Imaging in systemic vasculitis

Giant cell arteritis: incidence and phenotypic distribution in Western Norway 2013-2020

Objectives

There is an increasing awareness of the spectrum of phenotypes in giant cell arteritis (GCA). However, there is sparse evidence concerning the phenotypic distribution which may be influenced by both genetic background and the environment. We established a cohort of all GCA-patients in the Bergen Health Area (Western Norway), to describe the phenotypic distribution and whether phenotypes differ with regards to incidence and clinical features.

Methods

This is a retrospective cohort study including all GCA-patients in the Bergen Health Area from 2013-2020. Data were collected by reviewing patient records, and patients considered clinically likely GCA were included if they fulfilled at least one set of classification criteria. Temporal artery biopsy (TAB) and imaging results were used to classify the patients according to phenotype. The phenotype "cranial GCA" was used for patients with a positive TAB or halo sign on temporal artery ultrasound. "Non-cranial GCA" was used for patients with positive findings on FDG-PET/CT, MRI-, or CT angiography, or wall thickening indicative of vasculitis on ultrasound of axillary arteries. Patients with features of both these phenotypes were labeled "mixed." Patients that could not be classified due to negative or absent examination results were labeled "unclassifiable".

Results

257 patients were included. The overall incidence of GCA was 20.7 per 100,000 persons aged 50 years or older. Overall, the cranial phenotype was dominant, although more than half of the patients under 60 years of age had the non-cranial phenotype. The diagnostic delay was twice as long for patients of non-cranial and mixed phenotype compared to those of cranial phenotype. Headache was the most common clinical feature (78% of patients). Characteristic clinic features occurred less frequently in patients of non-cranial phenotype compared to cranial phenotype.

Conclusion

The overall incidence for GCA was comparable to earlier reports from this region. The cranial phenotype dominated although the non-cranial phenotype was more common in patients under 60 years of age. The diagnostic delay was longer in patients with the non-cranial versus cranial phenotype, indicating a need for examination of non-cranial arteries when suspecting GCA.

Non-infectious diseases of the aorta and large arteries

This article describes the various forms of inflammatory lesions of the aorta and large arteries, including chronic periaortitis, as well as the diagnostic methods are considered. Large vessel vasculitis represent the most common entities, however, there is also an association with other rheumatological or inflammatory diseases, drug-induced or paraneoplastic entities. Instrumental imaging modalities play an important role in the diagnosis.

Overview of imaging in adult- and childhood-onset Takayasu arteritis

Takayasu Arteritis is an idiopathic large vessel vasculitis, that affects young adults and children and can lead to ischemia and end-organ damage. Vascular imaging is crucial for diagnosis, assessment of disease extent and management of the disease. In this article, we critically review evidence for the clinical use of the different imaging modalities conventional angiography, magnetic resonance imaging, computed tomography, Doppler ultrasound and ¹⁸fluorodeoxyglucose positron emission tomography. We thereby focus on their clinical applicability, challenges and specific use in children.

Ultrasound Technologies and the Diagnosis of Giant Cell Arteritis

Giant cell arteritis (GCA) is a primary autoimmune vasculitis that specifically affects medium-sized extracranial arteries, like superficial temporal arteries (TAs). The most important data to be considered for the ultrasound (US) diagnosis of temporal arteritis are stenosis, acute occlusions and “dark halo” sign, which represent the edema of the vascular wall. The vessel wall thickening of large vessels in GCA can be recognized by the US, which has high sensitivity and is facile to use. Ocular complications of GCA are common and consist especially of anterior arterial ischemic optic neuropathies or central retinal artery occlusion with sudden, painless, and sharp loss of vision in the affected eye. Color Doppler imaging of the orbital vessels (showing low-end diastolic velocities and a high resistance index) is essential to quickly differentiate the mechanism of ocular involvement (arteritic versus non-arteritic), since the characteristics of TAs on US do not correspond with ocular involvement on GCA. GCA should be cured immediately with systemic corticosteroids to avoid further visual loss of the eyes.

