What is the role of ultrasound in Giant Cell Arteritis diagnosis?
Temporal artery duplex ultrasonography, which may show homogenous wall thickening (the “halo sign” ), has been proposed as a diagnostic alternative to biopsy; however, sensitivity (55%–100%) and specificity (78%–100%) studies are somewhat heterogenous (probably reflecting the importance of operator technique and experience to its utility).
Despite these limitations, recent EULAR recommendations suggest ultrasound as an initial diagnostic modality in predominantly cranial GCA.
Ultrasound has little role in the evaluation of intrathoracic/large-vessel involvement.