The role of 18F-FDG PET/CT in large-vessel vasculitis: appropriateness of current classification criteria?

Isolated Coronary Arteritis Treated With FDG-PET/CT-Guided Immunosuppressant to Break the Vicious Cycle of In-Stent Restenosis

Recurrent in-stent restenosis of the coronary artery is a rare but intractable problem. In this situation, coronary arteritis should be considered as an etiology. This case highlights the use of immunosuppressive drugs, including tocilizumab, and follow-up F-18-fluorodeoxyglucose positron emission tomography/computed tomography to break the vicious circle of recurrent stenosis caused by isolated coronary arteritis of unknown cause.

Isolated Coronary Arteritis in Adults: a Single-Center Experience from China

Isolated coronary arteritis (ICA) is an extremely rare and life-threatening vasculitis with only a limited number of reports in the literature. We retrospectively reviewed the clinical data of 10 ICA patients in our center from 2012 to 2022 and compared them with patients with Takayasu arteritis who presented with coronary arteritis initially (TAK-CA patients). We found that ICA predominantly affected women and most commonly involved the ostium and the proximal segment of the coronary arteries, causing mainly stenotic lesions. The C-reactive protein and erythrocyte sedimentation rate were grossly normal and significantly lower than those of TAK-CA patients (p = 0.027, p = 0.009, respectively). Intravascular ultrasound imaging showed superiority in differentiating coronary vasculitis from atherosclerosis. Restenosis of the coronary arteries occurred rapidly if not treated promptly and appropriately. Systemic glucocorticoid combined with immunosuppressive agents, especially cyclophosphamide, was a promising strategy for treating ICA.

Development of a simple standardized scoring system for assessing large vessel vasculitis by 18F-FDG PET-CT and differentiation from atherosclerosis

PURPOSE

This study is to develop a structured approach to distinguishing large-artery vasculitis from atherosclerosis using 18-fluorodeoxyglucose positron emission tomography combined with low-dose computed tomography (FDG PET/CT).

METHODS

FDG PET/CT images of 60 patients were evaluated, 30 having biopsy-proven giant cell arteritis (GCA; the most common form of large-artery vasculitis), and 30 with severe atherosclerosis. Images were evaluated by 12 nuclear medicine physicians using 5 criteria: FDG uptake pattern (intensity, distribution, circularity), the degree of calcification, and co-localization of calcifications with FDG-uptake. Criteria that passed agreement, and reliability tests were subsequently analysed for accuracy using receiver operator curve (ROC) analyses. Criteria that showed discriminative ability were then combined in a multi-component scoring system. Both initial and final 'gestalt' conclusion were also reported by observers before and after detailed examination of the images.

RESULTS

Agreement and reliability analyses disqualified 3 of the 5 criteria, leaving only FDG uptake intensity compared to liver uptake and arterial wall calcification for potential use in a scoring system. ROC analysis showed an area under the curve (AUC) of 0.90 (95%CI 0.87-0.92) for FDG uptake intensity. Degree of calcification showed poor discriminative ability on its own (AUC of 0.62; 95%CI 0.58-0.66). When combining presence of calcification with FDG uptake intensity into a 6-tiered scoring system, the AUC remained similar at 0.91 (95%CI 0.88-0.93). After exclusion of cases with arterial prostheses, the AUC increased to 0.93 (95%CI 0.91-0.95). The accuracy of the 'gestalt' conclusion was initially 89% (95%CI 86-91%) and increased to 93% (95%CI 91-95%) after detailed image examination.

CONCLUSION

Standardised assessment of arterial wall FDG uptake intensity, preferably combined with assessment of arterial calcifications into a scoring method, enables accurate, but not perfect, distinction between large artery vasculitis and atherosclerosis.

Diagnostics of atherosclerosis: Overview of the existing methods

Atherosclerosis was and remains an extremely common and serious health problem. Since the elderly are most at risk of cardiovascular risk, and the average life expectancy is increasing, the spread of atherosclerosis and its consequences increases as well. One of the features of atherosclerosis is its asymptomaticity. This factor makes it difficult to make a timely diagnosis. This entails the lack of timely treatment and even prevention. To date, in the arsenal of physicians, there is only a limited set of methods to suspect and fully diagnose atherosclerosis. In this review, we have tried to briefly describe the most common and effective methods for diagnosing atherosclerosis.