ACR Appropriateness Criteria® Noncerebral Vasculitis

Noncerebral vasculitis is a wide-range noninfectious inflammatory disorder affecting the vessels. Vasculitides have been categorized based on the vessel size, such as large-vessel vasculitis, medium-vessel vasculitis, and small-vessel vasculitis. In this document, we cover large-vessel vasculitis and medium-vessel vasculitis. Due to the challenges of vessel biopsy, imaging plays a crucial role in diagnosing this entity. While CTA and MRA can both provide anatomical details of the vessel wall, including wall thickness and enhancement in large-vessel vasculitis, FDG-PET/CT can show functional assessment based on the glycolytic activity of inflammatory cells in the inflamed vessels. Given the size of the vessel in medium-vessel vasculitis, invasive arteriography is still a choice for imaging. However, high-resolution CTA images can depict small-caliber aneurysms, and thus can be utilized in the diagnosis of medium-vessel vasculitis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

An advanced ultrasound application used to assess peripheral vascular diseases: superb microvascular imaging

Over the past several years, a novel ultrasound imaging modality termed superb microvascular imaging (SMI) has enabled visualization of microvessels. SMI ultrasound studies of peripheral artery diseases have significantly extended our knowledge of tissue microcirculation and the arterial microenvironments of atherosclerotic lesions. We here present an overview of current knowledge on the utility of SMI assessment of vascular diseases and highlight certain peripheral microcirculation disorders for which SMI is particularly valuable. The evidence indicates that SMI can detect intraplaque neovascularization and usefully assess carotid plaque vulnerability; vascularization of the carotid arterial wall detected by SMI is a potential marker of disease activity in patients with Takayasu arteritis; SMI reveals the foot microcirculation and yields a quantitative vascular index (in line with the angiosome concept); and, SMI may serve as an auxiliary diagnostic modality for hereditary hemorrhagic telangiectasia and Raynaud syndrome. In general, microcirculatory evaluation by SMI is an attractive field for future research on therapeutic strategies for peripheral vascular diseases.

Real-world Risk of Relapse of Giant Cell Arteritis Treated With Tocilizumab: A Retrospective Analysis of 43 Patients

OBJECTIVE

Tocilizumab (TCZ), an interleukin 6 (IL-6) receptor antagonist, is approved for giant cell arteritis (GCA) as a cortisone-sparing strategy and in refractory patients. This study assessed the real-world efficacy, safety, and long-term outcomes of patients with GCA treated with TCZ.

METHODS

We conducted a multicenter retrospective observational study at 3 French centers. All patients aged ≥ 50 years who met the American College of Rheumatology (ACR) criteria, and had received at least 1 dose of TCZ were included. Relapse was defined by therapeutic escalation, such as increased doses of corticosteroids (CS), resumption of CS after weaning, or introduction or intensification of adjuvant therapy.

RESULTS

Between 2013 and 2019, 43 patients were included. Patients were followed up for a median 511 days between GCA diagnosis and inclusion, with 34/43 (79%) patients experiencing relapses. At inclusion, median age was 77 years, and median dose of CS was 15 mg/day. After inclusion, the mean cumulative dose of CS was 2.1 g/year vs 9.4 g/year before inclusion (P < 2 × 10^-7), with 12/43 (28%) patients experiencing relapses on TCZ. Among 29 patients undergoing TCZ discontinuation, 18 (62%) experienced relapses. Factors associated with relapse after inclusion were introduction of TCZ > 6 months after diagnosis (P = 0.005), absence of ischemic signs at diagnosis (P = 0.006), relapse rate > 0.8/year (P = 0.03), and absence of CS tapering ≤ 5 mg/day (P = 0.03) before inclusion. Serious adverse events occurred in 18/43 patients (42%), including 4 deaths.

CONCLUSION

Our results confirm the effectiveness of TCZ for CS sparing, but after discontinuation of treatment, TCZ allows for a prolonged remission in < 50% of patients. Attention must be paid to the tolerance of this long-term treatment in this elderly, heavily treated refractory population.

