How is DVT diagnosed?
An appointment to find out if you have a DVT includes an exam and review of your medical history. You will also need testing. Common tests to diagnose a DVT are:
A duplex venous ultrasound. This is the most common test used to diagnose a DVT. It shows the blood flow in the veins and any blood clots that exist. An ultrasound technician will apply pressure while scanning your arm or leg. If the pressure does not cause the vein to compress, it could mean there is a blood clot.
Venography. This test uses X-rays to show your deep veins. A special dye (contrast material) is injected into your veins so the X-rays show the veins and any blood clots. Any blockage in blood flow may also be seen. Venography may be used if the results of the duplex ultrasound aren’t clear.
Other tests you may have include:
- Magnetic Resonance Imaging (MRI) or Magnetic Resonance Venography (MRV): MRI shows pictures of organs and structures inside the body, and MRV shows pictures of the blood vessels in the body. In many cases, MRI and MRV can offer more information than an X-ray.
- Computed tomography (CT) scan is a type of X-ray that shows structures inside the body. A CT scan may be used to find a DVT in the abdomen or pelvis, as well as blood clots in the lung (pulmonary embolism).
If your doctor thinks you may have a genetic disorder that causes blood clots, you may need blood tests. This may be important if:
- You have a history of blood clots that cannot be linked to any other cause
- You have a blood clot in an unusual location, such as in a vein from the intestines, liver, kidney or brain
- You have a strong family history of blood clots