The most common tests used to diagnose DVT are: Ultrasound. This is the most common test for diagnosing deep vein blood clots. A D-dimer test. This test measures a substance in the blood that’s released when a blood clot dissolves. Venography. This test is used if ultrasound doesn’t provide a clear diagnosis.What does a positive Hoffman sign mean?
A positive Hoffman’s sign may indicate that you have a neurological or nervous system condition that affects the cervical spine nerves or brain. If the sign is positive on only one hand, you may have a condition that only affects one side of your body.