Subarachnoid hemorrhage as the initial presentation of dural sinus thrombosis

Cerebral venous thrombosis (CVT) can be difficult to diagnose because of its wide spectrum of clinical manifestations. Its diagnosis may be further complicated when patients initially present with acute subarachnoid hemorrhage (SAH). We report on four patients with SAH revealing a CVT and discuss the role of imaging for diagnostic and pretherapeutic workup. In three women and one man presenting with severe headaches, images initially suggested SAH with no associated parenchymal bleeding. In all patients, SAH involved the sulci of the convexity and spared the basal cisterns. Digital subtracted angiography showed occlusion of intracranial venous sinuses but did not reveal any other cause of SAH. All patients improved with anticoagulant therapy. Risk factors for CVT and SAH, namely, head trauma and oral contraception, were identified in two patients. These cases highlight the fact SAH may reveal a CVT, which should be considered in the diagnostic workup of SAH, especially when the basal cisterns are not involved.     

Cerebral venous thrombosis: state of the art diagnosis and management

Purpose

This review article aims to discuss the pathophysiology, clinical presentation, and neuroimaging of cerebral venous thrombosis (CVT). Different approaches for diagnosis of CVT, including CT/CTV, MRI/MRV, and US will be discussed and the reader will become acquainted with imaging findings as well as limitations of each modality. Lastly, this exhibit will review the standard of care for CVT treatment and emerging endovascular options.

Methods

A literature search using PubMed and the MEDLINE subengine was completed using the terms “cerebral venous thrombosis,” “stroke,” and “imaging.” Studies reporting on the workup, imaging characteristics, clinical history, and management of patients with CVT were included.

Results

The presentation of CVT is often non-specific and requires a high index of clinical suspicion. Signs of CVT on NECT can be divided into indirect signs (edema, parenchymal hemorrhage, subarachnoid hemorrhage, and rarely subdural hematomas) and less commonly direct signs (visualization of dense thrombus within a vein or within the cerebral venous sinuses). Confirmation is performed with CTV, directly demonstrating the thrombus as a filling defect, or MRI/MRV, which also provides superior characterization of parenchymal abnormalities. General pitfalls and anatomic variants will also be discussed. Lastly, endovascular management options including thrombolysis and mechanical thrombectomy are discussed.

Conclusions

CVT is a relatively uncommon phenomenon and frequently overlooked at initial presentation. Familiarity with imaging features and diagnostic work-up of CVT will help in providing timely diagnosis and therapy which can significantly improve outcome and diminish the risk of acute and long-term complications, optimizing patient care.

     

Cerebral venous thrombosis: a potential mimic of primary traumatic brain injury in infants

OBJECTIVE: Hyperdense venous thrombi on unenhanced head CT may be misinterpreted as different types of extraaxial hemorrhages, and hemorrhagic venous infarctions may be interpreted as parenchymal contusion, leading to an incorrect diagnosis of trauma as the cause of the blood products. The purpose of this article is to show the various appearances of cerebral venous thrombosis (CVT) that mimic different types of hemorrhages and to show hemorrhagic venous infarctions that mimic parenchymal contusions. CONCLUSION: CVT, as an entity, must be kept in the differential diagnosis when patients present with extraaxial hyperdensities on unenhanced head CT so appropriate management can be initiated to minimize potentially devastating consequences.     

Cerebral venous thrombosis as a rare cause of subarachnoid hemorrhage: case report and literature review

We report a 48-year-old woman presenting with subarachnoid hemorrhage (SAH) as the first manifestation of superior sagittal sinus thrombosis. In a literature review of 73 cases, SAH associated with cerebral venous thrombosis (CVT) was usually seen at the cerebral convexities. SAH was adjacent to thrombosed venous structures; therefore, the most possible explanation seems to be the rupture of cortical veins due to extension of thrombosis. Computed tomography (CT) was effective for diagnosis of CVT in only 32% of the cases. CVT should be considered when SAH is limited to cerebral convexities and magnetic resonance (MR) imaging with MR venography should be performed.     

Acute dural venous sinus thrombosis without brain parenchymal abnormality: assessment with cerebral blood volume using dynamic susceptibility contrast magnetic resonance imaging

We report results applying the dynamic susceptibility contrast (DSC) magnetic resonance (MR) technique to a patient with dural venous sinus thrombosis (DVST) of the right transverse-sigmoid sinus without brain parenchymal abnormality. The DSC-MR technique clearly demonstrated increased regional cerebral blood volume of the right temporo-parieto-occipital region adjacent to a right transverse-sigmoid sinus thrombosis in a patient with DVST without cerebral edema or hemorrhage.     

