Diffusion-weighted mr in cerebral venous thrombosis

Magnetic resonance imaging protocols in pediatric stroke

Neuroimaging protocols play an important role in the timely evaluation and treatment of pediatric stroke and its mimics. MRI protocols for stroke in the pediatric population should be guided by the clinical scenario and neurologic examination, with consideration of age, suspected infarct type and underlying risk factors. Acute stroke diagnosis and causes in pediatric age groups can differ significantly from those in adult populations, and delay in stroke diagnosis among children is a common problem. An awareness of pediatric stroke presentations and risk factors among pediatric emergency physicians, neurologists, pediatricians, subspecialists and radiologists is critical to ensuring timely diagnosis. Given special considerations related to unique pediatric stroke risk factors and the need for sedation in some children, expert consensus guidelines for the imaging of suspected pediatric infarct have been proposed. In this article the authors review standard and rapid MRI protocols for the diagnosis of pediatric stroke, as well as the key differences between pediatric and adult stroke imaging.

Diagnosis and Management of Cerebral Venous Thrombosis Due to Polycythemia Vera and Genetic Thrombophilia: Case Report and Literature Review

(1) Background: Cerebral venous and dural sinus thrombosis (CVT) rarely appears in the adult population. It is difficult to diagnosis because of its variable clinical presentation and the overlapping signal intensities of thrombosis and venous flow on conventional MR images and MR venograms. (2) Case presentation: A 41-year-old male patient presented with an acute isolated intracranial hypertension syndrome. The diagnosis of acute thrombosis of the left lateral sinus (both transverse and sigmoid portions), the torcular Herophili, and the bulb of the left internal jugular vein was established by neuroimaging data from head-computed tomography, magnetic resonance imaging (including Contrast-enhanced 3D T1-MPRAGE sequence), and magnetic resonance venography (2D-TOF MR venography). We detected different risk factors (polycythemia vera-PV with JAK2 V617F mutation and inherited low-risk thrombophilia). He was successfully treated with low-molecular-weight heparin, followed by oral anticoagulation. (3) Conclusions: In the case of our patient, polycythemia vera represented a predisposing risk factor for CVT, and the identification of JAK2 V617F mutation was mandatory for the etiology of the disease. Contrast-enhanced 3D T1-MPRAGE sequence proved superior to 2D-TOF MR venography and to conventional SE MR imaging in the diagnosis of acute intracranial dural sinus thrombosis.

An Integrated Approach on the Diagnosis of Cerebral Veins and Dural Sinuses Thrombosis

(1) Objective: This review paper aims to discuss multiple aspects of cerebral venous thrombosis (CVT), including epidemiology, etiology, pathophysiology, and clinical presentation. Different neuroimaging methods for diagnosis of CVT, such as computer tomography CT/CT Venography (CTV), and Magnetic Resonance Imaging (MRI)/MR Venography (MRV) will be presented. (2) Methods: A literature analysis using PubMed and the MEDLINE sub-engine was done using the terms: cerebral venous thrombosis, thrombophilia, and imaging. Different studies concerning risk factors, clinical picture, and imaging signs of patients with CVT were examined. (3) Results: At least one risk factor can be identified in 85% of CVT cases. Searching for a thrombophilic state should be realized for patients with CVT who present a high pretest probability of severe thrombophilia. Two pathophysiological mechanisms contribute to their highly variable clinical presentation: augmentation of venular and capillary pressure, and diminution of cerebrospinal fluid absorption. The clinical spectrum of CVT is frequently non-specific and presents a high level of clinical suspicion. Four major syndromes have been described: isolated intracranial hypertension, seizures, focal neurological abnormalities, and encephalopathy. Cavernous sinus thrombosis is the single CVT that presents a characteristic clinical syndrome. Non-enhanced CT (NECT) of the Head is the most frequently performed imaging study in the emergency department. Features of CVT on NECT can be divided into direct signs (demonstration of dense venous clot within a cerebral vein or a cerebral venous sinus), and more frequently indirect signs (such as cerebral edema, or cerebral venous infarct). CVT diagnosis is confirmed with CTV, directly detecting the venous clot as a filling defect, or MRI/MRV, which also realizes a better description of parenchymal abnormalities. (4) Conclusions: CVT is a relatively rare disorder in the general population and is frequently misdiagnosed upon initial examination. The knowledge of wide clinical aspects and imaging signs will be essential in providing a timely diagnosis.

Cerebral Venous Sinus Thrombosis in Closed Head Injury: Systematic Review and Meta-analysis

BACKGROUND

Cerebral venous sinus thrombosis (CSVT) is a rare condition, causing 0.5% of all strokes only, several mechanisms might be involved in forming the thrombosis, including closed head injury.

METHODS

Systematic review was done by using the following databases: PubMed, Google Scholar, Microsoft Academic, Clinical Trials, Cochrane Library, and Web of Science.

RESULTS

25 articles met our criteria out of 152 articles, average and standard deviation of the age was 38.2 ± 16.8 years with an age range of 18-82. The majority of cases presented with loss of consciousness or decreased GCS (41%), followed by headache (26%), scalp abrasions/lacerations (21%), paralysis (18%), visual disturbance (18%), nystagmus (15%), and agitation (15%). The most commonly used diagnostic method was angiography. Thrombosis was the most frequently reported radiological finding among all the cases (26/34, 76%). Comparisons of outcomes between patients who underwent surgical intervention and those who did not undergo surgery revealed a significant difference in outcome favoring non-surgical treatment (p < 0.005, odds ratio (OR) 0.04, (95% CI) 0.003 - 0.30).

