All four arteriovenous shunts were detected by MR-DSA by virtue of early venous filling.

Conclusion: MR-DSA can be performed satisfactorily in the setting of acute ICH and provides an alternative method to catheter angiography for identifying shunting vascular abnormalities such as arteriovenous malformations and fistulae, as well as large aneurysms and venous occlusions. MR-DSA is a contrast-medium-based technique that does not suffer from the T1 shortening effects of acute hemorrhage that can obscure abnormalities on conventional flow-based non-dynamic techniques.     

颅内动静脉瘘的CT和MRI诊断价值

目的:探讨CT和MRI对颅内动静脉瘘的诊断价值。方法:回顾性分析18例颅内动静脉瘘的CT和MRI表现。18例均经DSA检查明确诊断。其中12例行CT检查;16例行MRI检查,同期6例行MRA检查。结果:颅内动静脉瘘的CT和MRI的特征性表现为脑沟、脑裂、基底池内血管影增粗、增多,呈散在分布,受累及的静脉窦增粗,且病变区没有畸形血管团。海绵窦硬脑膜动静脉瘘在T2WI上表现为局部流空信号增宽,MRA原始图像显示局部有较丰富的异常纤细血流信号。结论:认识颅内动静脉瘘的CT和MRI表现,有助于早期诊断及治疗。MRI对显示软脑膜血管扩张优于CT。选择性脑血管造影是确诊本病的可靠手段。     

Unilateral subcortical calcification: a manifestation of dural arteriovenous fistula

We describe the imaging findings in a dural arteriovenous fistula (AVF) with unilateral subcortical calcification. A 50-year-old woman patient suffered from hypertension and chronic headache. Recently, marked headache and a changed consciousness level were noted. The imaging studies demonstrated left subcortical calcification and cerebral sulcus effacement. MR imaging and angiography revealed multiple abnormal tortuous vessels, mainly from left external carotid artery with left-sided transverse sinus occlusion. The final diagnosis was type II a + b dural AVF (classification of Djindjian and Merland), and the patient underwent endovascular embolization and radiosurgery.     

Incidental discovery of a dural arteriovenous fistula in a patient with activated protein C resistance

A dural arteriovenous fistula was discovered incidentally in a 58-year-old man with activated protein C resistance who underwent routine outpatient cerebral angiography for workup of multiple intracranial aneurysms.     

椎管内血管畸形的血管造影诊断与血管内介入治疗

目的:探讨椎管内血管畸形的血管造影诊断与血管内介入治疗效果。方法:回顾性分析66例椎管内血管畸形的选择性动脉造影与栓塞治疗资料。结果:66例椎管内血管畸形的血管造影表现为隐匿性髓内血管畸形者6例,余60例均能显示病变的范围、血供情况及其特征。12例髓内动静脉畸形、17例硬脊膜动静脉瘘和9例髓周动静脉瘘接受了栓塞治疗,其愈显率分别为58.3%、64.7%和66.7%。所有栓塞病例均无严重并发症发生。结论:经选择性血管造影确诊后行栓塞治疗是椎管内血管畸形安全有效的治疗手段。     

MR imaging findings of intracranial dural arteriovenous fistulas: relations with venous drainage patterns

BACKGROUND AND PURPOSE: Venous drainage patterns are a major determinant of clinical outcome in intracranial dural arteriovenous fistula (DAVF) patients. In this study, we sought to identify MR imaging finding differences between DAVF types classified on the basis of venous drainage patterns. METHODS: Twenty-seven patients diagnosed as having DAVFs by conventional angiography were included. Medical records (n = 27), and MR imaging (n = 27) and MR angiography (MRA; n = 11) findings were retrospectively reviewed. MR imaging findings included flow void cluster, engorged ophthalmic vein/proptosis, white matter hyperintensity, intracranial hemorrhage, dilated leptomeningeal or medullary vessels, venous pouch, and leptomeningeal or medullary vascular enhancements. MRA findings included identifiable fistula, venous flow-related enhancement, and prominent extracranial vessels. Patients' presentations and MR imaging findings were compared among angiographic type I, II, and III cases (according to Borden's classification), and MRA findings were compared between cases with and without retrograde leptomeningeal venous drainage (RLVD). RESULTS: Patient presentations were aggressive in one (13%) of the type I cases, 5 (50%) of the type II cases, and 8 (100%) of the type III cases (P = .002). Aggressive presentations included hemorrhage, focal neurologic deficits, seizures, intracranial hypertension, and an altered mental status. MR images showed significantly higher frequencies of dilated leptomeningeal or medullary vessels in a higher type [0 in type I, 5 (42%) in type II, and 7 (100%) in type III], and of leptomeningeal or medullary vascular enhancements [0 in type I, 4 (33%) in type II, and 7 (100%) in type III]. By using MRA, fistulas were identified only in cases with RLVD (5 [83%]). Venous flow-related enhancement was present in 10 cases (91%). A sole false-negative case on MRA, as compared with conventional angiography, resulted from nonvisualization of the slow venous flow (8%). No false-positive fistula was found at the other intracranial sites in all cases. Overall, MRA assessment for DAVF was adequate for both fistula and venous flow-related enhancement in 10 cases (91%) and inadequate in a remaining case because of the fistular location out of field. CONCLUSION: MR imaging demonstration of leptomeningeal or medullary vascular dilation and enhancements may be associated with features that are considered predictors of a poor outcome and indicates a need for urgent therapy in intracranial dural AVF patients. MRA is a complementary tool for the identification of dural AVF with venous flow-related enhancement.     

