Diagnostic performance and utility of very high-resolution ultrasonography in diagnosing giant cell arteritis of the temporal artery

Abstract

Objective Very-high resolution US (VHRU; 55 MHz) provides improved resolution and could provide non-invasive diagnostic information in GCA of the temporal artery. The objective of this study was to assess the diagnostic utility of VHRU-derived intima thickness (VHRU-IT) in comparison to high-resolution US halo-to-Doppler ratio (HRU-HDR) in patients referred for temporal artery biopsy. Methods VHRU and HRU of the temporal artery were performed before a biopsy procedure in 78 prospectively recruited consecutive patients who had received glucocorticoid treatment for a median of 8 days (interquartile range 0–13 days) before imaging. Based on the final diagnosis and biopsy findings, the study population was divided into the following four groups: non GCA (n = 40); clinical GCA with no inflammation on biopsy (n = 15); clinical GCA with inflammation limited to adventitia (n = 9); and clinical GCA with transmural inflammation (TMI; n = 11). Results Both VHRU and HRU were useful for identifying subjects with TMI, with VHRU outperforming HRU (area under curve: VHRU-IT 0.99, 95% CI 0.97, 1.00; HRU-HDR 0.74, 95% CI 0.52, 0.96; P=0.026). The diagnostic utility for diagnosing clinical GCA (negative biopsy) or inflammation limited to the adventitia was poor for both VHRU and HRU-HDR. From 5 days after initiation of glucocorticoid treatment, VHRU-IT was increased in eight of nine patients, whereas HRU-HDR was positive in three of seven patients. Both methods showed excellent inter-observer agreement (Cohen’s κ: VHRU-IT 0.873; HRU-HDR 0.811). Conclusion In suspected GCA, VHRU allows non-invasive real-time imaging of TMI manifestations of the temporal artery wall. VHRU-derived intimal thickness measurement seems to be more sensitive than the halo sign and HRU-HDR in detecting TMI in patients with prolonged glucocorticoid treatment.

Diagnostic Accuracy of Symptoms, Physical Signs, and Laboratory Tests for Giant Cell Arteritis

“…Of the 1436 reports screened, 68 studies 14-17,24-87 fulfilled the selection criteria and were used for the systematic review and metaanalysis (eFigure 1 in the Supplement). These studies included 14 037 patients, of whom 4277 (30.5%) were classified as having GCA ( 16,17,[24][25][26][27][28][29][30][31][32][33][34][35]37,38,[40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][59][60][61][62][66][67][68][69]72,73,[75][76][77][78][79][80][81][82][83][84]…”

“…The clinical diagnosis was typically based on clinical and laboratory findings, imaging and/or TAB results, and a good initial response to glucocorticoid treatment (eTable 5 in the Supplement). In 16 of c Seven studies with the clinical diagnosis as the reference standard 46,68,71,[75][76][77]82 also allowed evaluation of TAB as the reference standard (558 patients). One study with the clinical diagnosis as the reference standard 68 also allowed evaluation of ultrasonography as the reference standard (23 patients).…”

“…the studies using clinic al diagnosis as reference standard, 17,29,31,33,34,36,47,51,53,54,57,61,68,69,76,82 patients were all followed up to verify that the clinical diagnosis was not later revised. Only 1 study 68 allowed us to evaluate imaging as the reference standard in addition to the clinical diagnosis and TAB.…”

“…16,33,37,46,51,61,64,69 n From 10 of the analyzed studies. 16,17,36,52,58,71,73,80,82,84 o From 8 of the analyzed studies. 16,17,39,58,73,80,84,87 p From 18 of the analyzed studies.…”

Correspondence to ‘Slope sign’: a feature of large vessel vasculitis?

“…Consequently, visualisation of this zone in a single image helps to conclude on the presence of pathological IMT compared with the nearby normal vessel (figure 1). In addition to thickness, wall structure should be assessed: in a normal brachial artery intima-media appears as a double line, which disappears due to the inflammation in the axillary artery 7. Thus, the slope sign is best-observed at a long longitudinal view that avoids skipping areas or inadequate imaging from a series of short scans.…”