CONCLUSION

Non-surgical outcomes were better than the surgical outcomes. However, no significant difference was seen comparing anti-coagulation versus conservative management (supportive without anticoagulation), single versus multi-sinuses (≥2 sinuses) involvement, and between any of the sinuses involved.

Different patterns of white matter lesions among patent foramen ovale, atherosclerotic cerebral small vessel disease and cerebral venous thrombosis

None of studies are available on the predictive ability of white matter lesions (WMLs) among patent foramen ovale (PFO), atherosclerotic cerebral small vessel disease (aCSVD) and cerebral venous thrombosis (CVT). Herein, we aimed to uncover the difference of the WML patterns among the three disease entities in a real-world setting to provide clinical references for predicting probable WML etiologies. We retrospectively reviewed data from consecutive patients with imaging-confirmed PFO, aCSVD, or CVT enrolled from 2014 through 2020. WMLs presented on fluid-attenuated inversion recovery (FLAIR) maps were compared among the three groups based on visual evaluation, Fazekas and modified Scheltens scales. Propensity score matching (PSM) was implemented to correct age and hypertension differences among groups. A total of 401 patients were entered into final analysis, including PFO (n = 112, 46.5 ± 12.8 years), aCSVD (n = 177, 61.6 ± 11.8 years) and CVT (n = 112, 37.4 ± 11.4 years) groups. In this study, WMLs occurred in all of the involved patients in the three groups (100%), which were independent to age, symptom onset and disease durations. On visual evaluation, PFO-WMLs were multiple spots distributed asymmetrically around bilateral subcortex and peri-ventricles. aCSVD-WMLs were dots or sheets distributed symmetrically in subcortex and peri-ventricles, and often coexisted with lacunar infarctions. CVT-WMLs were cloud-like around bilateral peri-ventricles, and enabled to attenuate after recanalization. Fazekas and modified Scheltens scores of PFO-WML vs. aCSVD-WML were significantly different even after being matched by 1:2 PSM (all p < 0.05), meaning that the WML burden in aCSVD was considerably heavier than that in PFO. WML patterns induced by PFO, aCSVD and CVT were obviously different, and were therefore of great clinical significance to preliminarily predict and differentiate the three diseases entities.

Headache in cerebral venous thrombosis

Headache has been consistently reported as the most common symptom of cerebral venous thrombosis and as the most frequent presenting feature. It is often the heralding symptom, preceding other manifestations of the disease by days or even weeks. This aspect highlights the importance of recognizing headache due to cerebral venous thrombosis, as early recognition of the disease can lead to a rapid diagnosis with appropriate imaging techniques and as early treatment with heparin can dramatically change the course of the disease and alter the prognosis. Unfortunately, although common, the headache has no specific features, and the clinical presentation of CVT is highly variable, making the correct diagnosis in the emergency setting a challenging task for clinicians, even in the case of highly specialized ones such as neurologists. In this review, we will briefly summarize the epidemiology and physiopathology of CVT, and then we will discuss in more details the causes, features, and course of headache, focusing on its relevance for differential diagnosis and on red flags that should suggest the possibility of CVT as the cause of the headache.

Diffusion-Weighted Magnetic Resonance Imaging in the Diagnosis of Cerebral Venous Thrombosis : A Meta-Analysis

Objective

A role of diffusion-weighted imaging (DWI) in the diagnosis of cerebral venous thrombosis (CVT) is not wellunderstood. This study evaluates the effectiveness of DWI in the diagnosis of CVT.

Methods

Literature search was conducted in electronic databases for the identification of studies which reported the outcomes of patients subjected to DWI for CVT diagnosis. Random-effects meta-analyses were performed to achieve overall estimates of important diagnostic efficiency indices including hyperintense signal rate, the sensitivity and specificity of DWI in diagnosing CVT, and the apparent diffusion coefficient (ADC) of DWI signal areas and surrounding tissue.

Results

Nineteen studies (443 patients with 856 CVTs; age 40 years [95% confidence interval (CI), 33 to 43]; 28% males [95% CI, 18 to 38]; symptom onset to DWI time 4.6 days [95% CI, 2.3 to 6.9]) were included. Hyperintense signals on DWI were detected in 40% (95% CI, 26 to 55) of the cases. The sensitivity of DWI for detecting CVT was 22% (95% CI, 11 to 34) but specificity was 98% (95% CI, 95 to 100). ADC values were quite heterogenous in DWI signal areas. However, generally the ADC values were lower in DWI signal areas than in surrounding normal areas (mean difference−0.33×10^-3 mm²/s [95% CI, −0.44 to −0.23]; p<0.00001).

Conclusion

DWI has a low sensitivity in detecting CVT and thus has a high risk of missing many CVT cases. However, because of its high specificity, it may have supporting and exploratory roles in CVT diagnosis.

