Cerebral Venous Sinus Thrombosis, a Nonenhanced CT Diagnosis?

Determining the Diagnostic Value of Venous Sinus Density Indices in Non-Contrast Brain CT Scan for Early Diagnosis of Cerebral Venous Sinus Thrombosis

BACKGROUND AND AIM

A non-contrast brain CT Non-contrast computed tomography (NCCT) scan is a valuable and cost-effective way to detect cerebral venous sinus thrombosis (CVST) during its acute phase. The goal of this study was to evaluate how effective this diagnostic approach is, including its various density indices, to enable a more precise and timely diagnosis of this debilitating condition.

METHOD

This retrospective case-control study was conducted on 88 patients with suspected acute CVST. We analyzed NCCT scans of patients with suspected CVST using a Bayesian regression model with a 95% confidence level. We also conducted ROC analysis in R4.1.0 to determine the optimal cut-off point.

RESULT

We discovered a significant variance in the average sinus attenuation when comparing patients with acute CVST (p < 0.001). By utilizing an optimal cutoff of 61 HU (Hounsfield unit), we achieved sensitivities of 77.1% and specificities of 92.5% for average sinus attenuation. In addition, the optimal cutoff for standardized parameters included the ratios of HU/H (Hematocrit), HU/ICA (internal carotid artery), HU/BA (basilar artery), HU/FRONTAL lobe, HU/TEMPORAL lobe, and HU-BA, which were 1.41, 1.52, 1.63, 1.6, 1.6, and 23, respectively (p < 0.001). Area under the ROC curve for absolute venous Hounsfield was 0.88.

CONCLUSION

NCCT is a reliable diagnostic approach for acute cerebral venous sinus thrombosis in emergency scenarios. Standardized parameters of absolute Hounsfield unit venous sinus thrombosis increase diagnosis accuracy. It is suggested to use these parameters as a complement to each other for more accurate diagnosis.

Deep cerebral venous system involvement in patients with cerebral sinus thrombosis. A proposal of neuroradiological score systems useful for clinical assessment

PURPOSE

To develop a neuroradiological score in patients with deep cerebral venous thrombosis (DCVT), capable of assessing extension of intracranial changes and venous occlusion at diagnosis; to assess the relationship between neuroradiological and clinical features at follow-up.

MATERIAL AND METHODS

In 14 patients with DCVT, we developed 2 score systems on non-enhanced and contrast-enhanced CT: Intracranial Imaging Score (IIS) and Venous Occlusion Imaging Score (VOIS). ISS considers parenchymal venous strokes, hemorrhage, mass effect, and hydrocephalus; VOIS evaluates unilateral or bilateral venous occlusion extension. Modified Rankin Scale (mRS) and vessel recanalization status were assessed at follow-up.

RESULTS

At diagnosis, higher IIS was related to bilateral venous thrombosis involvement (p 0,02; r:0,60), but parenchymal strokes were not related to venous occlusion extension (unilateral or bilateral) (p > 0,05). Moreover, the symptoms' onset time did not correlate with the severity scores (p > 0,05). At follow-up, 8 out of 14 patients showed good clinical outcomes with complete recanalization and neurological improvement, 1 patient showed a poor neurological outcome, whereas 5 patients died within 1 week. Positive correlations were found between IIS and mRS (p 0,003, r = 0,73), between IIS and vessels' recanalization status (p 0,002, r = 0,75), and between vessels' recanalization status and mRS (p < 0,001, r = 0,98).

CONCLUSION

Neuroradiological scores may enhance diagnostic accuracy, and they may have a predictive significance. In patients with DCVT, although intracranial involvement was not influenced by symptoms' onset time or extension of venous occlusion, clinical outcome was related to both intracranial involvement and venous recanalization state. Collateral venous drainage status may counterbalance the thrombotic process improving prognosis.

The diagnostic utility of unenhanced computed tomography of the brain and D-dimer levels in acute cerebral venous sinus thrombosis: A quantitative study

Objectives

(1) To calculate the sensitivity and specificity of the Hounsfield Unit (HU), the HU to hematocrit (H:H) ratio, and the D-dimer level in the diagnosis of acute CVST. (2) To assess the D-dimer level's linear relationship with the HU and the H:H ratio.

