Blood Clot in the Legs (cont.)

Medical Author:

John P. Cunha, DO, FACOEP

John P. Cunha, DO, FACOEP

John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Exams and Tests

Upon hearing the patient's symptoms, the health care practitioner may suspect that the patient has a deep vein thrombosis, especially if they have any of the risk factors.

No accurate blood test is available to diagnose deep vein thrombosis. Therefore, a variety of imaging tests are used to confirm the diagnosis.

• Doppler ultrasound: Using high-frequency sound waves, this system can visualize the large, proximal veins and detects a clot if one is present. Painless and without complications, this is the most commonly used method to diagnose deep vein thrombosis. However, sometimes the test can miss a clot, especially in the smaller veins.
  
  
• Venography: A liquid dye is injected into the veins for imaging studies. It highlights blockage of blood flow by a clot. This is the most accurate test, but also the most uncomfortable and invasive. It is rarely done today because of the availability of better ultrasound machines.
  
  
• Impedance plethysmography: Electrodes are used to measure volume changes within veins. Because this test does not detect clots better than ultrasound and is harder to perform, it is rarely used.
  
  
• CT scan: This is a type of X-ray that gives a very detailed look at the leg veins in cross section and can detect clots. It is rarely used for this purpose as it is more difficult to interpret and is time consuming. The CT scan is more useful for identification of blood clots in the lung.