• systemic vasculitis
• giant cell arteritis
• ultrasonography

We thank Chattopadhyay and Ghosh for their interest in our paper describing a novel ultrasonographic Halo Score for giant cell arteritis (GCA).1 The Halo Score quantifies the extent of inflammation in the three temporal artery segments and axillary arteries.2 The total score is the sum of all halo grades, which reflect the thickness of each halo. Halo grades of the axillary arteries are multiplied by a factor of 3 in order to give equal weight to inflammation of the cranial and large systemic arteries. Chattopadhyay and Ghosh underscore the importance of ultrasonography for the diagnosis of GCA, and recognise the potential of the Halo Score for the monitoring of disease activity. The authors propose to include the subclavian artery into the Halo Score and to use it for patients with Takayasu arteritis.

Chattopadhyay and Ghosh suggest that the subclavian artery is more frequently affected by GCA than the …