Identifying Biomarkers Associated with Venous Infarction in Acute/Subacute Cerebral Venous Thrombosis

Among cerebral venous thrombosis (CVT) patients, those with venous infarction have more severe clinical presentations and worse outcomes. Identifying biomarkers associated with venous infarction in CVT may help understand the pathogenesis and provide potentially useful therapeutic markers. Fifty-two CVT patients were prospectively recruited and divided into three groups: acute/subacute CVT with venous infarction (ASVI, n=30), without venous infarction (ASOVI, n=13), and chronic CVT (n=9). Blood brain barrier (BBB) permeability-related proteins, including claudin-5, occludin, matrix metalloproteinase-9, glial fibrillary acidic protein, and S100B, and inflammation-related factor high-sensitivity C-reactive protein (hs-CRP), were tested in serum and/or cerebrospinal fluid upon admission. We compared these biomarkers between the three groups and investigated their associations with venous infarction and clinical symptom severity in acute/subacute CVT patients on admission using the NIH Stroke Scale (NIHSS). Serum hs-CRP was significantly higher in acute/subacute CVT patients than chronic CVT patients. For acute/subacute CVT patients, levels were significantly higher in the ASVI group than the ASOVI group for serum claudin-5 (medians 2.80 vs. 2.50 mg/I, respectively, P = 0.039) and hs-CRP (medians 17.25 vs. 2.27 mg/l, respectively, P = 0.003). Both these biomarkers, analyzed as categorical or continuous variables, were also significantly associated with venous infarction in acute/subacute CVT patients after logistic regression analysis. Additionally, hs-CRP was positively correlated with the NIHSS (r = 0.710, P < 0.001) on admission in acute/subacute CVT patients. In CVT patients, venous infarction was associated with BBB disruption and potentially inflammation. Hs-CRP might serve as a biomarker reflecting the clinical severity of CVT in the acute/subacute stages.

Role, Effectiveness, and Outcome of Decompressive Craniectomy for Cerebral Venous and Dural Sinus Thrombosis (CVST): Is Surgery Really an Option?

Cerebral venous and dural sinus thrombosis (CVST) is predominantly a disease of young people. It accounts for 0.5% of all strokes, and patients usually have good outcomes. However, a minority of patients may present with elevated intracranial pressure characteristics in a serious illness type and may die from brain herniation if not treated promptly. Decompressive craniectomy (DC) is the only treatment modality that can prevent death in such cases of imminent brain herniation. Unfortunately, due to the condition's rarity and ethical concerns, randomized controlled trials are not available. This review assessed the available literature on cerebral venous and dural sinus thrombosis in different age groups and decompressive craniectomy in cerebral venous and dural sinus thrombosis. It revealed that decompressive surgery is extremely effective when done early and for the correct indications with patients achieving excellent functional outcomes post-surgery. Decompressive surgery is recommended in rapidly deteriorating patients with computed tomography (CT) scan evidence of basal cisterns effacement, a mass effect from haemorrhage and/or infarction, and significant midline shift.

Role of diffusion-weighted imaging in the diagnosis of cerebral venous thrombosis

OBJECTIVE

To evaluate the hyperintense signal (HIS) performance on diffusion-weighted imaging (DWI) in diagnosing cerebral venous thrombosis (CVT).

METHODS

Seventy-eight patients with CVT hospitalized from January 2004 to January 2015 were retrospectively studied alongside 78 controls without intracranial organic diseases. Diagnostic accuracy indices of HIS on DWI or T2-weighted imaging (T2WI) to diagnose CVT at different sites and states were analyzed.

RESULTS

The overall sensitivity of HIS on DWI for the diagnosis of CVT was significantly lower than that of HIS on T2WI (34.6% vs. 79.5%). HIS on T2WI was more sensitive than HIS on DWI in detecting thrombosis, especially in the superior sagittal sinus and transverse sinus. HIS on DWI was inversely related to the time between disease onset and imaging. Compared with HIS on T2WI, combining HIS on DWI and T2WI did not increase the sensitivity for detecting CVT. HIS on DWI was not detected in the control group, but HIS on T2WI was detected in 26.3% of control individuals. The specificity of HIS on DWI for CVT was higher than that of HIS on T2WI (97.4% vs. 76.9%).

CONCLUSION

HIS on DWI has a lower sensitivity, but a higher specificity, than HIS on T2WI for diagnosing CVT.

Imaging Ischemic and Hemorrhagic Disease of the Brain in Dogs

Strokes, both ischemic and hemorrhagic, are the most common underlying cause of acute, non-progressive encephalopathy in dogs. In effect, substantial information detailing the underlying causes and predisposing factors, affected vessels, imaging features, and outcomes based on location and extent of injury is available. The features of canine strokes on both computed tomography (CT) and magnetic resonance imaging (MRI) have been described in numerous studies. This summary article serves as a compilation of these various descriptions. Drawing from the established and emerging stroke evaluation sequences used in the investigation of strokes in humans, this summary describes all theoretically available sequences. Particular detail is given to logistics of image acquisition, description of imaging findings, and each sequence's advantages and disadvantages. As the imaging features of both forms of strokes are highly representative of the underlying pathophysiologic stages in the hours to months following stroke onset, the descriptions of strokes at various stages are also discussed. It is unlikely that canine strokes can be diagnosed within the same rapid time frame as human strokes, and therefore the opportunity for thrombolytic intervention in ischemic strokes is unattainable. However, a thorough understanding of the appearance of strokes at various stages can aid the clinician when presented with a patient that has developed a stroke in the days or weeks prior to evaluation. Additionally, investigation into new imaging techniques may increase the sensitivity and specificity of stroke diagnosis, as well as provide new ways to monitor strokes over time.

[Cerebral venous thrombosis: Clinical and radiological features, about 62 cases]

The work's purpose is to make a general review on the various clinical-radiological aspects and the management of cerebral venous thrombosis (CVT) in our hospital and compare them to those described in the literature.

