How is Takayasu's arteritis diagnosed?
The diagnosis of TA is based on a combination of factors, including:
- Complete medical history and careful physical exam to exclude other illnesses that may have similar symptoms
- X-rays, which show location and severity of vessel damage
- Procedures to detect blood vessel narrowing or aneurysm, including:
Magnetic resonance imaging (MRI): a test that produces images of the human body without the use of X-rays. MRI uses a large magnet, electromagnetic energy waves and a computer to produce these images.
Computed axial tomography (CAT scan): X-rays and computers are used to produce images of internal organs, including large blood vessels.
Angiography: X-ray pictures of the inside of blood vessels. During angiography, a long slender tube called a catheter is inserted into a large artery (generally, in the groin area or arm). The catheter is slowly and carefully threaded through the artery until its tip reaches the segment of vessel to be examined. A small amount of contrast material is injected into the blood vessel through the catheter, and X-rays are taken. The contrast agent enables the blood vessels to appear on the X-ray pictures.
- Significant narrowing of blood vessels may result in turbulent blood flow through the narrowed area that creates an unusual sound called a bruit.
Note: With most other forms of vasculitis, a biopsy (tissue sample) of the affected area may confirm the presence of blood vessel inflammation. A biopsy is most appropriate when easily accessible areas, such as the skin, are affected. However, when large blood vessels are affected, a biopsy is often not practical because of the risks of surgery.