Potential Cardiovascular Applications of Total-body PET Imaging

Cardiovascular conditions can exist as part of a systemic disorder (eg, sarcoidosis, amyloidosis, or vasculitis) or have systemic consequences as a result of the cardiovascular insult (eg, myocardial infarction). In other circumstances, multisystem evaluation of metabolism and blood flow might be key for evaluation of multisystemic syndromes or conditions. Long axial field-of-view PET/computed tomography systems hold the promise of transforming the investigation of such systemic disorders. This article aims at reviewing some of the potential cardiovascular applications of this novel instrumentation device.

Imaging for Diagnosis, Monitoring, and Outcome Prediction of Large Vessel Vasculitides

Purpose of Review

To discuss and summarize the latest evidence on imaging techniques in giant cell arteritis (GCA) and Takayasu arteritis (TAK). This is a report on the performance of ultrasound (US), magnetic resonance imaging (MRI), computed tomography (CT), 18F-fluorodeoxyglucose positron emission tomography (18-FDG-PET), and other emerging imaging techniques in diagnosis, outcome prediction, and monitoring of disease activity.

Recent Findings

Imaging techniques have gained an important role for diagnosis of large vessel vasculitides (LVV). As signs of vasculitis, US, MRI, and CT show a homogeneous arterial wall thickening, which is mostly concentric. PET displays increased FDG uptake in inflamed artery walls. US is recommended as the initial imaging modality in GCA. MRI and PET/CT may also detect vasculitis of temporal arteries. For TAK, MRI is recommended as the first imaging modality as it provides a good overview without radiation. Extracranial LVV can be confirmed by all four modalities. In addition, MRI and PET/CT provide consistent examination of the aorta and its branches. New techniques such as contrast-enhanced ultrasound, PET/MRI, and auxiliary methods such as “computer-assisted quantitative analysis” have emerged and need to be further validated.

Summary

Imaging has partly replaced histology for confirming LVV. Provided experience and adequate training, US, MRI, CT, or PET provide excellent diagnostic accuracy. Imaging results need to complement history and clinical examination. Ongoing studies are evaluating the role of imaging for monitoring and outcome measurement.

The Clinical Impact of Using 18F-FDG-PET/CT in the Diagnosis of Suspected Vasculitis: The Effect of Dose and Timing of Glucocorticoid Treatment

¹⁸F-Fluorodeoxyglucose positron-emission tomography (¹⁸F-FDG-PET) with computed tomography (CT) is effective for diagnosing large vessel vasculitis, but its usefulness in accurately diagnosing suspected, unselected vasculitis remains unknown. We evaluated the feasibility of ¹⁸F-FDG-PET/CT in real-life cohort of patients with suspicion of vasculitis. The effect of the dose and the timing of glucocorticoid (GC) medication on imaging findings were in special interest. 82 patients with suspected vasculitis were evaluated by whole-body ¹⁸F-FDG-PET/CT. GC treatment as prednisolone equivalent doses at the scanning moment and before imaging was evaluated. 38/82 patients were diagnosed with vasculitis. Twenty-one out of 38 patients had increased ¹⁸F-FDG accumulation in blood vessel walls indicating vasculitis in various sized vessels. Vasculitis patients with a positive vasculitis finding in ¹⁸F-FDG-PET/CT had a significantly shorter duration of GC use (median = 4.0 vs 7.0 days, P=0.034), and they used lower GC dose during the PET scan (median dose = 15.0 mg/day vs 40.0 mg/day, p=0.004) compared to ¹⁸F-FDG-PET/CT-negative patients. Vasculitis patients with a positive ¹⁸F-FDG-PET/CT result had significantly higher C-reactive protein (CRP) than patients with a negative ¹⁸F-FDG-PET/CT finding (mean value = 154.5 vs 90.4 mg/L, p=0.018). We found that ¹⁸F-FDG-PET/CT positivity was significantly associated with a lower dose and shorter duration of GC medication and higher CRP level in vasculitis patients. ¹⁸F-FDG-PET/CT revealed clinically significant information in over half of the patients and was effective in confirming the final diagnosis.

