Ultrasound cut-off values for intima-media thickness of temporal, facial and axillary arteries in giant cell arteritis

Utility of applying a diagnostic algorithm in giant cell arteritis based on the level of clinical suspicion

INTRODUCTION

To reach the diagnosis of giant cell arteritis (GCA), signs, symptoms, laboratory tests, imaging findings, and occasionally anatomopathological results from temporal artery biopsy are evaluated. This study describes the results of an algorithm analysis based on clinical and ultrasound evaluation of patients with suspected GCA, highlighting its diagnostic utility by contrasting its use in different clinical suspicion scenarios.

METHOD

Prospective multicenter study evaluating patients referred with suspected GCA through a preferential circuit (fast track), grouping them according to low or high clinical suspicion of GCA. Each of these scenarios is evaluated by biopsy and ultrasound for all patients, resulting in positive, indeterminate, or negative outcomes, yielding six possible groups. Potential areas of improvement are explored, emphasizing that, following a negative or indeterminate ultrasound, 18-FDG-PET-CT could be recommended. We analyze the results and application of a diagnostic algorithm, confirming its efficiency and applicability based on whether there is high or low clinical suspicion.

RESULTS

Sixty-nine patients (41 in the high suspicion group and 28 in the low suspicion group). There were 41 new diagnoses of GCA: 35 in the high suspicion group and 6 in the low suspicion group. Using ultrasound alone, the initial algorithm has an overall diagnostic efficiency of 72.5%, which improves to 80.5% when including 18F-FDG-PET/CT. The negative predictive value of ultrasound in patients with low clinical suspicion is 84.6%, and the positive predictive value of ultrasound in patients with high suspicion is 100%, improving sensitivity from 57.1% to 80.8% with 18F-FDG-PET/CT in this scenario. Temporal artery biopsy was performed on all patients, with no differences in sensitivity or specificity compared to ultrasound. In cases where all three tests - ultrasound, biopsy, and 18F-FDG-PET/CT - are performed, sensitivity increases to 92.3% in patients with high clinical suspicion.

CONCLUSION

In situations of high clinical suspicion, the algorithm provides sufficient information for the diagnosis of GCA if ultrasound is positive. A negative ultrasound is sufficient to rule out the diagnosis in the context of low clinical suspicion. 18-FDG-PET-CT may be useful in patients with high suspicion and negative or indeterminate ultrasound results.

Clinical Manifestations and Prognosis of Giant Cell Arteritis: A Retrospective Cohort Study

The aim of the study was to evaluate the clinical manifestations and survival of patients with giant cell arteritis (GCA).

MATERIALS AND METHODS

. A retrospective study included 166 patients with newly diagnosed GCA. Clinical, laboratory, and instrumental data and three sets of classification criteria were used to confirm the diagnosis: the American College of Rheumatology (ACR) 1990, the revised ACR criteria of 2016 and/or the new ACR and European Alliance of Rheumatologic Associations (EULAR) 2022 criteria. Some of the patients underwent instrumental investigations: temporal artery ultrasound Doppler (n = 61), contrast-enhanced computed tomography (n = 5), CT angiography (n = 6), magnetic resonance imaging (n = 4), MR angiography (n = 3), and 18F-FDG PET/CT (n = 47). Overall and recurrence-free survival rates were analyzed using survival tables and Kaplan-Meier method.

RESULTS

. The most frequent first manifestations of GCA were headache (81.8%), weakness (64%), fever (63.8%), and symptoms of rheumatic polymyalgia (56.6%). Changes in temporal arteries in color duplex scanning were detected in 44 out of 61 patients. GCs therapy was performed in all patients who agreed to be treated (n = 158), methotrexate was used in 49 out of 158 patients, leflunomide in 9 patients. In 45 (28.5%) out of 158 patients, a stable remission was achieved as a result of GC monotherapy; in 120 (75.9%) patients, long-term maintenance therapy with GCs was required to prevent exacerbations, including 71 (44.9%) patients in combination with methotrexate or other immunosuppressive drugs. The follow-up period of patients with a history of relapses was 21.0 (8.0-54.0) months. Relapses developed in 73 (46.2%) patients. The overall one-year survival rate was 97.1% [95% CI 94.3; 99.9], and the five-year survival rate of patients was 94.6% [95% CI 90.2; 99.0]. The one-year relapse-free survival rate was 86.4% [95% CI 80.5; 92.3], and the five-year relapse-free survival rate was 52.4% [95% CI 42.0; 62.8]. Twelve (7.2%) of 166 patients died. The cause of death was myocardial infarction in two patients, stroke in two patients, and breast cancer in one patient; in the remaining seven cases, the cause of death was not determined.

CONCLUSIONS

: Given the high frequency of disease exacerbation, patients with GCA require long-term follow-up, especially during the first year after diagnosis.

Optical frequency domain imaging (OFDI) represents a novel technique for the diagnosis of giant cell arteritis

BACKGROUND/OBJECTIVES

Giant cell arteritis (GCA) is an inflammatory vascular disease in which prompt and accurate diagnosis is critical. The efficacy of temporal artery biopsy (TAB) is limited by 'skip' lesions and a delay in histological analysis. This first-in-man ex-vivo study aims to assess the accuracy of optical frequency domain imaging (OFDI) in diagnosing GCA.

SUBJECTS/METHODS

29 TAB samples of patients with suspected GCA were submerged in 0.9% sodium chloride and an OFDI catheter was passed through the lumen to create cross-sectional images prior to histological analysis. The specimens were then preserved in formalin for histological examination. Mean intimal thickness (MIT) on OFDI was measured, and the presence of both multinucleate giant cells (MNGCs) and fragmentation of the internal elastic lamina (FIEL) was assessed and compared with histology, used as the diagnostic gold standard.

RESULTS

MIT in patients with/without histological evidence of GCA was 0.425 mm (±0.43) and 0.13 mm (±0.06) respectively compared with 0.215 mm (±0.09) and 0.135 mm (±0.07) on OFDI. MIT measured by OFDI was significantly higher in patients with histologically diagnosed arteritis compared to those without (p = 0.0195). For detecting FIEL and MNGCs, OFDI had a sensitivity of 75% and 28.6% and a specificity of 100% and 77.3% respectively. Applying diagnostic criteria of MIT > 0.20 mm, or the presence of MNGCs or FIEL, the sensitivity of detecting histological arteritis using OFDI was 91.4% and the specificity 94.1%.

CONCLUSIONS

OFDI provided rapid imaging of TAB specimens achieving a diagnostic accuracy comparable to histological examination. In-vivo imaging may allow imaging of a longer arterial section.

Multimodality imaging to assess diagnosis and evaluate complications of large vesselarteritis

Different types of vasculitis can be distinguished according to the blood vessel's size that is preferentially affected: large-vessel, medium-vessel, and small-vessel vasculitides. Giant cell arteritis (GCA) and Takayasu's arteritis (TAK) are the main forms of large-vessel vasculitis, and may lead to lumen narrowing. Clinical manifestations of arterial narrowing on the short- and long term include vision loss, stroke, limb ischemia, and heart failure. Imaging tools are well established diagnostic tests for large-vessel vasculitis and may aid therapy monitoring in selected cases while providing important information regarding the occurrence of vascular damage, tissue and organ complications. This review aims to provide the current status of multimodality imaging for the diagnosis and identification of vascular complications in the field of large vessel vasculitis.

