Imaging modalities for the diagnosis and disease activity assessment of Takayasu's arteritis: A systematic review and meta-analysis

Application of the 2022 ACR/EULAR criteria for Takayasu arteritis to previously diagnosed patients based on the 1990 ACR criteria

OBJECTIVES

Recently, a joint group of the American College of Rheumatology (ACR) and the European Alliance of Associations for Rheumatology (EULAR) proposed new criteria for Takayasu arteritis (TAK) (the 2022 ACR/EULAR criteria). This study applied the 2022 ACR/EULAR criteria to patients with previously diagnosed TAK based on the 1990 ACR criteria and investigated the concordance rate between the two criteria according to the four imaging modalities.

METHODS

This study reviewed the medical records of 179 patients who met the 1990 ACR criteria for TAK. The imaging modalities included conventional angiography, computed tomography angiography, fluorodeoxyglucose-positron emission tomography, and magnetic resonance angiography.

RESULTS

Regardless of the imaging modalities, the concordance rate between the two criteria was 85.5% when including all patients, whereas it increased to 98.1% when only patients aged ≤60 years were included. Among the four imaging modalities, computed tomography angiography exhibited the highest concordance rate between the two criteria (85.6%). The concordance rate among patients aged >60 years was 95.7%. Only one patient aged 50-60 years was reclassified as having both TAK and giant cell arteritis.

CONCLUSIONS

The concordance rate was 85.5% regardless of the imaging modalities and increased to 86.9% on simultaneous computed tomography angiography and fluorodeoxyglucose-positron emission tomography imaging.

Role and potential of 18F-fluorodeoxyglucose-positron emission tomography-computed tomography in large-vessel vasculitis: a comprehensive review

Large-vessel vasculitis (LVV) is a group of diseases characterized by inflammation of the aorta and its main branches, which includes giant cell arteritis (GCA), polymyalgia rheumatica (PMR), and Takayasu's arteritis (TAK). These conditions pose significant diagnostic and management challenges due to their diverse clinical presentations and potential for serious complications. 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG-PET-CT) has emerged as a valuable imaging modality for the diagnosis and monitoring of LVV, offering insights into disease activity, extent, and response to treatment. 18F-FDG-PET-CT plays a crucial role in the diagnosis and management of LVV by allowing to visualize vessel involvement, assess disease activity, and guide treatment decisions. Studies have demonstrated the utility of 18F-FDG-PET-CT in distinguishing between LVV subtypes, evaluating disease distribution, and detecting extracranial involvement in patients with cranial GCA or PMR phenotypes. Additionally, 18F-FDG-PET-CT has shown promising utility in predicting clinical outcomes and assessing treatment response, based on the correlation between reductions in FDG uptake and improved disease control. Future research should focus on further refining PET-CT techniques, exploring their utility in monitoring treatment response, and investigating novel imaging modalities such as PET-MRI for enhanced diagnostic accuracy in LVV. Overall, 18F-FDG-PET-CT represents a valuable tool in the multidisciplinary management of LVV, facilitating timely diagnosis and personalized treatment strategies to improve patient outcomes.

Real-World Biomarkers for Pediatric Takayasu Arteritis

Childhood-onset Takayasu arteritis (TA) is a rare, heterogeneous disease with limited diagnostic markers. Our objective was to identify and classify all candidates for biomarkers of TA diagnosis in children reported in the literature. A systematic literature review (PRISMA) of MEDLINE, EMBASE, Wiley Cochrane Library, ClinicalTrias.gov, and WHO ICTRP for articles related to TA in the pediatric age group between January 2000 and August 2023 was performed. Data on demographics, clinical features, laboratory measurements, diagnostic imaging, and genetic analysis were extracted. We identified 2026 potential articles, of which 52 studies (81% case series) met inclusion criteria. A total of 1067 TA patients were included with a peak onset between 10 and 15 years. Childhood-onset TA predominantly presented with cardiovascular, constitutional, and neurological symptoms. Laboratory parameters exhibited a low sensitivity and specificity. Imaging predominantly revealed involvement of the abdominal aorta and renal arteries, with magnetic resonance angiography (MRA) being the preferred imaging modality. Our review confirms the heterogeneous presentation of childhood-onset TA, posing significant challenges to recognition and timely diagnosis. Collaborative, multinational efforts are essential to better understand the natural course of childhood-onset TA and to identify accurate biomarkers to enhance diagnosis and disease management, ultimately improving patient outcomes.

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.

Molecular imaging of large vessel vasculitis

Large vessel vasculitis (LVV) affects mainly large arteries with giant cell arteritis (GCA) and Takayasu arteritis (TAK) being the two most frequent forms. Clinical symptoms can be non-specific, including headache, fatigue, weight loss, and change in vision. Untreated, LVV may also lead to serious complications such as blindness, aortic aneurysm and dissection. Therefore, rapid recognition of the disease leading to accurate diagnosis and appropriate treatment is essential. FDG-PET/CT imaging has emerged as a sensitive marker of active vascular inflammation and its use in the management of LVV is now integrated in guidelines. In this article, we will discuss the role of FDG-PET/CT for the diagnosis of LVV and monitoring of therapy, as well as review technical and interpretation parameters.