[Contribution of Doppler ultrasound for the diagnosis of giant cell arteritis]

Ultrasound is a useful imaging modality for the diagnosis of giant cell arteritis. Ultrasound of temporal arteries is recommended as the first imaging modality in patients with suspected predominantly cranial giant cell arteritis. The thickening of the arterial wall (halo sign) is the ultrasound finding most suggestive of giant cell arteritis. In patients in whom there is a high clinical suspicion of giant cell arteritis and a halo sign, the diagnosis of giant cell arteritis may be made without temporal artery biopsy.

EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice summary

Large vessel vasculitis (LVV) is the most common form of primary vasculitis comprising of giant cell arteritis (GCA), Takayasu's arteritis (TAK) and idiopathic aortitis. Early diagnosis and treatment of LVV are paramount to reduce the risk of ischemic complications such as visual loss and strokes, vascular stenosis and occlusion, and aortic aneurysm formation. Use of imaging modalities [ultrasound (US), magnetic resonance imaging (MRI), computed tomography (CT) and [18F]-fluorodeoxyglucose positron emission tomography (PET)] has steadily increased to enable assessment of cranial and extracranial arteries, as well as the aorta. These imaging modalities are less invasive, more sensitive and readily available compared to temporal artery biopsy (TAB). Modern imaging methods have changed the role of TAB in diagnosing GCA and have replaced diagnostic angiography. Over the last two decades, several studies have evaluated the use of US, MRI, CT and PET in LVV. However, these various imaging tools are not yet uniformly used in routine clinical practice and controversy exists as to which imaging modality best provides meaningful assessments of disease activity and damage in LVV. In January 2018, evidence-based recommendations for the use of imaging modalities in LVV were published. The aim of this review is to summarize the current evidence of imaging in patients with or suspected of having LVV, and to highlight the clinical implications of the EULAR recommendations.

Hypereosinophilic vasculitis: A case report

INTRODUCTION

The Revised International Chapel Hill Consensus Conference 2012 subdivides vasculitides based on combinations of features that separate different forms of vasculitis into definable categories. Hypereosinophilic vasculitis with sparing of the respiratory tract and renal system is a rare presentation that is yet to be described in the Revised International Chapel Hill Consensus Conference 2012 report that addresses nomenclature of vasculitides. This is a condition that involves a vascular injury due to either a primary eosinophilic vasculitis or an underlying connective tissue disease and it predisposes patients to a prothrombotic state.

PATIENT CONCERNS

A 39-year-old patient presented with left hand digital ischemia, preceded by Raynaud phenomenon, and vasculitic rash. For 3 months, he was having digital ischemia affecting the left 2nd and 3rd digits in the form of pallor and gangrenous discoloration with a preceding history of a pinpoint pruritic rash affecting his lower limbs that extended to involve the trunk and upper limbs over a short period of time and responded to only a tapering dose of oral steroids. Examination revealed a delayed capillary refill in all left-hand digits and a weak left radial pulse but no bruit. The rest of his peripheral vascular examination was unremarkable.

DIAGNOSIS

Investigations revealed an absolute eosinophilic count of 4.34 K/μL and erythrocyte sedimentation rate of 44 mm/h. A magnetic resonance angiogram showed a beaded appearance of the left ulnar artery distally and the radial artery branches in the left hand and subsequently was diagnosed with hypereosinophilic vasculitis.

INTERVENTIONS

He was started on oral prednisone of 1 mg/kg daily orally tapering done as well as azathioprine for maintenance.