Diagnosing vasculitis with ultrasound: findings and pitfalls

Rheumatologists are increasingly utilizing ultrasound for suspected giant cell arteritis (GCA) or Takayasu arteritis (TAK). This enables direct confirmation of a suspected diagnosis within the examination room without further referrals. Rheumatologists can ask additional questions and explain findings to their patients while performing ultrasound, preferably in fast-track clinics to prevent vision loss. Vascular ultrasound for suspected vasculitis was recently integrated into rheumatology training in Germany. New European Alliance of Associations for Rheumatology recommendations prioritize ultrasound as the first imaging tool for suspected GCA and recommend it as an imaging option for suspected TAK alongside magnetic resonance imaging, positron emission tomography and computed tomography. Ultrasound is integral to the new classification criteria for GCA and TAK. Diagnosis is based on consistent clinical and ultrasound findings. Inconclusive cases require histology or additional imaging tests. Robust evidence establishes high sensitivities and specificities for ultrasound. Reliability is good among experts. Ultrasound reveals a characteristic non-compressible 'halo sign' indicating intima-media thickening (IMT) and, in acute disease, artery wall oedema. Ultrasound can further identify stenoses, occlusions and aneurysms, and IMT can be measured. In suspected GCA, ultrasound should include at least the temporal and axillary arteries bilaterally. Nearly all other arteries are accessible except the descending thoracic aorta. TAK mostly involves the common carotid and subclavian arteries. Ultrasound detects subclinical GCA in over 20% of polymyalgia rheumatica (PMR) patients without GCA symptoms. Patients with silent GCA should be treated as GCA because they experience more relapses and require higher glucocorticoid doses than PMR patients without GCA. Scores based on intima-thickness (IMT) of temporal and axillary arteries aid follow-up of GCA, particularly in trials. The IMT decreases more rapidly in temporal than in axillary arteries. Ascending aorta ultrasound helps monitor patients with extracranial GCA for the development of aneurysms. Experienced sonologists can easily identify pitfalls, which will be addressed in this article.

Cranial involvement in giant cell arteritis

Since its first clinical description in 1890, extensive research has advanced our understanding of giant cell arteritis, leading to improvements in both diagnosis and management for affected patients. Imaging studies have shown that the disease frequently extends beyond the typical cranial arteries, also affecting large vessels such as the aorta and its proximal branches. Meanwhile, advances in comprehending the underlying pathophysiology of giant cell arteritis have given rise to numerous potential therapeutic agents, which aim to minimise the need for glucocorticoid treatment and prevent flares. Classification criteria for giant cell arteritis, as well as recommendations for management, imaging, and treat-to-target have been developed or updated in the last 5 years, and current research encompasses a broad spectrum covering basic, translational, and clinical research. In this Series paper, we aim to discuss the current understanding of giant cell arteritis with cranial manifestations, describe the clinical approach to this condition, and explore future directions in research and patient care.

Ultrasound intima-media thickness cut-off values for the diagnosis of giant cell arteritis using a dual clinical and MRI reference standard and cardiovascular risk stratification

Objectives

To derive segmental cut-off values and measures of diagnostic accuracy for the intima-media thickness of compressed temporal artery segments for the diagnosis of giant cell arteritis (GCA) on the patient level. To examine the influence of cardiovascular risk.

Methods

Retrospectively, patients evaluated for GCA with an ultrasound of the temporal arteries and an MRI of the head, including a T1-fatsat-black blood (T1-BB) sequence, were identified and classified based on cardiovascular risk and a dual reference standard of T1-BB on the segmental level and the clinical diagnosis on the patient level. Intima-media thickness of the common superficial temporal artery (CSTA), frontal and parietal branches (FB, PB) were measured by compression technique. Statistically and clinically optimal (specificity of approx. 90% for the patient level) cut-offs were derived. Diagnostic accuracy was evaluated on the patient level.

Results

The population consisted of 144 patients, 74 (51.4%) with and 70 (48.6%) without GCA. The statistically optimal cut-offs were 0.86 mm, 0.68 mm and 0.67 mm for the CSTA, the FB and PB, respectively. On the patient level sensitivity and specificity were 86.5 and 81.4%. Clinically optimal cut-offs were 1.01 mm, 0.82 mm and 0.69 mm and showed a sensitivity of 79.7% and a specificity of 90.0%. For patients without high cardiovascular risk, statistically optimal cut-offs showed a sensitivity of 89.6% and a specificity of 90.5%.

Conclusion

Newly derived ultrasound intima-media thickness cut-offs with a dual reference standard show high diagnostic accuracy on the patient level for the diagnosis of GCA, particularly in patients without high cardiovascular risk.

Determination of the Value of Color Doppler Ultrasound in Patients With a Clinical Suspicion of Giant Cell Arteritis

OBJECTIVE

It is urgent to diagnose giant cell arteritis (GCA) as quickly as possible to prevent irreversible blindness. The traditional gold standard for diagnosing GCA is temporal artery biopsy (TAB). However, TAB lacks diagnostic performance and carries out risks of surgical intervention. The noninvasive color Doppler ultrasound (CDU) seems to be a promising alternative. This study is designed to assess the diagnostic value of CDU in daily clinical practice.

METHODS

In this prospective cohort study, patients with a clinical suspicion of active GCA were included and underwent a CDU of the temporal arteries. If deemed necessary by the referrer, a TAB and/or 18F-fluorodeoxyglucose positron emission tomography with computed tomography was performed. The retrospective clinical diagnosis was determined 1 year after inclusion by two physicians experienced in the field of vasculitis.

RESULTS

242 patients were included and GCA was diagnosed in 73 (30%) patients by the defined retrospective clinical diagnosis. Compared with the retrospective diagnosis, CDU has a sensitivity of 60% (48-72), specificity of 94% (89-97), positive predictive value (PPV) of 81% (70-89), negative predictive value (NPV) of 85% (80-88), and an accuracy of 84% (78-88). A total of 84 (35%) patients underwent TAB. TAB has a sensitivity of 66% (51-79), specificity of 100% (90-100), PPV of 100% (100), NPV of 67% (58-75), and an accuracy of 80% (70-88).

CONCLUSION

This study shows comparable diagnostic performance for CDU and TAB and even better CDU results with a bilateral halo present. Considering the advantages of the noninvasive CDU, it is the diagnostic tool of choice.

Primary Large Vessel Vasculitis: Takayasu Arteritis and Giant Cell Arteritis

Takayasu arteritis (TA) and Giant cell arteritis (GCA) are large vessel vasculitides, with TA targeting the aorta and its branches, and GCA targeting both large and medium-sized arteries. Early diagnosis of TA and GCA are of great importance, since delayed, inappropriate or no treatment can result in severe and permanent complications. Imaging plays a central role in establishing diagnosis, targeting lesions for confirmational diagnostic biopsy, specifically for GCA, and longitudinal disease evolution. In this article, we discuss imaging diagnosis of large artery vasculitis and the value of different imaging modalities.

[Diagnostics and treatment of large vessel vasculitis]

BACKGROUND

Giant cell arteritis (GCA) and Takayasu arteritis (TAK), as the main representatives of large vessel vasculitis, are rheumatological autoimmune disorders associated with inflammatory vessel wall changes in the arterial system that can lead to many types of organ damage.

MATERIAL AND METHODS

In this review the current scientific evidence on the diagnostics and treatment of large vessel vasculitis is evaluated and discussed.

RESULTS

In addition to the medical history and clinical presentation, imaging techniques nowadays represent the core of large vessel vasculitis diagnostics and have largely replaced the histological confirmation of GCA. After the diagnosis, acute treatment with glucocorticoids should be initiated as rapidly as possible but in the long term this should be tapered out or replaced by a steroid-sparing basic treatment. In contrast to GCA with already available options and other biologic disease-modifying antirheumatic drugs (DMARDs) about to be approved, there are still no approved biologic DMARD treatment options available for the less common TAK.

CONCLUSION

In contrast to the substantial progress in imaging diagnostics of large vessel vasculitis and with respect to the treatment of GCA, the much rarer TAK still requires intensive research efforts, especially to improve the treatment situation.

The Meteoritics Trial: efficacy of methotrexate after remission-induction with tocilizumab and glucocorticoids in giant cell arteritis-study protocol for a randomized, double-blind, placebo-controlled, parallel-group phase II study

BACKGROUND

Glucocorticoids (GC) are the standard treatment for giant cell arteritis (GCA), even though they are associated with adverse side effects and high relapse rates. Tocilizumab (TCZ), an interleukin-6 receptor antagonist, has shown promise in sustaining remission and reducing the cumulative GC dosage, but it increases the risk of infections and is expensive. After discontinuation of TCZ, only about half of patients remain in remission. Additionally, only few studies have been conducted looking at remission maintenance, highlighting the need for alternative strategies to maintain remission in GCA. Methotrexate (MTX) has been shown to significantly decrease the risk of relapse in new-onset GCA and is already a proven safe drug in many rheumatologic diseases.

