Association Between Vascular FDG Uptake at Diagnosis and Evolution in Aortic Dimensions in Giant Cell Arteritis: A Prospective Study

Abstract

Scientific Abstracts 335 Conclusion: Patients with atypical PMR could represent an early form of the classic PMR. Atypical PMR used to have a shorter evolution of symptoms, have predominantly hip/pelvic girdle affection. US of the shoulders and hips may have an added value for stratifying PMR patients and differentiating atypical PMR from other musculoskeletal conditions. Background: Temporal Artery Biopsy (TAB) is costly, invasive and has a false negative rate as high as 60% [1]. Temporal Artery Ultrasound (TAUS) and Superficial Temporal Artery (STA) MR-Angiography (MRA) have shown widely dispa-rate results in studies to date [1-3]. ACR GCA Classification Criteria are often misused in clinical practice as diagnostic criteria. Objectives: In this prospective study, we compare TAUS, TAB and STA MRA to physician diagnosis of GCA at 6 months. Methods: We performed a prospective study of all new referrals (n=124) to our Rapid Access GCA clinic over 18 months. US of all 6 branches of the STA and both axillary arteries was performed using a GE P9 device. Abnormalities considered indicative of vasculitis in the STA included the halo sign (Figure 1) and non-com-pressible arteries with a thickened intima-media complex [4]. In the axillary arteries , a halo sign and an intima-media thickness of >1.0mm was considered positive. A subset of our patients were referred for TAB and/or MRA. MRAs were scored 0-4 based on mural wall thickness and signal intensity of mural peri-adventitial contrast enhancement [5]. We compared results to a clinical diagnosis of GCA at 6 months, verified by 2 rheumatologists. We performed Chi-Square tests with ROC analyses to determine the performance of each diagnostic modality. Figure 1. Transverse view of STA, demonstrating a halo sign, as indicated by the anechoic region (green arrow) surrounding the inner Doppler (red arrow) signal.