MATERIAL AND METHOD

Our series included 62 patients aged over 18 years, collected over 7 years (2009-2016) in the radiology department of the CHU Hassan II of Fez (Morocco), in which the radiological diagnosis of TVC was retained. Our patients have benefited from a brain CT scan and brain MRI. Clinical and radiological characteristics and post-treatment progression were described.

RESULTS

The average age was 35 years with a female predominance; sex ratio 3.76 (49F/13H). The symptomatology was non-specific, made mainly of headaches, comic crises, disturbances of consciousness and focal signs. The upper longitudinal sinus was dominant topography (51.61%). The etiological factors were varied: infectious (sinusitis, chronic otitis media, oto-mastoiditis, bacterial meningitis, and septicemia), gyneco-obstetrical (oral contraception, pregnancy, and postpartum), systemic (Behçet diseases, polycythemia of Vaquez, paraneoplastic syndrome, antiphospholipid syndrome), local (head trauma), undetermined etiological factors. The CT scan, but especially the cerebral MRI, made it possible to make the diagnosis but also to direct towards the etiology.

CONCLUSION

Cerebral MRI is currently the best imaging in the diagnosis of CTV, allowing an accurate assessment of its location, extent and impact on the cerebral parenchyma. Multiple conditions are responsible for CTVs. Therapeutic management is based on heparinotherapy and etiological treatment.

Clinical applications of diffusion weighted imaging in neuroradiology

Abstract

Diffusion-weighted imaging (DWI) has revolutionised stroke imaging since its introduction in the mid-1980s, and it has also become a pillar of current neuroimaging. Diffusion abnormalities represent alterations in the random movement of water molecules in tissues, revealing their microarchitecture, and occur in many neurological conditions. DWI provides useful information, increasing the sensitivity of MRI as a diagnostic tool, narrowing the differential diagnosis, providing prognostic information, aiding in treatment planning and evaluating response to treatment. Recently, there have been several technical improvements in DWI, leading to reduced acquisition time and artefacts and enabling the development of diffusion tensor imaging (DTI) as a tool for assessing white matter. We aim to review the main clinical uses of DWI, focusing on the physiological mechanisms that lead to diffusion abnormalities. Common pitfalls will also be addressed.

Teaching Points

• DWI includes EPI, TSE, RESOLVE or EPI combined with reduced volume excitation.

• DWI is the most sensitive sequence in stroke diagnosis and provides information about prognosis.

• DWI helps in the detection of intramural haematomas (arterial dissection).

• In diffusion imaging, ADC is inversely proportional to tumour cellularity.

• DWI and DTI derived parameters can be used as biomarkers in different pathologies.

Time-of-flight MR angiography in cerebral venous sinus thrombosis

Recently, time-of-flight (TOF) and gadolinium-enhanced MR angiography (MRA) imaging have been used to demonstrate subacute intramural hematoma in cervical artery dissection and to detect intraplaque haemorrhage. Our aim was to perform an exploratory study to analyse if venous thrombus-related signal changes (potentially showing iso- or hyperintensity) in cerebral venous sinus thrombosis (CVST) could be observed on 3D-TOF MRA imaging. We analysed retrospectively MRIs of CVST patients in whom both contrast-enhanced MR venography (CEMRV) and 3D-TOF sequences were performed in the acute/subacute phase (i.e. < 31 days after symptom onset). The occluded sinus segments were defined on CEMRV. First, analyses of signal changes in occluded venous sinuses segments (defined by and unblinded to CEMRV) on native 3D-TOF images and morphological MRI sequences were performed. Second, a blinded (to CEMRV and other morphological MRI sequences) analysis was performed on 3D-TOF imaging assessing signal changes on 3D-TOF considering all sinus segments. Twenty-five CVST patients were included. 3D-TOF imaging showed signal changes (most often hyperintensity and less often isointensity) in 84% of the occluded sinus segments. Signal changes were observed in 91% of the occluded sinus segments on T1-weighted imaging, in 69% on T2-weighted imaging, in 68% on FLAIR, in 32% on DWI, and in 55% on T2*-weighted imaging. On blinded analysis, sensitivity of 3D-TOF sequences decreased to 80%, whereas specificity was only 65%. Abnormal signal in the venous sinuses on 3D-TOF may possibly help to suspect CVST, especially when CEMRV sequences lack.

Cerebral venous thrombosis

Cerebral venous thrombosis (CVT) is an important cause of stroke in young adults. Data from large international registries published in the past two decades have greatly improved our knowledge about the epidemiology, clinical manifestations and prognosis of CVT. The presentation of symptoms is highly variable in this disease, and can range from a patient seen at the clinic with a 1-month history of headache, to a comatose patient admitted to the emergency room. Consequently, the diagnosis of CVT is often delayed or overlooked. A variety of therapies for CVT are available, and each should be used in the appropriate setting, preferably guided by data from randomized trials and well-designed cohort studies. Although deaths from CVT have decreased in the past few decades, mortality remains ∼5-10%. In this Review, we provide a comprehensive and contemporary overview of CVT in adults, with emphasis on advancements made in the past decade on the epidemiology and treatment of this multifaceted condition.