Materials and Methods

A single-center retrospective case-control study was conducted from 2005 to 2020. The inclusion criteria for the thrombosed and control groups were specified. A region of interest (ROI) was plotted on the respective sinuses to calculate the HU. The H:H ratio was calculated by dividing the HU value by the hematocrit value. The receiver operating characteristic curve was used to calculate the sensitivity and specificity of the HU and the H:H ratio at different cutoff values. The Pearson correlation was used to assess the linear relationship between the D-dimer level and the HU and H:H ratio.

Results

There were 19 patients in the thrombosed group and 28 patients in the control group. There were significant differences in the mean HU (71 ± 6.3 vs. 45 ± 4.8, P < 0.001) and the mean H:H ratio (2.11 ± 0.38 vs. 1.46 ± 0.63,P < 0.001). An optimal HU value of 56 yielded 100% sensitivity and specificity. An H:H value of 1.48 yielded a sensitivity of 100% and a specificity of 65%, an H:H ratio of 1.77 demonstrated a sensitivity of 85% and a specificity of 90%, and an H:H ratio of 1.88 yielded a sensitivity of 79% and a specificity of 93%. D-dimer levels had a 95% and 71% sensitivity and specificity, respectively. There was a significant moderately positive linear correlation between the D-dimer level and the HU (r = 0.52, P < 0.001) and the H:H ratio (r = 0.61, P < 0.001).

Conclusion

Unenhanced CT of the brain can be a valuable objective diagnostic tool for acute CVST diagnosis. Hounsfield blood density and its normalized ratio with hematocrit are positively correlated with D-dimer levels, which may indicate active blood coagulation in a cerebral venous sinus.

Cerebral Venous Thrombosis: A Challenging Diagnosis; A New Nonenhanced Computed Tomography Standardized Semi-Quantitative Method

Cerebral venous sinus thrombosis (CVST) on non-contrast CT (NCCT) is often challenging to detect. We retrospectively selected 41 children and 36 adults with confirmed CVST and two age-matched control groups with comparable initial symptoms. We evaluated NCCT placing four small circular ROIs in standardized regions of the cerebral dural venous system. The mean and maximum HU values were considered from each ROI, and the relative percentage variations were calculated (mean % variation and maximum % variation). We compared the highest measured value to the remaining three HU values through an ad-hoc formula based on the assumption that the thrombosed sinus has higher attenuation compared with the healthy sinuses. Percentage variations were employed to reflect how the attenuation of the thrombosed sinus deviates from the unaffected counterparts. The attenuation of the affected sinus was increased in patients with CVST, and consequently both the mean % and maximum % variations were increased. A mean % variation value of 12.97 and a maximum % variation value of 10.14 were found to be useful to distinguish patients with CVST from healthy subjects, with high sensitivity and specificity. Increased densitometric values were present in the site of venous thrombosis. A systematic, blind evaluation of the brain venous system can assist radiologists in identifying patients who need or do not need further imaging.

Cerebral Venous Infarct After Recovery From COVID-19 Pneumonia

The coronavirus disease 2019 (COVID-19) may have multisystem organ involvement. Thrombotic events are well-recognized complications of COVID-19. Such complications may include the pulmonary, renal, and other organs vasculature. The risk of coagulopathy is usually related to the severity of COVID-19 pneumonia. Few cases suggested that the coagulopathy risk may persist for some period after the recovery from COVID-19. We report the case of a middle-aged man with severe COVID-19 pneumonia that required seven days of endotracheal intubation and mechanical ventilation who presented with headache and left-sided weakness that occurred three days after his discharge. A computed tomography scan was performed to rule out intracranial hemorrhage before initiating the thrombolytic therapy. The scan demonstrated hemorrhage in the right temporal lobe with surrounding vasogenic edema along with density in the right transverse sinus. Subsequently, computed tomography venography was performed and demonstrated the filling defect representing right sigmoid venous sinus thrombosis. The patient received conservative measures in the form of intravenous hydration, anticoagulation, analgesics, and anticonvulsants. During the hospital stay, the patient had improvement in his symptom and mild neurological deficit persisted. The case highlighted that risk of thrombotic complications in COVID-19 pneumonia may persist for some period after the recovery from the disease. Hence, thromboprophylaxis may be indicated in selected patients with a risk of thrombotic events after their recovery from severe COVID-19.