64层螺旋CT血管成像诊断脊髓血管畸形的价值

目的 探讨64层螺旋CT 血管成像(CTA)对脊髓血管畸形的诊断价值.方法 经临床和MR检查拟诊为脊髓血管畸形的15例患者进行了CTA.所有患者均在1周内进行了DSA检查.其中4例行于术治疗.将CTA图像与DSA和手术所见进行对照,从判定畸形的类型、显示病变累及的范围、供血动脉、引流静脉和可能存在的瘘口等方面,对CTA图像进行评价.结果 15例脊髓血管畸形经DSA和手术确诊,分别为6例髓内动静脉畸彤、2例髓周动静脉瘘、3例硬脊膜动静脉瘘和4例Cobb综合征.CTA对15例患者的分类和对病变累及范围的判断与DSA结果一致.CTA清晰显示了病变的主要供血动脉和引流静脉.5例动静脉瘘中4例CTA判断的瘘口位置与DSA所见一敛,另1例为复杂血管畸形,瘘口难以辨别.CTA还清晰显示了4例Cobb综合征位于椎旁和皮下的畸形血管团.结论 64层螺旋CTA可以判定脊髓血管畸形的类型,快速、无创地显示其主要病变特征,可作为该病的筛查手段.     

Tinnitus: imaging algorithms.

The causes of tinnitus can be grouped according to whether the noise is continuous or pulsatile, whether it is subjective or objective and whether there is a retrotympanic mass. Imaging algorithms can be based on these symptoms and signs. For patients with nonpulsatile tinnitus and a normal drum, magnetic resonance imaging is preferred if a retrocochlear lesion is suspected, whereas high-resolution computed tomography (HRCT) is recommended if a cochlear abnormality is likely. If a chronic inflammation in the middle ear is suspected, HRCT is the study of choice to differentiate cholesteatoma from chronic otitis media. If the bruit is objective and the tympanic membrane normal, selective cerebral angiography should be the initial investigation, because most such patients have an acquired vascular abnormality, usually a dural arteriovenous fistula. If there is pulsatile tinnitus and a retrotympanic mass, HRCT should be the first examination because this technique allows differentiation of a vascular variation, such as an aberrant carotid artery or jugular dehiscence, from a paraganglioma.     

血管内介入治疗硬脑膜动静脉瘘的新进展

硬脑膜动静脉瘘是较常见的颅内血管畸形,目前尚无理想治疗方案,且易并发脑出血。数字减影血管造影(DSA)技术可清楚显示瘘口发生部位、供血动脉及引流静脉,是诊断硬脑膜动静脉瘘的金标准。本研究着重介绍新型材料Onyx在血管内栓塞治疗中的应用、疗效与注意事项,主要探讨血管内介入治疗硬脑膜动静脉瘘的研究新进展。     

Spinal vascular malformations

Spinal vascular malformations are rare diseases that consist of true inborn cavernomas and arteriovenous malformations (including perimedullary fistulae, glomerular and juvenile AVMs) and presumably acquired dural arteriovenous fistulae. This review article gives an overview of the imaging features both on MRI and angiography, the differential diagnoses, the clinical symptomatology and the potential therapeutic approaches to these diseases. It is concluded that MRI is the diagnostic modality of first choice in suspected spinal vascular malformation and should be complemented by selective spinal angiography. Treatment in symptomatic patients offers an improvement in the prognosis, but should be performed in specialized centers. Patients with spinal cord cavernomas and perimedullary fistulae type I are surgical candidates. Dural arteriovenous fistulae can either be operated upon or can be treated by an endovascular approach, the former being a simple, quick and secure approach to obliterate the fistula, while the latter is technically demanding. In spinal arteriovenous malformations, the endovascular approach is the method of first choice; in selected cases, a combined therapy might be sensible.