Lisette van Dam

Chapter 4 60 Figure 1 . The Theia study flowchart in patients with clinically suspected acute recurrent ipsilateral DVT. 11 CUS, compression ultrasound; DVT, deep vein thrombosis; MRDTI, magnetic resonance direct thrombus imaging. criteria were DVT diagnosed by CUS < 6 months before presentation, symptom duration of > 10 days, suspected concomitant acute pulmonary embolism and general contraindications for MRI. 11 Patients treated with full-dose anticoagulation initiated ≥ 48 hours before eligibility assessment were initially excluded, but allowed later on as they represented a high proportion of the screened population (30%) in the first year after study initiation. According to the Theia study algorithm, patients with a MRDTI negative for DVT were subjected to a standardized CUS examination within 48 hours after the MRDTI; this CUS served as a reference test in case a patient would return with symptoms of DVT recurrence during the follow- up period. However, the management decision was based on the MRDTI results only. Assessment of the Wells rule and measurement of D-dimer was performed in all patients. All study patients received a 3-month follow-up for the outcome