METHODS

This study aims to evaluate the efficacy and safety of MTX in maintaining remission in patients with GCA who have previously been treated with GC and at least 6 months with TCZ. We hypothesize that MTX can maintain remission in GCA patients, who have achieved stable remission after treatment with GC and TCZ, and prevent the occurrence of relapses. The study design is a monocentric, randomized, double-blind, placebo-controlled, parallel-group phase II trial randomizing 40 GCA patients 1:1 into a MTX or placebo arm. Patients will receive 17.5 mg MTX/matching placebo weekly by subcutaneous injection for 12 months, with the possibility of dose reduction if clinically needed. A 6-month follow-up will take place. The primary endpoint is the time to first relapse in the MTX group versus placebo during the 12-month treatment period. Secondary outcomes include patient- and investigator-reported outcomes and laboratory findings, as well as the prevalence of aortitis, number of vasculitic vessels, and change in intima-media thickness during the study.

DISCUSSION

This is the first clinical trial evaluating remission maintenance of GCA with MTX after a previous treatment cycle with TCZ. Following the discontinuation of TCZ in GCA, MTX could be a safe and inexpensive drug.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05623592. Registered on 21 November 2022. EU Clinical Trials Register, 2022-501058-12-00. German Clinical Trials Register DRKS00030571.

Prevalence and characteristics of subclinical giant cell arteritis in polymyalgia rheumatica

OBJECTIVE

The main objective of this study was to analyse the prevalence and characteristics of subclinical GCA in patients with PMR.

METHODS

This was a cross-sectional multicentre international study of consecutive patients with newly diagnosed PMR without symptoms or signs suggestive of GCA. All patients underwent US of the temporal superficial, common carotid, subclavian and axillary arteries. Patients with halo signs in at least one examined artery were considered to have subclinical GCA. The clinical, demographic and laboratory characteristics of the PMR group without subclinical vasculitis were compared with subclinical GCA, and the pattern of vessel involvement was compared with that of a classical single-centre GCA cohort.

RESULTS

We included 346 PMR patients, 267 (77.2%) without subclinical GCA and 79 (22.8%) with subclinical GCA. The PMR patients with subclinical GCA were significantly older, had a longer duration of morning stiffness and more frequently reported hip pain than PMR without subclinical GCA. PMR with subclinical GCA showed a predominant extracranial large vessel pattern of vasculitic involvement compared with classical GCA, where the cranial phenotype predominated. The patients with PMR in the classical GCA group showed a pattern of vessel involvement similar to classical GCA without PMR but different from PMR with subclinical involvement.

CONCLUSION

More than a fifth of the pure PMR patients had US findings consistent with subclinical GCA. This specific subset of patients showed a predilection for extracranial artery involvement. The optimal screening strategy to assess the presence of vasculitis in PMR remains to be determined.

Ultrasonography in the assessment of disease activity in cranial and large-vessel giant cell arteritis: a prospective follow-up study

OBJECTIVES

We evaluated sensitivity to change and discriminative abilities of vascular US scores in disease monitoring in the follow-up of a prospective cohort of new-onset cranial and large-vessel (LV) GCA patients.

METHODS

Baseline and follow-up (8 weeks, 24 weeks and 15 months) US of temporal arteries (TA), carotid and axillary arteries (LV) included assessment of halo and measurement of the intima media complex (IMC). Max IMC, max halo IMC, sum IMC, sum halo IMC, mean IMC, halo count and the Southend halo score were calculated. The provisional OMERACT US score, OGUS, was obtained, taking the average of temporal arteries and axillary arteries IMCs divided by their normal cut-off values.

RESULTS

Baseline US was positive in 44/47 patients (72% TA, 72% LV). Sensitivity to change of all composite US scores containing TAs was evident by week 8 onward. LVs responded poorly and new axillary US lesions emerged in six patients despite clinical remission. The OGUS showed a large magnitude of change and is considered the score least prone to potential bias. All TA-based US scores showed moderate-strong correlation with disease activity markers. OGUS, TA halo count, Southend TA halo score, TA sum IMC and TA mean IMC showed potential to discriminate remission and relapse with area under the curve ≥0.8.

CONCLUSIONS

The OGUS is suggested as an outcome measurement for the assessment of treatment response in clinical trials. The abilities of US scores to discriminate remission and relapse are encouraging and should be further explored.

The Role of Imaging in Diagnosis and Monitoring of Large Vessel Vasculitis

Technological advances and increased recognition of the prevalence and implications of large vessel vasculitis have led to robust research into various imaging techniques. Although there is still debate about which modality to choose in specific clinical scenarios, Ultrasound, PET/CT, MRI/A, and CT/A offer complementary information regarding diagnosis, disease activity, and vascular complication monitoring. Recognition of the strengths and limitations of each technique is important for appropriate application in clinical practice.

Diagnostic validity of ultrasound including extra-cranial arteries in giant cell arteritis

OBJECTIVES

Color Doppler ultrasound (CDUS) of the temporal arteries (TA) is becoming the first test to be performed for suspected giant cell arteritis (GCA). Our aim was to assess the added value of including CDUS of large vessels (LV) in the diagnosis of GCA.

METHODS

We performed an observational and retrospective study of consecutive patients with suspected GCA. Baseline CDUS of the TA and LV (axillary, subclavian, and carotid) were conducted. We defined the CDUS finding as positive if the halo sign was present.

RESULTS

Of 198 patients with suspected GCA, 87 were eventually diagnosed with GCA: 45 (51.7%) had a cranial pattern exclusively, 31 (35.6%) had both a cranial and an LV pattern, and 11 (12.6%) had an isolated LV pattern. CDUS of the TA had a sensitivity of 83.9%, specificity of 97.3%, and positive and negative predictive values (PPV, NPV) of 96.1% and 88.5%, respectively. When LV was added, sensitivity increased to 96.6% and NPV to 98.2%. Specificity was 97.3% and PPV was 96.6%. As for LVs, the axillary, subclavian, and carotid arteries were involved in 87.8%, 77.4%, and 34.4%, respectively. Isolated axillary examination resulted in a loss of 12.2% of patients with LV involvement; however, inclusion of the axillary and subclavian arteries retained 100% of patients with LV involvement.

CONCLUSIONS

Detection of GCA by ultrasound should routinely include examinations of the TA and LV (at least the axillary and subclavian arteries) to improve diagnostic accuracy. More than 12% of patients in our cohort had isolated LV involvement. Key Points • Extracranial involvement in GCA is very common: half of patients have extracranial vasculitis and more than 12% isolated LV involvement that can be demonstrated with CDUS. • Adding a CDUS examination of LV to TA increased sensitivity (from 83.9 to 96.6%) and the negative predictive value (from 88.5 to 98.2%) for diagnosis of GCA. • In our cohort, if we only examined the axillary arteries, 12.2% of the CGA with LV involvement would not have been diagnosed. • We propose a CDUS protocol that includes examination of the TA and LV (at least the axillary and subclavian arteries) routinely in cases of suspected GCA.

The provisional OMERACT ultrasonography score for giant cell arteritis

OBJECTIVES

To develop an Outcome Measures in Rheumatology (OMERACT) ultrasonography score for monitoring disease activity in giant cell arteritis (GCA) and evaluate its metric properties.

METHODS

The OMERACT Instrument Selection Algorithm was followed. Forty-nine members of the OMERACT ultrasonography large vessel vasculitis working group were invited to seven Delphi rounds. An online reliability exercise was conducted using images of bilateral common temporal arteries, parietal and frontal branches as well as axillary arteries from 16 patients with GCA and 7 controls. Sensitivity to change and convergent construct validity were tested using data from a prospective cohort of patients with new GCA in which ultrasound-based intima-media thickness (IMT) measurements were conducted at weeks 1, 3, 6, 12 and 24.

