CT density measurement and H:H ratio are useful in diagnosing acute cerebral venous sinus thrombosis

Diagnostic Accuracy of Hounsfield Unit Value and Hounsfield Unit to Hematocrit Ratio in Predicting Cerebral Venous Sinus Thrombosis: A Retrospective Case-Control Study

OBJECTIVE

Non-contrast computed tomography (CT) of the brain is a primary neuroimaging modality in emergency patients suspected of having cerebral venous sinus thrombosis (CVST). The objective of the study was to determine the diagnostic accuracy of Hounsfield unit (HU) values and the ratio of HU to hematocrit value (HU/Htc) in predicting CVST in suspected patients.

MATERIAL AND METHODS

A retrospective, case-control study was done in a tertiary care institute which included 35 patients with CVST constituted as cases and 41 patients without CVST as controls on the basis of magnetic resonance venography (MRV). Non-contrast CT brain of all 76 subjects were assessed by two experienced radiologists independently. HU values of dural venous sinuses were calculated in both groups, and HU/Htc ratio was also determined. Statistical Package for Social Sciences (SPSS) version 25.0 (SPSS© for Windows, IBM© Corp.) was used for statistical analysis. Independent samples t-test was applied to compare the means of continuous variables. The diagnostic values were computed using the Calculator 1 tool on clinical research calculators tab on vassarstats.net. The predictive values of HU and HU/Htc ratio were estimated by the receiver operating characteristic (ROC) curve analysis.

RESULTS

In CVST group, the mean Hounsfield Unit (HU) value was "75.9±3.9 (mean±SD)", while in control group, it was 57.78±4.65 (mean±SD), p < 0.001. The mean HU/Htc ratio was 1.98±0.42 (mean±SD) in the CVST group and 1.51±0.12 (mean±SD) in the control group (p < 0.001). Optimum cut-off HU value was calculated as 68, with 97% sensitivity and 100% specificity. For HU/Htc ratio, optimum cut-off was calculated as 1.69, yielding 71.4% sensitivity and 100% specificity on the basis of ROC curves. The difference was not statistically significant in hemoglobin and hematocrit (Htc) values between the cases and controls.

CONCLUSION

The quantitative measurements like HU value and HU/Htc ratio provide an easily obtainable metric in patients with suspected CVST on non-contrast CT brain, thus enhancing the role of non-contrast CT brain in diagnosing CVST.

Hypodense cerebral venous sinus thrombosis on unenhanced CT: Time-dependent change of CT attenuation in intravenous thrombus

Cerebral venous sinus thrombosis (CVST) is an important cause of stroke, which accounts for 0.5%-1% of all strokes. CVST is principally manifested as headaches, papilledema, psychiatric symptoms, impaired consciousness and seizure disorders, with or without neurological defects. We encountered a case of CVST after subacute phase, revealing a hypodense thrombus in the superior sagittal sinus (SSS) on unenhanced CT. Retrospective observation of the serial unenhanced CT images taken at another hospital showed that the SSS thrombus changed from high to low attenuation for 10 days. RBCs dominant CVST at acute phase shows high attenuation on unenhanced CT and is effective for heparin therapy, whereas CVST after subacute phase shows low attenuation on unenhanced CT by the thrombus contents of fibrin, hemosiderin and collagen, and may be ineffective to heparin therapy. Therefore, it is important to accurately identify high attenuation of the CVST at acute phase on unenhanced CT and treat with heparin as early as possible.

Clinical application of three-dimensional T1-weighted BrainVIEW in magnetic resonance imaging of cerebral venous thrombosis: a case report and literature review

