Compression ultrasound is commonly used in emergency department. Accuracy to rule out deep vein thrombosis is excellent but lower then Ddimer assessment which is actually gold standard. With progress in formation of emergency physicians (EP), quality of material used, the investigators hypothesize that compression ultrasound can rule out deep vein thrombosis in case of non high probability, as standard care and DDimer assay.

Inclusion Criteria:

• adult patient
• Patient presenting to the emergency department with clinical suspicion of DVT (i.e. pain and/or lower extremity edema).
• Patient with a non-high probability according to the modified Wells score, i.e. a score of 0 or 1
• Subject with a social health insurance plan
• Subject able to understand the objectives and risks of the research and to give a signed and dated informed consent

Exclusion Criteria:

• Patient with suspected pulmonary embolism
• Patient with a high probability of DVT
• Impossible to perform a whole leg doppler ultrasound within 5 days
• Pregnant or breast-feeding woman, on patient's declaration
• Subject under court protection
• Subject under guardianship or curatorship