Diagnostic Utility of Computed Tomographic Angiography in Giant-Cell Arteritis

Background and Purpose— The diagnosis of giant-cell arteritis (GCA) is challenging. Superficial temporal artery biopsy and ultrasound are positive in only 50%. We evaluated computed tomographic angiography (CTA) of the head in GCA. Methods— This case-control study was performed using a prospective GCA registry. Cases presented with stroke symptoms, had a CTA, and were subsequently diagnosed with GCA. Age- and sex-matched controls presented with stroke symptoms, had a CTA, and were not diagnosed with GCA. CTAs were evaluated for the presence of superficial temporal artery abnormalities. Results— Fourteen cases met the inclusion criteria and were matched with 14 controls. Blurred vessel wall margins and perivascular enhancement was found in 10 cases (71.4%) and 2 controls (14.3%). CTA has an accuracy of 78.6%, sensitivity of 71.4%, and a specificity of 85.7% for GCA. Conclusions— CTA detects superficial temporal artery abnormalities in GCA. This may facilitate early diagnosis and prompt implementation of potentially sight-saving and stroke-preventing treatment.