To date, there is no clinical scoring system or laboratory indicator that can rule out cerebral venous thrombosis (CVT) or provide diagnostic proof for evaluating post-treatment thrombosis recanalization during follow-up. We therefore explored an imaging method for quantitative assessment of CVT and assessed thrombotic changes during follow-up. A patient presented with severe posterior occipital distension extending to the top of the forehead and an elevated plasma D-dimer (DD2) level. Computed tomography and pre-contrast-enhanced magnetic resonance imaging revealed only a small amount of cerebral hemorrhage. Three-dimensional (3D) T1-weighted (T1W) BrainVIEW pre-contrast-enhanced magnetic resonance scanning showed subacute thrombosis in the venous sinus, and the post-contrast-enhanced scan combined with volume rendering reconstruction showed cerebral thrombosis of the venous sinus and allowed for measurement of the thrombus volume. On days 30 and 60 of post-treatment follow-up, post-contrast-enhanced scans showed progressive reduction of the thrombus volume as well as recanalization and fibrotic flow voids in the chronic thrombosis. 3D T1W BrainVIEW was helpful to observe the size of the thrombi and the situation of venous sinus recanalization during the follow-up after clinical treatment of CVT. This technique can reflect the imaging manifestations of CVT throughout the whole process to guide clinical treatment decisions.

Diagnostic Sensitivity of Unenhanced CT for Cerebral Venous Thrombosis: Can Clot Density Measurement Replace CT Venogram?

Objectives Cerebral venous sinus thrombosis is an important cause of stroke in young adults. Noncontrast-enhanced CT head (NECT) is almost always the first investigation.

Our objectives were as follows:

1. How accurately does venous sinus density on NECT predict the presence of clot on CT venogram (CTV)?

2. Whether repeated measurements changed the confidence?

3. How many venous sinus thrombus would be missed if we do not do a CTV?

4. Can clot density measurement replace CTV?

Methods Multicenter case–control study was designed with data from seven hospitals. Inclusion criteria: all CT and magnetic resonance imaging venograms with a prior NECT, performed between 1.1.2018 and 31.12.2018 (12 months), were included. Hounsfield unit (HU) values were calculated at the site of highest density on the NECT. Logistic regression analysis was performed using STATA.

Result Two-hundred seventy-seven cases met the criteria with 33 positive cerebral venous thrombosis (density on NECT 60–92 HU) and 244 negative examinations (density on NECT 31–68 HU). Area under the curve for average clot density on NECT was 0.9984.

Conclusion We found a strong relationship between sinus density on NECT and outcome of CTV. Repeating density measurements did not add any predictive value or changed outcome.

Advances in Knowledge Density 70 HU or higher on NECT always resulted in a positive CTV but would miss a fifth of the positives. Cutoff at 60 HU would not miss any but result in significant false positives. An efficient option could be to limit CTV to sinus densities 60 to 70 HU only. However, a larger study would be required for such change in practice.

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.

Imaging the Cerebral Veins in Pediatric Patients: Beyond Dural Venous Sinus Thrombosis

The range of intracranial venous anomalies in children differs from that in adults. As a commonly encountered highly morbid disease, sinovenous thrombosis has been discussed extensively in the literature, and the associated imaging considerations are similar in pediatric and adult patients. The authors shift the focus to less frequently discussed cerebral venous diseases in pediatric patients. First, the practical embryology pertinent to malformations, syndromes, and variants such as vein of Galen aneurysmal malformation, Sturge-Weber syndrome, and developmental venous anomalies are discussed. Second, anatomic considerations that are applicable to neuroimaging in pediatric patients with cerebral venous anomalies are reviewed. In the discussion of anatomy, special attention is given to the medullary venous system that serves the cerebral white matter, superficial cortical veins (tributaries of the dural venous sinuses), and bridging veins, which carry blood from the superficial cortical veins through the potential subdural space into the dural venous sinuses. Third, the selection of imaging modalities (US, CT and CT venography, and MRI) is addressed, and various MR venographic pulse sequences (time-of-flight, phase-contrast, and contrast-enhanced sequences) are compared. Finally, a broad variety of congenital and acquired superficial and deep venous diseases in children are reviewed, with emphasis on less frequently discussed entities involving the medullary (eg, deep medullary venous engorgement and thrombosis, periventricular hemorrhagic venous infarction due to germinal matrix hemorrhage), cortical (eg, cortical venous thrombosis), and bridging (eg, acute and chronic manifestations of injury in abusive head trauma) veins, as well as the deep veins and dural venous sinuses (eg, varix). © RSNA, 2023 Quiz questions for this article are available through the Online Learning Center. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Clinical value of deep vein thrombosis density on pre-contrast and post-contrast lower-extremity CT for prediction of pulmonary thromboembolism

Background

There was a lack of studies assessing the relationship between deep vein thrombosis (DVT) Hounsfield unit (HU) density and pulmonary thromboembolism (PTE).

