Diagnostic Performance of Routine Brain MRI Sequences for Dural Venous Sinus Thrombosis

Trends in cerebral venous thrombosis before and during the COVID-19 pandemic: Analysis of the National Inpatient Sample

OBJECTIVES

We sought to provide updated incidence and trend data for cerebral venous thrombosis (CVT) in the United States from 2016-2020, examine the impact of the COVID-19 pandemic on CVT, and identify predictors of in-hospital mortality.

MATERIALS AND METHODS

Validated ICD-10 codes were used to identify discharges with CVT in the National Inpatient Sample (NIS). Sample weights were applied to generate nationally representative estimates, and census data were used to compute incidence rates. The first wave of the COVID-19 pandemic was defined as January-May 2020. Trend analysis was completed using Joinpoint regression.

RESULTS

From 2016 to 2020, the incidence of CVT increased from 24.34 per 1,000,000 population per year (MPY) to 33.63 per MPY (Annual Percentage Change (APC) 8.6 %; p < 0.001). All-cause in-hospital mortality was 4.9 % [95 % CI 4.5-5.4]. On multivariable analysis, use of thrombectomy, increased age, atrial fibrillation, stroke diagnosis, infection, presence of prothrombotic hematologic conditions, lowest quartile of income, intracranial hemorrhage, and male sex were associated with in-hospital mortality. CVT incidence was similar comparing the first 5 months of 2020 and 2019 (31.37 vs 32.04; p = 0.322) with no difference in median NIHSS (2 [IQR 1-10] vs. 2 [1-9]; p = 0.959) or mortality (4.2 % vs. 5.6 %; p = 0.176).

CONCLUSIONS

CVT incidence increased in the US from 2016 to 2020 while mortality did not change. Increased age, prothrombotic state, stroke diagnosis, infection, atrial fibrillation, male sex, lowest quartile of income, intracranial hemorrhage, and use of thrombectomy were associated with in-hospital mortality following CVT. During the first wave of the COVID-19 pandemic, CVT volumes and mortality were similar to the prior year.

Full sample analysis of cerebral venous sinus thrombosis in ophthalmology inpatients

PURPOSE

We hope that by analyzing the clinical features of cerebral venous sinus thrombosis (CVST), we can help ophthalmologists reduce misdiagnosis or delayed diagnosis.

DESIGN

We evaluated 47 patients with CVST in terms of clinical manifestations.

METHODS

All cases were analyzed in terms of risk factors, clinical symptoms, ophthalmic examination, imaging examination and lumbar puncture.

RESULTS

The body mass indices (BMIs) of 41 patients (87.2%; 95% CI, 77.7-96.8%) were≥24, which is overweight by Chinese standards. There were 22 patients (46.8%; 95% CI, 32.5-61.1%) with BMIs≥28, who were considered obese. Thirteen were hypertensive (27.7%; 95% CI, 14.9-40.5%). The initial symptoms included blurred vision (23, 48.9%; 95% CI, 34.6-63.2%), amaurosis fugax (13, 27.7%; 95% CI, 14.9-40.5%), headache (11 patients, 23.4%; 95% CI, 11.3-35.5%), dizziness (3, 6.4%; 95% CI, -0.6-13.4%), and bilateral diplopia (3, 6.4%; 95% CI, -0.6-13.4%). There were 9 patients (9, 19.2%; 95% CI, 7.9-30.4%) with blindness, 23 patients (48.9%; 95% CI, 34.6-63.2%) with pupillary abnormalities, and 40 patients (85.1%; 95% CI, 74.9-95.2%) with papilledema. Forty-three of the 45 patients who successfully underwent a routine lumbar puncture showed high intracranial pressure (91.7%; 95.6% CI, 89.6-101.6%). Finally, two cases are reported in greater detail for illustrative purposes.

CONCLUSION

The main reasons interfering with the diagnosis of CVST might be its nonspecific ocular symptoms and the physicians' clinical thought process being limited to the scope of common ophthalmological diseases.

