Karahaliou M et al. (2006) Colour duplex sonography of temporal arteries before decision for biopsy: a prospective study in 55 patients with suspected giant cell arteritis. Arthritis Res Ther 8: R116

Color duplex sonography (CDS) of the temporal arteries should be performed before temporal-artery biopsy (TAB; the gold-standard diagnostic method) in patients with giant cell arteritis (GCA), say Greek researchers.

Karahaliou and colleagues investigated whether CDS could replace TAB in a prospective study of 60 consecutive patients aged ≥50 years with clinically suspected GCA. Baseline CDS was performed in 60 patients and 30 sex-matched, age-matched controls (15 healthy individuals; 15 with diabetes and/or a history of stroke).

Overall, 21 of the 55 participants who completed the 3-month follow-up had presented with a concentric, hypoechogenic halo at baseline CDS, suggestive of arterial-wall inflammation; 18 of these 21 patients were subsequently diagnosed with GCA. A unilateral halo had 82% sensitivity and 91% specificity in diagnosing GCA, and halos of just 0.7 mm diameter were able to predict GCA. Bilateral halos (present in 9 patients with confirmed GCA) had 100% specificity and 41% sensitivity in diagnosing GCA. The presence of blood-flow abnormalities did not improve the diagnostic power of CDS.

The authors recommend that CDS be performed after clinical examination and assessment of laboratory data of patients with suspected GCA. If bilateral halos are present, GCA is confirmed; if a unilateral halo or no halo is present, TAB (directed to the halo area) should be performed. If TAB is positive, GCA is diagnosed; if not, a second TAB or occipital-artery biopsy, and/or imaging of large arteries, might be required to rule out GCA.