RESULTS

Agreement was obtained (92.7%) for the OMERACT GCA Ultrasonography Score (OGUS), calculated as follows: sum of IMT measured in every segment divided by the rounded cut-off values of IMTs in each segment. The resulting value is then divided by the number of segments available. Thirty-five members conducted the reliability exercise, the interrater intraclass correlation coefficient (ICC) for the OGUS was 0.72-0.84 and the median intrareader ICC was 0.91. The prospective cohort consisted of 52 patients. Sensitivity to change between baseline and each follow-up visit up to week 24 yielded standardised mean differences from -1.19 to -2.16, corresponding to large and very large magnitudes of change, respectively. OGUS correlated moderately with erythrocyte sedimentation rate, C reactive protein and Birmingham Vasculitis Activity Score (corrcoeff 0.37-0.48).

CONCLUSION

We developed a provisional OGUS for potential use in clinical trials.

Vascular ultrasound in rheumatology practice

Rheumatologists are increasingly using vascular ultrasound. Several guidelines now recommend ultrasound as the first diagnostic modality in giant cell arteritis (GCA). The German curriculum for rheumatology training has recently included ultrasound for the acute diagnosis of vasculitis. Recent studies have shown that ultrasound of temporal, axillary, subclavian, and vertebral arteries has sensitivities and specificities of >90%. Vascular ultrasound detects subclinical GCA in approximately 20% of patients with "pure" polymyalgia rheumatica. GCA fast-track clinics might regularly include these patients. A new score based on the intima-media thickness of the temporal and axillary arteries allows the monitoring of structural changes with treatment. The score decreases faster for the temporal arteries than it does for the axillary arteries. Measuring the diameter of the ascending aorta and the aortic arch might become a fast and cost-effective tool for the long-term monitoring of aortic aneurysms in extracranial GCA. Vascular ultrasound also has a role for Takayasu arteritis, thrombosis, Behçet's syndrome, and Raynaud's phenomenon.

Prevalence and characteristics of giant cell arteritis in patients with newly diagnosed polymyalgia rheumatica - a prospective cohort study

Background

It is known that giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) often occur together. So far, the prevalence of GCA in newly diagnosed PMR patients has not been evaluated in a prospective ultrasound study.

Objective

The aim of this study was to assess the prevalence of GCA using vascular ultrasound in patients with newly diagnosed PMR.

Design

A consecutive cohort of newly diagnosed PMR patients was prospectively evaluated for the presence of GCA with the use of systematic musculoskeletal and vascular ultrasound examination.

Methods

Overall, 60 patients with newly diagnosed PMR were prospectively enrolled. Symptoms and laboratory findings were collected. All patients underwent ultrasound of shoulder and hip joints, and vascular ultrasound evaluating the facial, temporal, carotid, vertebral and axillary arteries. Patients were diagnosed with GCA if they had ultrasound imaging findings of GCA. Patients with PMR (PMR-group) and patients with PMR and GCA (PMR-GCA-group) were compared, and a C-reactive protein (CRP) cut-off value was evaluated.

Results

GCA was diagnosed in 28 of 60 PMR patients (46%). The PMR-group consisted of 20 (62.5%) females with a mean age of 69 (±9.9) years, while the PMR-GCA-group consisted of 11 (39.3%) females with a mean age of 74 (±8.4) years. In 13 of 28 patients (46%) in the PMR-GCA-group, GCA was subclinical and only diagnosed by ultrasound. The PMR-GCA-group showed higher values of joint effusion and significantly higher CRP values. A CRP cut-off value of 26.5 mg/litre (reference range 0-5 mg/litre) yielded a sensitivity of 66% with a specificity of 73% for GCA.

Conclusion

GCA was found in 46% of newly diagnosed PMR patients; 22% of the patients with PMR had asymptomatic GCA. Joint effusions were higher in the PMR-GCA-group, with significant results for the hip joint. A CRP cut-off value of ⩾26.5 mg/litre in PMR can help in the identification of subclinical GCA.

Diagnostic Ultrasonography in Neurology

OBJECTIVE

Ultrasonography allows neurologists to complement clinical information with additional useful, easily acquired, real-time data. This article highlights its clinical applications in neurology.

LATEST DEVELOPMENTS

Diagnostic ultrasonography is expanding its applications with smaller and better devices. Most indications in neurology relate to cerebrovascular evaluations. Ultrasonography contributes to the etiologic evaluation and is helpful for hemodynamic diagnosis of brain or eye ischemia. It can accurately characterize cervical vascular atherosclerosis, dissection, vasculitis, or other rarer disorders. Ultrasonography can aid in the diagnosis of intracranial large vessel stenosis or occlusion and evaluation of collateral pathways and indirect hemodynamic signs of more proximal and distal pathology. Transcranial Doppler (TCD) is the most sensitive method for detecting paradoxical emboli from a systemic right-left shunt such as a patent foramen ovale. TCD is mandatory for sickle cell disease surveillance, guiding the timing for preventive transfusion. In subarachnoid hemorrhage, TCD is useful in monitoring vasospasm and adapting treatment. Some arteriovenous shunts can be detected by ultrasonography. Cerebral vasoregulation studies are another developing field of interest. TCD enables monitoring of hemodynamic changes related to intracranial hypertension and can diagnose cerebral circulatory arrest. Optic nerve sheath measurement and brain midline deviation are ultrasonography-detectable signs of intracranial hypertension. Most importantly, ultrasonography allows for easily repeated monitoring of evolving clinical conditions or during and after interventions.

ESSENTIAL POINTS

Diagnostic ultrasonography is an invaluable tool in neurology, used as an extension of the clinical examination. It helps diagnose and monitor many conditions, allowing for more data-driven and rapid treatment interventions.

Comparison of temporal artery ultrasound versus biopsy in the diagnosis of giant cell arteritis

BACKGROUND/OBJECTIVES

Giant cell arteritis (GCA) is a medical and ophthalmological emergency due to risk of stroke and sudden irreversible loss of vision. Fast and accurate diagnosis is important to prevent complications and long-term high dose glucocorticoids toxicity. Temporal artery biopsy is gold standard for diagnosing GCA. However, temporal artery ultrasound is a fast and non-invasive procedure which may provide a supplement or an alternative to biopsy. This study assesses the diagnostic performance of ultrasound and biopsy in the diagnosis of GCA.

SUBJECTS/METHODS

Examination results of patients suspected of having GCA in the period from August 2018 to June 2019 were reviewed. Patients underwent clinical examination and blood tests. Within a few days of starting glucocorticoid treatment, temporal ultrasound and unilateral biopsy were performed. Experienced physicians established the final clinical diagnosis at 6-months follow-up.

RESULTS

Seventy-eight patients underwent both ultrasound and biopsy. Thirty-five (45%) received the final clinical diagnosis of GCA. Compared with the final clinical diagnosis, biopsy had a sensitivity of 69% (51-83%) and a specificity of 100% (92-100%), and ultrasound a sensitivity of 63% (45-79%) and a specificity of 79% (64-94%). Area under the receiver operating characteristics curves were 0.84 and 0.71 for biopsy and ultrasound respectively (p = 0.048). False negative rate of ultrasound was 4 out of 78 (5%).

CONCLUSION

Sensitivity of ultrasound is almost on par with that of biopsy although the overall diagnostic accuracy of ultrasound was slightly lower. We find that ultrasound is a reliable tool for first line diagnosis of GCA.

