Imaging findings in extracranial (giant cell) temporal arteritis.

Patients with extracranial giant cell arteritis (GCA) present with occlusive arterial lesions that may be detected with multiple imaging modalities: arteriography, intravenous angiography (IV-DSA), CT scanning, and magnetic resonance angiography (MRA). The lesions often present with a typical arteriographic pattern of bilateral stenoses or occlusions with a smooth, tapered appearance in the subclavian, axillary and proximal brachial arteries. A few patients have aneurysmal lesions. Less commonly involvement may be found in the femoral arteries and their branches. Angiographic study of 65 patients (56 women, 9 men; average age, 65) revealed involvement of the upper extremities in 61 patients, and lower extremities in 13, while 9 had both areas affected. Detection of these lesions requires a diagnostic modality that depicts the vessel lumen such as: angiographic techniques, CT scanning with reconstructed images, and MRA. However, inflammation of the arterial wall cannot be detected by these means. Standard CT imaging with contrast enhancement, and certain MR sequences as well as ultrasound permit identification of the edema and inflammation of the vessel wall. This is an important marker for active disease.