Altered glycosylation profiles of serum IgG in Takayasu arteritis

BACKGROUND

Takayasu arteritis (TAK) is an autoimmune inflammatory disorder with an undefined etiology. This study aimed to characterize the glycosylation profiles of serum immunoglobulin G (IgG) in patients with TAK.

METHODS

Lectin microarrays containing 56 types of lectins were used to detect the glycan levels of serum IgG in 164 patients with TAK, 128 patients with atherosclerosis used as disease controls (DCs), and 100 healthy controls (HCs). Differentially altered glycosylation patterns between TAK and control groups as well as between TAK subgroups were identified and further validated by lectin blot. The classification performance of the TAK-specific glycosylation change was measured by receiver-operating characteristic (ROC) curve analysis.

RESULTS

Lectin microarray analysis revealed significantly increased N-Acetylgalactosamine (GalNAc) levels in the TAK group compared to the DC and HC groups (all p < 0.01). For TAK subgroups, significantly decreased mannosylation was observed in patients with active TAK compared to patients with inactive disease (p < 0.01). These differences were validated by lectin blot. In addition, GalNAc levels exhibited a considerable potential for discriminating patients with TAK from patients with atherosclerosis, with an area under the curve of 0.749 (p < 0.001), a sensitivity of 71.7%, and a specificity of 73.8%.

CONCLUSIONS

Serum IgG in patients with TAK displayed disease-specific glycosylation alterations. Aberrant GalNAc glycosylation showed substantial value as a diagnostic biomarker. The potential proinflammatory properties of the abnormal glycans may provide new insights into the role of humoral immunity in the pathogenesis of TAK.

Inflammatory Diseases of the Aorta: JACC Focus Seminar, Part 2

Inflammatory aortitis is most often caused by large vessel vasculitis (LVV), including giant cell arteritis, Takayasu's arteritis, immunoglobulin G4-related aortitis, and isolated aortitis. There are distinct differences in the clinical presentation, imaging findings, and natural history of LVV that are important for the cardiovascular provider to know. If possible, histopathologic specimens should be obtained to aide in accurate diagnosis and management of LVV. In most cases, corticosteroids are utilized in the acute phase, with the addition of steroid-sparing agents to achieve disease remission while sparing corticosteroid toxic effects. Endovascular and surgical procedures have been described with success but should be delayed until disease control is achieved whenever possible. Long-term management should include regular follow-up with rheumatology and surveillance imaging for sequelae of LVV.

COVID-19 among patients with giant cell arteritis: a single-centre observational study from Slovenia

OBJECTIVES

Patients with giant cell arteritis (GCA) represent a fragile population with an increased infection risk. In a recent study, older age, a higher number of comorbidities, higher disease activity and prednisolone ≥ 10 mg/day were associated with worse COVID-19 outcome. We aimed to evaluate the frequency and severity of COVID-19 in a well-defined GCA cohort.

METHODS

We reviewed medical records of histologically and/or by imaging-proven GCA patients diagnosed between September 2011 and February 2020 at our secondary/tertiary centre and followed during the COVID-19 pandemic between March 2020 and February 2022 (24 months). Descriptive statistics were used to explore the studied population.

RESULTS

Of 314 patients with GCA diagnosed for the first time during a 102-month period, 49 patients died before March 2020. Of the remaining 265 patients, 55 (20.8%) patients suffered from a total of 57 SARS-CoV-2 infections. We observed 44 (77.2%) mild and 13 (22.8%) severe COVID-19 episodes (the latter defined as needing hospitalization, death or thrombotic complication). Patients with severe COVID-19 were more likely to have arterial hypertension (12 [92.3%] vs. 25 [56.8%]; p = 0.022), cardiovascular disease (7 [53.8%] vs. 10 [22.7%]; p = 0.043) or obesity (5 [38.5%] vs. 5 [11.4%]; p = 0.038). Neither prednisolone dose 1-5 mg/day (p = 0.483) nor leflunomide use (p = 1.000) was associated with COVID-19 course. There were no significant differences in sex, age, GCA type, GCA disease duration and other comorbidities in patients with mild and severe COVID-19 in our cohort.

CONCLUSION

More than a fifth of our GCA patients had severe COVID-19. Treatment with leflunomide or low doses of glucocorticoids were not associated with severe course in our cohort. Key Points • Treatment with leflunomide or low doses of glucocorticoids were not associated with worse COVID-19 outcome. • Outcomes of COVID-19 improved as the COVID-19 pandemic, prevention and treatment options evolved. • Arterial hypertension, cardiovascular disease or obesity were associated with severe COVID-19.

