Dilated Cortical Veins Research Articles

Diagnostic Accuracy of 3D Contrast-Enhanced T1 High Resolution Isotropic Volume Excitation MRI for Non-Cavernous Intracranial Dural Arteriovenous Fistula

Objective: To determine the accuracy of 3D contrast-enhanced THRIVE MRI in diagnosis of non-cavernous intracranial dural AVF compared with DSA. Materials and Methods: Thirty-three patients including fourteen dural AVF cases and nineteen control subjects, were included in the present study. They underwent 3D contrast-enhanced THRIVE MRI by 3T, contrast-enhanced MRA, and DSA. Two independent readers reviewed 3D contrast-enhanced THRIVE images for the presence of transosseous arterial feeders, low signal intensity curvilinear structures in the dural venous sinus, shaggy dural sinus, and cortical venous dilatation. Diagnostic performance values were calculated for 3D contrast-enhanced THRIVE MRI. Results: The 3D contrast-enhanced THRIVE MRI identified 23 from 29 locations of dural AVFs. The overall accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 91.4%, 79.3%, 93.5%, 67.6% and 96.3%, respectively. Shaggy dural sinus and dilated cortical veins were found in 78.6% and 85.7%, respectively. Conclusion: The 3D contrast-enhanced THRIVE MRI is a valuable tool for diagnosis of dural AVF as well as exclusion of dural AVF due to high sensitivity and specificity. Keywords: Dural arteriovenous fistula; Dural AVF; 3D contrast-enhanced THRIVE MRI

Teaching Neuro Images : Reversible cognitive impairment with bithalamic lesions caused by a dural arteriovenous fistula

A 54-year-old man developed apathy and memory impairment in 3 months. MRI showed bilateral thalamic hyperintensities with dilated cortical veins in the right cerebellum. Angiography revealed dural arteriovenous fistula (dAVF) at right transverse-sigmoid sinuses with retrograde flow through the vein of Galen (figure 1). Transvenous coil embolization improved his MRI findings (figure 2) and Wechsler Memory Scale–Revised scores from 55 at baseline to 105 in the delayed recall index.

Change in cortical vein appearance on susceptibility-weighted MR imaging before and after carotid artery stenting

<title/>Objectives: Susceptibility-weighted (SW) magnetic resonance (MR) imaging is a sensitive test to detect intravenous deoxygenated blood. On SW images, dilated appearing draining veins in tissue with perfusion impairment occur due to an increase in intravenous deoxyhemoglobin levels, and could indicate poor perfusion areas in which there is an elevated oxygen extraction fraction. In this study, patients with possible chronic ischemia caused by internal carotid artery stenosis underwent carotid artery stenting (CAS). Changes in cortical vein diameters were evaluated before and after CAS using SW imaging.Methods: Twenty-two patients with 25 lesions underwent 3 T SW imaging before and after CAS. The diameters of cortical veins were measured on SW images. Blood flow reduction and cerebrovascular reserve were examined before CAS using a single-photon emission computed tomography (SPECT) study, including an acetazolamide stress test.Results: Two of six patients with both decreased blood flow and reduced cerebrovascular reserve on SPECT showed significantly increased cortical vein diameters on pre-CAS SW images (P<0·05). After CAS, these same two patients demonstrated a significant decrease in their cortical vein diameters (P<0·05).Discussion: The present study demonstrates that dilated cortical veins as seen on SW imaging may reflect areas of altered oxygen extraction fraction due to chronic ischemia in patients with carotid artery stenosis, and that cortical venous dilatation is reversed after successful CAS. In the future, estimations of the cortical vein diameters on SW imaging may help to qualitatively evaluate areas of poor perfusion in chronic ischemia.

Susceptibility-Weighted Magnetic Resonance Imaging Detects Impaired Cerebral Hemodynamics in the Superior Sagittal Sinus Thrombosis -Case Report-

An 11-year-old female receiving treatment for acute lymphoblastic leukemia presented with superior sagittal sinus (SSS) thrombosis. T(1)-weighted, T(2)-weighted, and fluid-attenuated inversion recovery magnetic resonance (MR) imaging, and MR venography showed that the SSS was totally occluded by thrombus. Susceptibility-weighted MR imaging showed hypointense thrombus in the SSS and markedly dilated cortical veins over the bilateral cerebral hemispheres. Two days later, her symptoms had slightly resolved. Iodine-123 N-isopropyl-p-iodoamphetamine single photon emission computed tomography showed marked decrease of cerebral blood flow in the bilateral frontal lobes, indicating that venous congestion had disturbed the cerebral hemodynamics. MR venography showed that the SSS was still mostly occluded, but susceptibility-weighted imaging showed that the dilation of the cortical veins was less marked, suggesting that collateral venous routes had gradually developed. The finding of dilated cortical veins had almost disappeared at 28 days after the onset. Susceptibility-weighted imaging can be used as a non-invasive method to monitor the severity of venous congestion caused by cerebral venous sinus thrombosis.

Venous Aneurysm Development Associated With a Dural Arteriovenous Fistula of the Anterior Cranial Fossa With Devastating Hemorrhage-Case Report-

A 67-year-old man presented with devastating intracranial hemorrhage (ICH) from an anterior cranial fossa dural arteriovenous fistula (DAVF). Four years earlier, digital subtraction angiography had disclosed a DAVF at the right anterior cranial fossa fed mainly by the ethmoidal branches of the bilateral sphenopalatine arteries and slightly by the ethmoidal arteries of the bilateral ophthalmic arteries, and drained primarily by the sphenoparietal and cavernous sinuses via two dilated cortical veins and slightly by the superior sagittal sinus via a frontal ascending vein. Three-dimensional computed tomography angiography revealed the development of a venous aneurysm on the main draining vein over a 4-year period, but no other changes. Venous aneurysm development may be part of the natural history of DAVF with cortical venous drainage and may contribute to the occurrence of ICH.