Hypersensitive MR angiography based on interlocking stratagem for diagnosis of cardiac-cerebral vascular diseases

Magnetic resonance (MR) angiography is one of the main diagnostic approaches for cardiac-cerebral vascular diseases. Nevertheless, the non-contrast-enhanced MR angiography suffers from its intrinsic problems derived from the blood flow-dependency, while the clinical Gd-chelating contrast agents are limited by their rapid vascular extravasation. Herein, we report a hypersensitive MR angiography strategy based on interlocking stratagem of zwitterionic Gd-chelate contrast agents (PAA-Gd). The longitudinal molar relaxivity of PAA-Gd was 4.6-times higher than that of individual Gd-chelates as well as appropriate blood half-life (73.8 min) and low immunogenicity, enabling sophisticated micro-vessels angiography with a resolution at the order of hundred micrometers. A series of animal models of cardiac-cerebrovascular diseases have been built for imaging studies on a 7.0 T MRI scanner, while the clinical translation potential of PAA-Gd has been evaluated on swine on a 3.0 T clinical MRI scanner. The current studies offer a promising strategy for precise diagnosis of vascular diseases.

Utility of MRI in surgical planning for parasagittal meningiomas

BACKGROUND

Surgical resection is the standard treatment for parasagittal meningioma (PSM), but complete resection may be challenging due to superior sagittal sinus (SSS) involvement. The SSS may be partially or completely obstructed, and collateral veins are commonly present. Thus, knowing the status of the SSS in PSM cases prior to treatment is essential to a successful outcome. MRI is utilized prior to surgery in order to determine SSS status and to check for presence of collateral veins. The objective of this study is to evaluate the reliability of MRI in predicting both SSS involvement and presence of collateral veins in subsequent comparison to actual intra-operative findings, and to report on complications and outcomes.

METHODS

27 patients were retrospectively analyzed for this study. A blinded radiologist reviewed all pre-operative images, noting SSS status and collateral vein presence. Intraoperative findings were obtained from hospital records to similarly categorize SSS status and collateral vein presence.

RESULTS

Sensitivity of the MRI to SSS status was found to be 100% and specificity was 93%. However, sensitivity and specificity of MRI to collateral vein presence was only 40% and 78.6%, respectively. Complications were experienced by 22% of patients, the majority neurologic in nature.

CONCLUSION

MRI accurately predicted SSS occlusion status, but was less consistent in identification of collateral veins. These findings suggest MRI should be used with caution prior to PSM resection surgery particularly with regards to the presence of collateral veins which may complicate resection.

Imaging Approach to Venous Sinus Thrombosis

Cerebral venous thrombosis (CVT) is a rare cerebrovascular disease caused by an occlusion of the cerebral venous sinuses or cortical veins. It has a favorable prognosis if diagnosed and treated early. CVT can be difficult to diagnose on clinical grounds, and imaging plays a key role. We discuss clinical features and provide an overview of current neuroimaging methods and findings in CTV.

Comparison of susceptibility-weighted angiography (SWAN) and T2 gradient-echo sequences for the detection of acute cerebral venous thrombosis

OBJECTIVES

To assess the diagnostic accuracy and lesion conspicuity of susceptibility-weighted angiography (SWAN) and T2* for the clot detection in acute cerebral venous thrombosis (CVT) by comparison with contrast-enhanced MR venography.

METHODS

Venous thrombi detection and conspicuity were assessed by two readers for 18 venous segments on both T2*, SWAN source images, 2D SWAN reformats matching with T2*, and 3D SWAN images (SWAN-MinIP). Images obtained with the three reading techniques were systematically scored and compared to CE MRV findings, in a blinded fashion, per patient and per segment, and compared to each other.

RESULTS

In 30 patients, 137 thrombosed venous segments were evaluated. The sensitivity of T2*, SWAN source images, 2D SWAN, and SWAN MinIP were, respectively, of 89.3%/82.1%, 82.1%, and 82.1% for dural sinus thrombosis and of 100%/100%/100%/96.6% for cortical venous thrombosis. There were significant differences in thrombus detection between T2* and SWAN: T2* versus SWAN source images and 2D SWAN (p = 0.04) and versus SWAN MinIP (p = 0.03). There were no significant differences between the three modalities of SWAN images. T2* was more sensitive than all SWAN images for both sigmoid sinus thrombosis and intracranial internal jugular vein thrombosis (p = 0.04). Inter-observer agreement was slightly superior with T2* (p < 0.05).

CONCLUSION

In this small cohort, SWAN sequence at 3T did not yield additional value for thrombus detection in acute CVT compared to T2*. This study highlights SWAN's greatest weakness both for diagnostic accuracy and lesion conspicuity compared to T2* for acute venous clot detection near the skull base.

