AJR:187, December 2006 1637 AJR 2006; 187:1637–1643 0361–803X/06/1876–1637 © American Roentgen Ray Society M E D I C A L I M A G I N G A C E N T U R Y O F M E D I C A L I M A G I N G A C E N T U R Y O F Khandelwal et al. CT Venography and MR Venography of Cerebral Thrombosis Neuroradiology • Original Research Comparison of CT Venography with MR Venography in Cerebral Sinovenous Thrombosis N. Khandelwal 1 Ajay Agarwal 1,2 Rohit Kochhar 1 J. R. Bapuraj 1 Paramjeet Singh 1 S. Prabhakar 3 S. Suri 1 Khandelwal N, Agarwal A, Kochhar R, et al. Keywords: cerebral sinovenous thrombosis, CT, MRI, neuroradiology, venography DOI:10.2214/AJR.05.1249 Received July 19, 2005; accepted after revision October 25, 2005. 1 Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh 160012, India. Address correspondence to N. Khandelwal (khandelwaln@hotmail.com). 2 Present address: Kesri Bhavan, 2/1/1B Munshi Bazar Rd., Kolkata 700015, India. 3 Department of Neurology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India. OBJECTIVE. The purpose of this study was to compare cerebral CT venography with MR venography and determine the reliability of CT venography in the diagnosis of cerebral sino- venous thrombosis. SUBJECTS AND METHODS. Fifty patients who were clinically suspected of having cerebral sinovenous thrombosis, irrespective of age and sex, underwent cerebral CT venogra- phy and MR venography. Projection venograms were displayed using maximum-intensity-pro- jection images for both CT venography and MR venography. The CT venograms were also dis- played using the integral algorithm, which depicts the average intensity value of the first five voxels deep in relation to the model surface that is nearest the viewer, allowing direct visual- ization of the thrombus in the sinuses. All CT venograms and MR venograms were indepen- dently evaluated by experienced neuroradiologists. RESULTS. Of these 50 patients, 30 patients were diagnosed as having cerebral sinovenous thrombosis on both CT venography and MR venography. The total numbers of sinuses involved were 81 and 77 (CT venography and MR venography). When MR venography was used as the gold standard, CT venography was found to have both a sensitivity and a specificity of 75–100%, depending on the sinus and vein involved. CONCLUSION. CT venography is as accurate as MR venography for diagnosing cere- bral sinovenous thrombosis. erebral sinovenous thrombosis, or cerebral venous thrombosis (CVT), as a cause of serious neurologic symptoms and a fatal outcome was first described in the early 19th century [1]. The true incidence of CVT is unknown because of lack of adequate epidemiologic studies [2]. In- tracranial dural sinus thrombosis is a relatively common and potentially fatal condition. The diverse clinical presentations and lack of accu- rate diagnostic techniques have made CVT a difficult diagnosis with a grave prognosis. That milder forms of CVT can now be recognized and that most patients with CVT recover with recanalization of the thrombosed blood vessel have contributed to the decrease in mortality [3]. Various radiologic techniques have been used to visualize the intracranial venous sys- tem. Conventional and digital subtraction cere- bral angiography, CT, MRI, and recently, MR venography and CT venography have increased our ability to detect this condition. MRI, including MR venography, is now established as the imaging technique of choice for the immediate evaluation and follow-up of CVT [4]. With the advent of helical CT, 3D vascular imaging has also become possible, and large volumes of tis- sue can be scanned during peak arterial and venous enhancement, maintaining high spatial resolution. The term “CT venogra- phy” was first used by Casey et al. [5], who described the technique as a rapid method of depicting the intracranial venous circula- tion with consistently high quality. CT venography can be instantly performed as an adjunct to unenhanced CT in patients un- dergoing an initial workup for CVT. Be- cause the scanning duration is less than 1 minute, image quality is hardly impaired by patient motion, and patient monitoring is easier in critically ill patients as compared with MRI. The purpose of this study was to determine the reliability of CT venography in diagnosing CVT using MR venography as the gold standard. MR venography has well-known shortcomings in diagnosing venous thrombosis, but because no gold standard exists, MR venography was the reference standard in our series. C Downloaded from www.ajronline.org by 52.73.204.196 on 05/13/22 from IP address 52.73.204.196. Copyright ARRS. For personal use only; all rights reserved