Evaluation of Arterial Histopathology and microRNA Expression That Underlie Ultrasonography Findings in Temporal Arteries of Patients with Giant Cell Arteritis

The aim of this study was to assess the interrelation between vascular ultrasonography (US) findings, histopathological data, and the expression of selected dysregulated microRNAs (miRNAs) in giant cell arteritis (GCA). The study included data on the clinical parameters, US measurements, and temporal artery biopsies (TABs) of 46 treatment-naïve patients diagnosed with GCA and 22 age-matched non-GCA patient controls. We performed a comprehensive comparative and correlation analysis along with generation of receiver operating characteristic (ROC) curves to ascertain the diagnostic performance of US examination parameters and selected miRNAs for GCA diagnosis. We showed significant differences in the US-measured intima-media thickness of the temporal arteries, the presence of a halo sign, and the presence of luminal stenosis between GCA-positive/TAB-positive, GCA-positive/TAB-negative, and non-GCA patients. Correlation analysis revealed significant associations between several histopathological parameters, US-measured intima-media thickness, and the halo sign. We found that the significant overexpression of miR-146b-5p, miR-155-5p, miR-511-5p, and miR-21-5p, and the under-expression of the miR-143/145 cluster, miR-30a-5p, and miR-125a-5p, coincides and is associated with the presence of a halo sign in patients with GCA. Notably, we determined a high diagnostic performance of miR-146b-5p, miR-21-3p, and miR-21-5p expression profiles in discriminating GCA patients from non-GCA controls, suggesting their potential utilization as putative biomarkers of GCA. Taken together, our study provides an insight into the US-based diagnostic evaluation of GCA by revealing the complex interrelation of clearly defined image findings with underlying vascular immunopathology and altered arterial tissue-specific miRNA profiles.

Multimodality imaging of large-vessel vasculitis

Multimodality cardiovascular imaging is an essential component of the clinical management of patients with large-vessel vasculitis (LVV), a chronic, relapsing and remitting inflammatory disease of the aorta and its major branches. Imaging is needed to confirm the initial diagnosis, to survey the extent and severity of arterial involvement, to screen for cardiovascular complications and for subsequent long-term disease monitoring. Indeed, diagnosing LVV can be challenging due to the non-specific nature of the presenting symptoms, which often evoke a broad differential. Identification of disease flares and persistent residual arteritis following conventional treatments for LVV present additional clinical challenges. However, by identifying and tracking arterial inflammation and injury, multimodality imaging can help direct the use of disease-modifying treatments that suppress inflammation and prevent or slow disease progression. Each of the non-invasive imaging modalities can provide unique and complementary information, contributing to different aspects of the overall clinical assessment. This article provides a focused review of the many roles of multimodality imaging in LVV.

Updates on the diagnosis and monitoring of giant cell arteritis

This mini-review offers a critical appraisal of the currently employed imaging or histopathological tools to diagnose and monitor giant cell arteritis (GCA). An overview of the most updated evidence and current application of color duplex ultrasonography (US), temporal artery biopsy (TAB), 18-fluorodeoxyglucose [18F] FDG-PET/CT, magnetic resonance imaging, and computed tomography angiography is provided. The main limitations of each tool, and the most relevant research developments are discussed. The review highlights the complementary value of the available modalities to ensure a correct diagnosis of GCA, and to provide valuable prognostic information. Novel evidence is accumulating to support the role of imaging, and particularly US, as a monitoring tool for the disease, opening new perspectives for the future management of large vessel vasculitis.

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

Background

Vascular ultrasound enables fast-track diagnosis of giant cell arteritis (GCA), but this method remains subjective. We aimed to determine intima-media thickness (IMT) cut-off values for large vessel GCA (LV-GCA) and identify the clinically relevant factors influencing it.

Methods

We included 214 patients referred for ultrasound evaluation within a fast-track clinic due to suspected GCA. IMT was measured in axillary, brachial, subclavian, superficial femoral, and common carotid arteries (CCA), in a place without identifiable atherosclerotic plaques. IMT cut-off values for vasculitis were determined by comparing measurements in arteries classified as vasculitis vs. controls without GCA/polymyalgia rheumatica (PMR).

Results

Giant cell arteritis was diagnosed in 81 individuals, including extracranial LV-GCA in 43 individuals. Isolated PMR was diagnosed in 50 subjects. In 83 remaining patients, another diagnosis was confirmed, and they served as controls. The rounded optimal IMT cut-off values for the diagnosis of axillary vasculitis were 0.8 mm, subclavian-0.7 mm, superficial femoral-0.9 mm, CCA-0.7 mm, and brachial-0.5 mm. The IMT cut-off values providing 100% specificity for vasculitis (although with reduced sensitivity) were obtained with axillary IMT 1.06 mm, subclavian-1.35 mm, superficial femoral-1.55 mm, CCA-1.27 mm, and brachial-0.96 mm. Axillary and subclavian arteritis provided the best AUC for the diagnosis of GCA, while carotid and axillary were most commonly involved (24 and 23 patients, respectively). The presence of calcified atherosclerotic plaques was related to an increase of IMT in both patients and controls, while male sex, age ≥ 68, hypertension, and smoking increased IMT in controls but not in patients with GCA.

Conclusion

Cut-off values for LV-GCA performed best in axillary and subclavian arteritis but expanding examination to the other arteries may add to the sensitivity of GCA diagnosis (another location, e.g., brachial arteritis) and its specificity (identification of calcified atherosclerotic plaques in other arteries such as CCA, which may suggest applying higher IMT cut-off values). We proposed a more linear approach to cut-off values with two values: one for the most accurate and the other for a highly specific diagnosis and also considering some cardiovascular risk factors.

Impact of cardiovascular risk on the diagnostic accuracy of the ultrasound Halo Score for giant cell arteritis

OBJECTIVE

To evaluate the impact of cardiovascular risk (CVR) on the diagnostic accuracy of the ultrasonographic (US) Halo Score in patients with suspected giant cell arteritis (GCA).

METHODS

Retrospective observational study of patients referred to our US fast track clinic with suspected GCA for a 2-year period. The intima-media thickness (IMT) of cranial and extra-cranial arteries and the Halo Score was determined to assess the extent of vascular inflammation. The European Society of Cardiology Guidelines on CV Disease Prevention were used to define different categories of CVR and patients were classified according to the Systemic Coronary Risk Evaluation (SCORE). The gold standard for GCA diagnosis was clinical confirmation after a 6-month follow-up.

RESULTS

Of the 157 patients included, 47 (29.9%) had GCA after a 6-month follow-up. Extra-cranial artery IMT was significantly higher in patients with high/very high CVR than in those with low/moderate CVR, but only among patients without GCA. Non-GCA patients with high/very high CVR had also a significantly higher Halo Score in contrast with low/moderate CVR [9.38 (5.93) vs 6.16 (5.22); p = 0.007]. The area under the ROC curve of the Halo Score to identify GCA was 0.835 (95% CI 0.756-0.914), slightly greater in patients with low/moderate CVR (0.965 [95% CI 0.911-1]) versus patients with high/very high CVR (0.798 [95% CI 0.702-0.895]). A statistically weak positive correlation was found between the Halo Score and the SCORE (r 0.245; c = 0.002).

CONCLUSIONS

Elevated CVR may influence the diagnostic accuracy of the US Halo Score for GCA. Thus, CVR should be taken into consideration in the US screening for GCA.

Evolution of ultrasound in giant cell arteritis

Ultrasound (US) is being increasingly used to diagnose Giant Cell Arteritis (GCA). The traditional diagnostic Gold Standard has been temporal artery biopsy (TAB), but this is expensive, invasive, has a false-negative rate as high as 60% and has little impact on clinical decision-making. A non-compressible halo with a thickened intima-media complex (IMC) is the sonographic hallmark of GCA. The superficial temporal arteries (STA) and axillary arteries (AA) are the most consistently inflamed arteries sonographically and imaging protocols for evaluating suspected GCA should include at least these two arterial territories. Studies evaluating temporal artery ultrasound (TAUS) have varied considerably in size and methodology with results showing wide discrepancies in sensitivity (9–100%), specificity (66–100%), positive predictive value (36–100%) and negative predictive value (33–100%). Bilateral halos increase sensitivity as does the incorporation of pre-test probability, while prior corticosteroid use decreases sensitivity. Quantifying sonographic vasculitis using Halo Counts and Halo Scores can predict disease extent/severity, risk of specific complications and likelihood of treatment response. Regression of the Halo sign has been observed from as little as 2 days to as late as 7 months after initiation of immunosuppressive treatment and occurs at different rates in STAs than AAs. US is more sensitive than TAB and has comparable sensitivity to MRI and PET/CT. It is time-efficient, cost-effective and allows for the implementation of fast-track GCA clinics which substantially mitigate the risk of irreversible blindness. Algorithms incorporating combinations of imaging modalities can achieve a 100% sensitivity and specificity for a diagnosis of GCA. US should be a standard first line investigation in routine clinical care of patients with suspected GCA with TAB reserved only for those having had a normal US in the context of a high pre-test probability.

