Lisette van Dam

Imaging modalities for diagnosing cerebral vein thrombosis 7 113 INTRODUCTION Cerebral vein thrombosis (CVT) refers to dural sinus as well as cerebral vein (cortical and deep vein) thrombosis, and is a rare but potentially life threatening presentation of venous thromboembolism. 1 It accounts for 0.5-1% of all strokes in the adult population with an incidence of 1.32 per 100 000 person-years. 2,3 The clinical presentation of CVT is highly variable and nonspecific. Since there are no validated diagnostic algorithms incorporating decision rules or D-dimer tests, the diagnosis of CVT mainly relies on neuroimaging. 2,4 Neuroimaging is also the main method for evaluation of CVT related complications relevant for prognosis and therapeutic management. 2,5 Therefore, knowledge of the diagnostic performance of available imaging modalities is of great importance for optimal management of the individual patient. Different imaging modalities and techniques can be used for the diagnosis of CVT in adults. Digital subtraction angiography (DSA) once was the diagnostic standard for CVT but is rarely used nowadays due to its invasive nature which harbours a small risk for serious complications, including neurologic complications (i.e. neurologic sign or symptom or worsening of a preexisting neurologic deficit that occurred during the procedure or within 24 hours). 6,7 Neurologic complications are reported to occur in around 1.3% of patients undergoing DSA; with permanent deficits in 0.5% of patients. 7 Additional disadvantages of DSA include radiation exposure, andallergic or nephrotoxic effects of iodinated contrast agent. 8 In current clinical practice, DSA is reserved for exceptional cases, often when reperfusion therapy (such as thrombosuction) is considered. 4,9 Computed tomography (CT)/CT venography andmagnetic resonance imaging (MRI) are presently the first line tests used in clinical practice 5,10-12 , but each modality and technique has its advantages and disadvantages. 13 Randomized controlled diagnostic trials comparing these imaging modalities are absent, probably because of the low incidence of the disease. Therefore, knowledge of the diagnostic performance of each of these modalities is based on small observational studies. Results on diagnostic accuracy of the different imaging modalities from available studies must be interpreted with caution and cannot directly be compared nor translated into daily clinical practice, due to heterogeneity in study design, patient population (clinical presentation), imaging methods and used reference standard. Consequently, the diagnostic approach for the diagnosis of CVT differs considerably per country and even per hospital. 5