Clinical features and risk factors of intracranial artery disease in patients with Takayasu arteritis

OBJECTIVES

It has been known that aorta, subclavian, and extracranial arteries are commonly involved in Takayasu arteritis (TA). However, the involvement of intracranial artery in TA has not been well explored. The purpose of this study was to describe the clinical characteristics of intracranial artery lesions in TA patients and identify associated risk factors.

METHODS

A total of 160 patients diagnosed with TA at Beijing Anzhen Hospital from November 2012 to November 2019 were retrospectively enrolled in this study and assigned to different groups according to the presence or absence of intracranial artery lesions.

RESULTS

Our data showed that 20% of the enrolled 160 patients developed intracranial artery lesions and the right internal carotid artery (ICA) was the most common involved artery (53%). The average age of patients with intracranial artery lesions was significantly older compared to that of patients without intracranial artery involvement (43.56 ± 11.40 vs 36.41 ± 12.22, p = 0.003). In addition, more patients in the intracranial artery group had concomitant disease histories of stroke and/or hypertension (p = 0.010, 0.033). Chest tightness, chest pain, palpitation, coronary artery lesions, and extracranial segment lesions of ICA were more commonly observed in patients with intracranial artery lesions (p < 0.001, 0.017, 0.015, < 0.001, 0.003). Furthermore, we discovered that patients with coronary artery involvement, extracranial segment lesions of ICA, and higher Vasculitis Damage Index (VDI) score had an increased risk of developing intracranial artery lesions (p = 0.013, 0.019, 0.019).

CONCLUSION

Our study showed that the intracranial artery disease was common in TA and was associated with coronary artery lesions, extracranial segment lesions of ICA, and higher VDI score. Key Points • Intracranial artery disease in TA patients had advanced age and higher triglyceride level. • Besides coronary artery lesions, intracranial artery disease in TA patients was associated with the extracranial segment lesions of ICA and higher VDI score.

Carotid Artery Stenosis and Ischemic Strokes in Patients with Giant Cell Arteritis: A Characteristic Pattern-Literature Review and Case Report

Purpose  Ischemic stroke is a relatively rare complication of giant cell arteritis often accompanied by vessel stenosis. Our purpose was to compare the location of internal carotid artery stenosis in GCA patients by performing a literature review suggesting a specific and characteristic pattern. Methods  We performed a PubMed research including all articles and cited articles reporting cases and case series about giant cell arteritis patients with internal carotid artery stenosis and ischemic strokes. Results  In this case series 39 cases were included. We found a clear tendency of giant cell arteritis-related stenosis to be in the intracranial segments (35/39 (89.7%)). Only in 8/39 (20.5%) patients there was further involvement of extracranial segments. Many cases (27/39 [69.2%]) showed a bilateral involvement. Discussion  This literature review reveals a specific pattern of internal carotid artery involvement in patients with giant cell arteritis and ischemic strokes. To our knowledge this pattern has not been reported as a sign strongly pointing toward giant cell arteritis before. We have not found case reports mentioning other common types of vasculitis reporting this involvement pattern. Conclusion  Internal carotid artery stenosis and ischemic stroke is a rare complication in patients with giant cell arteritis. Considering the characteristic features of bilateral distal internal carotid artery stenosis giant cell arteritis should be suspected which potentially leads to an early diagnosis and immunotherapy.

Diffused coronary involvement in Takayasu arteritis with concomitant malignancy

Large vessel vasculitis (LVV) is composed of conditions in which inflammation of blood vessel walls affects mainly large arteries, such as the aorta and its main branches, and in some cases the coronary arteries. Coronary artery involvement in systemic vasculitis is associated with significant morbidity and mortality. We present a case of a young patient diagnosed with extensive coronary disease diagnosed as Takayasu arteritis, when whom a concomitant diagnosis of Hodgkin's lymphoma was made. The literature review revealed ten cases of malignancies associated with Takayasu arteritis. We discuss the complexity of the management of concurrent hematological malignancy with TAK and extensive coronary arteritis. This complicated and cross-disciplinary case also represents the pivotal importance of multi-disciplinary team decision in order to achieve the best clinical outcome of both disorders.

Vascular Uptake on 18F-FDG PET/CT During the Clinically Inactive State of Takayasu Arteritis Is Associated with a Higher Risk of Relapse

PURPOSE

To evaluate whether vascular uptake on ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) during the clinically inactive state of Takayasu arteritis (TAK) is associated with disease relapse.