Role of MRI and CT in the Evaluation of Headache in Pregnancy and the Postpartum Period

Approximately 35% of acute headaches in pregnant women are secondary to an underlying condition. Headaches are also common in the postpartum period where they occur in 30% to 40% of patients. The majority of secondary headaches are due to hypertensive disorders: preeclampsia-eclampsia, posterior reversible encephalopathy syndrome, and acute arterial hypertension. Other causes include reversible cerebral vasoconstriction syndrome and pituitary apoplexy, as well as life-threatening conditions such as cerebral venous thrombosis. In this article, we review general recommendations for imaging the pregnant patients and discuss the imaging findings of common causes of headaches in pregnancy and the postpartum period.

High-resolution susceptibility-weighted imaging of clots in cerebral venous thrombosis

PURPOSE

To distinguish cerebral venous clots from patent dural sinuses, cortical veins, and calvarium on high-resolution susceptibility-weighted imaging, since there is lack of a well-designed study in the literature.

METHODS

A retrospective review of 51 consecutive cases and 27 controls was performed with susceptibility-weighted imaging independently by two investigators. MR venography along with MR sequences other than the susceptibility-weighted imaging served as the reference standard.

RESULTS

There were 29 males and 49 females in the age range of 1 month to 70 years (mean 27 ± 19.8 years). Substantial (k 0.84 to 1.0) to good (k 0.60 to 0.75) inter-rater agreement was observed on the magnitude images for the demonstration of clots in all venous segments, excluding left sigmoid sinus, jugular bulb, and internal jugular vein (k 0.43 to 0.56). Comparatively magnitude images demonstrated better sensitivity (0.83 (0.54-1.13) to 1.0), specificity (0.92 (0.85-0.99) to 1.0), and negative predictive value (0.98 (0.94-1.02) to 1.0) for the detection of clots across all venous segments. Magnitude images showed positive predictive value ranging from 0.83 (0.66-1.0) to 1.0 for clots anywhere from the anterior aspect of superior sagittal sinus to bilateral transverse sinuses. For the detection of clots from bilateral sigmoid sinuses to internal jugular veins, magnitude images showed relatively better positive predictive value ranging from 0.57 (0.20-0.94) to 0.75 (0.45-1.06) in comparison to the processed magnitude and minimum intensity pixel images.

CONCLUSION

Susceptibility-weighted imaging can successfully distinguish majority of clots from patent dural sinuses, cortical veins, and calvarium with excellent inter-rater agreements.

Diagnostic Accuracy of High-Resolution 3D T2-SPACE in Detecting Cerebral Venous Sinus Thrombosis

BACKGROUND AND PURPOSE

Assessment of cerebral venous sinus thrombosis on MR imaging can be challenging. The aim of this study was to evaluate the diagnostic accuracy of high-resolution 3D T2 sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE) in patients with cerebral venous sinus thrombosis and to compare its performance with contrast-enhanced 3D T1-MPRAGE.

MATERIALS AND METHODS

We performed a blinded retrospective analysis of T2-SPACE and contrast-enhanced MPRAGE sequences from patients with cerebral venous sinus thrombosis and a control group. The results were compared with a reference standard, which was based on all available sequences and clinical history. Subanalyses were performed according to the venous segment involved and the clinical stage of the thrombus.

RESULTS

Sixty-three MR imaging examinations from 35 patients with cerebral venous sinus thrombosis and 51 examinations from 40 control subjects were included. The accuracy, sensitivity, and specificity calculated from the initial MR imaging examination for each patient were 100% each for T2-SPACE and 95%, 91%, and 98%, respectively, for contrast-enhanced MPRAGE. The interrater reliability was high for both sequences. In the subanalysis, the accuracy for each venous segment involved and if subdivided according to the clinical stage of thrombus was ≥95% and ≥85% for T2-SPACE and contrast-enhanced MPRAGE, respectively.

CONCLUSIONS

Both T2-SPACE and contrast-enhanced MPRAGE offer high accuracy for the detection and exclusion of cerebral venous sinus thrombosis; however, T2-SPACE showed a better overall performance and thus could be a useful tool if included in a multiparametric MR imaging protocol for the diagnosis of cerebral venous sinus thrombosis, especially in scenarios where gadolinium administration is contraindicated.

Diagnostic performance of MR black-blood thrombus imaging for cerebral venous thrombosis in real-world clinical practice

OBJECTIVES

MR black-blood thrombus imaging (BTI) has been developed for the detection of cerebral venous thrombosis (CVT). Yet, there is a lack of real-world data to verifying its clinical performance. This study aims to evaluate the performance of BTI in diagnosing and staging CVT in a 5-year period.

METHODS

Patients suspected of CVT were enrolled between 2014 and 2019. Patients with or without BTI scans were classified into group A and group B, respectively. The prevalence of correct diagnosis of CVT and patients with evaluable clot age were compared. The diagnostic performance of BTI including sensitivity, specificity, and specific staging information was further analyzed.