Plain CT vs MR venography in acute cerebral venous sinus thrombosis: Triumphant dark horse

Context

Most patients with cerebral venous sinus thrombosis (CVST) present with nonspecific signs and symptoms and are likely to undergo nonenhanced head computed tomography (NCT) at presentation, which may show a normal report in up to two-thirds of patients. However, in case of acute thrombosis, sensitivity of diagnosing CVST is high as sinuses are hyperdense. Though magnetic resonance imaging (MRI) is considered the imaging modality of choice for diagnosing CVST, it is not universally available in an acute setting.

Aims

To evaluate whether increased attenuation in cerebral venous sinuses in acute condition can be used to diagnose acute CVST and to determine its diagnostic value.

Materials and Methods

The study involves two independent groups. One group of patients with sinus thrombosis were confirmed by MR venography (group A). The other group included patients without sinus thrombosis (group B). The HU (CT attenuation), hemoglobin (HGB), hematocrit (HCT), and H: H (HU: HCT) ratio of both groups were compared. Thirty-six patients (59 thrombotic sinuses) were studied in group A and 40 in group B.

Statistical Analysis

Average HU and H: H ratio were compared using two-tailed t-test, and linear regression analysis was used to assess correlation between HCT and HU.

Results

Average HU (73.7 vs 48.6) and H: H ratio values were higher in group A patients compared to group B (P < 0.05). Linear regression analysis showed positive correlation between HGB and HCT with HU among both the groups (P < 0.05).

Conclusions

Our study demonstrates that acute CVST can be diagnosed using HU values in NCT.

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.

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.

Diagnostic value of non-contrast brain computed tomography in the evaluation of acute cerebral venous thrombosis

Acute cerebral vein thrombosis is usually seen as increased attenuation in brain non-contrast computed tomography. It is so helpful to define measurable parameters for subjective evaluation of sinus thrombosis in non-enhanced brain computed tomography, especially where advanced neuroimaging techniques are not available. The purpose of this study is to evaluate the diagnostic value of venobasilar attenuation ratio and venobasilar attenuation difference in the evaluation of acute cerebral venous sinuous thrombosis in non-enhanced brain CT scan. Fifty confirmed cases of acute cerebral vein thrombosis were sex- and age-matched with 73 subjects who did not have the condition. Average venous sinus attenuation, Hounsfield to hematocrit ratio, basilar artery density, venobasilar attenuation ratio and venobasilar attenuation difference were measured. Mean attenuation was 65.8 in thrombosed and 44.9 in non-thrombosed sinuses (P < 0.0001). A cutoff absolute sinus attentuaion of 61 HU led to a sensitivity of 82%, specificity of 100% and accuracy of 92%. A cutoff ratio of 1.4 for venobasilar ratio led to a sensitivity of 100%, specificity of 78% and accuracy of 87%. A cut-off value of 24 for venobasilar difference resulted in the sensitivity of 80%, specificity of 100% and accuracy of 92%. The additional measurement of venous sinus and basilar artery attenuations and calculation of venobasilar ratio and difference can increase the sensitivity and specificity of NCCT in the diagnosis of acute CVST.

Are cerebral veins hounsfield unit and H: H ratio calculating in unenhanced CT eligible to diagnosis of acute cerebral vein thrombosis?

Background:

For both the clinician and a radiologist, the diagnosis of cerebral venous sinus thrombosis (CVST), because of the variety of signs and symptoms, remains a challenge. In this study, the role of unenhanced brain computed tomography (CT) in the diagnosis of CVST was assessed.

Materials and Methods:

In this case–control study, unenhanced CT of 35 patients with acute CVST was compared with 70 normal patients. Hematocrit (HCT), creatinine, and blood urea nitrogen were recorded in all patients. CT images were read, and the attenuation was measured by two independent experienced radiologists. The H:H ratio was calculated for all patients in both case and control groups to normalized densities regarding HCT.

Results:

The mean of attenuation in patients was 66.95 ± 10.63 Hounsfield unit (HU) and in the controls was 52.51 ± 2.92 HU (P < 0.0001). The mean of H:H ratio in patients was 1.78 ± 0.40 and in controls was 1.46 ± 0.28 (P < 0.0001). Attenuation >60.4 HU was the best optimal cutoff with area under the curve of 0.918 (0.848–0.962) and had 71.4% sensitivity and 100% specificity. H:H ratio >1.42 as the optimal cutoff had 94.3% sensitivity and 54.3% specificity for identifying the CVST.