Purpose

To evaluate the clinical value of DVT density measured on pre- and post-contrast lower-extremity computed tomography (CT) for the prediction of PTE.

Material and Methods

From 2017 to 2021, patients who underwent pulmonary CT angiography within one week after diagnosis of DVT on lower-extremity CT were included in this retrospective study. Then, the patients without PTE were included in “DVT group” and those with both DVT and PTE were included in the “DVT-PTE group.” The DVT HU density was measured by drawing free-hand region of interests (ROIs) within the thrombus at the most proximal filling defect level. A receiver operating characteristic (ROC) analysis was used to evaluate the predictive value of DVT density for the risk of PTE.

Results

This study included a total of 94 patients (DVT group: n=56; DVT-PTE group: m=38). DVT density was significantly higher in the DVT-PTE group than the DVT group in both pre-contrast (53.5 ± 6.2 HU vs. 44.1 ± 7.9 HU; P < 0.001) and post-contrast CT (67.0 ± 8.6 HU vs. 57.1 ± 10.6 HU; P < 0.001). ROC analysis revealed that the area under curve, sensitivity, and specificity for predicting the risk of PTE were 0.739, 71.1%, and 64.2%, respectively, at a DVT density cutoff of 48.2 HU on pre-contrast CT and were 0.779, 73.7%, and 69.6% at a DVT density cutoff of 61.8 HU on post-contrast CT.

Conclusion

The DVT density on both pre- and post-contrast CT could be a predictive factor of PTE.

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.

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.

Use of intravascular hypo- and hyper-attenuation on non-contrast-enhanced computed tomography in diagnosing acute septic thrombophlebitis

Septic thrombi, such as those observed in pylephlebitis and Lemierre's syndrome, are characterized by portal vein thrombosis and venous thrombosis with bacterial infection. Although radiographic findings of septic thrombus on contrast-enhanced computed tomography have been well described, no report has described the characteristics of non-contrast-enhanced computed tomography. We describe a case series of septic thrombophlebitis exhibiting intravascular hypo- and hyper-attenuation on non-contrast-enhanced computed tomography. These radiographic features reflect the pathophysiology of septic thrombus, and therefore, it is important and useful to evaluate thrombus attenuation on non-contrast-enhanced computed tomography.

Unruptured Arteriovenous Malformations in the Multidetector Computed Tomography Era: Frequency of Detection and Predictable Failures

Objectives:

While hemorrhage arising from ruptured arteriovenous malformations (AVMs) is usually evident on multidetector non-contrast computed tomography (NCCT), unruptured AVMs can be below the limits of detection. We performed a retrospective review of NCCT of patients with a proven diagnosis of unruptured AVM to determine if advances in CT technology have made them more apparent and what features predict their detection.

Material and Methods:

Twenty-five NCCTs met inclusion criteria of having angiography or MR proven AVM without hemorrhage, prior surgery, or other CNS disease. Demographic variables, clinical symptoms at presentation, abnormal CT imaging findings, attenuation of the superior sagittal sinus (SSS), and Spetzler-Martin grade of each AVM were recorded. We examined the relationship between AVM detection and SSS attenuation through Kruskal–Wallis test. Exploratory serial logistic principal components analysis was performed including demographics, symptoms, and CT features in the multivariate model.

Results:

About 80% of the NCCTs showed an abnormality while 20% were normal. All those with an identifiable abnormality showed hyperdensity (80%). Logistic regression models indicate that clustered associations between several CT features, primarily calcifications, hyperdensity, and vascular prominence significantly predicted Spetzler-Martin grade (likelihood ratio 7.7, P = 0.006). SSS attenuation was significantly lower in subjects with occult AVMs when compared to those with CT abnormalities (median 47 vs. 55 HU, P < 0.04).

Conclusion:

Abnormal hyperdensity was evident in all detectable cases (80%) and multiple CT features were predictive of a higher Spetzler-Martin AVM grade. Moreover, SSS attenuation less than 50 HU was significantly correlated with a false-negative NCCT.

