AUTHOR=Skoog Johan , Svensson Christina , Eriksson Per , Sjöwall Christopher , Zachrisson Helene 

TITLE=High-frequency ultrasound with superb microvascular imaging: a potential tool for ultrasound assessment in patients with giant cell arteritis

JOURNAL=Frontiers in Medicine

VOLUME=Volume 11 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2024.1431385

DOI=10.3389/fmed.2024.1431385

ISSN=2296-858X

ABSTRACT=The objective of this study was twofold: first, to evaluate whether superb microvascular imaging (SMI) could be used to visualize neovascularization in temporal arteries, and, second, to evaluate the diagnostic performance of high frequency ultrasound with SMI using an extended protocol in patients with suspected giant cell arteritis (GCA).Methods: This retrospective study comprised 120 patients consecutively examined with an extended CDU protocol (temporal, facial, axillary, subclavian, brachiocephalic and carotid arteries) between 2020 and 2022. Of all patients, 107 had no previous GCA diagnosis and 13 had a previous GCA diagnosis. SMI was used to evaluate neovascularisation in the temporal arteries. Arteritis were characterised as low-or medium-echogenic, homogeneous wall thickening, with or without a positive compression sign in the temporal arteries. The Halo count, i.e., the number of temporal and axillary artery segments with signs of arteritis, was evaluated. The reference was clinically diagnosed GCA confirmed after ≥6-month follow-up.Results: Of the eligible 107 patients with new suspected GCA, 33 (31%) received a clinical GCA diagnosis. Neovascularisation was detected in 14 patients (43%). Patients with neovascularization displayed a higher halo count (median 6 (25 th -75 th percentile 4.75-7) vs. 3 (2-4), p=0.005). CDU of only the temporal arteries showed sensitivity and specificity (95% confidence intervals) of 94% (80-100%) and 100% (95-100%), respectively. The addition of extra-cranial arteries increased the sensitivity to 100%. Of the 13 patients investigated for suspected relapse, three had a clinically confirmed relapse. One of them displayed neovascularisation together with other signs of inflammation.We show for the first time that inflammatory neovascularisation of the temporal arteries can be detected by SMI. Neovascularisation is associated with a more-widespread cranial disease. The value of neovascularisation should be further investigated, especially for the detection of GCA relapse.