Parenchymal abnormalities associated with cerebral venous sinus thrombosis: assessment with diffusion-weighted MR imaging

BACKGROUND AND PURPOSE: The common entity cerebral venous sinus thrombosis is associated with the poorly characterized imaging finding of parenchymal abnormalities; diffusion-weighted imaging has offered some insight into these manifestations. We assessed the relationship between the diffusion constant from apparent diffusion coefficient (ADC) maps in patients with cerebral venous thrombosis (CVT) with follow-up imaging findings and clinical outcome. METHODS: We evaluated the medical records and T2-weighted MR images of 13 patients with CVT complicated by intraparenchymal abnormality. Diffusion-weighted (DW) images and ADC maps were evaluated for increased, decreased, or unchanged signal intensity and were compared with signal intensity of contralateral, normal-appearing brain. In addition, ADCs were obtained in nine pixel regions of interest in abnormal regions in eight of the 13 patients. RESULTS: Eight patients had superficial CVT, and five had superficial and deep CVT. CVT of deep veins was associated with deep gray nucleus and deep white matter abnormalities, whereas superficial CVT was associated with cortical and subcortical abnormalities. Twenty-four nonhemorrhagic lesions were identified in 10 of 13 patients on the basis of follow-up imaging findings. Four patients without seizures had lesions with decreased diffusion that appeared hyperintense on follow-up T2-weighted images, three patients with seizures had lesions with decreased diffusion that resolved, and seven patients had lesions with increased diffusion that resolved. Three of 10 patients had more than one lesion type. No difference was noted in mean ADCs for lesions with decreased diffusion that resolved compared with lesions with decreased diffusion that persisted. CONCLUSION: DW imaging in these patients disclosed three lesion types: lesions with elevated diffusion that resolved, consistent with vasogenic edema; lesions with low diffusion that persisted, consistent with cytotoxic edema in patients without seizure activity; and lesions with low diffusion that resolved in patients with seizure activity. This information may be important in prospectively determining severity of irreversible injury and in patient treatment.     

Reversible MR imaging abnormalities following cerebral venous thrombosis

BACKGROUND AND PURPOSE: Although rare, cerebral venous thrombosis (CVT) is being diagnosed more frequently owing to improved imaging techniques. The venous infarcts caused by CVT in 50% of patients are largely reversible and differ from arterial stroke. Our purpose was to study the time-dependent changes of venous infarcts on MR images and to define the variables that influence lesion volume in humans. METHODS: MR images and venous angiograms were evaluated in 15 consecutive patients with venous infarcts due to CVT of sinus, cortical, or internal veins. All patients were treated with intravenous dose-adjusted heparin followed by oral anticoagulation for 12 months. Reduction of signal intensity changes on T1- and T2-weighted images was correlated to the degree of recanalization, age, initial absolute lesion size, and hemorrhage. RESULTS: Within the first 30 days, we found a significant correlation between the volume of the lesion on T1-weighted images and recanalization. However, early recanalization did not influence the final lesion volume after 12 months. Eleven patients showed complete resolution of changes on T1- and T2-weighted images. Age of the patients influenced initial absolute volume of brain damage. CONCLUSION: In venous stroke, even large parenchymal changes can resolve completely independent from recanalization of the thrombosed veins and sinuses. A plausible hypothesis is that venous infarcts largely consist of a persistent edema and that the lesion volume is influenced by the development of collateral veins. However, further investigations are necessary to understand the underlying abnormal mechanisms.     

Cerebral venous thrombosis in childhood

This was a retrospective study to determine different etiologies of cerebral venous thrombosis (CVT) in childhood and to correlate extent and location of thrombosis with the etiology and the age of the child as well as the final outcome. In addition, the radiologic approach is discussed. This was a retrospective analysis of 19 children with CVT. The children were examined by contrast-enhanced dynamic CT. Radiologic findings were correlated with the etiology of CVT. Cerebral venous thrombosis is not as infrequent in children as has been thought. Cerebral venous thrombosis in children can occur due to trauma (n=9), infections (n=7), or coagulation disorders (n=3). Extent and location of thrombosis, as well as complications, final outcome, and therapy, depend on the etiology. Computed tomography remains a valuable primary imaging modality in the diagnosis of CVT in the acutely injured or diseased child.     

CT evaluation of renovascular disease.