Multi-Modality Imaging in Vasculitis

Systemic vasculitides are a rare and complex group of diseases that can affect multiple organ systems. Clinically, presentation may be vague and non-specific and as such, diagnosis and subsequent management are challenging. These entities are typically classified by the size of vessel involved, including large-vessel vasculitis (giant cell arteritis, Takayasu's arteritis, and clinically isolated aortitis), medium-vessel vasculitis (including polyarteritis nodosa and Kawasaki disease), and small-vessel vasculitis (granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis). There are also other systemic vasculitides that do not fit in to these categories, such as Behcet's disease, Cogan syndrome, and IgG4-related disease. Advances in medical imaging modalities have revolutionized the approach to diagnosis of these diseases. Specifically, color Doppler ultrasound, computed tomography and angiography, magnetic resonance imaging, positron emission tomography, or invasive catheterization as indicated have become fundamental in the work up of any patient with suspected systemic or localized vasculitis. This review presents the key diagnostic imaging modalities and their clinical utility in the evaluation of systemic vasculitis.

Evaluation of intramural hematoma: a novel use of 18F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging

BACKGROUND

Aortic intramural hematoma (IMH) is one of the typical entities of acute aortic syndrome and probably accounts for 5-25% of all cases. The ulcer-like projections (ULP), which are described as a focal, blood-filled pouch protruding into the hematoma of the aortic wall, are regarded as one of the high-risk imaging features of IMH and may cause initial medical treatment failure and death.

CASE PRESENTATION

We present a case report of an acute type B IMH patient with impaired renal function and newly developed ULP in the acute phase. The 18F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (18F-FDG PET/MR) was performed to evaluate the condition of aortic hematoma. The 18F-FDG focal uptake along the aortic wall of the hematoma was normal compared to the background (SUVmax 2.17; SUVSVC 1.6; TBR 1.35). We considered the IMH stable in such cases and opted for medical treatment and watchful observation. Six months after discharge, the patient's recovery was satisfactory, and aortic remodeling was ideal.

CONCLUSIONS

The 18F-FDG PET/MR is a novel tool to evaluate the risk of IMH patients and thus provides information for therapy selection.

Hybrid PET/MRI of large vessel vasculitis : Radiation dose compared to PET/CT with view on cumulative effective dose

BACKGROUND

The diagnosis of large vessel vasculitis (LVV) is often challenging due to the various clinical appearances and the low prevalence. Hybrid imaging by positron emission tomography and computed tomography (PET/CT) is a highly relevant imaging modality for diagnostics and disease surveillance but may be associated with a significant amount of radiation dose especially in patients with complications.

OBJECTIVE

The aim of this retrospective analysis was to compare the image quality and impact of hybrid imaging methods PET/CT and PET/MRI on the potential for dose reduction.

METHODS

This retrospective single-center study included a cohort of 32 patients who were referred to PET/MRI for the evaluation of LVV, including graft infections and fever of unknown origin. This cohort was compared to a similar cohort of 37 patients who were examined with PET/CT in the same period. Mean radiation dose as well as image quality to establish a diagnosis were compared between the groups.

RESULTS

The mean radiation dose applied in PET/MRI was significantly lower when compared to PET/CT (mean 6.6 mSV vs. 31.7 mSV; p < 0.001). This effect was based on the partially multiphasic CT protocols. At the same time, diagnostic image quality using a 4-point scale showed similar results for both imaging modalities in the work-up of LVV.

CONCLUSION

With PET/MRI, the radiation exposure can be significantly reduced with similar image quality and diagnostic impact. Patients with LVV have a higher risk of receiving a clinically relevant cumulative effective dose (CED) and PET/MRI should be made available to them.

Chinese guideline for the diagnosis and treatment of Takayasu's arteritis (2023)

Takayasu's arteritis (TAK) is a chronic granulomatous inflammatory disease that involves aorta and its primary branches. It is characterized by wall thickening, stenosis/obliteration or aneurysm formation of the involved arteries. In order to standardize the diagnosis and treatment of TAK in China, a clinical practice guideline with an evidence-based approach is developed under the leadership of National Clinical Medical Research Center for Dermatologic and Immunologic Diseases (NCRC-DID). Eleven recommendations for 11 clinical questions that are important to the diagnosis and treatment of TAK are developed based on the latest evidence and expert opinions combined with real clinical practice in China.

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 feasibility of quantitative assessment of dynamic 18F-fluorodeoxyglucose PET in Takayasu's arteritis: a pilot study

PURPOSE

PET has been demonstrated to be sensitive for detecting active inflammation in Takayasu's arteritis (TAK) patients, but semi-quantitative-based assessment may be susceptible to various biological and technical factors. Absolute quantification via dynamic PET (dPET) may provide a more reliable and quantitative assessment of TAK-active arteries. The purpose of this study was to investigate the feasibility and efficacy of dPET in quantifying TAK-active arteries compared to static PET.

MATERIALS AND METHODS

This prospective study enrolled 10 TAK-active patients (fulfilled the NIH criteria) and 5 control participants from March to October 2022. One-hour dPET scan (all TAK and control participants) and delayed static PET scan at 2-h (all TAK patients) were acquired. For 1-h static PET, summed images from 50 to 60 min of the dPET were extracted. PET parameters derived from 1- and 2-h static PET including SUV (SUV1H and SUV2H), target-to-background ratio (TBR) (TBR1H and TBR2H), net influx rate (Ki), and TBRKi extracted from dPET were obtained. The detectability of TAK-active arteries was compared among different scanning methods using the generalized estimating equation (GEE) with a logistic regression with repeated measures, and the GEE with gamma distribution and log link function was used to evaluate the different study groups or scanning methods.