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

Objective

To 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).

Methods

Retrospective 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.

Results

A 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).

Conclusion

IMT 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.

Large vessel vasculitis with rare presentation of acute rhabdomyolysis: A case report and review of literature

BACKGROUND

Musculoskeletal involvement in primary large vessel vasculitis (LVV), including giant cell arteritis and Takayasu's arteritis (TAK), tends to be subacute. With the progression of arterial disease, patients may develop polyarthralgia and myalgias, mainly involving muscle stiffness, limb/jaw claudication, cold/swelling extremities, etc. Acute development of rhabdomyolysis in addition to aortic aneurysm is uncommon in LVV. Herein, we report a rare case of LVV with the first presentation of acute rhabdomyolysis.

CASE SUMMARY

A 70-year-old Asian woman suffering from long-term low back pain was hospitalized due to limb claudication, dark urine and an elevated creatine kinase (CK) level. After treatment with fluid resuscitation and antibiotics, the patient remained febrile. Her workup showed persistent elevated levels of inflammatory markers, and imaging studies revealed an aortic aneurysm. A decreasing CK was evidently combined with elevated inflammatory markers and negativity for anti-neutrophilic cytoplasmic antibodies. LVV was suspected and confirmed by magnetic resonance angiography and positron emission tomography with 18F-fluorodeoxyglucose/computed tomography. With a favourable response to immunosuppressive treatment, her symptoms resolved, and clinical remission was achieved one month later. However, after failing to follow the tapering schedule, the patient was readministered 25 mg/d prednisolone due to disease relapse. Follow-up examinations showed decreased inflammatory markers and substantial improvement in artery lesions after 6 mo of treatment. At the twelve-month follow-up, she was clinically stable and maintained on corticosteroid therapy.

CONCLUSION

An exceptional presentation of LVV with acute rhabdomyolysis is described in this case, which exhibited a good response to immunosuppressive therapy, suggesting consideration for a differential diagnosis when evaluating febrile patients with myalgia and elevated CK. Timely use of high-dose steroids until a diagnosis is established may yield a favourable outcome.

Validity of the EULAR recommendations on the use of ultrasound in the diagnosis of giant cell arteritis

Objectives

The European Alliance of Associations for Rheumatology (EULAR) recommendations for the use of imaging in large vessel vasculitis establish that an imaging test supported by clinical pretest probability (PTP) is sufficient for the diagnosis of giant cell arteritis (GCA). Our objective was to determine the validity of the EULAR recommendations on the use of Colour duplex ultrasound (CDUS) in GCA after calculating the PTP.

Methods

We collected data of all patients referred to our fast-track clinic between 2016 and 2020. The Southend pretest probability score (SPTPS) was calculated and classified as low (LR), intermediate and high risk (HR) according to the values obtained by its authors, <9, 9–12 and >12, respectively. All patients underwent a CDUS of the temporal arteries with their common, parietal and frontal branches, and the most also axillary (86.5%), and subclavian and carotid arteries. The gold-standard diagnosis was made according to the physician’s criteria after at least 9 months of follow-up.

Results

Of the 297 referred patients, 97 (32.7%) were diagnosed with GCA. The SPTPS area under the ROC curve was 0.787. The LR category included 105 patients (35.4%), of which 10 (9.5%) had GCA and 1 had a CDUS false negative result. The HR category included 67 patients (22.5%), 47 with GCA, and in 1 case the CDUS result was a false positive.

Conclusion

Combining the results of a PTP score, such as SPTPS, and the CDUS allows for an accurate diagnosis of GCA, as established by the EULAR group, with less than 2% misclassification of diagnosis.

Cranial giant cell arteritis mimickers: A masquerade to unveil

Giant cell arteritis (GCA) is a large-vessel vasculitis that affects cranial and extra-cranial arteries. Extra-cranial GCA presents mainly with non-specific symptoms and the differential diagnosis is very broad, while the cranial form has more typical clinical picture and physicians have a lower threshold for diagnosis and treatment. Although temporal artery biopsy (TAB) has an established role, ultrasound (US) is being increasingly used as the first-line imaging modality in suspected GCA. Vasculitides (especially ANCA-associated), hematological disorders (mainly amyloidosis), neoplasms, infections, atherosclerosis and local disorders can affect the temporal arteries or might mimic the symptoms of cranial GCA and produce US and TAB findings that resemble those of temporal vasculitis. Given that prompt diagnosis is essential and proper treatment varies significantly among these diseases, in this review we aimed to collectively present disorders that can masquerade cranial GCA.

The Diagnostic Performance of an Extended Ultrasound Protocol in Patients With Clinically Suspected Giant Cell Arteritis

Objective

To evaluate the diagnostic performance of an extended ultrasound protocol in patients referred under the suspicion of giant cell arteritis (GCA).

Methods

Consecutive patients with suspected GCA were examined with an extended color duplex ultrasound (CDU) protocol during a period of 2 years. The extended CDU protocol included temporal, axillary, subclavian, brachiocephalic, and carotid arteries. The reference was clinically diagnosed GCA, confirmed after ≥6-month follow-up. Hypo- or medium-echogenic, circumferential, homogenous wall thickening, and/or a positive compression sign in temporal arteries, were regarded as typical signs of arteritis.

Results

Of the eligible 201 patients, 83 (41%) received a clinical GCA diagnosis at follow-up ≥6 months post CDU examination. Among these cases, 48 (58%) demonstrated inflammation solely in temporal arteries, 8 (10%) showed abnormalities restricted to extra-cranial vessels, and 23 (28%) patients displayed inflammatory changes in both temporal and extra-cranial arteries. Color duplex ultrasound of temporal arteries yielded a diagnostic sensitivity and specificity [95% confidence intervals (CI)] of 86% (76–92%) and 99% (95–99%), respectively. By adding axillary artery examination, the sensitivity increased to 92% (83–97%) while the specificity remained unchanged. Further, inclusion of subclavian artery marginally increased the sensitivity by 1%. Finally, by also including brachiocephalic and common carotid arteries resulted in a sensitivity of 95% (88–99%) and a specificity of 98% (94–99%).

Conclusions

Color duplex ultrasound examination demonstrated a high accuracy in diagnosing patients both with cranial and extra-cranial GCA. Further examination of brachiocephalic and common carotid arteries can increase the sensitivity without affecting the specificity when temporal and axillary findings are indecisive. Finally, the extended CDU protocol allows measurement of the general burden of inflammation, which could be relevant for future monitoring purposes.

Use of Contrast-Enhanced Ultrasound Sonography in Giant Cell Arteritis: A Proof-of-Concept Study

C-Reactive protein and erythrocyte sedimentation rate are crucial parameters used to monitor giant cell arteritis (GCA). Given that tocilizumab is approved for the treatment of GCA, these parameters are less sensitive because of the effects of interleukin-6 receptor blockade. Thus, the optimal method for monitoring GCA patients undergoing tocilizumab therapy, especially patients exhibiting a persistent thickened vessel wall in large vessels, remains unclear. Contrast-enhanced ultrasonography (CEUS) can increase the visibility of tissue perfusion by slow blood flow, which cannot be detected by power color doppler. We used CEUS to investigate patients with active and inactive GCA of the large vessels (active large vessel arteritis [aLVV]/inactive large vessel arteritis [iLVV]) who were not administered tocilizumab in this proof-of-concept study. After injection of the ultrasound contrast agent, the contrasted area (CA) of large vessels in a transverse section was calculated twice: first when the lumen was contrasted completely and once again 4-8 s later. We investigated the value of increase in CA that exhibited the best sensitivity and specificity for aLVV. Twenty-four patients were included in this study: 15 with aLVV and 9 with iLVV. The CA increased from 32.2 ± 16.8 to 52.5 ± 21.3 mm² (p < 0.0001) in aLVV. The mean CA remained unchanged in iLVV. The best cutoff value to differentiate between aLVV and iLVV was a ≥25% increase in CA with a sensitivity and specificity of 91.7% and 100%, respectively. Our study indicates that CEUS can detect aLVV with high sensitivity and specificity. Incorporation of CEUS into routine clinical practice might result in a good method for monitoring disease activity in LVV in GCA patients. The limitation of our study was the small number of patients and the lack of investigator blinding to clinical data.