RESULTS

Two hundred and twenty-one of the 308 patients suspected of CVT were eligible in the current study (114 in group A and 97 in group B), with 125 diagnosed by multidisciplinary teams to have CVTs (56 in group A, 69 in group B). The rate of correct diagnosis of CVT was higher in group A than that in group B (94.7% vs 60.8%, p < 0.001, x² = 36.517) after adding BTI images. The percent of patients with evaluable staged segments between the two groups were 96.4% and 33.9%, respectively (x² = 48.191, p < 0.001). BTI showed a sensitivity of 96.4% and 87.9% in the detection of CVT on per-patient and per-segment level, respectively. Up to 98.1% of all thrombosed segments could be staged by BTI and 59.6% of them were matched with clinical staging.

CONCLUSIONS

In the actual clinical practice, BTI improves diagnostic confidence and has an excellent performance in confirming and staging CVT.

KEY POINTS

• Black-blood thrombus imaging has good diagnostic performance in detecting cerebral venous thrombosis compared to traditional imaging methods with strong evidence in the actual clinical setting. • BTI helps clinicians to diagnose CVT with more accuracy and confidence, which can be served as a promising imaging examination. • BTI can also provide additional information of different thrombus ages objectively, the valuable reference for clinical strategy.

Associations Between Doppler Internal Jugular Vein Blood Flow and Transverse Sinus Stasis Detected by Magnetic Resonance Imaging

OBJECTIVES

This study aimed to compare the estimated internal jugular vein (IJV) volume flow with Doppler ultrasound in patients with slow flow in the transverse sinuses and normal transverse sinuses on brain magnetic resonance imaging (MRI).

METHODS

Eighty patients between the ages of 18 and 80 years who did not have any signs of sinus vein thrombosis on brain MRI were included. On MRI, cases with hyperintensity due to a signal void loss in the transverse sinuses in coronal fluid attenuation inversion recovery sequences were included in the slow-flow group. The presence of sinus thrombosis was excluded with other MRI pulse sequences and clinical findings. The participants were divided into 2 groups as having normal and slow flow according to MRI findings. Then bilateral IJV volume flow measurements were made by Doppler ultrasound. Bilateral volume flow was estimated by time-averaged blood flow velocities sampled in the center of the IJV, and IJV cross-sectional areas were measured. We defined the dominant IJV as the one having the higher estimated volume flow of the 2 sides.

RESULTS

Total estimated IJV blood flow was lower (P < .001) in patients with slow flow on MRI (546 mL/min) compared to those without (768 mL/min). A similar finding was seen for the nondominant IJV. In a receiver operating characteristic analysis, the cutoff value for the total estimated IJV volume flow was determined to be 590 mL/min, and the cutoff value for nondominant estimated IJV volume flow was determined to be 202 mL/min to distinguish between the groups.

CONCLUSIONS

Low estimated volume blood flow in the IJV is associated with MRI evidence of stasis in the ipsilateral transverse sinus.

Association between tumor size and peritumoral brain edema in patients with convexity and parasagittal meningiomas

Background and purpose

Peritumoral brain edema (PTBE) is a common complication in meningioma and disruption of the tumor-brain barrier in meningioma is crucial for PTBE formation. To evaluate the association between meningioma size and PTBE, we measured meningioma volumes using the 3D slicer in patients with convexity and parasagittal meningiomas.

Methods

Receiver operating characteristic curve analysis was used to determine the optimal cut-off meningioma volume values for predicting PTBE occurrence. Logistic regressions were used to estimate the odds ratios for PTBE occurrence in patients with convexity and parasagittal meningiomas according to several predictive factors.

Results

A total of 205 convexity or parasagittal meningioma patients with no other brain disease who underwent one or more contrast-enhanced brain MRIs were enrolled in this 10-year analysis in two hospitals. The optimal cut-off meningioma volume value for prediction of PTBE in all study patients was 13.953 cc (sensitivity = 76.1%; specificity = 92.5%). If a meningioma is assumed to be a complete sphere, 13.953 cc is about 2.987 cm in diameter.

Conclusions

Our study suggests a cut-off value of 3 cm meningioma diameter for prediction of PTBE in patients with convexity and parasagittal meningiomas. We believe that we have revealed why the meningioma diameter of 3 cm is clinically meaningful.