RESULTS

Based on the disease states, 5 cases of TAK were classified as untreated and relapsed, respectively. The SUVmax on 2-h PET was higher than that on 1-h PET in the untreated patients (P < 0.05). However, no significant differences were observed in the median SUVmax between 1-h PET and 2-h PET in the relapsed patients (P > 0.05). The TBRKi was significantly higher than both TBR1H and TBR2H (all P < 0.001). Moreover, the detectability of TAK-active arteries by dPET-derived Ki was significantly higher than 1-h and 2-h PET (all P < 0.001). Significant differences were observed in Kimax, SUVmax-1H, TBR1H, and TBRKi among untreated, relapsed, and control groups (all P < 0.05).

CONCLUSIONS

Absolute quantitative assessment by dPET provides an improved sensitivity and detectability in both visualization and quantification of TAK-active arteries. This elucidates the clinical significance of dPET in the early detection of active inflammation and monitoring recurrence.

2022 ACC/AHA guideline for the diagnosis and management of aortic disease: A report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

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.

Pathophysiology, Diagnosis, and Management of Takayasu Arteritis: A Review of Current Advances

Takayasu arteritis (TA) is a rare, chronic, inflammatory vasculitis that primarily affects large arteries, causing significant morbidity and mortality. This review provides an overview of the pathophysiology, diagnosis, and management of TA based on current advances in the field. TA is characterized by autoimmune-mediated inflammation, vascular remodeling, and endothelial dysfunction. The disease progresses through three stages (active, chronic, and healing phase) each presenting distinct clinical features. Diagnosis of TA can be challenging due to non-specific clinical manifestations and the lack of specific diagnostic tests. Various imaging modalities, such as angiography, ultrasound, and Doppler techniques, play a crucial role in the diagnosis of TA by visualizing arterial involvement and assessing disease extent. Management of TA involves a multidisciplinary approach, with disease-modifying anti-rheumatic drugs (DMARDs) as the cornerstone of medical therapy. Synthetic and biologic DMARDs are used to induce remission, control inflammation, and prevent complications. Non-pharmacologic interventions, such as resistance exercises and curcumin supplementation, show potential benefits. Invasive interventions, including endovascular therapy and open surgery, are used for managing vascular lesions. However, challenges remain in disease understanding and management, including the heterogeneity of disease presentation and the lack of standardized treatment guidelines. The future of TA management lies in precision medicine, utilizing biomarkers and molecular profiling to personalize treatment approaches and improve patient outcomes. Further research is needed to unravel the underlying mechanisms of TA and develop targeted therapies.

Role of 18F-FDG PET/CT in Large Vessel Vasculitis and Polymyalgia Rheumatica

Systemic vasculitides comprise a group of autoimmune diseases affecting blood vessels, including large vessel vasculitis (LVV) and medium-sized vessel vasculitis such as giant cell arteritis (GCA) and Takayasu arteritis (TAK). GCA frequently overlaps with polymyalgia rheumatica (PMR), a rheumatic inflammatory condition affecting bursae, tendons or tendon sheaths, and joints. ¹⁸F-FDG PET/CT plays an important role in the diagnostic work-up of GCA, PMR, and TAK and is increasingly used to monitor treatment response. This continuing education article provides up-to-date guidance on the role of ¹⁸F-FDG PET/CT in patients with LVV, medium-sized vessel vasculitis, and PMR. It provides a general introduction on the clinical presentation and challenges in the diagnostic work-up of LVV and medium-sized vessel vasculitis, with a focus on the 2 major LVV subtypes: GCA, including PMR, and TAK. Next, practice points to perform and interpret the results of ¹⁸F-FDG PET/CT are described in line with the published procedure recommendations. Furthermore, the diagnostic performance and its role for treatment monitoring are discussed, taking into account recent international recommendations for the use of imaging in LVV and medium-sized vessel vasculitis in clinical practice. This is illustrated by several clinically representative PET/CT scan examples. Lastly, knowledge of limitations and pitfalls is essential to understand the role of ¹⁸F-FDG PET/CT in LVV, medium-sized vessel vasculitis, and PMR. Challenges and opportunities, as well as future research and conclusions, are highlighted. Learning objectives provide up-to-date guidance for the role of ¹⁸F-FDG PET/CT in patients with suspected LVV, medium-sized vessel vasculitis, and PMR.

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.

18-Fluorodeoxyglucose positron emission tomography/computed tomography for large vessel vasculitis in clinical practice

Diagnosis, prognostic assessment, and monitoring disease activity in patients with large vessel vasculitis (LVV) can be challenging. Early recognition of LVV and treatment adaptation is essential because vascular complications (aneurysm, dilatations, ischemic complications) or treatment related side effects can occur frequently in these patients. 18-fluorodeoxyglucose positron emission tomography/computed tomography (2-[18F]FDG-PET/CT) is increasingly used to diagnose, follow, and evaluate treatment response in LVV. In this review, we aimed to summarize the current evidence on the value of 2-[18F]FDG-PET/CT for diagnosis, follow, and treatment monitoring in LVV.

