Recent studies have described characteristic sonographic signs in patients with manifest temporal arteritis (TA). It was the aim of this study to determine whether sonography can identify TA without clinical signs but biopsy evidence of giant-cell arteritis in patients with rheumatic polymyalgia (RP).
22 patients (14 women, 8 men; average age 67.4 +/- 9.1 years) with RP but no clinical signs of TA were prospectively examined for TA by colour-coded duplex sonography (ATL HDI 3000, linear 12-5 Mhz) before temporal artery biopsy was taken. If there was clinical suspicion of extratemporal involvement, other vessels were also examined selectively. The biopsy was taken from a site identified by the sonography. A definitive diagnosis of TA was made only if there was a positive biopsy.
In seven of the 22 patients (32%) sonography showed an echo-poor halo around the lumen of the temporal artery. Five of these seven patients also had histological evidence of giant-cell arteritis. Conversely, all of the five patients had abnormal sonographic findings, namely a marked halo with a minimal thickness of 0.7 mm. Two of the five patients also had temporal artery stenosis, i.e. there was a 100% sensitivity and 80% specificity with respect to the halo sign in conformance with the histology. Two patients with TA were also shown sonographically to have stenosis in arteries of the shoulder girdle and arm. Stenoses in the renal and mesenteric arteries as well of the coeliac trunk were demonstrated in one patient.
Colour-coded sonography with a high-frequency transducer head probably provides reliable diagnosis of TA in patients with RP, even in the absence of clinical signs of vascular inflammation. It remains to be proven whether sonography without biopsy is reliable enough for the diagnosis and treatment of asymptomatic TA.