 Good morning everyone. I am Dr. Harika, third year postgraduate in the department of radio diagnosis in NRA Institute of Medical Sciences, Vishakhapatnam. Today I'm going to present a comparative study between conventional MR sequences including time of flight MR-venography and contrast enhanced MR-venography in diagnosing cerebral venous sinus thrombosis. CBT is not an uncommon condition and is potentially treatable cause with low mortality. Its clinical presentation is varied and often dramatic and it often affects young to middle-aged patients and more commonly women. The aim of this study is to compare the accuracy between conventional MR sequences in contrast enhanced MR-venography in diagnosing CBT thereby trying to avoid exposure of the patient to contrast and also save time in diagnosing CBT. This is to start early treatment as soon as possible at an appropriate time. This study was done in a department of radio diagnosis NRA MS Vishakhapatnam over a duration of 18 months between December 2019 and June 2021. The source of the data included all the patients with signs and symptoms of headache, convulsions, altered sensorium, focal neurological deficit and cranial loop palsy referred to our department for MR scan of the head. It included approximately 60 cases sent for MR scan of the brain with signs and symptoms. The inclusion criteria were all the patients suspected to have CBT. The exclusion criteria were the patients who are not willing for the study and all the patients with absolute contraindications for MRI. The pre-contrast images were taken followed by post contrast images after administration of 0.1 millimoles per kg body weight of gadolinium intravenously. The standard imaging protocol was followed. CBT is an important cause of stroke in young. More than a hundred causes of CBT have been decoded but even in 20 to 25 cases after extensive investigation still no cause can be identified. 50% of the strokes in Indian women are related to pregnancy and perperium. Neuroimaging is the cornerstone in the diagnosis of CBT. The imaging modality of choice is MRI with MR venogram but MRI with MR contrast venography is almost 100% diagnostic. Coming to the anatomy of the venous system the three groups of veins that drawn blood supply from the brain are superficial cerebral, deep cerebral and veins of posterior posa. The superficial cerebral veins depending on the venous sinuses into which they empty are divided into dorsomedial system. The drains into the superior sinus, postro inferior system, the drains into the lateral sinus and anterior system, the drains into the cavernous at the pterigoid venous plexuses via the sylvan vein. The deep cerebral vein there are three pairs of veins that is coroid vein, septal and thalamus striate vein that unite behind the interventicular foramen of one row to form the internal cerebral veins. The point of the union is called as the venous angle. The etiology of CBT can be varied. It can be due to antithrombin deficiency, protein C, protein S, pregnancy, perperium etc. Pathogenesis can be infective, embolism, local endothelial damage or hypercoagulability. The unenhanced MR imaging is usually more sensitive than unenhanced CT for reduction of venous thrombi. The primary finding of sinus thrombosis on MR images is the absence of flow void and the presence of altered single intensity in the sinus on routine T1, T2 sequences. Geri imaging may be an important diagnostic aid in acute stage thrombosis, especially when the single intensities on T1, T2 images are more subtle. The stage of formation of the thrombus is the easiest stage to detect a thrombus and the finding of increased single intensity on both T1 and T2 images is consistent with subacute stage of thrombosis. Chronic thrombosis with incomplete recanelization of the sinus may pose a diagnostic challenge at MR imaging. As many as 15% of patients in whom sinus thrombosis is diagnosed at MR imaging have a chronic 15 day old thrombus. Compared with the MR signal in the normal brain parenchyma, the signal in a chronic thrombus is typically ISO to hyperintense on T2 weighted images and ISO intense on T1 weighted images. So, these are some images showing partially recanelized thrombosis in the left transverse and sigmoid sinuses compared to the right transverse and sigmoid sinuses. The enhancement is also less compared to the right side. These are the axial flare images showing bilateral thalamic hyperintensities and the corresponding MR venogram image shows non-visualization of the deep venous system that is consistent with thrombosis. This is the image of a female patient 57 year old presenting with headache. The sastral and coronal MR vmip images shows no flow in the anterior one-third of the superior sastral sinus. Now, also the distal portion of the right transverse sinus. In our study, majority of the patients were in the age group of 20 to 30 years, almost 60 percent, followed by more than 30 years, that is 27 percent. Majority of females constituting approximately 58 percent. The most common symptom of presentation was headache constituting approximately 83 percent, that is followed by vomiting, convulsions and hemiparesis. In our study group of 60 patients, 50 cases were in the acute subacute stage, accounting for 83 percent, followed by 10 cases, which were in the chronic stage, accounting to 17 percent of the cases. In the acute or subacute cases, most of them were hyperintense on sastral T1 weighted sequences and in the chronic cases, most of them were isointense on the sastral T1 weighted sequences. These are the pie diagrams, depending the same, that is in the acute cases, most of them were hyper on T1 weighted images, whereas in case of chronic cases, most of them were iso. Distribution of sinuses, the most commonly involved sinus was superior sastral sinus, followed by transverse sinus, followed by sigmoid sinus. Of the 50 acute cases, 48 were true positive and 2 cases were false positive on plain MRI with top MRV as compared to contrast MRV. Of the 10 chronic cases, 6 had complete recanolization and 4 cases were positive for CBT on contrast MRV. Of the 4 positive chronic cases, 2 were positive on plain MRV as well as 2 cases were false negative. So, the conclusion, the most common age group was 20 to 29 years of age, accounting for 60 percent of the study population and amongst the female patients, high incidence was same in women with pregnancy and peripheral phase, accounting 57 percent as compared to non-pregnant women, who accounted for 43 percent of the female population for the study. So, superior sastral sinus was the most common sinus to be involved, accounting for almost 62 percent of cases followed by transverse sinus. Complete recanolization was seen in 60 percent of chronic CBT cases. The sensitivity and the positive predictive value of plain MRI, including non-contrast MRVnography in diagnosing CBT was 100 percent and 96 percent respectively. Specificity could not be calculated in the acute cases as there were no false negative cases on plain MRI. The sensitivity of the non-contrast MRVnography for chronic cases was 50 percent, specificity was 100 percent and the positive predictive value was 100 percent. Overall sensitivity and specificity of the plain MRI with MRV in diagnosing CBT as compared to contrast MRV in our study was 96 percent and 75 percent. By using limited sequence imaging, we were able to reduce the routine MR scan time of 20 to 25 minutes, just 10 minutes in suspected case of CBT. This in turn leads to avoiding contrast exposure, reduced cost of imaging and also hazing the treatment of the patient. These are my references. Thank you.