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.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate. Structure: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Survey of the American Society of Neuroradiology Membership on the Use and Value of Extracranial Carotid Vessel Wall MRI

BACKGROUND AND PURPOSE

Extracranial vessel wall MRI (EC-VWI) contributes to vasculopathy characterization. This survey study investigated EC-VWI adoption by American Society of Neuroradiology (ASNR) members and indications and barriers to implementation.

MATERIALS AND METHODS

The ASNR Vessel Wall Imaging Study Group survey on EC-VWI use, frequency, applications, MR imaging systems and field strength used, protocol development approaches, vendor engagement, reasons for not using EC-VWI, ordering provider interest, and impact on clinical care was distributed to the ASNR membership between April 2, 2019, to August 30, 2019.

RESULTS

There were 532 responses; 79 were excluded due to minimal, incomplete response and 42 due to redundant institutional responses, leaving 411 responses. Twenty-six percent indicated that their institution performed EC-VWI, with 66.3% performing it ≤1-2 times per month, most frequently on 3T MR imaging, with most using combined 3D and 2D protocols. Protocols most commonly included pre- and postcontrast T1-weighted imaging, TOF-MRA, and contrast-enhanced MRA. Inflammatory vasculopathy (63.3%), plaque vulnerability assessments (61.1%), intraplaque hemorrhage (61.1%), and dissection-detection/characterization (51.1%) were the most frequent applications. For those not performing EC-VWI, the reasons were a lack of ordering provider interest (63.9%), lack of radiologist time/interest (47.5%) or technical support (41.4%) for protocol development, and limited interpretation experience (44.9%) and knowledge of clinical applications (43.7%). Reasons given by 46.9% were that no providers approached radiology with interest in EC-VWI. If barriers were overcome, 51.1% of those not performing EC-VWI indicated they would perform it, and 40.6% were unsure; 48.6% did not think that EC-VWI had impacted patient management at their institution.

CONCLUSIONS

Only 26% of neuroradiology groups performed EC-VWI, most commonly due to limited clinician interest. Improved provider and radiologist education, protocols, processing techniques, technical support, and validation trials could increase adoption.

Does [18F]F-FDG-PET/MRI add metabolic information to magnetic resonance image in childhood-onset Takayasu’s arteritis patients? A multicenter case series

Background

The observation that 2-deoxy-2[18F]fluoro-D-glucose-positron emission tomography/magnetic resonance imaging ([18F]F-FDG-PET/MRI) revealed high-grade arterial wall FDG uptake, without arterial wall thickening with contrast-enhancement, in a considerable number of c-TA patients in our previous study, encouraged us to compare patients with both PET and MR angiography (MRA) positives, with those with PET positive but MRA negative. Our aim was to evaluate the relevance of these two imaging modalities together.

Methods

A three-center cross-sectional study with 17 patients who fulfilled the EULAR/PRINTO/PReS criteria for c-TA and who underwent [18F]F-FDG-PET/MRI was previously performed. Herein we compared patients/vessels with positive PET (arterial wall 18F-FDG uptake higher than liver) and positive MRA (arterial wall thickening with contrast-enhancement)—group 1, with those with positive PET but negative MRA—group 2.

Results

Median disease duration of 17 c-TA patients was 10.4 years. Nine patients were classified as group 1 and six as group 2. Median of metabolic inflammatory volume (MIV) of all arterial segments was significantly higher in group 1 (2346 vs. 1177 cm3; p = 0.036). Fifty-four (19%) from 284 available arterial segments presented positive findings in vessel wall in one or both images. Positive findings were concordant between PET and MRA in only 13% arterial segments (group 1); most changes (28–59.6%) that were discordant between both images, were positive in PET and negative in MRA (group 2).

Conclusion

Our study demonstrated that [18F]F-FDG-PET/MRI added information about inflammation in vessel wall of c-TA patients. Prospective multicenter studies are needed in order to get solid data to guide immunosuppressive tapering and withdrawal.

Outcome Measures and Biomarkers for Disease Assessment in Takayasu Arteritis

Takayasu arteritis (TAK) is a less common large vessel vasculitis where histopathology of involved arteries is difficult to access except during open surgical procedures. Assessment of disease activity in TAK, therefore, relies on surrogate measures. Clinical disease activity measures such as the National Institutes of Health (NIH) score, the Disease Extent Index in TAK (DEI.TAK) and the Indian TAK Clinical Activity Score (ITAS2010) inconsistently associate with acute phase reactants (APRs). Computerized tomographic angiography (CTA), magnetic resonance angiography (MRA), or color Doppler Ultrasound (CDUS) enables anatomical characterization of stenosis, dilatation, and vessel wall characteristics. Vascular wall uptake of 18-fluorodeoxyglucose or other ligands using positron emission tomography computerized tomography (PET-CT) helps assess metabolic activity, which reflects disease activity well in a subset of TAK with normal APRs. Angiographic scoring systems to quantitate the extent of vascular involvement in TAK have been developed recently. Erythrocyte sedimentation rate and C-reactive protein have a moderate performance in distinguishing active TAK. Numerous novel biomarkers are under evaluation in TAK. Limited literature suggests a better assessment of active disease by combining APRs, PET-CT, and circulating biomarkers. Validated damage indices and patient-reported outcome measures specific to TAK are lacking. Few biomarkers have been evaluated to reflect vascular damage in TAK and constitute important research agenda.