MRI and SPECT studies of dural arteriovenous fistulas presenting as pure progressive dementia with leukoencephalopathy: a cause of treatable dementia

We report two patients with dural arteriovenous fistulas (DAVFs) who presented with pure progressive dementia. Both patients showed only slowly progressive dementia, without headache, papilledema and other neurologic signs associated with diffuse white matter changes in MRI. MR cerebral angiography showed sigmoid sinus DAVFs that were mainly supplied by the occipital artery, together with retrograde filling of the superior sagittal and straight sinus and dilated cortical veins. SPECT studies showed extensive blood flow reduction in the occipital and parieto-occipital areas and right temporal lobe in one patient. Selective embolization for treatment of the DAVF improved cognitive function associated with the abnormal white matter MRI signal. MRI and SPECT showed that severity of dementia correlated with diffuse white matter changes and regional cerebral blood flow. Our cases suggest that gradually impaired cerebral circulation due to venous hypertensive encephalopathy could be involved in slowly progressive dementia with leukoencephalopathy resulting from a DAVF. DAVFs may be particularly important for differential diagnosis in elderly patients with pure progressive dementia. Thus, early diagnosis of DAVFs and treatment by endovascular surgery is important as treatable or reversible dementia.

Rapid cognitive decline following lumbar puncture in a patient with a dural arteriovenous fistula

Dural arteriovenous fistulas (DAVFs) are frequently accompanied with raised intracranial pressure and clinical findings suggestive of pseudotumor cerebri. However, unlike pseudotumor cerebri, the clinical response to lumbar cerebrospinal fluid (CSF) removal can vary from beneficial to acute clinical deterioration leading to death. The criteria for the safe use of lumbar puncture (LP) in patients with a DAVF are not well established. A 61-year-old man presented with visual difficulty. Magnetic resonance imaging (MRI) and angiography revealed a left transverse sinus DAVF. He underwent multiple embolizations of arterial feeders over 3 years. He was then noted to have cognitive deficits in short term memory, listening, and concentrating. Over several days after an LP he became increasingly lethargic but arousable. Within hours after a repeat LP there was a rapid deterioration in the patient's level of consciousness and he became unarousable. A brain MRI revealed extensive dilated cortical veins and left temporal lobe venous ischemia without tonsillar herniation. A cerebral angiogram showed an extensive left transverse sinus DAVF with an occluded lateral transverse sinus and increased retrograde venous drainage. Embolization of the arterial feeders in combination with trans-venous coil embolization of the left transverse sinus reversed the patient's neurologic decline. He was discharged neurologically intact except for his chronic visual acuity problems. We speculate that when a DAVF manifests retrograde venous flow sufficient to cause cognitive deficits, lumbar CSF drainage must be undertaken with extreme caution.

Phase-contrast MR angiography of intracranial dural arteriovenous fistulae.

MRI and phase-contrast MR angiography (PC MRA) were obtained in 13 patients with angiographically confirmed intracranial dural arteriovenous fistulae (DAVF). Three- and two-dimensional PC MRA was obtained with low (6-20 cm/s) and high (> 40 cm/s) velocity encoding along the three main body axes. MRI showed focal or diffuse signal abnormalities in the brain parenchyma in six patients, dilated cortical veins in seven, venous pouches in four with type IV DAVF and enlargement of the superior ophthalmic vein in three patients with DAVF of the cavernous sinus. However, it showed none of the fistula sites and did not allow reliable identification of feeding arteries. 3D PC MRA enabled identification of the fistula and enlarged feeding arteries in six cases each. Stenosis or occlusion of the dural sinuses was detected in six of eight cases on 3D PC MRA with low velocity encoding. In six patients with type II DAVF phase reconstruction of 2D PC MRA demonstrated flow reversal in the dural sinuses or superior ophthalmic vein.

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.

Spontaneous closure of a high-risk dural arteriovenous malformation of the transverse sinus

The case of a 44-year-old woman with tinnitus of her left ear is presented. An arteriogram demonstrated a posterior dural arteriovenous malformation (AVM) on that side with drainage via dilated cortical veins into the superior sagittal sinus. No intervention was undertaken. When angiography was repeated 7 years later, no dural AVM was seen.

Dural arteriovenous fistulas: evaluation with MR imaging.

The preangiographic diagnosis of cerebral dural arteriovenous fistula (DAVF) can be difficult. The magnetic resonance (MR) images of 12 patients with angiographically proved DAVF were evaluated to characterize the appearance of these lesions and to identify those patients at increased risk for complications. Patients with DAVF demonstrating venous occlusive disease are at higher risk for complications from the arterialized collateral venous system. This venous occlusive disease is demonstrated best at arteriography. The MR imaging appearance of dilated cortical veins without a parenchymal nidus is suggestive of a DAVF with veno-occlusive disease. Eight of the 12 patients in our series demonstrated this finding at angiography. Complications, including infarction and hemorrhage, were identified at MR imaging in eight patients with MR imaging evidence of veno-occlusive disease. At angiography 42% of these complications were not apparent. In one patient with a DAVF draining into an unobstructed right sigmoid sinus, results of MR study were normal. Although patients with DAVF without veno-occlusive disease may have normal findings at MR imaging, DAVF associated with veno-occlusive disease and dilated pial venous drainage can be documented on MR images. This subset of DAVF patients, many of whom were identified only at MR imaging, is at higher risk for complications due to veno-occlusive disease. These patients are believed to require more urgent therapy. MR imaging is useful in the pretherapeutic planning for patients with DAVF.