MATERIALS AND METHODS

Patients with TAK who underwent ¹⁸F-FDG PET/CT during the clinically inactive state of the disease between 2006 and 2019 were included. Clinically inactive disease was defined as a status not fulfilling the National Institutes of Health (NIH) criteria for active disease in TAK. Relapse was defined as recurrence of clinically active disease after a clinically inactive period, requiring change in the treatment regimen. Vascular uptake on ¹⁸F-FDG PET/CT was assessed using target/background ratio (TBR), calculated as arterial maximum standardized uptake value (SUV)/mean SUV in venous blood pool. Multivariable Cox regression analysis was performed to identify factors associated with relapse.

RESULTS

A total of 33 patients with clinically inactive TAK were included. During a median observation period of 4.5 (0.9-8.1) years, relapse occurred in 9 (27.3%) patients at median 1.3 (0.7-6.9) years. Notably, TBR [1.5 (1.3-1.8) vs. 1.3 (1.1-1.4), p=0.044] was significantly higher in patients who relapsed than in those who did not. On multivariable Cox regression analysis, the presence of NIH criterion 2 [adjusted hazard ratio (HR): 7.044 (1.424-34.855), p=0.017] and TBR [adjusted HR: 11.533 (1.053-126.282), p=0.045] were significantly associated with an increased risk of relapse.

CONCLUSION

Vascular uptake on ¹⁸F-FDG PET/CT and the presence of NIH criterion 2 are associated with future relapse in patients with clinically inactive TAK.

Characterization of visual manifestations and identification of risk factors for permanent vision loss in patients with giant cell arteritis

BACKGROUND/PURPOSE

Permanent vision loss (PVL) is a feared complication and a leading cause of morbidity in giant cell arteritis (GCA). The objective of this study is to describe visual manifestations and identify risk factors of ocular involvement in GCA.

METHODS

A retrospective database from a single vasculitis referral center was used. Descriptive statistics comparing patients with and without ocular involvement were performed.

RESULTS

One hundred patients with GCA were included. Visual symptoms were present in 53% of patients at diagnosis and included blurred vision (30%), diplopia (16%), amaurosis fugax (14%), and blindness (19%). Out of 19 patients with blindness, 16 did not recover and had PVL. Patients with PVL were older (79.2 ± 6.7 vs 74.2 ± 7.6 years; p = 0.008) and more likely to have coronary artery disease (31% vs 10%; p = 0.018). However, they were less likely to have other cranial symptoms (81% vs 96%; p = 0.019), mainly headaches (64% vs 92%; p = 0.003). Risk factors associated with an abnormal ophthalmologic examination were the same as for PVL, but patients were also more likely to have diabetes (29% vs 7%; p = 0.040) and less likely to have constitutional symptoms (53% vs 80%; p = 0.033).

CONCLUSION

Patients with GCA and ocular involvement were more likely to have baseline diabetes and atherosclerosis. A predisposing vascular vulnerability might therefore increase the risk of ocular involvement. Key points • Most patients with GCA and complete vision loss at presentation will not recover and evolve to have permanent vision loss. • A GCA patient with visual manifestations at presentation has more baseline vascular risk factors (diabetes, atherosclerosis) than patients without ocular involvement. • Patients with GCA and visual manifestations have fewer constitutional symptoms and lower inflammatory markers than patients without ocular involvement.

Active Giant Cell Vasculitis Diagnosis with 68Ga PSMA PET/CT Imaging

Vasculitis is a multisystem disease characterized by inflammation with infiltration of leukocytes into the blood vessels. Giant cell arteritis (GCA) is the most common form of vasculitis that mostly affects medium- and large-sized arteries. ¹⁸Fluorine-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) is increasingly used to diagnose inflammation of large arteries in GCA. Galium-68 prostate-specific membrane antigen (PSMA) PET/CT has a vital role in the assessment of patients with prostate cancer for recurrence and metastasis of the disease. Various benign and non-prostate malignant conditions may give rise to increased PSMA uptake. Herein, we demonstrate that PSMA uptake can be seen in GCA.