The Treatment Dilemma of Arteriopathy in Takayasu Arteritis- A State-of-the-Art Approach

Takayasu Arteritis (TA) is a chronic idiopathic granulomatous pan-arteritis affecting the pulmonary artery, the aorta, and its principal derived branches. The majority of TA patients are female (82.9-97.0 percent). Due to the inflammatory character of the illness, arterial stenosis therapy must be treated differently than the atherosclerosis process. In this review paper, we outline a strategy using real-world challenging cases.

Advances in Takayasu arteritis: An Asia Pacific perspective

Takayasu Arteritis (TA) is a rare form of chronic granulomatous large vessel vasculitis that is more common in Asia compared to other parts of the world. There have been several developments in the field of Takayasu arteritis in relation to genetics, classification, clinical features, imaging, disease activity assessment and management and much of these works have been done in the Asia Pacific region. We will be discussing selected few in the current review.

Large-vessel vasculitis

Large-vessel vasculitis (LVV) manifests as inflammation of the aorta and its major branches and is the most common primary vasculitis in adults. LVV comprises two distinct conditions, giant cell arteritis and Takayasu arteritis, although the phenotypic spectrum of primary LVV is complex. Non-specific symptoms often predominate and so patients with LVV present to a range of health-care providers and settings. Rapid diagnosis, specialist referral and early treatment are key to good patient outcomes. Unfortunately, disease relapse remains common and chronic vascular complications are a source of considerable morbidity. Although accurate monitoring of disease activity is challenging, progress in vascular imaging techniques and the measurement of laboratory biomarkers may facilitate better matching of treatment intensity with disease activity. Further, advances in our understanding of disease pathophysiology have paved the way for novel biologic treatments that target important mediators of disease in both giant cell arteritis and Takayasu arteritis. This work has highlighted the substantial heterogeneity present within LVV and the importance of an individualized therapeutic approach. Future work will focus on understanding the mechanisms of persisting vascular inflammation, which will inform the development of increasingly sophisticated imaging technologies. Together, these will enable better disease prognostication, limit treatment-associated adverse effects, and facilitate targeted development and use of novel therapies.

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.

Vascular Imaging Techniques to Diagnose and Monitor Patients with Takayasu Arteritis: A Review of the Literature

Takayasu arteritis (TA) is a large vessel vasculitis that causes stenosis, occlusion, and sometimes the aneurysm of the aorta and its major branches. TA often occurs in young women, and because the symptoms are not obvious in the early stages of the disease, diagnosis is difficult and often delayed. In approximately 10% to 20% of patients, TA is reportedly complicated by ischemic stroke or transient ischemic attack. It is important to diagnose TA early and provide appropriate treatment to prevent complications from stroke. Diagnostic imaging techniques to visualize arterial stenosis are widely used in clinical practice. Even if no signs of cerebrovascular events are present at the time of the most recent evaluation of patients with TA, follow-up vascular imaging is important to monitor disease progression and changes in the cerebrovascular risk. However, the optimal imaging technique for monitoring of TA has not been established. Therefore, the purpose of this review is to describe newly available evidence on the usefulness of conventional imaging modalities (digital subtraction angiography, computed tomography angiography, magnetic resonance imaging/angiography, duplex ultrasound, and positron emission tomography) and novel imaging modalities (optical coherence tomography, infrared thermography, contrast-enhanced ultrasonography, and superb microvascular imaging) in the diagnosis and monitoring of TA.

Corticosteroid monotherapy for the management of Takayasu arteritis-a systematic review and meta-analysis

We evaluated clinical response, normalization of inflammatory markers, angiographic stabilization (primary outcomes), relapses and adverse events (secondary outcomes) in Takayasu arteritis (TAK) patients following corticosteroid monotherapy. MEDLINE, EMBASE, Web of Science, Scopus, Pubmed Central, Cochrane library, clinical trial databases and major international Rheumatology conferences were searched for studies reporting outcomes in TAK following corticosteroid monotherapy (without language/date restrictions). Risk ratios were calculated for controlled studies. Proportions were pooled for uncontrolled studies. Heterogeneity was assessed using I² statistic. Quality assessment of individual studies utilized the Newcastle-Ottawa scale. GRADE methodology ascertained certainty of individual outcomes across studies. Twenty-eight observational studies (1098 TAK) were identified. Twenty-three uncontrolled studies (580 TAK) were synthesized in meta-analysis. Clinical response was observed in 60% (95% CI 45-74%, 19 studies), normalization of inflammatory markers in 84% (95% CI 54-100%, 4 studies) and angiographic stabilization in 28% (95% CI 6-57%, 4 studies). Relapses occurred in 66% (95% CI 18-99%, 4 studies). Adverse events were reported in 51% (95% CI 2-99%, 4 studies). All pooled estimates had considerable heterogeneity, unexplained by subgroup analyses (time period, geographic location or number of patients). Two studies reported lesser restenosis following vascular surgery and fewer relapses when corticosteroids were combined with immunosuppressants compared with corticosteroid monotherapy. All outcomes had very low certainty. While corticosteroid monotherapy induces clinical response in most TAK patients, angiographic stabilization is observed in fewer than one-third. Most patients relapse following corticosteroid withdrawal. Preliminary evidence supports up-front addition of immunosuppressants to retard angiographic progression and reduce relapses (PROSPERO identifier CRD42021242910).

