Giant cell arteritis
 Discussion of Giant cell arteritis
- Giant cell arteritis is the most common primary systemic vasculitis
- Typically affects women who are older than 50 years of age.
- This pathologic condition affects the primary and secondary branches of the aorta and sometimes the aorta itself.
- A markedly elevated erythrocyte sedimentation rate is almost always present.
- There are two common constellations of findings in giant cell arteritis:
- Temporal arteritis
- Polymyalgia rheumatica.
- Symptoms of temporal arteritis include unilateral headache, facial pain, jaw claudication, or loss of vision.
- Temporal arteritis is a common manifestation of giant cell arteritis and may be confirmed by using temporal artery biopsy.
- In many patients, the clinical manifestation and laboratory values are suggestive of a diagnosis of temporal arteritis and a biopsy is unnecessary.
- Histologically, giant cell arteritis appears similar to Takayasu arteritis, showing granulomatous inflammation of arteries with infiltration predominantly by histiocytes, lymphocytes, and multinucleated giant cells.
- Prompt diagnosis and treatment of giant cell arteritis are important to reduce patient morbidity.
- In particular, vision loss can last for several hours or may be permanent; as many as 15-20% of patients with giant cell arteritis have permanent loss of vision.
 Imaging Findings for Giant cell arteritis
- Temporal arteriography may reveal the extent of vessels involved but is generally invasive and not sufficient for detecting milder degrees of vasculitis.
- CT angiography is useful for revealing luminal changes, such as stenosis, occlusion, dilation, and aneurysm.
- CT is also useful for showing mural changes to include wall thickening, calcification and mural thrombi
- A characteristic gray-scale US finding of giant cell arteritis involvement of the temporal artery is a diffusely thickened hypoechoic arterial wall or halo.
- Color and spectral Doppler US may depict turbulent flow and stenosis of the affected vessel.