Computed tomography (CT) plays an important role in evaluation and management of primary renovascular disease. Nonenhanced CT is useful for demonstrating renal hemorrhage, renal parenchymal or vascular calcifications, and masses. Contrast material-enhanced CT is essential to identify global or regional nephrographic abnormalities resulting from the vascular process (eg, renal infarcts, ischemia secondary to renal artery stenosis, arteriovenous communications). In addition, renal manifestations of a systemic disease (eg, vasculitis, thromboembolic disease) can be seen at CT. In trauma, occlusion of the main renal artery can be accurately diagnosed with contrast-enhanced CT. In cases of spontaneous renal hemorrhage without an apparent cause (eg, vasculitis, coagulopathy), a careful CT study should be performed to exclude renal cell carcinoma. The presence of fat in a hemorrhagic renal mass larger than 4 cm in diameter is characteristic of angiomyolipoma complicated by hemorrhage. Acute renal vein thrombosis appears as a clot in a distended renal vein, whereas renal vein retraction with collateral vessels is highly indicative of chronic thrombosis. Helical CT, especially with multiplanar two-dimensional and three-dimensional reconstruction following an intravenous injection of iodinated contrast material, has greatly improved our ability to directly image the proximal renal arteries and detect vascular lesions.     

MRV检测脑静脉窦血栓的作用

目的探讨磁共振静脉血管成像(MRV)用于检测脑静脉窦血栓(CVT)的应用价值。方法8例CVT患者均行MRI标准自旋回波T1WI、T2WI和VEN/3D/PCA。结果VEN/3D/PCA比标准SE序列T1WI和T2WI多检测出CVT3处,与脑血管造影的结果完全相符。结论MRV可以准确无创的诊断CVT。     

Diagnostic role of 64-slice multidetector row CT scan and CT venogram in cases of cerebral venous thrombosis

Retrospective review of patients with cerebral venous thrombosis (CVT) detected by 64-slice multidetector row computed tomography (MDCT). To evaluate the role of CT scan as the primary modality of imaging in suspected cases of CVT. Between October 2006 and September 2007, 53 patients, suspected to have CVT, underwent CT scan of the brain. Out of these, 33 patients were included in the study, who underwent non-contrast CT (NCCT), CT venous angiogram (MDCTA) and magnetic resonance venogram. Two blinded readers evaluated the NCCT and MDCTA. Final diagnosis was obtained after consensus reading of all the imaging by the two readers. Out of the total 33 patients, 20 patients were detected to have thrombosis of one or more of the cerebral venous sinuses or veins, at the concluding consensus reading. MDCTA together with NCCT could identify thrombosis in all of the 20 patients, i.e., 100% sensitivity and specificity. Sixty-four-slice MDCTA together with NCCT provided 100% sensitivity and specificity for the identification of CVT. It can be considered as a cost-effective and widely available, primary imaging modality in emergency situations.     

Portal and hepatic vein thrombosis in liver abscess: CT findings

OBJECTIVE: Our aim is to describe imaging findings of portal and hepatic vein thrombosis in pyogenic liver abscess on contrast-enhanced MDCT and to determine the incidence and evolving patterns on follow-up imaging. METHODS: Over a 5-year period, 67 patients with liver abscess underwent single-phase (n=30) or triphasic (n=37) contrast-enhanced CT. Images were reviewed for the presence of portal vein (PV) or hepatic vein (HV) thrombosis, regional parenchymal attenuation, and changes on follow-up CT. RESULTS: Venous thrombosis was seen in 28/67 patients (42%), involving PV in 16/67 (24%) and HV vein in 15/67 (22%); 3/67 (4%) had both PV and HV thrombosis. Thrombosis was seen as non-enhancing linear structures without expanding the lumen in all cases. Regional parenchymal attenuation during the portal-phase was hyperattenuating (10/16, 63%) or isoattenuating (6/16, 38%) in PV thrombosis, and mostly hypoattenuating (13/15, 87%) in HV thrombosis (P<.001). Of 27 patients with follow-up contrast-enhanced CT, venous thrombosis resolved in 10/27 (37%) within 6 months and persisted in 17/27 (63%) for 3-38 months, including 13 PV thrombosis and 4 HV thrombosis. Interval parenchymal atrophy was seen only in four all with persistent PV thrombosis. CONCLUSIONS: Both PV and HV thrombosis frequently occurs in liver abscess and is seen as non-enhancing linear structures without expanding the lumen on contrast-enhanced CT. Regional attenuation changes in hepatic vein thrombosis were often hypoattenuating whereas none with portal vein thrombosis showed hypoattenuation.     

