Diagnostic Strategy Using Color Doppler Ultrasound of Temporal Arteries in Patients With High Clinical Suspicion of Giant Cell Arteritis : A Prospective Cohort Study.

BACKGROUND: Giant cell arteritis (GCA) is the most prevalent systemic vasculitis in people older than 50 years. Any delay in diagnosis impairs patients' quality of life and can lead to permanent damage, particularly vision loss. OBJECTIVE: To evaluate a diagnostic strategy for GCA using color Doppler ultrasound of the temporal artery as a first-line diagnostic test, temporal artery biopsy (TAB) as a secondary test, and physician expertise as the reference method. DESIGN: Prospective multicenter study with a 2-year follow-up. (ClinicalTrials.gov: NCT02703922). SETTING: Patients were referred by their general practitioner or ophthalmologist to a physician with extensive experience in GCA diagnosis and management in one of the participating centers: 4 general and 2 university hospitals. PATIENTS: 165 patients with high clinical suspicion of GCA, aged 79 years (IQR, 73 to 85 years). INTERVENTION: The diagnostic procedure was ultrasound, performed less than 7 days after initiation of corticosteroid therapy. Only ultrasound-negative patients underwent TAB. MEASUREMENTS: Bilateral temporal halo signs seen on ultrasound were considered positive. Ultrasound and TAB results were compared with physician-diagnosed GCA based on clinical findings and other imaging. RESULTS: Diagnosis of GCA was confirmed in 44%, 17%, and 21% of patients by ultrasound, TAB, and clinical expertise and/or other imaging tests, respectively. Their diagnosis remained unchanged at 1 month, and 2 years for those with available follow-up data. An alternative diagnosis was made in 18% of patients. The proportion of ultrasound-positive patients among patients with a clinical GCA diagnosis was 54% (95% CI, 45% to 62%). LIMITATION: Small sample size, no blinding of ultrasound and TAB results, lack of an objective gold-standard comparator, and single diagnostic strategy. CONCLUSION: By using ultrasound of the temporal arteries as a first-line diagnostic tool in patients with high clinical suspicion of GCA, further diagnostic tests for patients with positive ultrasound were avoided. PRIMARY FUNDING SOURCE: Tender "Recherche CH-CHU Poitou-Charentes 2014."

Inter and intra-observer agreement of arterial wall contrast-enhanced ultrasonography in giant cell arteritis.

Objective: The aim of this study was to analyze inter- and intra-observer agreement for contrast-enhanced ultrasonography (CEUS) for monitoring disease activity in Giant Cell Arteritis (GCA) in the wall of axillary arteries, and common carotid arteries. Methods: Giant cell arteritis patients have CEUS of axillary arteries and common carotid. These images were rated by seven vascular medicine physicians from four hospitals who were experienced in duplex ultrasonography of GCA patients. Two weeks later, observers again rated the same images. GCA patients were recruited in from December 2019 to February 2021. An analysis of the contrast of the ultrasound images with a gradation in three classes (grade 0, 1, and 2) was performed. Grade 0 corresponds to no contrast, grade 1 to moderate wall contrast and grade 2 to intense contrast. A new analysis in 2 classes: positive or negative wall contrast; was then performed on new series of images. Results: Sixty arterial segments were evaluated in 30 patients. For the three-class scale, intra-rater agreement was substantial: κ 0.70; inter-rater agreement was fair: κ from 0.22 to 0.27. Thirty-four videos had a wall thickness of less than 2 mm and 26 videos had a wall thickness greater than 2 mm. For walls with a thickness lower than 2 mm: intra-rater agreement was substantial: κ 0.69; inter-rater agreement was fair: κ 0.35. For walls with a thickness of 2 mm or more: intra-rater agreement was substantial: κ 0.53; inter-rater agreement was fair: κ 0.25. For analysis of parietal contrast uptake in two classes: inter-rater agreement was fair to moderate: κ from 0.35 to 0.41; and for walls with a thickness of 2 mm or more: inter-rater agreement was fair to substantial κ from 0.22 to 0.63. Conclusion: The visual analysis of contrast uptake in the wall of the axillary and common carotid arteries showed good intra-rater agreement in GCA patients. The inter-rater agreement was low, especially when contrast was analyzed in three classes. The inter-rater agreement for the analysis in two classes was also low. The inter-rater agreement was higher in two-class analysis for walls of 2 mm thickness or more.

Colour Doppler ultrasound of temporal arteries for the diagnosis of giant cell arteritis: a multicentre deep learning study.

OBJECTIVES: Giant cell arteritis (GCA) is the most common systemic vasculitis in adults. In recent years, colour Doppler ultrasound of the temporal arteries (CDU) has proven to be a powerful non-invasive diagnostic tool, but its place in the diagnosis of GCA remains to be defined. A limitation of the CDU is the inter-operator reproducibility. Image analysis from a different perspective is now possible with the development of artificial intelligence algorithms. We propose to assess this technology for the detection of the halo sign on CDU images. METHODS: Three public hospitals retrospectively collected data from 137 patients suspected of having GCA between January 2017 and April 2019. CDU images (n=1,311) were labelled with the VIA software. Three sets (training, validation and test) were created and analysed with a semantic segmentation technique using a U-Net convolutional neural network. RESULTS: The area under the curve (AUC) was 0.931 and 0.835 on the validation and test set, respectively. An image positivity threshold was determined by focusing on the specificity. With this threshold, a specificity of 95% and a sensitivity of 60% were obtained for the test set. The analysis of the false interpretation showed that the acquisition modalities and the presence of thrombus caused confusion for the algorithm. CONCLUSIONS: We propose an automated image analysis tool for GCA diagnosis. The 2018 EULAR guidelines for image acquisition must be respected before generalising this algorithm. After external validation, this tool could be used as an aid for diagnosis, staff training and student education.

Diagnostic performance of colour duplex ultrasonography along with temporal artery biopsy in suspicion of giant cell arteritis.

OBJECTIVES: Giant cell arteritis (GCA) is a vasculitis that occurs in older adults, affecting vessels of medium and large caliber. GCA diagnosis is a challenge for general practitioners and specialists. The aim of this study was to retrospectively analyse performances of temporal artery biopsy (TAB) and colour duplex ultrasonography (CDU) for GCA diagnosis. METHODS: All patients with suspicion of GCA and who underwent both TAB and CDU between April 2009 and March 2014 were included in the study. A positive CDU examination was defined by halos on both superficial temporal arteries. Patients were classified based on the physician final diagnosis. RESULTS: Among the 42 eligible patients, 12 had an alternative diagnosis and 30 were diagnosed with GCA. Sensitivities were 77% and 80% for TAB and CDU examinations, respectively. Specificities were 100% for both tests. Twenty-nine (96.7%) patients with GCA had their diagnosis confirmed either by CDU and/or by TAB. Time lengths between the first medical examination and results of TAB and CDU were 15 and 4.2 days (p<0.001), respectively. CONCLUSIONS: Our study suggests that in suspected GCA, CDU may be used as first line examination followed by TAB in case of CDU negative results. Such algorithm needs to be further assessed in a multicentre prospective study.