Other cerebrovascular occlusive disease

In this chapter we review the optimal imaging modalities for subacute and chronic stroke. We discuss the utility of computed tomography (CT) and multimodal CT imaging. Further, we analyze the importance of specific magnetic resonance imaging sequences, such as diffusion-weighted imaging for acute ischemic stroke, T2/fluid-attenuated inversion recovery for subacute and chronic stroke, and susceptibility imaging for detection of intracranial hemorrhages. Different ischemic stroke mechanisms are reviewed, and how these imaging modalities may aid in the determination of such. Further, we analyze how topographic patterns in ischemic stroke may provide important clues to the diagnosis, in addition to the temporal evolution of the stroke. Lastly, specific cerebrovascular occlusive diseases are reviewed, with emphasis on the optimal imaging modalities and their findings in each condition.

Radiological and clinical features of cerebral sinovenous thrombosis in newborns and older children

BACKGROUND AND PURPOSE

Cerebral sinovenous thrombosis (CSVT) represents an increasingly recognized cause of pediatric stroke. Our purpose was to assess gender and age differences in the etiology, clinical presentation, and imaging features of CSVT in neonates and older children.

METHODS

Subjects aged newborn to 18 years diagnosed with CSVT at the Lille university hospital between 2011 and 2014 were included.

RESULTS

Eleven neonates and 16 non-neonates constituted the study population. The incidence of CSVT was significantly higher in male newborns. Clinical presentation did not vary significantly between the groups. Risk factors were age-dependent, with acute systemic illnesses significantly predominating in neonates (54%), whereas local infections, prothrombotic conditions, and trauma were more common in older children (36, 27, and 27% respectively). No predisposing factor could be identified in 36% of the neonates as compared to less than 5% of the non-neonates. Thrombosis of the deep venous structures was documented in 73% of the neonates whereas involvement of the superficial sinuses was significantly more frequent in the non-neonates group. Venous infarctions and extraparenchymal hemorrhages were significantly more frequent in the neonates group.

CONCLUSION

Male patients are at higher risk for CSVT than females. In neonates, involvement of the deep venous structures is significantly more common. Brain parenchymal and extraparenchymal changes occur more frequently in this age group than in older children.

Neuroimaging findings in pediatric cerebral sinovenous thrombosis

PURPOSE

Pediatric cerebral sinovenous thrombosis (CSVT) is a potentially life-threatening condition which is usually diagnosed by MRI. We analyzed the signal changes of the thrombus over time and the role of diffusion-weighted/tensor imaging (DWI/DTI) in the diagnosis of CSVT.

METHODS

Clinical histories were reviewed for risk factors for CSVT, neurologic manifestation, and interval from onset of symptoms related to CSVT to the neuroimaging diagnosis. MRI studies were retrospectively evaluated for the appearance of thrombi on T1- and T2-weighted, fluid-attenuated inversion recovery (FLAIR), DWI/DTI, susceptibility-weighted imaging (SWI), and magnetic resonance venography (MRV) images.

RESULTS

Thirty-three children with CSVT were included in this study. Seventy-seven thrombi were found. Seventy-four thrombi could be identified on T1- or T2-weighted images (96 %), 72 thrombi were seen on DWI/DTI (94 %) and 68 on FLAIR (88 %). DWI showed restricted diffusion in 29 thrombi (40 %). Thrombi older than 1 day were more likely to have a T1-hyperintense signal (p = 0.002). No additional correlation between signal intensity and age of the thrombi was found. Intraparenchymal changes secondary to CSVT were seen in 11 children.

CONCLUSION

MR sequences individually are not sensitive enough to provide the diagnosis. DWI/DTI does not provide complementary diagnostic value. Approximation of the age of the thrombus is difficult because of poor correlation between signal intensity and age of the thrombi.

[Therapeutic options in malignant cerebral venous and sinus thrombosis]

BACKGROUND

Cerebral venous and sinus thrombosis (CVST) constitutes less than 0.5-1 % of all strokes and occurs predominantly in young female adults. In general the clinical outcome is favorable but 3-15 % of patients die in the acute phase and in the majority of cases due to cerebral herniation. Intensive care treatment analogous to that of severe ischemic infarct leads to an aggressive interdisciplinary therapy concept that can achieve good clinical outcome. Based on five cases of severe CVST treatment options will be presented.

RESULTS

All five patients were affected by impending or incipient cerebral herniation and severe focal neurological deficits which resulted in the decision to implement thrombectomy, thrombolysis or hemicraniectomy. Despite the severe course and many intensive care complications which suggested a poor prognosis, all five patients could be transferred to rehabilitation after having survived the acute phase and achieved an amazingly good overall clinical outcome.

CONCLUSION

Considering the life-threatening course of severe CVST, aggressive interdisciplinary management by endovascular thrombectomy and hemicraniectomy can lead to a scarcely expected clinical outcome without disability or severe dependency. This treatment should be performed early and in an escalatory manner in patients with severe CVST who have an increased risk of an unfavorable outcome due to edema, infarction and hemorrhage.

Diffusion-Weighted MR Imaging Findings of Cortical Vein Thrombosis at 3 T

PURPOSE

Diagnosis of cortical vein thrombosis (CVT) on the basis of clot hyperintensity on diffusion-weighted imaging (DWI) has been reported as limited. Our aim was to evaluate different DWI findings of CVT either in isolated form or in combination with sinus thrombosis.