The utility of PET/CT in large vessel vasculitis

18F-FDG PET/CT occupies a growing role in the diagnosis of large vessel vasculitis (LVV), illustrating enhanced uptake in the lining of large vessels. A retrospective single center study was conducted of patients who underwent 18F-FDG PET/CT scans between 2009 and 2019 at Sheba Medical Center, Israel. The imaging results were analyzed for evidence of LVV. We reviewed the PET/CT scans of 126 patients and identified 57 studies that either showed evidence of active LVV or that had been performed in patients previously treated for systemic vasculitis. In 6 patients with fevers of unknown origin and elevated inflammatory markers, PET/CT revealed LVV. Six of 13 patients previously treated for systemic vasculitis demonstrated persistent large vessel uptake. LVV was identified in 8 patients with other autoimmune diseases, and in 4 diagnosed with infectious aortitis. In 26 patients who underwent malignancy surveillance, PET/CT revealed more localized large vessel wall inflammation. Our results illustrate that PET/CT may identify large vessel wall inflammation in patients with a suspicion of LVV, and incidentally in patients who undergo malignancy surveillance. PET/CT may also help delineate the presence and extent of vessel inflammation in patients with LVV and in those with other autoimmune diseases.

Advances in Therapies and Imaging for Systemic Vasculitis

Vasculitis is a systemic disease characterized by immune-mediated injury of blood vessels. Current treatments for vasculitis, such as glucocorticoids and alkylating agents, are associated with significant side effects. Furthermore, the management of both small and large vessel vasculitis is challenging because of a lack of robust markers of disease activity. Recent research has advanced our understanding of the pathogenesis of both small and large vessel vasculitis, and this has led to the development of novel biologic therapies capable of targeting key cytokine and cellular effectors of the inflammatory cascade. In parallel, a diverse range of imaging modalities with the potential to monitor vessel inflammation are emerging. Continued expansion of combined structural and molecular imaging using positron emission tomography with computed tomography or magnetic resonance imaging may soon provide reliable longitudinal tracking of vascular inflammation. In addition, the emergence of radiotracers able to assess macrophage activation and immune checkpoint activity represents an exciting new frontier in imaging vascular inflammation. In the near future, these advances will allow more precise imaging of disease activity enabling clinicians to offer more targeted and individualized patient management.

Role of PET/CT in the Evaluation of Aortic Disease

Positron emission tomography (PET) /computed tomography (CT) has been established as a standard imaging modality in the evaluation of malignancy. Although PET/CT has played a major role in the management of oncology patients, its clinical use has also increased for various disorders other than malignancy. Growing evidence shows that PET/CT images have many advantages in aortic disease as well. This review article addresses the potential role of PET/CT in diseases involving the aorta, emphasizing its usefulness with regard to acute thoracic aortic syndromes, aortic aneurysm, atherosclerotic lesions, aortitis and aortic tumors.

Positron emission tomography and reframing vasculitis as a spectrum of disease when investigating a patient with a fever of unknown origin

A retired businessman presented to the infectious diseases department with a history of ongoing fevers and myalgia and raised inflammatory markers. This continued despite adequate antibiotic treatment of an epididymo-orchitis. Extensive investigations, including bone marrow and liver biopsies and a positron emission tomography, did not reveal a cause but showed reactive change in the bone marrow. Later, he developed a vasculitic rash and vision loss due to non-arteritic anterior ischaemic optic neuropathy. High-dose steroids were immediately initiated. A temporal artery biopsy was performed, which confirmed a healing large vessel vasculitis, possibly giant cell arteritis. He has responded very well to therapy. We must better appreciate the limitations of positron emission tomography in investigating a fever of unknown origin. The case also encourages awareness of autoimmune disorders as the leading category of causative diseases for this in older age groups.

Large-vessel giant cell arteritis: diagnosis, monitoring and management

GCA is a chronic, idiopathic, granulomatous vasculitis of medium and large arteries. It comprises overlapping phenotypes including classic cranial arteritis and extra-cranial GCA, otherwise termed large-vessel GCA (LV-GCA). Vascular complications associated with LV-GCA may be due, in part, to delayed diagnosis, highlighting the importance of early identification and prompt initiation of effective therapy. Advancements in imaging techniques, including magnetic resonance angiography, CT angiography, PET and colour duplex ultrasonography, have led to improvements in the diagnosis of LV-GCA; however, the role imaging modalities play in the assessment of disease activity and long-term outcomes remains unclear. Glucocorticoids are the mainstay of therapy in LV-GCA, but their prolonged use is associated with multiple, sometimes serious, adverse effects. Recent data suggest that biologic therapies, such as tocilizumab, may be effective and safe steroid-sparing options for patients with GCA. However, data specifically evaluating the management of LV-GCA are limited.

