Isolated cortical venous thrombosis and ulcerative colitis.

Aseptic cortical venous thrombosis is rare without concomitant dural sinus thrombosis. Ulcerative colitis is associated with both dural sinus thrombosis and isolated cortical venous thrombosis. We describe a 26-year-old woman with ulcerative colitis who had a spontaneous cerebral hemorrhage. An overlying thrombosed cortical vein was identified on spin-echo MR images and confirmed with angiography. Signal characteristics of thrombosed cortical veins are similar to those described in dural sinus thrombosis.     

Evaluation of the intracranial dural sinuses with a 3D contrast-enhanced MP-RAGE sequence: prospective comparison with 2D-TOF MR venography and digital subtraction angiography

BACKGROUND AND PURPOSE: The diagnosis of dural sinus thrombosis is often difficult because of its variable and nonspecific clinical presentation and the overlapping signal intensities of thrombosis and venous flow on conventional MR images and MR venograms. We compared 3D contrast-enhanced magnetization-prepared rapid gradient-echo (MP-RAGE) sequences with 2D time-of-flight (TOF) MR venography, digital subtraction angiography (DSA), and conventional spin-echo (SE) MR imaging for the assessment of normal and abnormal dural sinuses. METHODS: In a phantom study, a plastic tube with pulsating flow was used to simulate the intracranial dural sinus. With 3D MP-RAGE, a variety of flow velocities, contrast material concentrations, and angulations between the phantom flow tube and the plane of acquisition were tested to measure their relationship to signal-to-noise ratio (SNR). In a clinical study, 35 patients, including 18 with suspected dural sinus thrombosis, were studied with both MR imaging and DSA. Receiver operating characteristic (ROC) analysis was performed in a blinded fashion using DSA as the reference standard. RESULTS: With the phantom, the SNR of flow increased with increasing contrast concentration, but was not affected by the angle between the tube and scan slab. There was no relationship between SNR and velocity when the contrast concentration was 1.0 mmol/L or greater. In the clinical study, dural sinus thrombosis as well as the normal anatomy of the dural sinuses were seen better with 3D contrast-enhanced MP-RAGE than with 2D-TOF MR venography. Three-dimensional contrast-enhanced MP-RAGE showed the highest diagnostic confidence on ROC curves in the diagnosis of thrombosis. CONCLUSION: Three-dimensional contrast-enhanced MP-RAGE is superior to 2D-TOF MR venography and conventional SE MR imaging in the depiction of normal venous structures and the diagnosis of dural sinus thrombosis, and is a potential alternative to DSA.     

Cerebral MR venography: normal anatomy and potential diagnostic pitfalls

BACKGROUND AND PURPOSE: MR venography is often used to examine the intracranial venous system, particularly in the evaluation of dural sinus thrombosis. The purpose of this study was to evaluate the use of MR venography in the depiction of the normal intracranial venous anatomy and its variants, to assess its potential pitfalls in the diagnosis of dural venous sinus thrombosis, and to compare the findings with those of conventional catheter angiography. METHODS: Cerebral MR venograms obtained in 100 persons with normal MR imaging studies were reviewed to determine the presence or absence of the dural sinuses and major intracranial veins. RESULTS: Systematic review of the 100 cases revealed transverse sinus flow gaps in 31% of the cases, with 90% of these occurring in the nondominant transverse sinus and 10% in the codominant transverse sinuses. No flow gaps occurred in the dominant transverse sinuses. The superior sagittal and straight sinuses were seen in every venogram; the occipital sinus was seen in only 10%. The vein of Galen and internal cerebral veins were also seen in every case; the basal veins of Rosenthal were present in 91%. CONCLUSIONS: Transverse sinus flow gaps can be observed in as many as 31% of patients with normal MR imaging findings; these gaps should not be mistaken for dural sinus thrombosis.     