METHODS

In this review-board-approved study, patients with the diagnosis of CVT on magnetic resonance venography (MRV) between 2004 and 2011 were evaluated, and 13 patients with 26 CVT (3 isolated and 23 combined CVT) sites were recruited. The evaluated DWI findings were as follows: (1) the hyperintense clot signal (CS) itself, and (2) clot susceptibility signal (CSS) that appears next to the CVT. Two blinded radiologists evaluated the data. Kappa (κ) statistics was applied for interobserver agreement.

RESULTS

Both readers reported CS within the vascular clot itself in 6 of 26 (23%) CVT sites on DWI. CSS was reported in 16 of 26 (61.5%) CVT sites by reader 1, and in 14 of 26 (54%) of the CVT sites by reader 2. At four CVT sites with thrombosed veins on MRV, both readers reported no DWI findings. When both CS and CSS were evaluated together, reader 1 reported a positive DWI finding in 22 of 26 (84%) of the CVT sites, and reader 2 reported in 20 of 26 (79%) of the sites. κ Statistics showed a very good agreement (κ: 0.87).

CONCLUSIONS

Besides the hyperintense CS, with additional evaluation of the presence of CSS, DWI can provide an additional clue in CVT patients and may suggest its diagnosis, which is important in clinically unsuspected patients.

Isolated cortical vein thrombosis: a rare cause of venous stroke with good prognosis after timely diagnosis and treatment

BACKGROUND

Isolated cortical vein thrombosis (ICoVT) is a rare condition representing approximately 6% of cerebral vein thromboses (CVT). In all its forms, CVT is more prevalent in women. ICoVT shares the same group of predisposing conditions typical of other CVT. It may thus be easily missed due to its non-specific clinical presentation and confounding radiological findings, which may lead to a delay in appropriate diagnosis and treatment.

METHODS

A comprehensive literature search was conducted to identify manuscripts discussing epidemiology, risk factors, clinical presentation, radiological techniques and presentation, management, and outcome in patients with ICoVT.

RESULTS

We identified 40 papers published between 1991 and 2012 that met our criteria for review.

DISCUSSION

MR techniques are essential in the diagnosis of this entity. Without appropriate therapy, these thromboses may extend bidirectionally and even compromise the dural sinuses. Correction of predisposing factors for venous thrombosis and anticoagulation is the therapy of choice for most patients. The overall prognosis with adequate and timely therapy is very good.

Imaging predictors of clinical deterioration in cerebral venous thrombosis

Cerebral venous thrombosis (CVT) is a rare stroke subtype with a highly variable clinical course. There is limited information on clinical deterioration in these patients, and imaging predictors of deterioration have not been studied adequately. Therefore, we aimed to investigate the radiological predictors of clinical deterioration in patients with CVT. We conducted a retrospective study of 106 consecutive patients from 1997 to 2010. All patients were confirmed as having CVT using imaging techniques. The following clinical data were collected: patient demographics, clinical presentation, radiological findings, treatment and clinical deterioration. Of the 106 patients, there were 77 females and 29 males, with a mean age of 43 years (range 19-79 years). The common symptoms of clinical presentation included headache (72%), seizure (29%) and severe motor impairment (20%). Overall, 34% of the patients with CVT developed clinical deterioration during hospital admission. Univariate analysis showed venous infarcts and hyperintensity on diffusion-weighted imaging (DWI) as predictors of clinical deterioration. Parenchymal haemorrhage, vasogenic oedema, midline shift and thrombosis location were not predictive of clinical deterioration. In conclusion, our study showed that venous infarcts and hyperintensity on DWI were associated with clinical deterioration in patients with CVT. These findings suggest that close monitoring is necessary in these groups of patients as they may require more aggressive therapy.

Stroke: high-field magnetic resonance imaging

Diagnostic modalities for the diagnosis of acute stroke have increased in number and quality. Magnetic resonance imaging has increasingly become a central tool for the management of patients with stroke. New sequences, such as diffusion and perfusion, provide insight into the infarcted core and the hypoperfused brain. The use of higher magnetic fields allows us to gain in signal strength, which can be used to improve imaging speed and/or resolution. Recent additional sequences allow perfusion without contrast and susceptibility-weighted imaging can help identify early bleeding. These new techniques should provide more information about the on going ischemic process.

Decompressive hemicraniectomy in severe cerebral venous thrombosis: a prospective case series

Small retrospective case series suggest that decompressive hemicraniectomy can be life saving in patients with cerebral venous thrombosis (CVT) and impending brain herniation. Prospective studies of consecutive cases are lacking. Thus, a single centre, prospective study was performed. In 2006 we adapted our protocol for CVT treatment to perform acute decompressive hemicraniectomy in patients with impending herniation, in whom the prognosis with conservative treatment was considered infaust. We included all consecutive patients with CVT between 2006 and 2010 who underwent hemicraniectomy. Outcome was assessed at 12 months with the modified Rankin Scale (mRS). Ten patients (8 women) with a median age of 41 years (range 26-52 years) were included. Before surgery 5 patients had GCS < 9, 9 patients had normal pupils, 1 patient had a unilaterally fixed and dilated pupil. All patients except one had space-occupying intracranial hemorrhagic infarcts. The median preoperative midline shift was 9 mm (range 3-14 mm). Unilateral hemicraniectomy was performed in 9 patients and bilateral hemicraniectomy in one. Two patients died from progressive cerebral edema and expansion of the hemorrhagic infarcts. Five patients recovered without disability at 12 months (mRS 0-1). Two patients had some residual handicap (one minor, mRS 2; one moderate, mRS 3). One patient was severely handicapped (mRS 5). Our prospective data show that decompressive hemicraniectomy in the most severe cases of cerebral venous thrombosis was probably life saving in 8/10 patients, with a good clinical outcome in six. In 2 patients death was caused by enlarging hemorrhagic infarcts.

