In radiology, the halo sign is a finding on ultrasound that suggests the diagnosis of temporal arteritis.^[1] The standard diagnostic test for temporal arteritis is biopsy; however, ultrasound and MRI^[2] show promise for replacing it. Also known as Deuel's sign.^{[citation needed]}

References

1. ^ Schmidt W, Kraft H, Vorpahl K, Völker L, Gromnica-Ihle E (1997). "Color duplex ultrasonography in the diagnosis of temporal arteritis.". N Engl J Med 337 (19): 1336-42. PMID 9358127.
2. ^ Bley T, Brink I, Reinhard M (2006). "[Imaging procedures for giant cell arteritis (Horton's disease)]". Ophthalmologe 103 (4): 308-16. PMID 16538476.