Quantitative ultrasound to monitor the vascular response to tocilizumab in giant cell arteritis

OBJECTIVES

To characterize the effect of ultra-short glucocorticoids followed by Tocilizumab monotherapy on the intima-media thickness (IMT) in GCA.

METHODS

Eighteen GCA patients received 500 mg for 3 consecutive days (total of 1500mg) i.v. methylprednisolone on days 0-2, followed by i.v. Tocilizumab (8 mg/kg) on day 3 and thereafter weekly s.c. Tocilizumab injections (162 mg) over 52 weeks. US of temporal (TAs), axillary (AAs) and subclavian (SAs) arteries was performed at baseline, on days 2-3, and at weeks 4, 8, 12, 24 and 52. The largest IMT of all segments and IMT at landmarks of AA/SA were recorded. IMT was scaled by mean normal values and averaged. Each segment was classified according to diagnostic cut-offs.

RESULTS

Of the 18 GCA patients, 16 patients had TA and 6 had extracranial large artery involvement. The IMT showed a sharp decline on day 2/3 in the TAs and AAs/SAs. In TAs, this was followed by an increase to baseline levels at week 4 and a subsequent slow decrease, which was paralleled by decreasing symptoms and achievement of clinical remission. The AAs/SAs showed a new signal of vasculitis at week 4 in three patients, with an IMT increase up to week 8.

CONCLUSION

Glucocorticoid pulse therapy induced a transient decrease of the IMT in TAs and AAs/SAs. Tocilizumab monotherapy resulted in a slow and steady decrease in IMT of the TAs and a smaller and delayed effect on the AAs/SAs. The data strongly support a remission-inducing effect of Tocilizumab and argue the case for US having an important role in monitoring disease activity in GCA.

TRIAL REGISTRATION

ClinicalTrials.gov, www.clinicaltrials.gov, NCT03745586.

Hyperechogenic intimal lesions and wall thickness of the temporal and facial arteries in elderly patients with arterial occlusions of the eye

OBJECTIVE

To determine the association of arteriosclerosis, characterised by hyperechogenic intimal lesions (HIL), with wall thickness of the temporal and facial arteries in elderly patients with ocular arterial occlusions.

METHODS

Patients suffering from non-arteritic ocular perfusion disorders were included. High-resolution compression sonography (18 MHz) images of the temporal arteries (frontal and parietal branch at the upper margin of the auricle) and facial arteries (at the crossing point of the artery over the mandible) were analysed for the presence of HIL (grade 0: absent; grade 1: moderate; grade 2: severe). Characteristics of patients with and without evidence of HIL >grade 1 were compared.

RESULTS

In total, 330 cranial artery segments of 55 patients were analysed. HIL ≥grade 1 was present in 13.0% of all artery segments and in 38.1% of all patients. Patients with HIL ≥grade 1 in at least one arterial segment displayed significantly increased maximum wall thickness of the temporal arteries (0.62±0.23 mm vs 0.50±0.13 mm; p<0.01) and facial arteries (0.71±0.20 mm vs 0.54±0.19 mm; p=0.01). Patients with at least one temporal or facial artery segment with HIL were older, more often male and more frequently suffered from diabetes mellitus.

CONCLUSION

The presence of HIL goes along with a significantly increased wall thickness of the temporal and facial arteries. These findings should be considered when interpreting the results of sonography of the cranial arteries in the diagnostic workup of suspected giant cell arteritis.

Imaging Tests in the Early Diagnosis of Giant Cell Arteritis

Early recognition of giant cell arteritis (GCA) is crucial to avoid the development of ischemic vascular complications, such as blindness. The classic approach to making the diagnosis of GCA is based on a positive temporal artery biopsy, which is among the criteria proposed by the American College of Rheumatology (ACR) in 1990 to classify a patient as having GCA. However, imaging techniques, particularly ultrasound (US) of the temporal arteries, are increasingly being considered as an alternative for the diagnosis of GCA. Recent recommendations from the European League Against Rheumatism (EULAR) for the use of imaging techniques for large vessel vasculitis (LVV) included US as the first imaging option for the diagnosis of GCA. Furthermore, although the ACR classification criteria are useful in identifying patients with the classic cranial pattern of GCA, they are often inadequate in identifying GCA patients who have the extracranial phenotype of LVV. In this sense, the advent of other imaging techniques, such as magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET)/CT, has made it possible to detect the presence of extracranial involvement of the LVV in patients with GCA presenting as refractory rheumatic polymyalgia without cranial ischemic manifestations. Imaging techniques have been the key elements in redefining the diagnostic work-up of GCA. US is currently considered the main imaging modality to improve the early diagnosis of GCA.

A Tale of Diagnostic Delay with Detrimental Consequences: Illustrating the Challenging Nature of Diagnosing Giant Cell Arteritis

Giant cell arteritis is a medical emergency as severe, irreversible complications may occur if it is not treated in a timely manner. However, in daily practice early diagnosis can be challenging. We report the case of a 70-year-old woman who presented with multiple ischaemic cerebral vascular accidents related to newly diagnosed giant cell arteritis. Review of her charts revealed a substantial delay from the onset of symptoms to diagnosis. This case demonstrates the need for additional efforts to reduce delay in referring patients with giant cell arteritis and the need to implement fast-track clinics to prevent serious complications.

LEARNING POINTS

Giant cell arteritis is a medical emergency and unnecessary diagnostic delay can result in severe complications.Despite implementation of fast-track clinics, diagnostic delay still occurs due to the generic nature of signs and symptoms and inadequate case finding.As diagnostic delay can lead to preventable complications, increased knowledge and awareness of the characteristics and urgency of giant cell arteritis is needed among referring physicians.

Diagnosing Giant Cell Arteritis: A Comprehensive Practical Guide for the Practicing Rheumatologist

Giant cell arteritis (GCA) is the most common large vessel vasculitis in the elderly population. In recent years, advanced imaging has changed the way GCA can be diagnosed in many locations. The GCA fast-track clinic (FTC) approach combined with ultrasound (US) examination allows prompt treatment and diagnosis with high certainty. FTCs have been shown to improve prognosis while being cost effective. However, all diagnostic modalities are highly operator dependent, and in many locations expertise in advanced imaging may not be available. In this paper, we review the current evidence on GCA diagnostics and propose a simple algorithm for diagnosing GCA for use by rheumatologists not working in specialist centres.

Ultrasound halo sign as a potential monitoring tool for patients with giant cell arteritis: a prospective analysis

OBJECTIVES

To assess the sensitivity to change of ultrasound halo features and their association with disease activity and glucocorticoid (GC) treatment in patients with newly diagnosed giant cell arteritis (GCA).

METHODS

Prospective study of patients with ultrasound-confirmed GCA who underwent serial ultrasound assessments of the temporal artery (TA) and axillary artery (AX) at fixed time points. The number of segments with halo and maximum halo intima-media thickness (IMT) was recorded. Time points in which >80% of patients were assessed were considered for analysis. Halo features at disease presentation and first relapse were compared.

