Neither CT venography nor MRI is recommended in patients with suspected first lower extremity DVT. However, in patients with suspected first lower extremity DVT in whom US is impractical or nondiagnostic, CT scan venography, MR venography, or MR direct thrombus imaging may be used.
The bottom line
The American College of Chest Physicians Guideline on Diagnosis of Venous Thromboembolic Disease recommend an approach to diagnosis of venous thromboembolic disease that begins with a clinical assessment that risk stratifies patients. For patients at low or moderate risk of DVT or PE, the initial preferred test is a highly-sensitive D-dimer. If the D-dimer is negative, no further work-up is needed. If the D-dimer is positive, then further testing to rule-in VTE is recommended.
• Reference: Diagnosis of DVT: Antithrombotic Therapy Evidence-Based Clinical Practice Guidelines American College of Chest Physicians and Prevention of Thrombosis, 9th ed: Chest 2012;141;e351S-e418S
Dr. Skolnik is an associate director of the family medicine residency program at Abington (Pa.) Memorial Hospital. Dr. Vaughn is a third year resident in the Family Medicine Residency Program at Abington Memorial Hospital.