Venous sinus occlusive disease: MR findings.

PURPOSETo study MR patterns of venous sinus occlusive disease and to relate them to the underlying pathophysiology by comparing the appearance and pathophysiologic features of venous sinus occlusive disease with those of arterial ischemic disease.METHODSThe clinical data and MR examinations of 26 patients with venous sinus occlusive disease were retrospectively reviewed with special attention to mass effect, hemorrhage, and T2-weighted image abnormalities as well as to abnormal parenchymal, venous, or arterial enhancement after intravenous gadopentetate dimeglumine administration. Follow-up studies when available were evaluated for atrophy, infarction, chronic mass effect, and hemorrhage.RESULTSMass effect was present in 25 of 26 patients. Eleven of the 26 had mass effect without abnormal signal on T2-weighted images. Fifteen patients had abnormal signal on T2-weighted images, but this was much less extensive than the degree of brain swelling in all cases. No patient showed abnormal parenchymal or arterial enhancement. Abnormal venous enhancement was seen in 10 of 13 patients who had contrast-enhanced studies. Intraparenchymal hemorrhage was seen in nine patients with high signal on T2-weighted images predominantly peripheral to the hematoma in eight. Three overall MR patterns were observed in acute sinus thrombosis: 1) mass effect without associated abnormal signal on T2-weighted images, 2) mass effect with associated abnormal signal on T2-weighted images and/or ventricular dilatation that may be reversible, and 3) intraparenchymal hematoma with surrounding edema.CONCLUSIONMR findings of venous sinus occlusive disease are different from those of arterial ischemia and may reflect different underlying pathophysiology. In venous sinus occlusive disease, the breakdown of the blood-brain barrier (vasogenic edema and abnormal parenchymal enhancement) does not always occur, and brain swelling can persist up to 2 years with or without abnormal signal on T2-weighted images. Abnormal signal on T2-weighted images may be reversible and does not always indicate infarction.     

Cortical vein thrombosis: the diagnostic value of different imaging modalities

Introduction  

Cortical vein thrombosis (CVT) is a rare disorder, and its diagnosis is challenging. The aim of our study was to evaluate the value of different imaging modalities for the detection of CVT.     

急性脑静脉窦血栓及其脑损伤的MRI技术探讨

目的：探讨不同MRI成像序列在急性脑静脉窦血栓形成及其脑损害诊断中的价值。方法：回顾性分析本院经临床和影像学证实的11例急性脑静脉窦血栓形成患者的影像学资料,比较常规T1WI、T2WI、T2＊WI、DWI、CE-T1WI和MRV对检出急性脑静脉窦闭塞及其继发脑损伤的优缺点,其中6例测量脑损害区的ADC值。结果：11例中平扫T1WI能明确显示静脉窦血栓9例,T2WI显示8例,CE-T1WI和CE-MRV对11例均能明确显示;CE-MRV还能更好地显示静脉窦的回流静脉和侧支血管。MRI检查发现继发性脑损伤8例,T2WI对缺血水肿的显示优于其它序列,对脑出血的检出以T2＊WI较好。ADC值与脑损伤的面积和位置有关。结论：MRI对脑静脉窦血栓及其相应脑损害的诊断具有重要作用,联合应用多种MRI检查方法能更可靠地提供脑静脉窦血栓的诊断信息及其脑损害的程度。     

MR imaging enhancement patterns as predictors of hemorrhagic transformation in acute ischemic stroke

BACKGROUND AND PURPOSE: Early parenchymal gadolinium enhancement on T1-weighted MR images is predictive of hemorrhagic transformation (HT) in rodent focal ischemia models, but its value in humans is unknown. We sought to investigate gadolinium enhancement in acute ischemic stroke patients to determine their association with subsequent HT. METHODS: We retrospectively examined 22 patients with ischemic stroke who underwent MR imaging within 4.9 hours (+/-1.4) of symptom onset. Patients receiving intravenous tissue plasminogen activator (tPA) (n = 6) were included. Twenty-one patients underwent repeat MR studies at 48 hours, 13 underwent additional MR imaging at 1 week, and one underwent follow-up head CT at 24 hours. Initial images were analyzed for enhancement patterns (vascular, meningeal, parenchymal). Follow-up T2- and T2*-weighted images were evaluated for hemorrhage. RESULTS: In all patients, initial MR images showed vascular enhancement in the vascular territory of the stroke lesion: 19 with vascular enhancement alone and three with vascular and parenchymal enhancement. All three patients with both enhancement patterns had HT: two large and symptomatic, and one asymptomatic (petechial hemorrhage). They received tPA before MR imaging. None of the patients without early parenchymal enhancement developed symptomatic hemorrhage. Six (32%) patients with vascular enhancement alone had petechial hemorrhage at follow-up imaging. In this limited sample, initial mean volumes on diffusion-weighted images, National Institute of Health Stroke Scale scores, and intervals from stroke onset to imaging did not differ between patients with vascular and parenchymal enhancement versus those with vascular enhancement alone. CONCLUSION: Early parenchymal enhancement of stroke lesions may be a good predictor of subsequent symptomatic HT may help identify patients at risk, especially after thrombolytic therapy.     