MRI of Emergent Intracranial Infections and Their Complications

Acute intracranial infections of the central nervous system and skull base are uncommon but time sensitive diagnoses that may present to the emergency department. As symptoms are frequently nonspecific or lack typical features of an infectious process, a high index of suspicion is required to confidently make the diagnosis, and imaging may not only serve as the first clue to an intracranial infection, but is often necessary to completely characterize the disease process and exclude any confounding conditions. Although computed tomography is typically the initial imaging modality for many of these patients, magnetic resonance imaging offers greater sensitivity and specificity in diagnosing intracranial infections, characterizing the full extent of infection, and identifying potential complications. The aim of this article is to serve as a review of the typical and most important imaging manifestations of these infections that can be encountered in the emergent setting.

Pearls and Pitfalls in the Magnetic Resonance Diagnosis of Dural Sinus Thrombosis: A Comprehensive Guide for the Trainee Radiologist

Dural sinus thrombosis (DST) is a potentially fatal neurological condition that can be reversed with early diagnosis and prompt treatment. Non-enhanced CT scan is often the first imaging investigation in patients presenting with acute neurological symptoms; however, its poor sensitivity in detecting DST is a major drawback. Magnetic resonance (MR) imaging offers multiple advantages such as excellent contrast resolution and unenhanced venography possibilities, making it the mainstay in the non-invasive diagnosis of DST. However, physiological variations, evolution of thrombi, and incorrect selection/application of MR techniques can lead to false positive and false negative interpretations impacting patient management and outcome. This article discusses the MR techniques useful to diagnose DST and describes pitfalls, with troubleshooting methods, to ensure an accurate diagnosis. We have used multiple diagrammatic illustrations and MR images to highlight pertinent take-home points and to serve as an easy guide for day-to-day clinical practice.

Clinical Profile and Prognosis of Cerebral Venous Sinus Thrombosis

Introduction

Cerebral venous sinus thrombosis (CVST) is an acute cerebrovascular disease diagnosed nowadays more frequently. Magnetic resonance venogram (MRV) is the modality of choice for accurate diagnosis. Young females in their childbearing age are prone to develop CVST. Clinical presentation is mainly with headache, focal neurologic deficits, and seizures. Around one third of the patients have altered sensorium at presentation. Prognosis of CVST is good if diagnosed and treated early. Long-term deficits may remain in one quarter of patients. The aim of our study was to do clinical profiling and prognosis of CVST patients.

Materials and methods

This is a descriptive study conducted at the department of Neurology, Sheikh Zayed Medical College/Hospital, Rahim Yar Khan. Study duration was one year. Patients fulfilling inclusion and exclusion criteria were included in the study. Patients confirmed to have CVST on magnetic resonance imaging (MRI)/MRV were included in final analysis. Ethical approval was taken from the Institutional Review Board. 

Results

Thirty three out of 54 patients were included in the final analysis. Out of them, 29 (87.8%) were females and four (12.1%) were males. The mean age at the time of presentation was 31.36 ± 9.61. Of the 29 females, only three were pregnant and 26 were in the postpartum period at the time of presentation. Twelve (41.4%) females were primigravida. Focal deficits were present in 30 (90.9%) patients; headache was present in 26 (78.8%) patients; seizures were present in 24 (72.7%) patients on presentation; and anemia was present in 20 (60.6%) patients.

Conclusion

CVST is an important cause of intracranial hypertension, seizures, and stroke in young people. Clinical presentation is extremely variable, and a high index of suspicion is needed. Magnetic resonance imaging brain with MRV is the current diagnostic modality of choice. Medical management with anticoagulants and supportive measures has excellent clinical outcomes.

Current imaging modalities for diagnosing cerebral vein thrombosis - A critical review

Cerebral vein thrombosis (CVT) is a rare presentation of venous thromboembolism. Prompt and accurate diagnosis is essential as delayed recognition and treatment may lead to permanent disability or even death. Since no validated diagnostic algorithms exist, the diagnosis of CVT mainly relies on neuroimaging. Digital subtraction angiography (DSA) is the historical diagnostic standard for CVT, but is rarely used nowadays and replaced by computed tomography (CT) and magnetic resonance imaging (MRI). High quality studies to evaluate the diagnostic test characteristics of state of the art imaging modalities are however unavailable to date. This review provides an overview of the best available evidence regarding the diagnostic performance of CT and MRI for the diagnosis of CVT. Notably, available studies are observational, mostly small, outdated, and with a high risk of bias. Therefore, direct comparison between studies is difficult due to large diversity in study design, imaging method, reference standard, patient selection and sample size. In general, contrast-enhanced techniques are more accurate for the diagnosis of CVT then non-contrast-enhanced techniques. CT venography and MRI have been both reported to be adequate for establishing a final diagnosis of CVT, but choice of modality as used in clinical practice depends on availability, local preference and experience, as well as patient characteristics. Our review underlines the need for high-quality diagnostic studies comparing CT venography and MRI in specific settings, to improve clinical care and standardize clinical trials.