Factors Contributing to Attenuation of Cerebral Venous Sinus in Brain Noncontrast Computed Tomography Scan

Background/Aim  In noncontrast computed tomography (NCCT), an apparently hyper-attenuated cerebral venous sinus (CVS) may lead to suspicion of CVS thrombosis. Understanding the factors affecting attenuation of CVS can guide us toward true diagnosis. Hence, the aim of the study was to determine the effect of different factors such as hematocrit, hemoglobin, age, blood urea nitrogen (BUN), creatinine, leukocyte and platelet count, and sex on the attenuation of CVS on brain NCCT.

Material and Methods  Total 1,680 patients were included in this study, and their demographic and laboratory data and brain NCCT were reviewed. In their brain NCCT, the average attenuation of superior sagittal sinus and both right and left sigmoid sinuses was measured. Data analysis was conducted using the Statistical Package for the Social Sciences version 21.0 software by Kolmogorov-Smirnov, Spearman's correlation coefficient, and multiple linear regression tests. The significance level was considered less than 0.05.

Results  Hematocrit (B = 0.251, p  < 0.001), hemoglobin (B = 0.533, p  < 0.001), and creatinine (B =  − 0.270, p  = 0.048) were determined as predictors of attenuation of superior sagittal sinus. For both sigmoid sinuses, hematocrit ( p  < 0.001) and hemoglobin ( p  < 0.001) were determined as positive predictors, and creatinine ( p  < 0.001) and BUN ( p  < 0.002) were determined as negative and positive predictors, respectively.

Conclusion  Hemoglobin, hematocrit, creatinine, and BUN are the main factors that should be considered in the assessment of CVS density on brain NCCT. As with increasing hematocrit and hemoglobin of the subject, the CVS density in NCCT increases, and with increasing creatinine and in some instance decreasing BUN of the subject, the CVS density in NCCT decreases.

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.

Case Report: Cerebral Venous Sinus Thrombosis and COVID-19 Infection

Coronavirus disease-2019 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 virus). Coronavirus disease-2019 (COVID-19) was declared a pandemic in March 2020 and has changed our lives in many ways. This infection induces a hypercoagulable state leading to arterial and venous thrombosis, but the exact pathophysiology of thrombosis is unknown. However, various theories have been postulated including excessive cytokine release, endothelial activation, and disseminated intravascular coagulation (DIC). We present a patient diagnosed with cerebral venous sinus thrombosis (CVST) with COVID-19 infection. A 66-year-old man presented to a hospital for evaluation of persistent headaches. He tested positive for COVID-19, and MRI of the brain and CT venogram revealed CVST. He was started on heparin drip in the hospital and transitioned to oral anticoagulants at the time of discharge. His headaches improved with treatment. Even though headache is the most frequent and initial symptom of cerebral venous thrombosis, it is rarely the only symptom. A high index of suspicion is therefore required to diagnose CVST especially if the patient presents with a simple complaint like a headache. Common complaints can delay the diagnosis leading to disease progression. Considering the high mortality rates in patients diagnosed with CVST, we suggest the importance of knowing the association between COVID-19 infection and CVST, especially in susceptible patients.

Clinicoradiological Profile and Functional Outcome of Acute Cerebral Venous Thrombosis: A Hospital-Based Cohort Study

Introduction

Acute cerebral venous thrombosis (CVT) may result in a variety of clinical presentations, with headache being the most common. The relationship between clinical and neuroradiological characteristics in acute CVT patients is still not univocally characterized.

Materials and methods

We enrolled 32 consecutive acute CVT patients admitted to our emergency department from January 1, 2012, to June 30, 2019. Clinicoradiological associations and their relationship with the functional outcome at the discharge were tested.

Results

Headache was the presenting symptom in 85% of patients, more frequently subacute (82%), new-onset (67%), with unusual features in respect to prior headache episodes (100%), and associated with concomitant neurological symptoms/signs (74%). Patients with holocranial headache showed more frequent venous ischemia (VI) compared to those with bilateral and unilateral headache (50% vs. 20% vs. 0%, respectively; p=0.027). Patients with concomitant neurological defects had a higher prevalence of VI (50.0% vs. 15.0%; p=0.049) and superior sagittal sinus thrombosis (67% vs. 30%; p=0.043) than those without. Vomit was more frequently observed in patients with straight sinus thrombosis (67% vs. 8%; p=0.005). Increasing age and VI were independently associated with poor (modified Rankin scale (mRS) 2-5) functional outcome (odds ratio (OR) = 1.081, 95% confidence interval (CI) 1.004-1.165; p=0.038 and OR = 12.089, 95% CI 1.141-128.104; p=0.039, respectively).