Application progress of multiple imaging modalities in Takayasu arteritis

Takayasu arteritis (TA) is a chronic, idiopathic, granulomatous large vessel vasculitis of unknown etiology. The clinical manifestations of TA are incredibly variable, mainly depending on the location of the lesions. In the light of its insidious progress and the diversity of clinical manifestations, a substantial proportion of patients might experience a considerable delay in diagnosis, which leads to irreversible malignant complications, highlighting the importance of early diagnosis. There has been accumulating evidence that early identification of disease is pivotal to initiate timely therapy and ameliorate the prognosis. Therefore, this review discusses and summarizes the latest evidence on the application progress of multiple imaging modalities.

Multimodality Imaging of Large Vessel Vasculitis, From the AJR Special Series on Inflammation

Large vessel vasculitis (LVV) is a non-infectious inflammation of the large vessels, including the aorta and its main branches. Imaging plays an essential role in diagnosing LVV, given the challenges of tissue biopsy. This article reviews the types of LVV, and the multimodality imaging tools available to establish the diagnosis in patients with LVV. The cornerstone of imaging diagnosis is morphologic assessment using grey-scale ultrasound, combined grey-scale US with color Doppler US, CTA, or MRA. In the last decade, substantial progress has been made in functional and molecular imaging with FDG PET/CT for the diagnosis of LVV. Investigation is ongoing to develop novel MRA techniques and new PET tracers to assess disease activity and to differentiate the various vasculitides. An algorithm is provided to guide imaging technique selection based on the patient's specific clinical presentation.

Tocilizumab in refractory Caucasian Takayasu's arteritis: a multicenter study of 54 patients and literature review

Objective:

To assess the efficacy and safety of tocilizumab (TCZ) in Caucasian patients with refractory Takayasu’s arteritis (TAK) in clinical practice.

Methods:

A multicenter study of Caucasian patients with refractory TAK who received TCZ. The outcome variables were remission, glucocorticoid-sparing effect, improvement in imaging techniques, and adverse events. A comparative study between patients who received TCZ as monotherapy (TCZ_MONO) and combined with conventional disease modifying anti-rheumatic drugs (cDMARDs) (TCZ_COMBO) was performed.

Results:

The study comprised 54 patients (46 women/8 men) with a median [interquartile range (IQR)] age of 42.0 (32.5–50.5) years. TCZ was started after a median (IQR) of 12.0 (3.0–31.5) months since TAK diagnosis. Remission was achieved in 12/54 (22.2%), 19/49 (38.8%), 23/44 (52.3%), and 27/36 (75%) patients at 1, 3, 6, and 12 months, respectively. The prednisone dose was reduced from 30.0 mg/day (12.5–50.0) to 5.0 (0.0–5.6) mg/day at 12 months. An improvement in imaging findings was reported in 28 (73.7%) patients after a median (IQR) of 9.0 (6.0–14.0) months. Twenty-three (42.6%) patients were on TCZ_MONO and 31 (57.4%) on TCZ_COMBO: MTX (n = 28), cyclosporine A (n = 2), azathioprine (n = 1). Patients on TCZ_COMBO were younger [38.0 (27.0–46.0) versus 45.0 (38.0–57.0)] years; difference (diff) [95% confidence interval (CI) = -7.0 (-17.9, -0.56] with a trend to longer TAK duration [21.0 (6.0–38.0) versus 6.0 (1.0–23.0)] months; diff 95% CI = 15 (-8.9, 35.5), and higher c-reactive protein [2.4 (0.7–5.6) versus 1.3 (0.3–3.3)] mg/dl; diff 95% CI = 1.1 (-0.26, 2.99). Despite these differences, similar outcomes were observed in both groups (log rank p = 0.862). Relevant adverse events were reported in six (11.1%) patients, but only three developed severe events that required TCZ withdrawal.

Conclusion:

TCZ in monotherapy, or combined with cDMARDs, is effective and safe in patients with refractory TAK of Caucasian origin.

Diagnostic Approaches for Large Vessel Vasculitides

The large vessel vasculitides comprise giant cell arteritis (GCA), Takayasu arteritis (TAK), and chronic periaortitis. The diagnostic approach to these conditions involves the correct use and interpretation of clinical criteria, imaging techniques, and, in case of GCA, temporal artery biopsy. Ultrasound, magnetic resonance imaging (MRI), and computed tomography (CT) reveal a homogeneous, concentric, thickening of the arterial wall. MRI and CT may also reveal aneurysms and stenoses. 18F-Fluorodeoxyglucose (FDG)-PET shows increased FDG uptake of inflamed artery walls delineating increased metabolic activity. Ultrasound, FDG-PET, and MRI are the recommended imaging techniques in GCA and TAK. In patients with a high suspicion of GCA who present with visual disturbances, initiation of high-dose intravenous corticosteroids should not be delayed by imaging. Extracranial large vessel vasculitis may be confirmed by all three modalities, particularly by FDG-PET in case of atypical clinical pictures. In this article, we review the role of the GCA and TAK ACR classification criteria, temporal artery biopsy, conventional angiography, ultrasound, MRI, magnetic resonance angiography (MRA), CT angiography (CTA), and FDG-PET in the diagnostic approach of large vessel vasculitis.