Dural sinus occlusion: evaluation with phase-sensitive gradient-echo MR imaging

The purpose of this study was to evaluate the usefulness of limited-flip-angle, phase-sensitive velocity imaging with gradient-recalled-echo (VIGRE) MR when combined with spin-echo MR in the diagnosis of dural sinus thrombosis. The VIGRE sequence consists of a rapid single-slice acquisition, 50/15/2 (TR/TE/excitations), and 30 degrees flip angle. At each slice position, a total of four images were reconstructed; these consisted of one magnitude image and three images sensitive to proton motion in each orthogonal direction. The flow direction and flow velocity (cm/sec) were obtained from each of the phase images, and results were correlated with data obtained from a phantom experiment. In normal controls, dural sinus velocities ranged from a mean of 9.9 to 14.4 cm/sec for the transverse and superior sagittal sinuses, respectively. Three patients with proved dural sinus occlusion were studied with spin-echo images at 1.5 T. Three-dimensional time-of-flight MR angiography was also performed in one patient. The presence of dural sinus occlusion was determined by the lack of flow void on the spin-echo images, the absence of phase shift on the VIGRE study, and the presence of retrograde flow on the phase image in the sinus proximal to the occluded segment. Time-of-flight angiography overestimated the extent of the thrombosis caused by spin saturation. Follow-up VIGRE studies detected the formation of collateral flow in one patient and recanalization with the establishment of normal antegrade sinus flow in the other. We conclude that phase-sensitive MR imaging is helpful in establishing the diagnosis and extent of dural sinus occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Dural arteriovenous fistula: a pitfall of time-of-flight MR venography for the diagnosis of sinus thrombosis

We report a case in which time-of-flight MR venography falsely suggested thrombosis of a dural sinus later shown to be patent by conventional angiography and superselective venography. Received: 30 January 1997 Accepted: 6 August 1997     

MR staging of acute dural sinus thrombosis: correlation with venous pressure measurements and implications for treatment and prognosis.

PURPOSETo correlate parenchymal brain changes, venous sinus pressure measurements, and outcome in 29 patients with acute dural sinus thrombosis.METHODSA retrospective review of 29 patients with angiographically proved acute dural sinus thrombosis was made from January 1989 to December 1993. MR examinations were performed on either a 0.5- or 1.5-T superconductive scanner in multiple planes. Direct dural sinus venography, cerebral angiography, and MR venography were performed. Venous sinus pressure measurements were obtained in 11 of 29 patients.RESULTSWe identified five distinct stages of brain parenchymal changes; each stage correlated with increasing intradural sinus pressure. The pressures measured in this study ranged from 20 to 50 mm Hg. Brain parenchymal changes were reversible up to stage III if thrombolytic treatment was performed. Beyond stage III, there were some residual changes, even after thrombolysis. All stage V patients died.CONCLUSIONAcute dural sinus thrombosis leads to distinct stages of parenchymal changes, the severity of which depends on the degree of venous congestion, which, in turn, is closely related to intradural sinus pressure. As intradural sinus pressure increases, progression from mild parenchymal change to severe cerebral edema and/or hematoma may occur if thrombolysis is delayed.     

Dural sinus thrombosis: study using intermediate field strength MR imaging

The magnetic resonance (MR) images of six patients with thrombosis of a dural sinus were reviewed. The diagnosis had been verified by computed tomographic scans in three patients and arteriograms in two; in the sixth patient, only MR imaging was used to confirm the clinical syndrome. In all patients, high-intensity signal was seen from the thrombus within the affected dural sinus on all echoes. This persistent signal intensity allowed intravascular clot to be distinguished from normal causes of increased signal such as flow-related enhancement (entry phenomenon) and even-echo rephasing. MR imaging demonstrated the cause of the thrombosis in three patients: two were secondary to adjacent tumors, and one was secondary to unsuspected mastoiditis. Complications such as infarction were also demonstrated. Using MR imaging, one can easily and safely diagnose thrombosis of a dural sinus. MR should be the imaging method of choice in patients suspected of having thrombosis of a dural sinus.     

Documented development of a dural arteriovenous fistula in an infant subsequent to sinus thrombosis: case report and review of the literature

Controversy exists as to whether sinus thrombosis is the cause or the result of dural arteriovenous fistula (DAVF) and to whether DAVF are congenital or acquired lesions, especially in children. An infant presented with rupture of an anterior communicating artery aneurysm diagnosed with computed tomography angiography and catheter angiography. Pretreatment hospital course was complicated by extensive dural sinus thrombosis. Subsequent arteriography showed a new adult-type dural arteriovenous fistula to the previously thrombosed right sigmoid sinus. This is the first report of definitive angiographic documentation of the development of an adult-type DAVF after recanalization of a thrombosed dural sinus in a child. This case confirms the acquired etiology of at least one type of DAVF in children, even at this young age. We review the previously documented cases of formation of DAVF subsequent to sinus thrombosis with serial angiography in adults.     

