Lisette van Dam

General discussion and summary 13 197 clinical relevance and most optimal treatment of these thrombi is often not known. With the introduction of MR-NCTI, we are able to directly visualize thrombosis and differentiate acute from chronic thrombosis, and with that determine the need for anticoagulant treatment. In suspected recurrent ipsilateral DVT, MR-NCTI is now increasingly used when a recurrence cannot be diagnosed or excluded with CUS. Formally a diagnostic outcome study on the safety of MR-NCTI for excluding UEDVT and CVT is needed before this technique can be implemented in these settings as well. Of note, when translating the findings of the Theia study to suspected UEDVT and CVT, MR-NCTI may be applied in complex clinical cases in which non-invasive diagnostic tests do not provide a definitive diagnosis, even in the absence of such a study. In splanchnic vein thrombosis (SVT), MR-NCTI could be used to guide the treatment decision in patients with suspected chronic SVT as current guidelines suggest no anticoagulation in patients with chronic rather than acute SVT. Therefore, when the accuracy of MR-NCTI for the differentiation between acute and chronic SVT has been proven in the Rhea study, an outcome study should be performed, ideally in a randomized controlled trial (RCT), in which patients with suspected chronic SVT and normal MR-NCTI will be randomized between therapeutic anticoagulant treatment and no anticoagulation to compare clinical outcome, i.e. the occurrence of recurrent or progressive SVT, major bleeding and death. This will be particularly relevant for patients with incidental SVT, a group of patients comprising 30% of all SVTs, even when conventional imaging tests do not indicate signs of chronicity. Before MR-NCTI can be widely implemented in daily clinical practice when its safety has been proven in diagnostic outcome studies, implementation challenges in real-world practice need to be assessed and addressed. Among those are the lower availability of and less experience with MR-NCTI compared to conventional VTE imaging techniques. Moreover, MRI is associated with higher imaging costs. Therefore, implementation studies are needed to develop the most optimal strategies to include MR-NCTI in daily clinical practice. These studies should among others focus on the exact indications of MR-NCTI imaging, the training of MR technicians and radiologist, the latter who have to learn to interpret MR-NCTI images. In the diagnostic management of suspected PE, CTPP and ventilation/perfusion single photon emission computed tomography (V/Q SPECT) scintigraphy can both provide lung perfusion images, however their place in the diagnostic and prognostic management of PE is still yet to be determined. Indeed, while MR-