RESULTS

49 patients were assessed at 354 visits. Halo sensitivity to change was assessed at weeks 1, 3, 6, 12 and 24 and showed a significant standardised mean difference between all time points and baseline for the TA halo features but only after week 6 for the AX halo features. The number of TA segments with halo and sum and maximum TA halo IMT showed a significant correlation with erythrocyte sedimentation rate (0.41, 0.44 and 0.48), C reactive protein (0.34, 0.39 and 0.41), Birmingham Vasculitis Activity Score (0.29, 0.36 and 0.35) and GC cumulative dose (-0.34, -0.37 and -0.32); no significant correlation was found for the AX halo features. Halo sign was present in 94% of first disease relapses but with a lower mean number of segments with halo and sum of halo IMT compared with disease onset (2.93±1.59 mm vs 4.85±1.51 mm, p=0.0012; 2.01±1.13 mm vs 4.49±1.95 mm, p=0.0012).

CONCLUSIONS

Ultrasound is a useful imaging tool to assess disease activity and response to treatment in patients with GCA.

Temporal artery compression sonography for the diagnosis of giant cell arteritis in elderly patients with acute ocular arterial occlusions

OBJECTIVES

To validate cut-off values of quantitative high-resolution temporal artery compression sonography (TCS) for the diagnosis of cranial GCA (cGCA) in patients with acute arterial ocular occlusions and in an independent control group.

METHODS

Consecutive patients who underwent TCS as part of the diagnostic workup of acute arterial ocular occlusions and controls not suffering from ocular ischaemia/systemic vasculitis were included. The diagnostic accuracy of the established TCS cut-off value of maximum temporal artery wall thickness (≥0.7 mm) and a novel numeric TCS score incorporating the degree of wall thickening in the four temporal artery segments assessed (0-3 points per segment) was tested by receiver operating characteristics analysis. Subgroup analyses were performed for female and male patients and patients older and younger than age of 70 years.

RESULTS

Of 114 patients with acute ocular arterial occlusions, 30 patients received a final clinical diagnosis of cGCA. The sensitivity and specificity of the ≥0.7 mm TCS cut-off for the diagnosis of cGCA were 100 and 84.5% in the overall cohort. The TCS score did not improve the diagnostic yield (cut-off ≥5; sensitivity 100%, specificity 85.7%). In male patients >70 years of age, the specificity of TCS was limited, secondary to age- and sex-related differences in temporal artery wall thickness, which we confirmed in the independent control group.

CONCLUSION

TCS yields high diagnostic accuracy in the diagnosis of cGCA in patients with acute ocular arterial occlusions. Age- and sex-related differences in temporal artery wall thickness influence the diagnostic accuracy of TCS.

The cut-off values for the intima-media complex thickness assessed by colour Doppler sonography in seven cranial and aortic arch arteries

OBJECTIVES

Colour Doppler sonography (CDS) is becoming ever more important in the diagnosis of GCA. Data on cut-off values for intima-media complex thickness (IMT) that can be used in clinical practice to distinguish between normal and inflamed arteries are limited. We aimed to derive potential cut-off values for IMT of seven preselected arteries by comparing IMT between GCA patients and a control group.

METHODS

We performed CDS of the preselected temporal, facial, occipital, carotid, vertebral, subclavian and axillary arteries in consecutive newly diagnosed GCA patients between October 2013 and September 2019. A 'halo' with positive compression sign was considered a positive finding. We measured the maximum IMT in the preselected arteries and compared it with the maximum IMT of the control group.

RESULTS

We were able to demonstrate a halo sign in at least one of the examined arteries of 244/248 (98.4%) GCA patients. Temporal arteries were the most commonly affected vessels, involved in 192 (77.4%) patients. We found extracranial large vessel involvement in 87 (35.1%) patients. The following cut-off values showed high levels of diagnostic accuracy: ≥0.4 mm for temporal, facial and occipital arteries, ≥0.7 mm for vertebral arteries, and ≥1 mm for carotid, subclavian and axillary arteries.

CONCLUSION

The involvement of a large array of arteries is easily and commonly detected by CDS and provides a high diagnostic yield in patients with suspected GCA. Proposed IMT cut-off values might further improve the diagnostic utility of CDS in these patients.

Ultrasonography in the diagnosis and follow-up of giant cell arteritis

Colour Doppler ultrasonography is the first measure to allow objective bedside assessment of GCA. This article discusses the evidence using the OMERACT filter. Consensus definitions for ultrasonographic changes were agreed upon by a Delphi process, with the 'halo' and 'compression' signs being characteristic. The halo is sensitive to change, disappearing within 2-4 weeks of starting glucocorticoids. Ultrasonography has moderate convergent validity with temporal artery biopsy in a pooled analysis of 12 studies including 965 participants [κ = 0.44 (95% CI 0.38, 0.50)]. The interobserver and intra-observer reliabilities are good (κ = 0.6 and κ = 0.76-0.78, respectively) in live exercises and excellent when assessing acquired images and videos (κ = 0.83-0.87 and κ = 0.88, respectively). Discriminant validity has been tested against stroke and diabetes mellitus (κ=-0.16 for diabetes). Machine familiarity and adequate examination time improves performance. Ultrasonography in follow-up is not yet adequately defined. Some patients have persistent changes in the larger arteries but these do not necessarily imply treatment failure or predict relapses.

Development and Proof of Concept of a Low-Cost Ultrasound Training Model for Diagnosis of Giant Cell Arteritis Using 3D Printing

Objectives: Currently, ultrasound (US) is widely used for the diagnosis of giant cell arteritis (GCA). Our aim was to develop a low-cost US training model for diagnosis of GCA of the temporal and axillary artery using a modern 3D printing system. Methods: We designed an US training model, which enables measurement of the intima-media thickness (IMT) of temporal and axillary arteries using Autodesk Fusion360. This model was printed using a modern 3D printer (Formlabs Form3) and embedded in ballistic gelatine. The ultrasound images including measurement of the IMT by ultrasound specialists in GCA were compared to ultrasound images in acute GCA and healthy subjects. Results: Our ultrasound training model of the axillary and temporal artery displayed a very similar ultrasound morphology compared to real US images and fulfilled the OMERACT ultrasound definitions of normal and pathological temporal and axillary arteries in GCA. The IMT measurements were in line with published cut-off values for normal and pathological IMT values in GCA and healthy individuals. When testing the models on blinded US specialists in GCA, they were identified correctly in all test rounds with an intra-class coefficient of 0.99. Conclusion: The production of low-cost ultrasound training models of normal and pathological temporal and axillary arteries in GCA, which fulfil the OMERACT ultrasound definitions and adhere to the published IMT cut-off values in GCA, is feasible. Ultrasound specialists identified each respective model correctly in every case.

OMERACT definition and reliability assessment of chronic ultrasound lesions of the axillary artery in giant cell arteritis

OBJECTIVES

To define chronic ultrasound lesions of the axillary artery (AA) in long-standing giant cell arteritis (GCA) and to evaluate the reliability of the new ultrasound definition in a web-based exercise.

METHODS

A structured Delphi, involving an expert panel of the Large Vessel Vasculitis subgroup of the Outcome Measures in Rheumatology (OMERACT) Ultrasound Working Group was carried out. The reliability of the new definition was tested in a 2-round web-based exercise involving 23 experts and using 50 still images each from AA of long-standing and acute GCA patients, as well as 50 images from healthy individuals.

RESULTS

The final OMERACT ultrasound definition of chronic changes was based on measurement and appearance of the intima-media complex. The overall reliability of the new definition for chronic ultrasound changes in longstanding GCA of the AA was good to excellent with Light's kappa values of 0.79-0.80 for inter-reader reliability and mean Light's-kappa of 0.88 for intra-reader reliability. The mean inter-rater and intra-rater agreements were 86-87% and 92%, respectively. Good reliabilities were observed comparing the vessels with longstanding versus acute GCA with a mean agreement and kappa values of 81% and 0.63, respectively.

CONCLUSION

The new OMERACT ultrasound definition for chronic vasculitis of the AA in GCA revealed a good to excellent inter- and intra-reader reliability in a web-based exercise of experts.