Extended Ultrasound Superior for Diagnosing Large Vessel GCA

Extended anteromedial ultrasound (A2-ultrasound) is more sensitive than limited ultrasound for diagnosing large vessel involvement in patients with giant cell arteritis (GCA), according to study results published in Rheumatology.

“Thus, we recommend the use of extended A2-ultrasound in all patients with new-onset GCA as inflammation of large vessels may be a predictor of more resistance to treatment disease with higher corticosteroid doses and potentially severe vascular damage,” wrote corresponding author Anne C. Bull Haaversen, MD, of the Martina Hansens Hospital Department of Rheumatology in Norway, and study coauthors. “However, A2-ultrasound requires high expertise and high-end equipment and should be performed by trained ultrasonographers.”

The study included 133 patients with new-onset GCA who underwent examination with recommended limited ultrasound of the temporal and axillary arteries. In addition, patients were examined with an A2-ultrasound technique expanded to include the carotid, vertebral, subclavian, and proximal axillary arteries. Researchers were interested in comparing large vessel involvement detected via limited ultrasound vs extended A2-ultrasound.

Extended A2-ultrasound revealed large vessel involvement in 69.9% of patients, according to the study, while limited ultrasound showed large vessel involvement in 42.1% of patients. In all, 37 patients had large vessel involvement missed by limited ultrasound but detected with extended A2-ultrasound.

“Even when examining the entire axillary artery, 16 patients with large vessel involvement (carotid, vertebral, and subclavian) captured by A2-ultrasound would have been missed,” researchers reported.

The only large vessel involvement in 12 of the 16 patients was vasculitis of the vertebral arteries, the study found.

“Of the 133 GCA patients, five patients (3.8%) with large vessel GCA had involvement of supraaortic arteries other than the distal axillary artery,” researchers wrote, “and the diagnosis of GCA would have been missed if only limited ultrasound had been performed unless large vessel evaluation was performed by using other imaging modalities.”

—Jolynn Tumolo

Reference:
Bull Haaversen AC, Brekke LK, Kermani TA, Molberg Ø, Diamantopoulos AP. Extended ultrasound examination identifies more large vessel involvement in patients with giant cell arteritis. Rheumatology. 2023;62(5):1887-1894. doi:10.1093/rheumatology/keac478