Conclusions

Our study confirms and enriches available data on the clinicoradiological profile of patients with acute CVT and suggests that increasing age and venous ischemia are independently associated with poor outcomes.

Objective Evaluation of Cerebral Venous Sinus Attenuation on Plain CT Brain and Detecting Anemia. Noticing the "Unnoticed"

Context

Plain computed tomography (CT) of the brain is an important first-line investigation of choice in an acute neurologic setup. Unless clinically suspected concealed areas like the confluence of venous sinuses often go unnoticed. Diagnosing anemia, thrombosis, or polycythemia correlating the CT attenuation values might prove to be fruitful in early patient management where the mode of varied clinical presentations causes a clinical dilemma.

Aims

1) To determine the objective correlation between CT attenuation of the cerebral venous sinus and hemoglobin (Hb) as well as hematocrit (HCT) value and 2) to detect anemia from measuring venous sinus attenuation.

Methods and Materials

An exploratory study design of 200 patients, who had plain CT of the head and Hb and HCT levels obtained within 24 h of the scan.

Statistical Analysis Used

Two-tailed unpaired t-test was used to test the difference between two independent samples. Correlation and regression analyses were used to assess the correlation between two quantitative variables.

Results

A significant correlation was observed between the Hb-Hounsfield unit (HU) and HCT-HU. The simple linear regression model revealed that HU (P value < 0.001) was significantly correlated with Hb and the regression model was, Hb = 2.1 + 0.2 × HU. Similarly, HU (P value < 0.001) was significantly correlated with HCT and regression model was HCT = 6.2 + 0.7 × HU.

Conclusions

Objective attenuation values of dural sinuses on plain CT can be positively correlated with Hb and HCT values. Considering the cutoff of 35.5 HU, we were able to show the specificity of 100% for the detection of anemia.

Diagnostic Value of Hounsfield Unit and Hematocrit Levels in Cerebral Vein Thrombosis in the Emergency Department

BACKGROUND

Unenhanced computed tomography (CT) is a frequently used imaging method in patients who are evaluated in the emergency department with suspected cerebral vein thrombosis (CVT).

OBJECTIVES

The aim of this study was to investigate the usefulness of the Hounsfield unit (HU) value determined by CT and its ratio to the patient's hematocrit (Htc) value in the diagnosis of cerebral vein thrombosis.

METHODS

This retrospective study evaluated 41 patients with acute cerebral venous sinus thrombosis and 41 age- and sex-matched control participants. Two experienced observers independently evaluated the CT scan and measured the attenuation of the dural sinuses.

RESULTS

There was no significant difference in age, gender, hemoglobin, and Htc values between the two groups. The mean HU value was 75 ± 7 HU in the CVT group and 52 ± 6 HU in the control group (p < 0.001). The mean HU/Htc ratio was 1.9 ± 0.3 in the CVT group and 1.3 ± 0.1 in the control group (p < 0.001). The optimal threshold value for HU was determined as 66, and sensitivity at this value was 93%, and specificity was 98%. The optimal threshold value for HU/Htc was determined as 1.64, and the sensitivity at this value was 90% and the specificity was 100%.

CONCLUSION

Hyperattenuation in the dural sinuses and the HU/Htc ratio in unenhanced brain CT scans have high diagnostic value in detecting CVT.