Emergency MR imaging of the central nervous system

Magnetic resonance (MR) of the central nervous system has few, but important indications for use in the acute setting. This report reviews the few true current clinical indications for emergency MR imaging, including ruling out spinal cord compression, vascular dissection or dural venous sinus thrombosis. Possible indications for emergency MR, including evaluation of acute stroke symptomatology, potential meningoencephalitis or vasculitis, are also presented. Future applications for MR, including MR angiography in the setting of acute subarachnoid hemorrhage and spectroscopy in acute ischemia, are mentioned.     

脑磁共振静脉成像

目的：磁共振静脉成像(MRV)已被广泛应用于颅内静脉系统检查，特别是用来评价静脉窦血栓形成。本研究的目的是评价脑MRV描述正常颅内静脉系统解剖和变异的作用，评价它在诊断硬脑膜窦血栓形成过程中潜在的误诊因素。材料和方法：对79例常规磁共振表现正常的MRV图像进行分析，观察硬脑膜窦和主要静脉的表现和缺失情况。其中7例志愿者接受了MRV和3DPCMRA两种方法检查。结果：上矢状窦、直窦、Galen静脉和大脑内静脉显示率为100％，枕窦显示率为10％，基底静脉显示率为92％。横窦血流间隙显示率约为34％，均出现在非优势侧横窦，优势侧横窦没有出现流动间隙。结论：MRV是有效的评价颅内静脉系统方法。常规MR表现正常者中有34％可以发现横窦流动间隙，这些流动间隙不应被误诊为静脉窦血栓形成。     

静脉窦血栓形成的CT和MR影像特点

目的：研究静脉窦血栓形成（ＶＳＴ）的ＣＴ和ＭＲ特点。方法：对１７例ＶＳＴ的ＣＴ和ＭＲ特点进行回顾性影像分析，重点研究ＶＳＴ与皮层下多发性脑内血肿（ＳＣＭＨ）的联系，诊断与鉴别诊断。结果：ＳＣＭＨ在ＶＳＴ中出现率为１００％（１７／１７）。９例ＶＳＴ病例ＭＲ随访显示血肿、水肿和静脉窦内血栓进行性吸收，血肿周围可见规则完整的含铁血黄素沉积圈。结论：ＣＴ上急性ＳＣＭＨ是ＶＳＴ很强的一个诊断指征。ＭＲ可以进一步除外瘤卒中，发现静脉窦内血栓，以明确ＶＳＴ的诊断     

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.     

Acute thrombosis of the intracranial dural sinus: direct thrombolytic treatment.

Acute intracranial dural sinus thrombosis may have severe morbidity or fatal complications without appropriate treatment. Direct dural sinus venography can be performed safely with a soft Tracker catheter to document the fresh thrombus as an adjunct to CT or MR. We are reporting our experience with successful direct urokinase thrombolytic therapy in three cases of superior sagittal sinus and two cases of transverse and sigmoid sinus thrombosis. All five patients have recovered completely without any residual clinical deficit.     

Diffusion- and perfusion-weighted MR imaging of dural sinus thrombosis

A patient with dural sinus thrombosis had progressively worsening symptoms and signs that resolved after intradural thrombolysis. Intradural sinus pressures were 54 mm Hg. Echo-planar MR imaging revealed complex abnormalities of diffusion and widespread delay in mean transit time that improved immediately after thrombolysis. This case suggests that diffusion- and perfusion-weighted imaging can provide valuable information noninvasively to help triage patients with dural sinus thrombosis between conservative and aggressive management.     

