Lisette van Dam

Chapter 13 194 thoracic cavity. Moreover, CUS examination is hindered due to overlying bone structures, such as the claviculae. We hypothesized that MR-NCTI would be an accurate diagnostic test without the invasive characteristics of (CT) venography imaging. MRDTI and T1-weighted Turbo Spin-echo Spectral Attenuated Inversion Recovery, which is another MR-NCTI sequence, were previously shown to successfully visualize acute thrombosis in three patients with UEDVT proven by conventional imaging. In Chapter 5 , the results of the Selene study were described in which the diagnostic accuracy of MR-NCTI for the diagnosis of UEDVT was evaluated. We showed that MR-NCTI was accurate with a sensitivity of 93% (95%CI 78-99%) and specificity of 100% (95%CI 88-100%) and had an excellent interobserver agreement. This technique may therefore be useful in patients with suspected UEDVT but with inconclusive CUS. Differentiation between acute and chronic thrombosis is also important in the diagnostic management of portal vein thrombosis (PVT), as current guidelines recommend different anticoagulant strategies in patients with acute or chronic PVT. With currently available imaging tests including doppler ultrasonography, CT venography and MRI, this is not always possible, especially in case of an organized non-occlusive chronic PVT without signs of cavernous transformation of the portal vein. We hypothesized that MR-NCTI could accurately differentiate acute from chronic PVT. In Chapter 6 , the first phase of the Rhea study was described, in which we evaluated the most optimal MR-NCTI sequences for the setting of PVT. We found that three-dimensional (3D) T1 Turbo Field Echo and 3D T1 Dixon Fast Field Echo were both able to diagnose and differentiate acute from chronic PVT. These MR-NCTI sequences will therefore be evaluated in the second phase of the Rhea study to assess its diagnostic accuracy for distinguishing acute from chronic PVT. The diagnosis of cerebral vein thrombosis (CVT) can also be challenging due to the complex anatomic variation of cerebral veins and sinuses. Digital subtraction angiography was previously the diagnostic standard for CVT but is now rarely used due to its invasive nature. In Chapter 7 , an overviewof all relevant papers regarding the diagnostic performance of the current available imaging techniques including CT, CT venography and MRI for the diagnosis of CVT is presented. Although large high-quality diagnostic studies are absent, we showed that contrast-enhanced imaging techniques are more accurate than non-contrast-enhanced techniques. We also described that CT venography and contrast-enhanced MRI both seem adequate for the diagnosis of CVT. MR-NCTI was previously shown to be accurate for the diagnosis of CVT too. Therefore, MR-NCTI could possibly be of value in