Interobserver variability in the detection of cerebral venous thrombosis using CT venography with matched mask bone elimination

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 Notably, available studies are observational, mostly small, outdated, and with a high risk of bias.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.

Cerebral venous thrombosis

Cerebral venous thrombosis (CVT) is an uncommon cause of stroke that mainly affects young adults and children. In contrast to venous thromboembolism, women are affected three times more often than men. Baseline symptoms can vary considerably between patients, but most present with headache, seizures, or focal neurological deficits. Patients can be diagnosed with magnetic resonance imaging, computerized tomography-venography, or catheter angiography, although the latter is rarely required anymore. Approximately 30-50% of patients have an intracerebral hemorrhage, which can range from a small juxtacortical hemorrhage to large space-occupying lesions. Based on limited evidence from clinical trials, the primary therapy for CVT is anticoagulation with heparin. Uncontrolled studies have shown promising results for the use of endovascular treatment in severely affected patients, but these studies require confirmation in prospective clinical trials. In patients who develop clinical and radiological signs of impending herniation decompressive surgery can be both life saving and result in a good functional outcome.

Dual-Energy CT: What the Neuroradiologist Should Know

Because of the different attenuations of tissues at different energy levels, dual-energy CT offers tissue differentiation and characterization, reduction of artifacts, and remodeling of contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR), hereby creating new opportunities and insights in CT imaging. The applications for dual-energy imaging in neuroradiology are various and still expanding. Automated bone removal is used in CT angiography and CT venography of the intracranial vessels. Monoenergetic reconstructions can be used in patients with or without metal implants in the brain and spine to reduce artifacts, improve CNR and SNR, or to improve iodine conspicuity. Differentiation of iodine and hemorrhage is used in high-density lesions, after intra-arterial recanalization in stroke patients or after administration of contrast media. Detection of underlying (vascular and non-vascular) pathology and spot sign can be used in patients presenting with (acute) intracranial hemorrhage.

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

BACKGROUND

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

METHODS

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

RESULTS

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

DISCUSSION

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