Imaging of acute ischemic stroke

In this article the individual components of multimodal computed tomography and multimodal magnetic resonance imaging are discussed, the current status of neuroimaging for the evaluation of the acute ischemic stroke is presented, and the potential role of a combined multimodal stroke protocol is addressed.

Diagnosis and management of cerebral venous thrombosis: a statement for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND

The purpose of this statement is to provide an overview of cerebral venous sinus thrombosis and to provide recommendations for its diagnosis, management, and treatment. The intended audience is physicians and other healthcare providers who are responsible for the diagnosis and management of patients with cerebral venous sinus thrombosis.

METHODS AND RESULTS

Members of the panel were appointed by the American Heart Association Stroke Council's Scientific Statement Oversight Committee and represent different areas of expertise. The panel reviewed the relevant literature with an emphasis on reports published since 1966 and used the American Heart Association levels-of-evidence grading algorithm to rate the evidence and to make recommendations. After approval of the statement by the panel, it underwent peer review and approval by the American Heart Association Science Advisory and Coordinating Committee.

CONCLUSIONS

Evidence-based recommendations are provided for the diagnosis, management, and prevention of recurrence of cerebral venous thrombosis. Recommendations on the evaluation and management of cerebral venous thrombosis during pregnancy and in the pediatric population are provided. Considerations for the management of clinical complications (seizures, hydrocephalus, intracranial hypertension, and neurological deterioration) are also summarized. An algorithm for diagnosis and management of patients with cerebral venous sinus thrombosis is described.

Neuroimaging of cerebral ischemia and infarction

The imaging workup for patients with suspected acute ischemic stroke has advanced significantly over the past few years. Evaluation is no longer limited to noncontrast computed tomography, but now frequently also includes vascular and perfusion imaging. Although acute stroke imaging has made significant progress in the last few decades with the development of multimodal approaches, there are still many unanswered questions regarding their appropriate use in the setting of daily patient care. It is important for all physicians taking care of stroke patients to be familiar with current multimodal computed tomography and magnetic resonance imaging techniques, including their strengths, limitations, and their role in guiding therapy.

Magnetic resonance imaging of vascular diseases of the white matter

Magnetic resonance imaging plays an important role in the diagnosis and management of cerebrovascular diseases. In addition to stroke, it can also demonstrate changes apparent in the white matter such as leukoaraiosis. These as well as other changes occurring with increasing age can be visualized. Among others, there is an increase in the number and size of perivascular spaces. Although many of these alterations may be clinically silent, with increasing load they may become symptomatic. Other vascular pathological findings such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and the posterior reversible encephalopathy syndrome can also provoke changes in the cerebral white matter that are visible on magnetic resonance imaging and are discussed.

[Iatrogenic venous cerebral air embolism without pulmonary manifestation: A retrograde mechanism?]

INTRODUCTION

Air embolism is a rare complication of various invasive medical procedures. Venous cerebral air embolism is usually the consequence of paradoxical embolism. We report a case of isolated cerebral air embolism resulting from a non-paradoxical mechanism.

CASE REPORT

A few minutes after his central venous catheter had been accidentally disconnected, a 63-year-old man developed left-sided rhythmic jerking movements followed by left hemiplegia. There were no associated cardiologic or pulmonary signs. Brain CT showed air bubbles in the right frontal cortical sulci. The brain MRI DWI and FLAIR sequences showed a high intensity right frontal cortical lesion without reduction in ADC. Transesophageal echocardiogram did not find a patent foramen ovale.

CONCLUSIONS

In this case of venous cerebral air embolism, the lack of any cardiopulmonary manifestation, the lack of a patent foramen ovale and the neuroradiological findings are not in favor of the hypothesis of paradoxical embolism. The hypothesis of retrograde venous cerebral air embolism is discussed.

Acute stroke magnetic resonance imaging: current status and future perspective

Cerebral stroke is one of the most frequent causes of permanent disability or death in the western world and a major burden in healthcare system. The major portion is caused by acute ischemia due to cerebral artery occlusion by a clot. The minority of strokes is related to intracerebral hemorrhage or other sources. To limit the permanent disability in ischemic stroke patients resulting from irreversible infarction of ischemic brain tissue, major efforts were made in the last decade. To extend the time window for thrombolysis, which is the only approved therapy, several imaging parameters in computed tomography and magnetic resonance imaging (MRI) have been investigated. However, the current guidelines neglect the fact that the portion of potentially salvageable ischemic tissue (penumbra) is not dependent on the time window but the individual collateral blood flow. Within the last years, the differentiation of infarct core and penumbra with MRI using diffusion-weighted images (DWI) and perfusion imaging (PI) with parameter maps was established. Current trials transform these technical advances to a redefined patient selection based on physiological parameters determined by MRI. This review article presents the current status of MRI for acute stroke imaging. A special focus is the ischemic stroke. In dependence on the pathophysiology of cerebral ischemia, the basic principle and diagnostic value of different MRI sequences are illustrated. MRI techniques for imaging of the main differential diagnoses of ischemic stroke are mentioned. Moreover, perspectives of MRI for imaging-based acute stroke treatment as well as monitoring of restorative stroke therapy from recent trials are discussed.