OUTCOMES

Two weeks postdischarge, the patient was seen in the outpatient department where his ischemic symptoms improved, and his skin rash healed. Noticed improvement in his splinter hemorrhages was also detected. He continued to do well on 2 years follow-up CONCLUSION:: This case reflects the importance of frequent reevaluation for vasculitic diseases criteria and nomenclature. Hypereosinophilic vasculitis with absent respiratory and renal involvement is a rare presentation with scarce evidence to guide treatment.

A Review and Hypothesized Model of the Mechanisms That Underpin the Relationship Between Inflammation and Cognition in the Elderly

Age is associated with increased risk for several disorders including dementias, cardiovascular disease, atherosclerosis, obesity, and diabetes. Age is also associated with cognitive decline particularly in cognitive domains associated with memory and processing speed. With increasing life expectancies in many countries, the number of people experiencing age-associated cognitive impairment is increasing and therefore from both economic and social terms the amelioration or slowing of cognitive aging is an important target for future research. However, the biological causes of age associated cognitive decline are not yet, well understood. In the current review, we outline the role of inflammation in cognitive aging and describe the role of several inflammatory processes, including inflamm-aging, vascular inflammation, and neuroinflammation which have both direct effect on brain function and indirect effects on brain function via changes in cardiovascular function.

Contrast-enhanced Ultrasonography for Monitoring Arterial Inflammation in Takayasu Arteritis

OBJECTIVE

To evaluate the utility of contrast-enhanced ultrasound (CEUS) compared with 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) in assessing vessel inflammation of Takayasu arteritis (TA).

METHODS

This is a retrospective analysis of 71 patients with TA who had undergone carotid CEUS. Twenty-two of 71 patients underwent FDG-PET after CEUS. Clinical disease activity was assessed by Kerr criteria and the Indian Takayasu Clinical Activity Score 2010 (ITAS2010). We investigated the correlation between carotid vascularization on CEUS and clinical data. The consistency of carotid CEUS and PET data has been analyzed for TA disease activity.

RESULTS

There was a statistically significant correlation between the results of CEUS and ITAS2010 (p = 0.004) or Kerr criteria (p < 0.001). According to ITAS2010, thirty-four of 71 patients with TA were clinically inactive. Assessment of 34 TA patients with clinically inactive disease yielded 11 CEUS scans that showed active lesions (visual grade ≥ 2) in the left or right carotid artery. In 22 cases that underwent CEUS and FDG-PET, 12 were active and 10 were inactive on the basis of ITAS2010. Moreover, bilateral carotid CEUS vascularization score positively correlated with vascular FDG uptake in these patients with TA (p = 0.004). When vascular inflammation was defined as FDG uptake with visual grade ≥ 2, carotid CEUS showed sensitivity of 100% and specificity of 80%.

CONCLUSION

For TA patients with clinically inactive disease, CEUS could help clinicians to identify active lesions in the carotid vascular region. Carotid CEUS may be a rapid and cost-effective imaging tool in the followup of patients with TA.

Tocilizumab as an add-on therapy to glucocorticoids during the first 3 months of treatment of Giant cell arteritis: A prospective study

BACKGROUND

The aim of this study was to evaluate tocilizumab (TCZ) as an add-on therapy to glucocorticoids (GC) during the first 3 months of treatment of giant cell arteritis (GCA).

METHODS

GCA patients, as defined by ≥3/5 ACR criteria and positive temporal artery biopsy (TAB) or angio-CT-scan or PET-scan-proven aortitis, were included in this prospective open-label study. Prednisone was started at 0.7 mg/kg/day and then tapered according to a standardized protocol. All patients received four infusions of TCZ (8 mg/kg/4 weeks) after inclusion. The primary endpoint was the percentage of patients in remission with ≤0.1 mg/kg/day of prednisone at week 26 (W26). Patients were followed for 52 weeks and data prospectively recorded.

