Background During the last decade of color Doppler ultrasonography (CDUS) has emerged as a noninvasive diagnostic modality in patients with suspected giant cell arteritis (GCA). Numerous studies suggest that the presence of the ‘halo sign’ [HS], which probably translates arterial wall edema, is highly specific for GCA, especially if it is bilateral. However, there are no studies correlating the number of branches affected with definitive diagnosis by biopsy.
Objectives To determine if the number of branches of the temporal artery with HS influences CDUS diagnostic performance parameters for ACG.
Methods We conducted a prospective observational study in all consecutive patients with suspected GCA treated in our department during the period 2007-2012, which underwent USDC and biopsy temporal arteries. We evaluated sensitivity (SE), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) of HS in temporal artery compared with histologic confirmation of arteritis (gold standard), in both global and according the number of branches involved.
Results The study included 52 patients, 36 were women (69%), with a mean age 77.3 ± 6.7 years (range 58-93). All patients met 3 or more classification criteria of the American College of Rheumatology for GCA, being the most common clinical manifestation recent-onset headache (85%) and presenting eritrosedimentation ratio ≥50 mm/h in 86.5% cases. The biopsy was positive in 22 cases (42%). CDUS detected HS in 28 cases (54%), with involvement of one branch in 13%, 2 branches in 33%, and 4 branches in 54%. The global values obtained for presence of HS were SE 91%, SP 73%, PPV 71% and NPV 73%. The values obtained analyzing each number of involved branches are shown in Table. There was statistical significance only when 2 or more branches were affected and the best diagnostic performance ocurred when 4 branches were affected.
Conclusions Conclusions: Our results demonstrate that the diagnostic performance of the DCUS can be improved taking into account the number of branches with HS. This would accelerate the onset of treatment without performing a biopsy in patients with typical symptoms and several branches affected, reserving it for patients with atypical or have only one or no branch with HS.
Disclosure of Interest None Declared