Lisette van Dam

MRI for diagnosis of recurrent ipsilateral DVT 2 23 Figure 3 . Coronal MRDTI images from three study patients: MRDTI negative for DVT with symmetric low signal intensity in both popliteal veins despite incompressible popliteal vein of the left leg upon CUS (Panel A); asymmetrical high signal intensity in the left popliteal vein diagnostic for acute recurrent DVT of the left leg (white arrow, Panel B); asymmetrical high signal intensity in the right great saphenous vein diagnostic for acute thrombophlebitis -but not DVT- in the right leg (white arrow, Panel C). Primary outcome In total, five patients met the primary outcome ( Table 2 ), including two of the 122 patients with MRDTI negative for both DVT and thrombophlebitis and off anticoagulant treatment at baseline. The first patient developed CUS-confirmed ipsilateral DVT 21 days after immobilization during a long-haul flight. In addition to CUS, showing new incompressible venous segments compared to the reference CUS, a repeat MRDTI showed a positive signal for acute recurrent DVT. The second patient was referred for a reference CUS one day after the MRDTI negative for DVT, but instead presented at the emergency department with sudden shortness of breath. CTPA showed segmental PE. Both patients were treated with anticoagulants in an outpatient setting and had an uncomplicated follow-up. Three of the 122 patients developed thrombophlebitis during follow-up and were treated with anticoagulants; recurrent DVT was ruled out in all three patients. The incidence of recurrent VTE in patients with MRDTI negative for both DVT and thrombophlebitis and who were not treated with any anticoagulant during follow- up was thus 1.7% (2/119; 95%CI 0.20-5.9%; Table 3 ). The 3-month incidence of the primary outcome in all patients with a MRDTI negative for DVT was 1.1% (2/189; 95%CI 0.13-3.8%; Table 3 ). Overall, two patients were lost to follow-up (0.66%; Figure 2 ).