The Promising Future of Low-Molecular-Weight Heparin in Pediatric Cerebral Venous Sinus Thrombosis Occurring as a Rare Complication of Ulcerative Colitis

Pediatric cerebral venous sinus thrombosis (CVST) is a rare complication of ulcerative colitis. Ulcerative colitis is a form of inflammatory bowel disease which accentuates hypercoagulation, thereby leading to thrombosis. Herein, we report a case of a 10-year-old girl who presented with chief complaints of headache, confusion, and new-onset seizure activity for one month as progressively worsening sequelae of ulcerative colitis. Her magnetic resonance venogram confirmed thrombosis in the right transverse, sigmoid, and superior sagittal sinus. The acute ulcerative colitis flare was managed with a short course of steroids and anti-inflammatory monoclonal antibody, and CVST got improved with low-molecular-weight heparin (LMWH). Our study emphasizes the emergence of fatal complications of ulcerative colitis in the pediatric population. It also endorses the pivotal role of thromboprophylaxis with LMWH in pediatric CVST patients. Nevertheless, further studies are required to standardize the use of LMWH in clinical practice.

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.

Magnetic resonance black-blood thrombus imaging can confirm chronic cerebral venous thrombosis: a case report and literature review

Background

Cerebral venous thrombosis (CVT) is easily missed or misdiagnosed in clinical settings because of its high variability in terms of symptoms and radiological findings. Herein, we aimed to explore a promising modality for confirming presumed CVT in the hope to uncover its superior diagnostic performance to conventional imaging modalities.

Case presentation: The patient complained of intolerable pain in her forehead and left eye. Her lumbar puncture opening pressure was 140 mmH₂O, and her cerebrospinal fluid composition was normal. No marked abnormalities were observed in routine brain images, including non-contrast computed tomography, magnetic resonance imaging, and contrast-enhanced magnetic resonance venography. However, chronic mural thrombi in the lumen of the left cortical veins, transverse/sigmoid sinus, and superior sagittal sinus were identified in magnetic resonance black-blood thrombus imaging (MRBTI) maps.

Conclusions

MRBTI can be used to directly and non-invasively visualize thrombi, and may thus be a promising tool over alternative routine techniques for confirming the diagnosis of CVT.

Cerebral venous thrombosis

Cerebral venous thrombosis (CVT) is a rare form of deep venous thrombosis (DVT), yet a leading cause of stroke in young adults, with an incidence that seems to be increasing in recent years. Risk factors for CVT overlap with those of DVT in other locations, with the addition of local risk factors, such as infections, head trauma and neurosurgery. The clinical presentation is highly variable, hence the diagnosis of CVT may be delayed or overlooked. Early recognition and timely initiation of anticoagulant treatment are of essence, while decompressive surgery can be lifesaving for patients with impending transtentorial herniation. Concomitant intracranial hemorrhage is not a contraindication to anticoagulant treatment. Endovascular treatment may be suggested for selected patients who deteriorate despite anticoagulant treatment. In this review we will provide an extensive and contemporary discussion of the incidence, pathophysiology, risk factors, clinical presentation, neuroimaging and management of CVT, in accordance with recent guidelines. Additionally, we will summarize the latest data with regards to direct oral anticoagulants (DOACs) treatment in CVT.

A Pictorial Review of Intracranial Haemorrhage Revisited

BACKGROUND

The many causes of Intracerebral Haemorrhage (IH) can be difficult to differentiate. However, there are imaging features that can provide useful clues. This paper aims to provide a pictorial review of the common causes of IH, to identify some distinguishing diagnostic features and to provide guidance on subsequent imaging and follow up. It is hoped that this review would benefit radiology and non-radiology consultants, multi-professional workers and trainees who are commonly exposed to unenhanced CT head studies but are not neuroradiology specialists.

DISCUSSION

In the absence of trauma, Spontaneous Intracerebral Haemorrhage (SIH) can be classified as idiopathic or secondary. Secondary causes of IH include hypertension and amyloid angiopathy (75-80%) and less common pathologies such as vascular malformations (arteriovenous malformations, aneurysms and cavernomas), malignancy , venous sinus thrombosis and infection. SIH causes between 10 to 15% of all strokes and has a higher mortality than ischaemic stroke. Trauma is another cause of IH with significant mortality and some of the radiological features will be reviewed.

CONCLUSION

Unenhanced CT is a mainstay of acute phase imaging due to its availability and, sensitivity and specificity for detecting acute haemorrhage. Several imaging features can be identified on CT and, along with clinical information, can provide some certainty in diagnosis. For those suitable and where diagnostic uncertainty remains CT angiogram, time-resolved CT angiography and catheter angiography can help identify underlying AVMs, aneurysms, cavernomas and vasculitides. MRI is more sensitive for the detection of subacute and chronic haemorrhage and identification of underlying mass lesions.