RESULTS

Twenty patients with a median (IQR) age of 72 (69-78) years were included. TAB were positive in 17/19 (90%) patients and 7/16 (44%) had aortitis. Remission was obtained in all cases. At W26, 15 (75%) patients met the primary endpoint. Ten patients experienced relapse during follow-up, mainly patients with aortitis (P = 0.048), or CRP >70 mg/L (P = 0.036) or hemoglobin ≤10 g/dL (P = 0.015) at diagnosis. Among 64 adverse events (AE) reported in 18 patients, three were severe and 30, mostly non-severe infections (n = 15) and hypercholesterolemia (n = 8), were imputable to the study.

CONCLUSION

This study shows that an alternative strategy using a short-term treatment with TCZ can be proposed to spare GC for the treatment of GCA. However, 50% of patients experienced relapse during the 9 months following TCZ discontinuation, especially patients with aortitis, or CRP > 70 mg/L or Hb ≤ 10 g/dL at diagnosis.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01910038).

Giant cell arteritis: beyond temporal artery biopsy and steroids

Giant cell arteritis is the most common primary vasculitis of the elderly. The acute complications of untreated giant cell arteritis, such as vision loss or occasionally stroke, can be devastating. The diagnosis is, however, not altogether straightforward due to variable sensitivities of the temporal artery biopsy as a reference diagnostic test. In this review, we discuss the increasing role of imaging in the diagnosis of giant cell arteritis. Glucocorticoid treatment is the backbone of therapy, but it is associated with significant adverse effects. A less toxic alternative is required. Conventional and novel immunosuppressive agents have only demonstrated modest effects in a subgroup of steroid refractory Giant cell arteritis due to the different arms of the immune system at play. However, recently a study of interleukin-6 blockade demonstrated benefits of giant cell arteritis. The current status of these immunosuppressive agents and novel therapies are also discussed in this review.

EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice

To develop evidence-based recommendations for the use of imaging modalities in primary large vessel vasculitis (LVV) including giant cell arteritis (GCA) and Takayasu arteritis (TAK). European League Against Rheumatism (EULAR) standardised operating procedures were followed. A systematic literature review was conducted to retrieve data on the role of imaging modalities including ultrasound, MRI, CT and [18F]-fluorodeoxyglucose positron emission tomography (PET) in LVV. Based on evidence and expert opinion, the task force consisting of 20 physicians, healthcare professionals and patients from 10 EULAR countries developed recommendations, with consensus obtained through voting. The final level of agreement was voted anonymously. A total of 12 recommendations have been formulated. The task force recommends an early imaging test in patients with suspected LVV, with ultrasound and MRI being the first choices in GCA and TAK, respectively. CT or PET may be used alternatively. In case the diagnosis is still in question after clinical examination and imaging, additional investigations including temporal artery biopsy and/or additional imaging are required. In patients with a suspected flare, imaging might help to better assess disease activity. The frequency and choice of imaging modalities for long-term monitoring of structural damage remains an individual decision; close monitoring for aortic aneurysms should be conducted in patients at risk for this complication. All imaging should be performed by a trained specialist using appropriate operational procedures and settings. These are the first EULAR recommendations providing up-to-date guidance for the role of imaging in the diagnosis and monitoring of patients with (suspected) LVV.

Clinical value of [18F]FDG-PET/CT and 3D-black-blood 3T-MRI for the diagnosis of large vessel vasculitis and single-organ vasculitis of the aorta

BACKGROUND

We aimed to investigate the clinical value of a 3D-T1w turbo-spin-echo (TSE) sequence and [18F]fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG-PET/CT) for the diagnosis of active large vessel vasculitis (LVV) and single-organ vasculitis (SOV) of the aorta.

METHODS

Twenty-four patients with suspected vasculitis who underwent MRI and PET/CT were retrospectively evaluated. MRI was analyzed for concentric contrast enhancement and wall thickening, and flow artifact intensity (4-point-scales). PET/CT analysis comprised qualitative, quantitative and semiquantitative methods. Imaging findings were correlated with final diagnosis derived from the clinical follow-up data.