Conclusion:

Attenuation value >60.4 HU and H: H ratio >1.42 calculated based on unenhanced CT can be used as reliable methods to detect CVST in the absence of magnetic resonance imaging and magnetic resonance venography in the emergency setting.

Factors affecting dural sinus density in non-contrast computed tomography of brain

The possibility of changing the intracranial vasculature computed tomography (CT) attenuation under the influence of variable factors is a long-held unestablished belief. The purpose of this study is to evaluate factors affecting dural sinus density in non-contrast computed tomography of the brain. Patients presented with acute neurologic symptoms to the emergency department were candidates to be enrolled in this study. A region of interest (ROI) measuring 1-2-mm² recorder (base on sinus size) used to measure the attenuation of each sinus in Hounsfield Unit (HU) and then mean density calculated. CBC, BUN and Cr were extracted from patients' records. Chi-square test, correlation analyze, independent sample unpaired student t-test and one-way ANOVA test and Multivariate logistic regression were used. Positive significant correlation (0.48) was found between the hematocrit level (HCT) and average attenuation in the four sinus segments (P value < 0.0001) and between the HCT and basilar artery attenuation (P value < 0.0001). There was no significant correlation between the age and average attenuation. There was a significant and negative correlation between the BUN/Cr and average attenuation. Using a multivariate analysis on a large sample volume, we conclude that Hgb and HCT are the only factors that have a significant correlation with average sinus attenuation. This correlation is relatively stronger for Hgb in comparison to HCT.

Utility of Hounsfield unit and hematocrit values in the diagnosis of acute venous sinus thrombosis in unenhanced brain CTs in the pediatric population

BACKGROUND

Cerebral venous sinus thrombosis (CVST) is a recognized cause of childhood and neonatal stroke with high morbidity and mortality and a challenging diagnosis in the pediatric population.

OBJECTIVE

We hypothesize that measuring Hounsfield units (HU) of blood in venous sinuses is a more reliable method to diagnose CVST and that normalizing the measured HU in relation to the patient's hematocrit levels may further improve detection of CVST in the pediatric population.

MATERIALS AND METHODS

We performed a retrospective chart review of 15 pediatric patients with acute CVST and 31 control patients. Regions of interest (ROIs) were plotted to measure HU values within the venous sinuses of each patient. Hounsfield unit to hematocrit (HU:Hct) ratios were also calculated. In patients with CVST, HU values were determined in thrombosed and non-thrombosed venous sinuses. Statistical analysis was performed to calculate the differences between patient and control groups and to determine optimal cutoff values for HU and HU:Hct measurements in diagnosing CVST on non-contrast brain computed tomography (CT).

RESULTS

A statistically significant difference in sinus attenuation and HU:Hct ratio was found between thrombosed (66.2±5.3 HU, 1.96±0.4) and non-thrombosed sinuses (47.2±4.5 HU, 1.38±0.25) in the patient group (P<0.0001), with the average attenuation difference being 19 HU. A statistically significant difference was also found between thrombosed sinuses in the patient group and sinuses (48.9±3.13 HU, 1.3±0.12) in the control group (P<0.0001).

CONCLUSION

Optimal cutoff values of 58 HU and HU:Hct ratios of 1.4 lead to sensitivities of 100% in diagnosing CVST.

Cerebral sinovenous thrombosis (CSVT) in children: what the pediatric radiologists need to know

Cerebral sinovenous thrombosis (CSVT) is a relatively uncommon and potentially life-threatening condition in childhood, occurring in various clinical settings. Nowadays, however, it is increasingly diagnosed as related to many causes, likely due to greater clinical awareness and improvement of neuroradiologic techniques. The prompt diagnosis is an important goal to significantly reduce the risk of acute complications and long-term sequelae. The purpose of this narrative overview is to provide a useful educational tool in daily clinical practice for radiologists with a broad perspective of CSVT including a discussion of more common potential pitfalls related to misinterpretation of images in children. This paper will also review the normal venous anatomy, its variants, risk factors that contribute to cause CSVT (neonates with their specific causes of CSVT are not included in this review) and the practical imaging feature of cerebral sinovenous thrombosis on MRI and CT. Finally, a brief overview of frequent and severe CSVT conditions in children with key points in imaging is shown.