18F-Fluorodeoxyglucose Positron Emission Tomography-computed Tomography in Evaluation of Large Vessel Vasculitis

18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) is a rapidly evolving hybrid imaging technique in evaluation of infection and inflammation. Usually, functional changes often precede anatomical changes. 18F-FDG PET-CT, a noninvasive diagnostic test and it is useful for the early detection of inflammation. Most of the large vessel vasculitis patients present with nonspecific signs and symptoms, which are difficult to diagnose clinically. Here, we discuss three cases of large vessel vasculitis with different clinical presentations, identified by 18F-FDG PET-CT scan.

Optimal management of Cogan's syndrome: a multidisciplinary approach

Cogan's syndrome (CS) is a rare disorder characterized by nonsyphilitic interstitial keratitis (IK) and audio-vestibular symptoms. CS affects mainly young Caucasian adults, mostly during their first three decades of age, and may develop into typical and atypical variants. Typical CS manifests primarily with IK and hearing loss, whereas atypical CS usually presents with inflammatory ocular manifestations in association with audio-vestibular symptoms but mostly different Ménière-like symptoms and, more frequently, with systemic inflammation (70%), of which vasculitis is the pathogenic mechanism. CS is considered as an autoimmune- or immune-mediated disease supported mainly by the beneficial response to corticosteroids. Using well-developed assays, antibodies to inner ear antigens, anti-Hsp70, and antineutrophil cytoplasmic antibodies were found to be associated with CS. Corticosteroids represent the first line of treatment, and multiple immunosuppressive drugs have been tried with variable degrees of success. Tumor necrosis factor-alpha blockers and other biological agents are a recent novel therapeutic option in CS. Cochlear implantation is a valuable rescue surgical strategy in cases with severe sensorineural hearing loss unresponsive to intensive and/or innovative immunosuppressive regimens.

Metabolic Imaging as a Novel Strategy in Evaluation of Mycotic Abdominal Aortic Aneurysm: A Case Report and Brief Clinical Review

Abdominal aortic aneurysm (AAA) is an uncommon entity with high mortality. Etiologically, they are classified as inflammatory and infective (mycotic), the latter being less common. Clinical presentation, laboratory investigations, and treatment for these may considerably overlap. However, choice of management and the need for surgical intervention depends on factors such as size and progression of aneurysm, persistent symptoms, and presence or absence of distant pathology. Although computed tomography (CT) is the gold standard for AAA, in selected cases, especially in infected AAA, fluorodeoxyglucose positron emission tomography-CT can provide valuable information.

Positron Emission Tomography/Computerized Tomography in Newly Diagnosed Patients with Giant Cell Arteritis Who Are Taking Glucocorticoids

OBJECTIVE

Large vessel uptake on positron emission tomography/computerized tomography (PET/CT) supports the diagnosis of giant cell arteritis (GCA). Its value, however, in patients without arteritis on temporal artery biopsy and in those receiving glucocorticoids remains unknown. We compared PET/CT results in GCA patients with positive (TAB+) and negative temporal artery biopsies (TAB-), and controls.

METHODS

Patients with new clinically diagnosed GCA starting treatment with glucocorticoids underwent temporal artery biopsy and PET/CT. Using a visual semiquantitative approach, 18F-fluorodeoxyglucose (FDG) uptake was scored in 8 vascular territories and summed overall to give a total score in patients and matched controls.

RESULTS

Twenty-eight patients with GCA and 28 controls were enrolled. Eighteen patients with GCA were TAB+. Mean PET/CT scores after an average of 11.9 days of prednisone were higher in patients with GCA compared to controls, for both total uptake (10.34 ± 2.72 vs 7.73 ± 2.56; p = 0.001), and in 6 of 8 specific vascular territories. PET/CT scores were similar between TAB+ and TAB- patients with GCA. The optimal cutoff for distinguishing GCA cases from controls was a total PET/CT score of ≥ 9, with an area under the receiver-operating characteristic curve of 0.75, sensitivity 71.4%, and specificity 64.3%. Among patients with GCA, these measures correlated with greater total PET/CT scores: systemic symptoms (p = 0.015), lower hemoglobin (p = 0.009), and higher platelet count (p = 0.008).

CONCLUSION

Vascular FDG uptake scores were increased in most patients with GCA despite exposure to prednisone; however, the sensitivity and specificity of PET/CT in this setting were lower than those previously reported.