RESULTS

Fifteen of 24 patients had a clinically confirmed active vasculitis, two had inactive vasculitis and 7 no vasculitis. [18F]FDG-PET/CT and 3D-T1w TSE-MRI revealed both a high diagnostic accuracy of 88% and 83%, respectively. In patients in whom both PET/CT and MRI showed concordant findings (19 patients), the accuracy increased to 95% with a high positive predictive value (92%) and negative predictive value (100%); thus, a correct diagnosis was obtained in 18 of 19 patients. Among the five patients with discordant findings PET/CT correctly identified the two patients without active vasculitis while rated false positive on MRI. Of the three remaining patients with active vasculitis, two were correctly identified by MRI and one by PET/CT.

CONCLUSIONS

3D-T1w TSE-MRI and [18F]FDG-PET/CT are both useful in the diagnosis of active vasculitis with high diagnostic accuracies. The diagnostic accuracy was even optimized by combining the two analysis methods. Therefore, there might be substantial potential for the application of whole-body hybrid PET/MRI in the evaluation of vasculitis in future studies.

The Expanding Role of Imaging in Systemic Vasculitis

Various imaging modalities, including color duplex ultrasonography, CT angiography, magnetic resonance angiography, and PET, are emerging as important aids to the diagnosis, staging, evaluation of disease activity and response to treatment in systemic vasculitis. Although large-vessel vasculitis is the main target of imaging, refinement and increasing accuracy of imaging modalities are also providing useful information in the evaluation of medium-vessel and small-vessel vasculitis.

Giant cell arteritis

Giant cell arteritis (GCA) is the most common vasculitis of the elderly. The diagnosis can be challenging at times because of the limitation of the American Rheumatology Association (ARA) classification criteria and the significant proportion of biopsy-negative patients with GCA. We discuss the role of advanced imaging techniques, including positron emission tomography (PET) scanning, in establishing diagnosis and improved histopathology techniques to improve the sensitivity of temporal artery biopsy. There have been significant advances in the understanding of the pathogenesis of GCA, particularly the role of cytokine pathways such as the interleukins, IL-6-IL-17 axis, and the IL-12-interferon-γ axis and their implication for new therapies. We highlight that glucocorticoids remain the primary treatment for GCA, but recognize the risk of steroid-induced side effects. A number of pharmacotherapies to enable glucocorticoid dose reduction and prevent relapse have been studied. Early diagnosis and fast-track pathways have improved outcomes by encouraging adherence to evidence-based practice.

Effect of glucocorticoid treatment on computed tomography angiography detected large-vessel inflammation in giant-cell arteritis. A prospective, longitudinal study

Computed tomography angiography (CTA) detects signs of large-vessel vasculitis (LVV) in about 67.5% of patients with giant-cell arteritis (GCA) at the time of diagnosis and early aortic dilatation in 15%. The outcome of CTA-findings of LVV upon glucocorticoid treatment has not been prospectively evaluated. The aim of our study was to prospectively assess glucocorticoid-induced changes in CTA findings of LVV in patients with GCA. Forty biopsy-proven GCA patients evaluated by CTA at diagnosis were prospectively followed and scheduled a new CTA approximately after 1 year of treatment. Vessel wall thickening, diameter, and contrast enhancement of the aorta and its tributaries were evaluated. Results were compared to those obtained at the time of diagnosis. CTA was repeated to 35 patients after a median follow-up of 13.5 months (IQ25-75% 12.4-15.8). Arterial wall thickening was still present in 17 patients (68% of the patients who initially had LVV). The number of affected segments and wall thickness at various aortic segments significantly decreased and no patients developed new lesions, new aortic dilation or increase in previous dilation. Contrast enhancement disappeared in 15 (93.75%) of 16 patients in whom this finding could be assessed. Signs of LVV improve with treatment. While contrast enhancement resolves in the majority of patients, vessel wall thickening persists in two thirds. However, the number of affected aortic segments as well as aortic wall thickness significantly decreases. Longer follow-up is necessary to determine the clinical significance of persisting wall thickening and its relationship with relapses or subsequent development of aortic dilatation or large-vessel stenoses.