Ultrasound intima media thickness cut-off values for cranial and extracranial arteries in patients with suspected giant cell arteritis

Abstract

ObjectiveTo determine the optimal ultrasound (US) cut-off values for cranial and extracranial arteries intima media thickness (IMT) to discriminate between patients with and without giant cell arteritis (GCA).MethodsRetrospective observational study including patients referred to an US fast-track clinic. All patients underwent bilateral US examination of the cranial and extracranial arteries including the IMT measurement. Clinical confirmation of GCA after 6 months was considered the gold standard for diagnosis. A receiver operating characteristic (ROC) analysis was performed to select the cut-off values on the basis of the best tradeoff values between sensitivity and specificity.ResultsA total of 157 patients were included, 47 (29.9%) with clinical confirmation of GCA after 6 months. 41 (87.2%) of patients with GCA had positive US findings (61.7% had cranial and 44.7% extracranial involvement). The best threshold IMT values were 0.44 mm for the common temporal artery; 0.34 mm for the frontal branch; 0.36 mm for the parietal branch; 1.1 mm for the carotid artery and 1 mm for the subclavian and axillary arteries. The areas under the ROC curves were greater for axillary arteries 0.996 (95% CI 0.991–1), for parietal branch 0.991 (95% CI 0.980–1), for subclavian 0.990 (95% CI 0.979–1), for frontal branch 0.989 (95% CI 0.976–1), for common temporal artery 0.984 (95% CI 0.959–1) and for common carotid arteries 0.977 (95% CI 0.961–0.993).ConclusionIMT cut-off values have been identified for each artery. These proposed IMT cut-off values may help to improve the diagnostic accuracy of US in clinical practice.

Intima-media thickness cut-off values depicting “halo sign” and potential confounder analysis for the best diagnosis of large vessel giant cell arteritis by ultrasonography

“…In addition, assessing calcified atherosclerotic plaques in typical places supplies clinically practical information on the potential confounding of IMT results by atherosclerosis (mean IMT was higher in patients with calcified atherosclerotic plaques), which may reduce false positive GCA rates. In our large real-life group, IMT highly specific for vasculitis was higher compared to the previously proposed IMT cut-off values ( 7 , 22 ). It may be explained by a large cohort and a substantial number of controls with atherosclerosis (patients with atherosclerosis predisposing conditions such as RA were included in the control group and a significant number of patients were referred by neurologists typically with atherosclerosis-related stroke to exclude its vasculitis etiology).…”

Performance of the 2022 ACR/EULAR giant cell arteritis classification criteria for diagnosis in patients with suspected giant cell arteritis in routine clinical care

“…14 In cases of uncertainty, the intima-media thickness was measured to confirm the findings according to published proposed cut-off values. [15][16][17][18] The ultrasonographers were not blinded to the clinical data.…”

Ultrasound halo count in the differential diagnosis of atherosclerosis and large vessel giant cell arteritis

“…The halo sign has been defined by OMERACT as representative of LV-GCA, and IMT measures of 0.9-1 mm have been used as cutoff points in the literature [15,17,[20][21][22] but this cutoff has been not validated yet. IMT increases have also been reported and well-known in atherosclerosis cases, mainly in carotid bifurcation.…”

“…Additionally, what is the cutoff point for accurately differentiating between a normal and pathological intima-media thickness (IMT) in the arterial wall? To date, a cutoff measure of 0.9 to 1.5 mm has been used in different studies, but there is no consensus or evidence for the selection of a specific value [ 5 , 15 – 17 ].…”