Diagnostic value of [18F]FDG-PET/CT for treatment monitoring in large vessel vasculitis: a systematic review and meta-analysis

PURPOSE

Monitoring disease activity in patients with large vessel vasculitis (LVV) can be challenging. [18F]FDG-PET/CT is increasingly used to evaluate treatment response in LVV. In this systematic review and meta-analysis, we aimed to summarize the current evidence on the value of [18F]FDG-PET/CT for treatment monitoring in LVV.

METHODS

PubMed/MEDLINE and the Cochrane library database were searched from inception through October 21, 2020. Studies containing patients with LVV (i.e. giant cell arteritis, Takayasu arteritis and isolated aortitis) that received treatment and underwent [18F]FDG-PET/CT were included. Screening, full-text review and data extraction were performed by 2 investigators. The risk of bias was examined with the QUADAS-2 tool. Meta-analysis of proportions and diagnostic test accuracy was performed by a random-effects model and bivariate model, respectively.

RESULTS

Twenty-one studies were included in the systematic review, of which 8 studies were eligible for meta-analysis. Arterial [18F]FDG uptake decreased upon clinical remission in longitudinal studies. High heterogeneity (I² statistic 94%) precluded meta-analysis of the proportion of patients in which the scan normalized during clinical remission. Meta-analysis of cross-sectional studies indicated that [18F]FDG-PET/CT may detect relapsing/refractory disease with a sensitivity of 77% (95%CI 57-90%) and specificity of 71% (95%CI 47-87%). Substantial heterogeneity was observed among the cross-sectional studies. Both variation in clinical aspects and imaging procedures contributed to the heterogeneity.

CONCLUSION

Treatment of LVV leads to reduction of arterial [18F]FDG uptake during clinical remission. [18F]FDG-PET/CT has moderate diagnostic accuracy for detecting active LVV. [18F]FDG-PET/CT may aid treatment monitoring in LVV, but its findings should be interpreted in the context of the clinical suspicion of disease activity. This study underlines the relevance of published procedural recommendations for the use of [18F]FDG-PET/CT in LVV.

ACR Appropriateness Criteria® Nontraumatic Aortic Disease

Nontraumatic aortic disease can be caused by a wide variety of disorders including congenital, inflammatory, infectious, metabolic, neoplastic, and degenerative processes. Imaging examinations such as radiography, ultrasound, echocardiography, catheter-based angiography, CT, MRI, and nuclear medicine examinations are essential for diagnosis, treatment planning, and assessment of therapeutic response. Depending upon the clinical scenario, each of these modalities has strengths and weaknesses. Whenever possible, the selection of a diagnostic imaging examination should be based upon the best available evidence. 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. The purpose of this document is to assist physicians select the most appropriate diagnostic imaging examination for nontraumatic aortic diseases.

Systemic vasculitides and the role of multitechnique imaging in the diagnosis

Vasculitis, a systemic disease characterised by inflammation of the blood vessels, remains challenging to diagnose and manage. Vessel size has been the basis for classifying systemic vasculitides. Imaging plays a vital role in diagnosing this challenging disease. This review article aims (a) to summarise up-to-date literature in this field, as well as include classification updates and (b) to review available imaging techniques, recent advances, and emphasis on imaging findings to diagnose large vessel vasculitides.

IS PET/MRI A RELIABLE TOOL FOR DETECTING VASCULAR ACTIVITY IN TREATED CHILDHOOD-ONSET TAKAYASU'S ARTERITIS (C-TA)? A MULTICENTER STUDY

OBJECTIVES

To assess whether 18F-fluordeoxiglucose-positron emission tomography/magnetic resonance imaging (18F-FDG-PET/MRI) with angiographic sequences can contribute to detecting vessel wall inflammation in patients with childhood-onset Takayasu's arteritis (c-TA) under immunosuppressive therapy.

METHODS

Three-centre cross-sectional study was conducted. 18F-FDG-PET/MRI scans were performed in c-TA patients and in oncologic patients, who served as the control group. Clinical and laboratorial characteristics were also analysed.

RESULTS

Seventeen c-TA patients (65% females) between the ages of 6 and 21 years, mean disease duration of 9.4 years were recruited. Only one patient presented clinical disease activity, and six (35.6%) had increased erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP) levels. The most frequent magnetic resonance angiography (MRA) findings were stenosis and thickening, observed in 82.4% and 70.6% of c-TA patients, respectively. 18F-FDG-PET revealed 18F-FDG uptake higher than the liver in at least one arterial segment in 15 (88.2%) patients in a qualitative analysis and median standardized uptake value (SUVmax) of 3.22 (2.76-3.69) in a semi-quantitative analysis. c-TA patients presented significantly higher SUVmax than oncologic patients (p < 0.001). A positive correlation between SUVmax and CRP levels (Rho=0.528; p=0.029) was evidenced.

CONCLUSION

A state-of-the-art imaging modality was used in c-TA patients and revealed a strong arterial FDG uptake even in patients in apparent remission. We suppose that this finding may represent a silent activity in the vessel wall; however, we cannot exclude the possibility of arterial remodelling. Importantly, a negative imaging scan may help in immunosuppression withdrawal in daily clinical practice.

Detection of mural inflammation with low b-value diffusion-weighted imaging in patients with active Takayasu Arteritis

OBJECTIVES

To evaluate the performance of low b-value diffusion-weighted imaging (DWI) for detection of inflamed vessels in active Takayasu arteritis (TA).