Radiological evaluation in patients with clinical suspicion of cerebral venous sinus thrombosis presenting with nontraumatic headache - a retrospective observational study with a validation cohort

BACKGROUND

Clinical suspicion of cerebral venous sinus thrombosis (CVST) is imprecise due to non-specific symptoms such as headache. The aim was to retrospectively assess the diagnostic value of nonenhanced CT (neCT) in patients with nontraumatic headache and clinically suspected CVST.

METHODS

A retrospective consecutive series of patients referred 2013-2015 for radiology were evaluated. Eligible patients had nontraumatic headache and suspicion of CVST stated in the referral, investigated with CT venography (CTV) and nonenhanced CT (neCT). neCT scans were re-evaluated for the presence of CVST or other pathology. All CTVs were checked for the presence of CVST. The validation cohort consisted of 10 patients with nontraumatic CVT (2017-2019).

RESULTS

Less than 1% (1/104) had a suspected thrombus on neCT, confirmed by subsequent CTV. The remaining 99% had a CTV excluding CVST. Eleven percent had other imaging findings explaining their symptoms. In the patient with CVST, the thrombosed dural sinus was high attenuating (maximum HU 89) leading to the suspicion of CVST confirmed by CTV. The validation cohort (n = 10) confirmed the presence of a high attenuating (HU > 65) venous structure in the presence of a confirmed thrombus in all patients presenting within 10 days (suspicion written in referral, 10%).

CONCLUSIONS

Despite clinical suspicion, imaging findings of CVST in nontraumatic headache are uncommon. Evaluating neCT for high attenuation in dural sinuses, followed by CTV for confirmation in selected cases seems reasonable. CVST should be recognized by all radiologists and requires a high level of awareness when reading neCT for other indications.

Unilateral Nonvisualization of a Transverse Dural Sinus on Phase-Contrast MRV: Frequency and Differentiation from Sinus Thrombosis on Noncontrast MRI

BACKGROUND AND PURPOSE

Unilateral decreased/nonvisualization of a transverse dural sinus on MRV poses a diagnostic dilemma when gadolinium administration is contraindicated. We determined the frequency of unilateral decreased/nonvisualization of the transverse dural sinus and the performance of pregadolinium MR imaging sequences in diagnosing transverse sinus thrombosis in the presence of unilateral decreased/nonvisualization on phase-contrast MRV.

MATERIALS AND METHODS

We conducted a retrospective review of consecutive 3D phase-contrast MRV (VENC, 30 cm/s) and routine brain imaging (noncontrast sagittal T1, axial T2, FLAIR, DWI, GRE, and postgadolinium 3D-MPRAGE images) performed during a 3-year period for a total of 208 patients. Nonvisualization of a transverse dural sinus was defined as ≥50% nonvisualization of the transverse sinus caliber versus the contralateral side on MRV. Noncontrast imaging findings were considered abnormal when hyperintense signal was present on T2, FLAIR, T1, and DWI, and there were T2* blooming artifacts on GRE and DWI. Postgadolinium 3D-MPRAGE was used to confirm the diagnosis of transverse sinus thrombosis.

RESULTS

Nonvisualization of a transverse dural sinus was observed in 72/208 (34.6%) patients on MRV; 56/72 (77.8%) were without transverse sinus thrombosis, and 16/72 (22.2%) patients had transverse dural sinus thrombosis. Nonvisualization of a transverse dural sinus was seen in 56/192 (29.2%) patients without transverse sinus thrombosis and 16/16 (100%) with transverse sinus thrombosis. Abnormal findings on DWI (transverse sinus hyperintense signal or T2* blooming artifact) are 93.8% sensitive and 100.0% specific for transverse sinus thrombosis. Other noncontrast MR imaging sequences ranged from 56.3%-68.8% sensitive and 91.1%-100.0% specific.

CONCLUSIONS

Nonvisualization of a transverse dural sinus is a frequent phenomenon on phase-contrast MRV. DWI can be effectively used to exclude sinus thrombosis when nonvisualization of a transverse dural sinus is a diagnostic conundrum on phase-contrast MRV and contrast-enhanced studies are contraindicated.

