Deep Venous Thrombosis

Preliminary Diagnosis: Deep Venous Thrombosis

I. What imaging technique is first-line for this diagnosis?

• Gray scale and Color Doppler ultrasound evaluation of the bilateral lower extremities.

II. Describe the advantages and disadvantages of this technique for diagnosing deep venous thrombosis.

Advantages

• Does not expose patients to ionizing radiation.

• Highly portable and fast imaging modality.

• Highly sensitive and specific for diagnosing and detecting a deep venous thrombosis.

• Highly sensitive and specific in differentiating acute from chronic thrombus.

Disadvantages

• Less adept in evaluating deep and tortuous venous structures.

• Less adept in characterizing the amount of luminal narrowing and residual flow in the venous structures in a patient with thrombus compared to CT imaging and catheter angiography.

III. What are the contraindications for the first-line imaging technique?

• No specific contraindications to ultrasound imaging exist.

IV. What alternative imaging techniques are available?

• CT of the lower extremities with intravenous contrast (venous phase).

• Catheter angiography of the lower extremity venous structures.

V. Describe the advantages and disadvantages of the alternative techniques for diagnosing deep venous thrombosis.

CT of the lower extremities with intravenous contrast (venous phase)

Advantages

• More specific and sensitive in detecting and characterizing the location and extent of a deep venous thrombosis than ultrasound imaging.

• More adept in evaluating smaller branch deep venous structures for thrombus.

• Better able to detect any underlying primary abnormalities or other secondary complications.

Disadvantages

• Exposes patients to ionizing radiation.

• More expensive than ultrasound imaging.

Catheter angiography of the lower extremity venous structures

Advantages

• Gold standard in evaluating for thrombus in the lower extremity deep venous structures.

• Better able to guide therapy and diagnosis at the same time.

Disadvantages

• Highly invasive procedure that exposes patients to greater morbidity and mortality than ultrasound and CT imaging.

• Exposure to ionizing radiation.

VI. What are the contraindications for the alternative imaging techniques?

CT of the lower extremities with intravenous contrast (venous phase)

May be contraindicated in pregnant patients.

Catheter angiography of the lower extremity venous structures

• Catheter angiography is contraindicated in patients in hypercoagulable states.

• Relative contraindication in pregnancy.