18F-fluoro-deoxy-glucose positron emission tomography combined with computed tomography can reliably rule-out infection and cancer in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis suspected of disease relapse

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of autoimmune diseases characterized by systemic inflammation in small- to medium-sized blood vessels. Although immunosuppressive therapy has greatly improved the prognosis for these patients, there are still significant comorbidities, such as cancer and infection, associated with AAV. These comorbidities are often indistinguishable from an underlying AAV disease relapse, and create a clinical conundrum, as these conditions are normally contraindications for immunosuppressive treatment. Thus, it is important to be able to rule out these comorbidities before initiation of immunosuppressive treatment. We examined F-fluoro-deoxy-glucose positron emission tomography combined with computed tomography (FDG-PET/CT)'s value in ruling out cancer or infection in patients with AAV.Data were obtained retrospectively for a clinically based cohort of AAV patients who underwent FDG-PET/CT during 2009 to 2014 owing to a suspicion of cancer, infection, or both cancer and infection indistinguishable from disease relapse. FDG-PET/CT conclusions were compared to the final diagnoses after follow-up analysis (mean 43 months).A total of 19 patients were included who underwent a total of 26 scans. The results of FDG-PET/CT outcome compared to final diagnosis were: 9 true positives, 3 false positives, 13 true negatives, and 1 false negative. The diagnostic probabilities for FDG-PET/CT with respect to overall comorbidity (i.e., cancer or infection) were: sensitivity 90% ( 95% confidence interval [CI] 60%-98%), specificity 81% ( 95% CI 57%-93%), positive predictive value 75% (95% CI 47%-91%), negative predictive value 93% (95% CI 68%-99%), and accuracy 84% (95% CI 66%-94%).FDG-PET/CT had a high negative predictive value and ruled out the comorbidities correctly in all but one case of urinary tract infection, a well-known limitation. Our study showed FGD-PET/CT's promise as an effective tool for ruling out cancer or infection in patients with AAV albeit in a limited population.

Diagnostic value of 18F-fluorodeoxyglucose uptake parameters to differentiate rheumatoid arthritis from other types of arthritis

We aimed evaluate F-fluorodeoxyglucose uptake at major joints for differentiating patients with rheumatoid arthritis (RA) from those with non-RA arthritis using F-fluorodeoxyglucose (FDG)-positron emission tomography (PET).Eighteen patients with RA (13 women; age, 66.8 ± 13.2 years) and 17 patients with non-RA (6 women; age, 50.8 ± 12.5 years) were included. Twelve joints of each patient were examined: shoulder, elbow, wrist, hip, knee, and ankle on both sides. A visual scoring (VS) system was used; quantitative parameters such as maximum standardized uptake value (SUVmax), metabolic active volume (MAV), and total lesion glycolysis (TLG) were evaluated. Total score and value of each parameter were compared between the RA and non-RA groups.Total VS score (mean, 37.7 ± 9.0 vs 21.9 ± 7.2; P < .0001) and SUVmax (mean, 28.1 ± 8.5 vs 17.9 ± 5.8; P < .001) were significantly higher in the RA group than in the non-RA group. A significant between-group difference was also observed with respect to total MAV (608.3 ± 370.7 vs 176.5 ± 217.8; P < .001) and total TLG (1139.3 ± 759.1 vs 289.5 ± 395.4; P < .001). Receiver operating characteristic curve analysis revealed that total VS had the highest area under curve (.92), with sensitivity and specificity of 88.9% and 76.4%, respectively.Quantitative PET parameters could differentiate RA from non-RA. Total VS score, however, appears to be the best convenient qualitative tool for diagnosing RA.

Vascular lesions in patient with Takayasu arteritis and massive elevated lipoprotein(a) levels. Residual involvement or premature aterosclerosis?

Lipoprotein (a) [Lp(a)] is a lipoprotein defined by presenting a specific apolipoprotein, ApoA, linked to the ApoB-100 by different types of chemical bonds, including a disulfide bridge. Despite their atherogenic mechanism is not fully understood, its importance has been demonstrated in the development of premature aterosclerosis. Multiple studies have shown its role as a cardiovascular risk factor associated with heart disease and stroke. We report the case of a patient with a diagnosis of Takayasu arteritis in which a massive elevation of Lp(a) was detected. We emphasize its diagnostic and therapeutic implications.

