Background Color duplex ultrasonography (CDU) is most promising tool for the assessment of large vessel giant cell arteritis (LV-GCA). There is a need to define ultrasound findings consistent with the diagnosis of GCA.
Objectives We aimed to score intima-media thickness (IMT) reference ranges for LV-GCA in polish patients.
Methods 214 patients suspected for GCA and evaluated with CDU were included in the study and followed up for min 9 months. Large vessel CDU, together with arteritis/non-arteritis categorization, were performed before or within 1 week after treatment initiation by a single physician. Vasculitis was defined as hypoechoic, homogenous, increase of IMT with distorted wall structure resulting in no clear intima-media structure, over long distance (not limited only to the place of arterial bifurcations). ROC curves were calculated.
Results GCA was diagnosed in 81 patients, polymyalgia rheumatica (PMR) in 131 (characteristics – Table 1). Extracranial LV-GCA was diagnosed in 43 patients: axillary vasculitis in 23 patients, common carotid artery (CCA) – 24, subclavian – 18, superficial femoral – 11, brachial (all spreading per continuum from axillary arteritis) – 8. In 83 remaining patients other diagnosis was confirmed, and they served as non-GCA/PMR controls. Mean IMT in LV-GCA was significantly higher versus controls and isolated PMR (Fig. 1). IMT in GCA was not significantly influenced by gender, hypertension and smoking in contrast with IMT in controls. Proposed cut off values for IMT depicting vasculitis in GCA patients are presented in Table 2. 100% specificity for vasculitis (vs GCA without large vessel vasculitis) was reached with axillary IMT of 1.06 mm (62% sens.), subclavian – 1.35 mm (38% sens.), superficial femoral – 1.55 mm (60% sens.), CCA – 1.27 mm (22% sens.).
Conclusions We demonstrated that cut off values may discriminate between GCA and its mimics as well as between presence and lack of vasculitis in different arteries in GCA.
Milchert M, Diamantopoulos A, Brzosko M. Atlas of ultrasound application in large vessel arteritis: giant cell arteritis and Takayasu arteritis. Wydawnictwo Pomorskiej Akademii Medycznej, Szczecin, 2016.
Disclosure of Interest None declared