Cerebral Venous Thrombosis: Review of Diagnosis, Follow-Up, Late Complications and Potential Pitfalls

Cerebral venous thrombosis is a less common but relevant cause of stroke in adults. The clinical manifestations are nonspecific leading frequently diagnostic delays, so imaging findings are is of vital importance. Conventional imaging modalities, namely computed tomography and magnetic resonance imaging (MRI), allow identification of the thrombus and parenchymal involvement due to venous congestion to a variable degree, but this entity may appears as a nonexpected finding in a nonvenographic study. computed tomography and MRI venographies allow noninvasive confirmation of the diagnosis and adequate characterization of the extent of the thrombus and acute complications, both of them being robust diagnostic techniques. MR venography also can be done without the use of contrast media, which is especially important in certain clinical situations. Cerebral venous thrombosis needs follow-up, and imaging plays a key role in detection of late complications of the disease, including dural arteriovenous fistulas and intracranial hypertension due to veno-occlusive disease. Knowledge of other diseases and conditions that may mimic a thrombus is needed to avoid wrong diagnosis. In this article, we conduct a pictorial comprehensive review of cerebral venous thrombosis, including also the technical aspects of different imaging modalities, diagnosis and acute complications, follow-up, late complications and potential imaging mimics.

Skull Base-related Lesions at Routine Head CT from the Emergency Department: Pearls, Pitfalls, and Lessons Learned

Routine non-contrast material-enhanced head CT is one of the most frequently ordered studies in the emergency department. Skull base-related pathologic entities, often depicted on the first or last images of a routine head CT study, can be easily overlooked in the emergency setting if not incorporated in the interpreting radiologist's search pattern, as the findings can be incompletely imaged. Delayed diagnosis, misdiagnosis, or lack of recognition of skull base pathologic entities can negatively impact patient care. This article reviews and illustrates the essential skull base anatomy and common blind spots that are important to radiologists who interpret nonenhanced head CT images in the acute setting. The imaging characteristics of important "do not miss" lesions are emphasized and categorized by their cause and location within the skull base, and the potential differential diagnoses are discussed. An interpretation checklist to improve diagnostic accuracy is provided. ^©RSNA, 2019.

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.

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.

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.

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.

Diagnostic accuracy of noncontrast CT imaging markers in cerebral venous thrombosis

Objective

To assess the added diagnostic value of semiquantitative imaging markers on noncontrast CT scans in cerebral venous thrombosis (CVT).

Methods

In a retrospective, multicenter, blinded, case-control study of patients with recent onset (<2 weeks) CVT, 3 readers assessed (1) the accuracy of the visual impression of CVT based on a combination of direct and indirect signs, (2) the accuracy of attenuation values of the venous sinuses in Hounsfield units (with adjustment for hematocrit levels), and (3) the accuracy of attenuation ratios of affected vs unaffected sinuses in comparison with reference standard MRI or CT angiography. Controls were age-matched patients with (sub)acute neurologic presentations.

Results

We enrolled 285 patients with CVT and 303 controls from 10 international centers. Sensitivity of visual impression of thrombosis ranged from 41% to 73% and specificity ranged from 97% to 100%. Attenuation measurement had an area under the curve (AUC) of 0.78 (95% confidence interval [CI] 0.74–0.81). After adjustment for hematocrit, the AUC remained 0.78 (95% CI 0.74–0.81). The analysis of attenuation ratios of affected vs unaffected sinuses had AUC of 0.83 (95% CI 0.8–0.86). Adding this imaging marker significantly improved discrimination, but sensitivity when tolerating a false-positive rate of 20% was not higher than 76% (95% CI 0.70–0.81).

Conclusion

Semiquantitative analysis of attenuation values for diagnosis of CVT increased sensitivity but still failed to identify 1 out of 4 CVT.

Classification of evidence

This study provides Class II evidence that visual analysis of plain CT with or without attenuation measurements has high specificity but only moderate sensitivity for CVT.