Hypodense cerebral venous sinus thrombosis on unenhanced CT: A potential pitfall. Report of a case and review of the literature

Cerebral venous sinus thrombosis is an uncommon disorder that requires prompt diagnosis and treatment to prevent serious complications. Due to the broad spectrum of clinical presentations, patients typically undergo noncontrast CT as the first imaging study. The classical description of cerebal venous sinus thrombosis on noncontrast CT is a hyperdense thrombus within the dural venous sinus. We report an unusual case of a hypodense cerebral venous sinus thrombosis on unenhanced CT imaging. It is important for radiologists to be aware of this atypical appearance that to our knowledge has not been previously published.

Clinical use of 99mTc-HMPAO-labeled platelets in cerebral sinus thrombosis imaging

Magnetic resonance imaging (MRI) and computed tomography (CT) are not always conclusive for the detection of cerebral venous sinus thrombosis (CVST). ^99mTc-HMPAO-labeled platelets may be useful in cases with high clinical suspicion. Three patients with headaches with or without intraparenchymal hemorrhage that were highly suspected to have CVST, despite inconclusive anatomical imaging, were selected for inclusion in the study. Platelets were extracted by two rounds of centrifugation from 49 ml of the patient's whole blood. The platelets were labeled with ^99mTc-HMPAO and any unbound ^99mTc was removed by centrifugation. The re-suspension of ^99mTc-HMPAO-labeled platelets in cell-free plasma was reinjected into the patients. After 2 h, planar and single photon emission computed tomography (SPECT) images of the head were obtained. Extensive clots were detected in all three patients, illustrated in the planar image and even clearer in the SPECT images. We propose that ^99mTc-HMPAO-labeled platelet scan is a favorable imaging method for patients suspected to have CVST with inconclusive CT and MRI results.

Dural Venous Sinus Thrombosis after Vestibular Schwannoma Surgery: The Anticoagulation Dilemma

Introduction  Dural venous sinus thrombosis (DVST) is a relatively understudied complication of vestibular schwannoma (VS) surgery. Several studies have examined this topic; however, there is limited data on the incidence, clinical progression, and proper management of this patient population. Methods  A retrospective review was performed for patients undergoing surgery for VS at a single institution. All postoperative imaging was reviewed for incidence of DVST. Demographic data were collected including tumor and surgical characteristics along with postoperative course. Results  A total of 63 patients underwent resection of their VS. The incidence of DVST was 34.9%. The operative time was greater in the dural venous sinus thrombosis (DSVT) group, at an average of 6.69 hours versus 4.87 in the no DSVT cohort ( p  = 0.04). Tumor size was correlationally significant ( p  = 0.051) at 2.75 versus 2.12 cm greatest diameter. The translabyrinthine approach was most prevalent (68.2%). The side of the thrombosis was ipsilateral to the tumor and surgery in all patients. The sigmoid sinus was most commonly involved (95.5%). Of them, 85% patients had a codominant or thrombus contralateral to the dominant sinus. All patients were asymptomatic. No patients were treated with anticoagulation. Resolution of thrombus was seen in five (22.7%) of the patients on last follow-up imaging. There were no hemorrhagic complications. Conclusion  The overall incidence of DVST was (34.9%) of 63 patients who underwent VS surgery. All patients were asymptomatic and none were treated with anticoagulation. In our study, continuing to observe asymptomatic patients did not lead to any adverse events.

Clinical Aspects, Diagnosis and Management of Cerebral Vein and Dural Sinus Thrombosis: A Literature Review

Cerebral vein and dural sinus thrombosis (CVST) is an uncommon cause of stroke, but its delayed diagnosis carries significant morbidity and mortality. Several studies have reported higher incidence of CVST than that previously reported. The clinical presentation of CVST varies and can be atypical. Advancement in neuroimaging modalities has made it possible to make an early diagnosis and initiate management with a wide range of therapeutic options, including direct oral anticoagulants and endovascular treatment. This narrative review summarizes the epidemiology, clinical aspects, diagnosis and management of CVST.

