MDA D-Dimer / Recurrent DVT Study

Inclusion Criteria: * Age 18 or older * Currently suspected for recurrent DVT * Has a prior history of objectively documented DVT or PE Exclusion Criteria: * Comorbid condition limiting survival to less than 3 months * History of hypersensitivity to contrast medium * Renal dysfunction with a creatinine of \> 150 mcmol/L * Treatment with full-dose therapeutic unfractionated or low molecular weight heparin that was initiated 24 hours or more prior to eligibility assessment * Pregnancy or lactation * Symptomatic for pulmonary embolism * Absence of symptoms within five days prior to presentation * Participation in another trial precluding the use of the diagnostic algorithm in this study * Geographically inaccessible for follow-up * Compression ultrasound, venogram, IPG, or D-dimer performed PRIOR to assessment