Report on the ECR2003 (European Congress of Radiology): non-contrast intracranial MR venography with 3D-phase contrast imaging: optimization of presaturation pulse and velocity encoding

BACKGROUND: Intracranial MR venography is useful for the diagnosis of dural sinus thrombosis and the preoperative assessment of sinus patency encased by tumors. Recently, contrast-enhanced MR venography has been applied for suspected dural sinus occlusion in a shorter time. However, it has some disadvantage for the evaluation of hypervascularized enhancing thrombus mimicking flow in chronic sinus thrombosis. So far, we have evaluated optimal imaging technique and slice orientation and have shown that sagittal three-dimensional (3D) -phase contrast (PC) imaging is the most suitable for the non-contrast intracranial MR venography. PURPOSE:To assess the optimal presaturation pulse (SAT) and velocity encoding (VENC) for the non-contrast intracranial 3D-PC MR venography. METHODS AND MATERIALS: Firstly, we performed phantom experiment to assess the best SAT thickness using arterial presaturation. Second, MR imaging was performed in 7 healthy volunteers to measure the dural sinus flow velocity using a 1.5 T MR. Third, 3D-PC MR venography was performed with a VENC settings at 10, 15, 20 and 30 cm/sec for healthy volunteers. All data were displayed as maximum intensity projection images and three neuroradiologists assessed the visibility of the dural sinuses and the cortical vein. RESULTS: The mean flow velocity of the dural sinuses was 6.3 cm/sec. The thickness of the best SAT was 100 mm. In the assessment of the visibility of the 3D-PC images, dural sinuses were adequately visualized at a VENC of 15 cm/sec. CONCLUSIONS: Non-contrast intracranial 3D-PC MR venography was optimized at 100mm thickness of SAT and a VENC of 15 cm/sec.     

Sinus pericranii: clinical and imaging findings in two cases of spontaneous partial thrombosis

Sinus pericranii is an unusual venous anomaly characterized by communication of pericranial varicosities with an underlying dural sinus. We report two cases of spontaneous partial thrombosis of sinus pericranii presenting as focally tender, nonreducible mass lesions different in character from the baseline venous abnormality. CT, CT angiography, and CT venography (CTV) were performed in both cases. CTV was essential in depicting thrombi within the varicosities. MR (in one case) demonstrated the anomaly well, but the thrombus was not evident. Conservative therapy was instituted in both cases.     

颅内静脉血栓形成的磁共振诊断

目的:探讨磁共振成像(MRI)及磁共振静脉成像(MRV)对颅内静脉窦血栓形成(CVST)的诊断价值。方法:回顾性分析经临床和影像学方法确诊的14例CVST患者。MR检查技术包括平扫,增强扫描及MRV,14例均行CT平扫,其中1例行DSA检查。结果:14例CVST累及上矢状窦血栓形成4例,横窦血栓形成6例、乙状窦5例,MRI可清晰显示颅内静脉窦血栓形成的直接征象和间接征象,MRV可显示受累静脉窦不显影或者充盈缺损形成。结论:常规MRI结合MRV对颅内静脉窦血栓形成的早期诊断具有重要价值。     

Suspected dural arteriovenous fistula: results with screening MR angiography in seven patients.

Previous studies have shown that spin-echo (SE) magnetic resonance (MR) imaging has been helpful in the assessment of dural arteriovenous fistula (DAVF); however, direct visualization of the fistula site is limited. Thus, conventional plain angiography is required to establish the diagnosis. Because of this limitation, the additional use of MR angiography may improve noninvasive screening for this disorder. Seven patients with DAVFs proved at plain angiography were evaluated with SE MR imaging and with three-dimensional (3D) time-of-flight (TOF) MR angiography. In six of seven cases, 3D TOF MR angiography demonstrated the fistula site. Correlation was good when compared with findings at plain angiography. Occlusion of the dural sinus was found at plain angiography in three of seven patients but was missed at SE imaging in all three. MR angiography also failed to demonstrate sinus occlusion in two of three patients. Arterial feeders could not be seen on SE MR images, but MR angiography improved their depiction. Plain angiography demonstrated abnormal venous drainage into distended cortical veins in three patients, but dilated cortical veins were noted in only two of the patients on both SE MR images and MR angiograms.     

Giant arachnoid granulation in a patient with benign intracranial hypertension

We report magnetic resonance (MR), computed tomography (CT) and angiographic imaging of an unusual giant arachnoid granulation in the superior sagittal sinus in a man with headache and vertigo. Intrasinus pressure measurements revealed a significant pressure gradient across the lesion. MR imaging is useful to identify giant arachnoid granulation and dural sinus thrombosis, whereas dural sinus pressure measurement in certain cases of giant arachnoid granulations can be used to evaluate the lesion as the cause of the patient's symptoms.