Should decompressive surgery be performed in malignant cerebral venous thrombosis?: a series of 12 patients

BACKGROUND AND PURPOSE

In malignant cerebral venous thrombosis (CVT) patients, emergency decompressive surgery has been suggested as a life-saving procedure. We report 12 patients with malignant CVT, among whom 8 underwent operation.

METHODS

Retrospective study of 12 patients from 3 stroke units who had a malignant CVT as defined: (1) supratentorial cortical lesions attributable to superficial venous system thrombosis with or without sinus involvement; (2) with clinical (decreased consciousness and dilated pupils) or radiological signs of transtentorial herniation; (3) either at onset or after worsening despite heparin therapy. Surgery or abstention was decided individually by neurosurgeons on call.

RESULTS

There were 9 women and 3 men with a mean age of 45+/-15 years. The delay between heparin therapy and signs of malignancy ranged from 2 to 30 hours. At malignant worsening all but 1 patient had hemorrhagic lesions; the median deviation of septum pellucidum was 12 mm (interquartile range, 6.7-13); 5 patients (including 3 who underwent operation) had a unilateral dilated pupil; and 4 (2 who underwent operation) had bilateral dilated pupils. Eight patients underwent surgical decompression, external decompression in 4, both external and internal decompression in 3, and internal decompression in 1. The 4 patients who did not undergo operation died within 1 to 5 days after diagnosis. One patient who underwent operation died of a pulmonary embolism. The 7 others survived, with, at last follow-up (median, 23.1 months; interquartile range, 19.7-45.6), an excellent recovery of mRS 0 or 1 in 6 and mRS 3 in 1.

CONCLUSION

Decompressive surgery may save lives and may even allow a good functional outcome in malignant CVT, even in patients with bilateral dilated pupils.

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.

METHODS

Thirteen patients with CVT, either isolated (n = 3) or in combination with sinus thrombosis (n = 10), and 20 control patients without any venous pathologies were included in this study. The analysis was performed independently by three blinded readers who evaluated the following imaging modalities and sequences separately: non-enhanced computed tomography (NCCT); multi-detector row CT angiography (MDCTA); diffusion-weighted (DWI), T1-weighted (T1w), PD-weighted (PDw), T2*-weighted (T2*w), and fluid-attenuated inversion recovery-weighted (FLAIRw) magnetic resonance (MR) sequences; as well as venous MR angiography (vMRA). The sensitivity, specificity, positive (PPV) and negative predictive values, and interobserver agreement of the different modalities were calculated.

RESULTS

T2*w showed the highest sensitivity for the detection of CVT (97.4%), followed by T1w (70%). FLAIRw and vMRA had a sensitivity of 50% and 41.7%, respectively, whereas the sensitivity of NCCT, MDCTA, DWI, and PDw was below 30%. The specificity and PPV of all modalities was 100%, with good to perfect interobserver agreement.

CONCLUSION

T2*w was the superior MR imaging sequence for diagnosing CVT. Besides T2*w, only T1w reached a sensitivity of over 50% for CVT, followed by FLAIRw, and vMRA. On the contrary, our results suggest that NCCT but also MDCTA might not be suitable for diagnosing CVT.

Cerebral sinovenous thrombosis after closed head injury

BACKGROUND

Cerebral sinovenous thrombosis (CSVT) after closed head injury is an uncommon but potentially serious complication. The aim of this study was to determine whether diffusion weighted imaging (DWI) provide predictive information regarding prognosis.

METHODS

We retrospectively reviewed a series of 11 patients with CSVT after closed head injury. Each patient underwent computed tomography and magnetic resonance imaging within 24 hours of onset of symptoms, including DWI, magnetic resonance venography, and conventional sequences. Apparent diffusion coefficient (ADC) values were measured in seven regions of interest in 7 of 11 patients using DWI. Follow-up imaging and clinical outcome were assessed 6 months or later after initial presentation.

RESULTS

The most affected sinus was the posterior portion of the superior sagittal sinus. There was a mean time interval of 4.1 days between subsequent venous stroke and the initial insult. Brain edema improved in 6 of 11 patients on follow-up imaging. Six of 11 patients recovered successfully, although high or mixed DWI intensity associated with moderately decreased ADC (0.53-0.57 x 10(-3) mm2/s). Two other patients with hematomas developed venous infarction, despite mixed DWI with heterogeneous ADC value (0.55-1.11 x 10(-3) mm2/s). The other three patients, with high DWI and strongly decreased ADC values (0.26-0.27 x 10(-3) mm2/s), developed severe brain atrophy after superior sagittal sinus thrombosis.

CONCLUSIONS

The prospective cutoff point of ADC value may be higher in CSVT after head injury with traumatic hematoma. The territory of venous infarction was found to be larger in infants after treatment failure. In infants, CSVT can demonstrate initially cytotoxic brain edema, which is reversible with anticoagulation therapy.

Serial T2*WI studies in the acute phase of cerebral venous thrombosis

We report a case of a 49-year-old woman with headache who was diagnosed with cerebral venous thrombosis (CVT) of the superior sagittal and right transverse sinuses. Serial gradient recalled-echo T2*-weighted imaging (T2*WI) studies demonstrated dynamic changes of thrombosed segments. T2*WI is useful not only as a diagnostic tool for CVT, but also in evaluating changes to thrombus.