PET/CT in giant cell arteritis: High 18F-FDG uptake in the temporal, occipital and vertebral arteries

¹⁸F-FDG PET/CT imaging is useful in patients with fever of unknown origin and can detect giant cell arteritis in extracranial large arteries. However, it is usually assumed that temporal arteries cannot be visualized with a PET/CT scanner due to their small diameter. Three patients with clinical symptoms of temporal arteritis were examined using a standard whole body PET/CT protocol (skull base - mid thighs) followed by a head PET/CT scan using the brain protocol. High ¹⁸F-FDG uptake in the aorta and some arterial branches were detected in all 3 patients with the whole body protocol. Using the brain protocol, head imaging led to detection of high ¹⁸F-FDG uptake in temporal arteries as well as in their branches (3 patients), in occipital arteries (2 patients) and also in vertebral arteries (3 patients).

Incremental value of PET and MRI in the evaluation of cardiovascular abnormalities

Abstract

The cardiovascular system is affected by a wide range of pathological processes, including neoplastic, inflammatory, ischemic, and congenital aetiology. Magnetic resonance imaging (MRI) and positron emission tomography (PET) are state-of-the-art imaging modalities used in the evaluation of these cardiovascular disorders. MRI has good spatial and temporal resolutions, tissue characterization and multi-planar imaging/reconstruction capabilities, which makes it useful in the evaluation of cardiac morphology, ventricular and valvar function, disease characterization, and evaluation of myocardial viability. FDG-PET provides valuable information on the metabolic activity of the cardiovascular diseases, including ischemia, inflammation, and neoplasm. MRI and FDG-PET can provide complementary information on the evaluation of several cardiovascular disorders. For example, in cardiac masses, FDG-PET provides the metabolic information for indeterminate cardiac masses. MRI can be used for localizing and characterizing abnormal hypermetabolic foci identified incidentally on PET scan and also for local staging. A recent advance in imaging technology has been the development of integrated PET/MRI systems that utilize the advantages of PET and MRI in a single examination. The goal of this manuscript is to provide a comprehensive review on the incremental value of PET and MRI in the evaluation of cardiovascular diseases.

Main Messages

• MRI has good spatial and temporal resolutions, tissue characterization, and multi-planar reconstruction

• FDG-PET provides valuable information on the metabolic activity of cardiovascular disorders

• PET and MRI provide complementary information on the evaluation of cardiovascular disorders

Electronic supplementary material

The online version of this article (doi:10.1007/s13244-016-0494-5) contains supplementary material, which is available to authorized users.

Use of positron emission tomography (PET) for the diagnosis of large-vessel vasculitis

The term vasculitis encompasses a heterogeneous group of diseases that share the presence of inflammatory infiltrates in the vascular wall. The diagnosis of large-vessel vasculitis is often a challenge because the presenting clinical features are nonspecific in many cases and they are often shared by different types of autoimmune and inflammatory diseases including other systemic vasculitides. Moreover, the pathogenesis of large-vessel vasculitis is not fully understood. Nevertheless, the advent of new imaging techniques has constituted a major breakthrough to establish an early diagnosis and a promising tool to monitor the follow-up of patients with largevessel vasculitis. This is the case of the molecular imaging with the combination of positron emission tomography with computed tomography (PET/CT) using different radiotracers, especially the (18)F-fluordeoxyglucose ((18)F-FDG). In this review we have focused on the contribution of (18)F-FDG PET in the diagnosis of large-vessel vasculitis.

NMR-Based Serum Metabolomics Discriminates Takayasu Arteritis from Healthy Individuals: A Proof-of-Principle Study

Takayasu arteritis (TA) is a debilitating, systemic disease that involves the aorta and large arteries in a chronic inflammatory process that leads to vessel stenosis. Initially, the disease remains clinically silent (or remains undetected) until the patients present with vascular occlusion. Therefore, new methods for appropriate and timely diagnosis of TA cases are needed to start proper therapy on time and also to monitor the patient's response to the given treatment. In this context, NMR-based serum metabolomic profiling has been explored in this proof-of-principle study for the first time to determine characteristic metabolites that could be potentially helpful for diagnosis and prognosis of TA. Serum metabolic profiling of TA patients (n = 29) and healthy controls (n = 30) was performed using 1D (1)H NMR spectroscopy, and possible biomarker metabolites were identified. Using projection to least-squares discriminant analysis, we could distinguish TA patients from healthy controls. Compared to healthy controls, TA patients had (a) increased serum levels of choline metabolites, LDL cholesterol, N-acetyl glycoproteins (NAGs), and glucose and (b) decreased serum levels of lactate, lipids, HDL cholesterol, and glucogenic amino acids. The results of this study are preliminary and need to be confirmed in a prospective study.