METHODS

Forty patients with active TA involving the thoracic aorta and its super-aortic branches underwent low b-value (50 s/mm²) DWI, T2-weighted imaging (T2WI), and delayed enhancement T1-weighted imaging (DEI). Corresponding images on these 3 sequences at the same diseased level were evaluated qualitatively and quantitatively using Friedman and Kruskal-Wallis test, and the agreement between them in detection of inflamed vessels was assessed using Cochran's Q test.

RESULTS

The overall image quality of DEI, DWI, and T2WI was scored 7.97 ± 1.15, 7.32 ± 1.73, and 6.51 ± 1.69 respectively. The score of DEI and DWI was higher than that of T2WI (p < 0.001). The quality of blood suppression was rated higher in DWI than T2WI and DEI (p < 0.001). Both the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the diseased vessel walls measured on DEI and DWI were significantly higher than those on T2WI (p < 0.001). However, there was no significant difference in SNR and CNR between DEI and DWI (p = 0.283 and 0.063). In detection of mural inflammation, significant advantage was observed when comparing the findings from DEI/DWI to those from T2WI (p < 0.001). But no significant difference was found between the findings of DWI and DEI (p > 0.99).

CONCLUSIONS

Low b-value DWI may be used as a promising alternative to DEI for detecting inflamed vessels in active TA.

KEY POINTS

• Currently, the most widely used imaging modality in detection of mural inflammation is contrast-enhanced MRI. • Low b-value DWI is shown comparable to contrast-enhanced MRI and superior to T2WI in identifying mural inflammation in patients with active Takayasu arteritis. • Low b-value DWI is a fast and unenhanced MRI technique which may potentially replace contrast-enhanced MRI in identifying disease activity of Takayasu arteritis.

Evaluation of tocilizumab for intractable Takayasu arteritis and 18F-fluorodeoxyglucose-positron emission tomography for detecting inflammation under tocilizumab treatment

BACKGROUND

Although high-dose glucocorticoids are effective in suppressing active inflammation of Takayasu arteritis (TAK), many patients experience relapse during tapering of glucocorticoids. Recently, the interleukin-6 receptor antibody, tocilizumab (TCZ), was reported to be effective for steroid-resistant TAK. However, there are no objective ways of diagnosing TAK recurrence because TCZ suppresses inflammatory biomarkers.

OBJECTIVES

To investigate the efficacy of TCZ at 1-year follow-up and of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography for detection of recurrence of inflammation during TCZ treatment.

METHODS AND RESULTS

We treated 19 patients with refractory TAK with TCZ. TCZ was discontinued in 2 cases because of side effects. Abatement of arteritis symptoms along with reduction of glucocorticoid dosage was achieved in 12 patients, resulting in a remission induction rate of 70.6%. The dosage of glucocorticoid was reduced from 16.1 ± 10.2 mg to 3.8 ± 1.7 mg at 1 year (p<0.001) in these patients. In the remaining 5 patients, glucocorticoid tapering led to exacerbation of symptoms and glucocorticoid dose had to be increased. FDG-PET scan results closely matched clinical course in all 5 patients with recurrence even during TCZ treatment, while the scan was negative for the remaining 12 patients.

CONCLUSIONS

TCZ injection provides robust steroid-sparing effect and improvement of inflammation without significant adverse effects. Recurrence of inflammation can be detected by FDG-PET even during TCZ treatment.

Large vessel vasculitis: imaging standards of 18F-FDG PET/CT

Improvements in positron emission tomography (PET) technology have contributed to increased diagnostic accuracy in patients with large-vessel vasculitis (LVV) over the last decades. Many systematic reviews and meta-analyses were conducted, and earlier diagnosis by ¹⁸F-FDG PET can be made in patients suspected of having LVV. Two subtypes, Takayasu arteritis and giant cell arteritis, will progress when poorly responding to corticosteroids and augmented immunosuppression. In most patients, disease activity cannot be monitored by laboratory tests alone; therefore, glucose metabolism may be a source for possible biomarkers. In this review, we present current concepts regarding ¹⁸F-FDG PET/CT imaging standards.

Carotid contrast-enhanced ultrasonographic assessment of disease activity in Takayasu arteritis

AIMS

To investigate the usefulness of carotid contrast-enhanced ultrasound (CEUS) in assessment of disease activity in patients with Takayasu arteritis (TA).

METHODS AND RESULTS

After screening 219 CEUS records from 124 consecutive patients followed at our clinic between October 2014 and May 2018, data were analysed from 159 carotid CEUS from 86 patients diagnosed with Type I TA. Patients were categorized based on disease activity according to National Institutes of Health criteria into two groups: active disease group (92 CEUS) and non-active disease group (67 CEUS). The enhanced intensity of carotid artery wall: (i) was higher in active disease group than in non-active disease group (3.09 ± 1.67 dB vs. 1.44 ± 1.29 dB, P < 0.0001, respectively); and (ii) had a high predictive value for TA disease activity with area under the curve (AUC) of 86.3% [95% confidence interval (CI) 79.7-92.9], sensitivity of 88.0%, and specificity of 79.1%. The latter AUC was not significantly affected (P > 0.05) when erythrocyte sedimentation rate, C-reactive protein level, or arterial wall thickness were added to assessment of disease activity in TA.

CONCLUSION

Carotid vascularization by CEUS, as sole inflammatory marker, had a high predictive value for disease activity in Type I TA.

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.