Imaging and Management of Blunt Cerebrovascular Injury

Blunt cerebrovascular injury (BCVI) is a relatively rare but potentially devastating finding in patients with high-energy blunt force trauma or direct cervical and/or craniofacial injury. The radiologist plays an essential role in identifying and grading the various types of vascular injury, including minimal intimal injury, dissection with raised intimal flap or intraluminal thrombus, intramural hematoma, pseudoaneurysm, occlusion, transection, and arteriovenous fistula. Early identification of BCVI is important, as treatment with antithrombotic therapy has been shown to reduce the incidence of postinjury ischemic stroke. Patients with specific mechanisms of injury, particular imaging findings, or certain clinical signs and symptoms have been identified as appropriate and cost-effective for BCVI screening. Although digital subtraction angiography was previously considered the standard examination for screening, technologic improvements have led to its replacement with computed tomographic angiography. Of note, although not appropriate for screening, improvements in magnetic resonance angiography with vessel wall imaging hold promise as supplemental imaging studies that may improve diagnostic specificity for vessel wall injuries. Understanding the screening criteria, imaging modalities of choice, imaging appearances, and grading of BCVI is essential for the radiologist to ensure fast and appropriate diagnosis and treatment. This article details the imaging evaluation of BCVI and discusses the clinical and follow-up imaging implications of specific injury findings. ^©RSNA, 2018.

Dural venous sinus thrombosis: The combination of noncontrast CT, MRI and PC-MR venography to enhance accuracy

Aim The aim of this article is to determine whether a combination of noncontrast CT (NCCT), three-dimensional-phase contrast magnetic resonance venography (3D PC-MRV), T1- and T2-weighted MRI sequences can help to identify acute and subacute dural venous sinus thrombosis (DVST) with greater accuracy. Methods A total of 147 patients with DVST ( n = 30) and a control group ( n = 117) underwent NCCT, T1- and T2-weighted MRI sequences, and 3D PC-MRV from 2012 to 2016. Two experienced observers interpreted the images retrospectively for the presence of DVST. Nonvisualization of the dural venous sinuses on 3D PC-MRV and signal changes supporting acute or subacute thrombus on T2- and T1-weighted images were considered a direct sign of DVST. Also, using circle region of interest (ROI) techniques, attenuation measurement from each sinus was obtained on NCCT. Sensitivity and specificity were computed for these modalities separately and in combination for diagnosis of DVST using digital subtraction angiography as the reference standard. Results Nonvisualization of venous sinuses on 3D PC-MRV (sensitivity 100%, specificity 71%) in combination with both applying Hounsfield unit (HU) threshold values of greater than 60 on NCCT (sensitivity 70%, specificity 94%) and acquiring signal changes supporting DVST on T2- and T1-weighted images (sensitivity 83%, specificity 96%), were found to have 100% sensitivity and 100% specificity in the identification of acute or subacute DVST. Conclusion The combination of NCCT, T1- and T2-weighted MRI and 3D PC-MRV may allow the diagnosis of acute or subacute DVST and may obviate the need for contrast usage in patients with renal impairment or contrast allergies.

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.

The Structural Imaging Characteristics and Its Clinical Relevance in Patients with Cerebral Venous Thrombosis-A Retrospective Analysis from One Single Center in China

Background

Few studies have investigated structural imaging findings of cerebral venous thrombosis (CVT) in China. The structural imaging [head computed tomography (CT) and routine brain magnetic resonance imaging (MRI)] can assess any parenchymal lesion secondary to the venous thrombosis and reveal direct signs of intraluminal thrombus. In recent years, many patients can be diagnosed with CVT more rapidly and directly by structural imaging. The aim of the present study is to determine the performance of structural imaging in the diagnosis and outcome of CVT in a large cohort single center of Chinese patients.

Methods

We evaluated consecutive patients admitted to our hospital with CVT receiving structural imaging from 1991 to 2015. A neuroradiologist, blinded to clinical data, independently reviewed the structural imaging, including head CT and routine MRI for parenchymal lesions and signs of dural venous sinus thrombosis, as well as the MRV/DSA findings. The Clinical and laboratory data were reviewed and recorded for further analysis.

Results

117 patients were included in this study, 68 (58.1%) were females. Parenchymal lesions were identified in 56.4% (66/117) of the patients on structural imaging, including focal edema in 30.8%, hemorrhage in 19.7%, and brain swelling in 4.3% of the patients. Patients with parenchymal lesions presented with more often seizures (P < 0.001) and less often headache (P = 0.049). Intraluminal thrombus within the sinuses or veins on structural imaging was found in 28.2% (33/117) of the patients. Patients with both intraluminal thrombus and parenchymal lesions on structural imaging had more acute onset (P = 0.01) and present more consciousness disturbance (P = 0.007).

Conclusion

Intracranial lesions on structural imaging are frequently found in patients with CVT. Patients with parenchymal lesions on structural imaging, especially with intraluminal thrombus simultaneously, tend to have a severe clinical picture and might lead to a devastating or fatal outcome. Structural imaging may help on early diagnosis and predict the poor outcome of CVT.