In case of positive D-dimer testing or in patients with a high clinical probability of PE, these patients have MRI protocol combined with venous ultrasonography of the legs. MRI includes 2 different sequences: Unenhanced steady-state-free precession sequences (SSFP) sequences and angiography sequences. (please see \\\"intervention section\\\" for more details). MRI readings will be performed centrally by two independent readers blinded to the results of diagnostic reference standard. Venous ultrasonography of the legs will be interpreted locally.

In case of positive D-dimer testing or in patients with a high probability of PE, MRI and a venous ultrasonography of the legs are done.MRI protocol includes 2 sequences: 1-Unenhanced steady-state-free precession sequences (SSFP) are acquired first without ECG-gating or breath-holding in the axial plane in the multiphase cine mode, with 6 phases per location.The acquisition is repeated to cover 2-3 of the thorax, from the roof of the aorta to the diaphragm. 2- A pulmonary gradient recalled echo (GRE) sequence is performed in the axial plane.The acquisition is triggered to start when contrast enhancement occurred in the right ventricle.Two acquisitions are necessary to cover the anatomy. For each acquisition, 0.15 mL kg-1 body weight of DOTAREM Gadolinium is injected at a rate of 3 mL s-1 followed by an injection of 15 mL of normal saline at 3 mL s-1.Venous ultrasonography of the legs: the examination consists of a real-time B-mode examination of the common femoral and popliteal veins.

sensitivity, specificity, positive and negative likelihood ratios of the combination of MRI and venous ultrasonography of the legs

3-month thromboembolic events rate in patients who were left untreated on the basis of negative D-dimer measurement or negative combination of MRI + venous ultrasonography of the legs