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.

Cerebral venous thrombosis: state of the art diagnosis and management

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Reversible cerebral vasoconstriction syndrome: an important and common cause of thunderclap and recurrent headaches

Reversible cerebral vasoconstriction syndrome is an intracranial vascular manifestation of a wide variety of diseases. It is the second most common cause of thunderclap headache, the most common cause of recurrent severe secondary headaches, and, in patients <60 years of age, has been reported as the commonest cause of isolated convexity subarachnoid haemorrhage. Radiologically, its key feature is vasoconstriction of the intracranial vessels, a dynamic process that is typically maximal at 2 weeks, varies in its distribution over the course of the disease, and typically resolves after 3 months. It can have haemorrhagic and ischaemic complications and sometimes occurs in concert with posterior reversible encephalopathy syndrome. It also has important associations with dissection and migraine. Rarer atypical cases can present with mild headache, no headache at all, or even a comatose state. This paper provides a detailed review of this syndrome, its pathophysiology, differential diagnosis, imaging findings, and work-up. It also describes the role that high-resolution magnetic resonance imaging (MRI) techniques can have in diagnosing the disease and emphasises the central role that all radiologists have in detecting this important and underdiagnosed condition.

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.

Factors Affecting Attenuation of Dural Sinuses on Noncontrasted Computed Tomography Scan

BACKGROUND AND PURPOSE

Noncontrasted computed tomography (NCCT) is used as the initial neuroimaging test of choice for patients who present with new-onset neurological symptoms. An apparently hyperattenuated venous sinus may lead to the suspicion of cerebral venous sinus thrombosis (CVST). Improved understanding of all factors that can affect attenuation of dural sinuses can guide triage of patients to or from further investigations of suspected CVST. The purpose of this retrospective study was to assess the effect of different factors including hematocrit (HCT), hemoglobin (Hb), age, BUN/Cr ratio (blood urea nitrogen-to-creatinine ratio), and gender on the attenuation of dural sinuses on brain NCCT.

METHODS

A total of 1293 patients with neurological symptoms who presented to the emergency department were included in this study. For each patient, clinical assessment, laboratory investigations, and brain NCCT were reviewed. For each brain NCCT, the average attenuation of superior sagittal sinus and both right and left sigmoid sinuses was measured.

RESULTS

Positive significant correlations were found between average attenuation of dural sinuses on one hand and each of age, Hb, and HCT on the other hand. No significant correlation was found between average attenuation and BUN/Cr ratio. Gender discrepancy was also significant as higher attenuation was found in men.

CONCLUSION

Age, gender, and Hb levels are the main factors that should be taken into account upon the assessment of dural sinuses on brain NCCT. The highest normal attenuation is predicted in an elderly polycythemic man and the lowest is predicted in a young anemic woman.

Non-contrast computed tomography in the diagnosis of cerebral venous sinus thrombosis

BACKGROUND

The aim of the study was to investigate the sensitivity and specificity of non-contrast computed tomography (NCCT) in the diagnosis of cerebral venous sinus thrombosis (CVST). Methods. Screening our neurological department database, we identified 53 patients who were admitted to neurological emergency department with clinical signs of CVST. Two independent observers assessed the NCCT scans for the presence of CVST. CT venography and/or MR venography were used as a reference standard. Interobserver agreement between the two readers was assessed using Kappa statistic. Attenuation inside the cerebral venous sinuses was measured and compared between the patient and the control group.

RESULTS

CVST was confirmed in 13 patients. Sensitivity and specificity of NCCT for overall presence of CVST were 100% and 83%, respectively, with Kappa value of 0.72 (a good agreement between observers). The attenuation values between CVST patients and control group were significantly different (73.4 ± 14.12 HU vs. 58.1 ± 7.58 HU; p = 0.000). The ROC analysis showed an area under the curve (AUC) of 0.916 (95% CI, 0.827 - 1.00) and an optimal cutoff value of 64 HU, leading to a sensitivity of 85% and specificity of 87%.

CONCLUSIONS

NCCT as a first-line investigation has a high value for diagnosis of CVST in the emergency setting. The additional measurement of the sinus attenuation may improve the diagnostic value of the examination.