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.     

脑静脉窦血栓形成合并脑出血临床分析（附7例报告）

目的：探讨脑静脉窦血栓合并脑出血的临床诊断和治疗。方法：回顾分析2006年6月～2008年10月收治的7例脑静脉窦血栓合并脑出血患者临床资料。结果：7例患者中,3例入院时已经发生脑疝的患者行开颅血肿清除加去骨瓣减压,术后给予脱水、抗炎治疗,1周后其中2例给予抗凝治疗。4例未发生脑疝患者入院后给予脱水、抗炎、低分子肝素抗凝治疗。1例术后未血凝治疗男性患者半月后并发下肢深静脉血栓家人放弃治疗,自动出院,6例女性患者痊愈出院。结论：抗凝治疗可作为当前治疗脑静脉及脑静脉窦血栓的主要方法,即使在合并颅内出血的情况下,也常作为首选方式,但对于急性颅内高压,在脱水药物治疗无效情况下,手术清除血肿及去骨瓣减压也可作为一种治疗手段。     

Spontaneous superficial parenchymal and leptomeningeal hemorrhage in term neonates

BACKGROUND AND PURPOSE: Intracranial hemorrhage in term neonates often results from asphyxia, obvious birth trauma, blood dyscrasia, or vascular malformation but may occur without an obvious inciting event. In this study, we review the clinical and neuroimaging features of healthy term neonates presenting with spontaneous superficial parenchymal and leptomeningeal (ie, subpial or subarachnoid) hemorrhage. METHODS: The clinical records and neuroimaging studies of seven term neonates with spontaneous superficial parenchymal and leptomeningeal hemorrhage were retrospectively reviewed. All underwent diffusion-weighted MR imaging and 6 underwent CT within 72 hours of birth. Magnetic susceptibility-weighted imaging was performed in five, MR angiography in two, and MR venography in two. Follow-up MR imaging was performed in one infant. Clinical follow-up was done in four patients. RESULTS: All neonates had normal birth weights and high 5-minute APGAR scores. All were delivered vaginally (one with forceps assistance, and one with vacuum assistance). No blood dyscrasias were noted. Within 36 hours after delivery, all neonates presented with apnea or seizures or both. Neuroimaging subsequently revealed superficial parenchymal and leptomeningeal hemorrhage. Four occurred in the anterior-inferior-lateral temporal lobe adjacent to the pterion. The remaining three were located in the parietal lobe, frontal lobe, and lateral temporal lobe under the squamosal suture. Decreased diffusion in parenchyma adjacent to the hemorrhage and overlying subcutaneous soft-tissue swelling were apparent in five patients. Susceptibility-weighted imaging showed no additional lesions. MR angiography and MR venography findings were normal. Follow-up MR imaging in one patient demonstrated encephalomalacia. Four patients with short-term clinical follow-up were neurologically normal. CONCLUSION: Spontaneous superficial parenchymal and leptomeningeal hemorrhage occurs in otherwise healthy term neonates. The hemorrhage is most often in the temporal lobe and in proximity to sutures, accompanied by overlying soft-tissue swelling and adjacent decreased diffusion. This pattern leads us to implicate local trauma with contusion or venous compression or occlusion in the development of these hemorrhages.     

Simultaneous renal vein thrombosis and bilateral adrenal hemorrhage: MR demonstration

A case of simultaneous renal vein thrombosis and bilateral adrenal hemorrhage is presented, demonstrating the ability of magnetic resonance (MR) imaging to identify these abnormalities without the use of intravenous contrast agents or radiopharmaceuticals. Adrenal hemorrhage appeared as markedly enlarged adrenal glands with homogeneous high signal intensity on both T1 and T2 weighted spin echo MR images. The kidney involved with renal vein thrombosis was enlarged and demonstrated increased signal from the renal parenchyma on T2 weighted images.