Giant Cell Arteritis Research Articles

Optical coherence tomography angiography findings in patients affected by giant cell arteritis, with and without ocular involvement: a pilot study.

We evaluated the clinical features and retinal and disk perfusion characteristics by using optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) in a subset of giant cell arteritis (GCA) patients who manifested anterior ischemic optic neuropathy (AION), in a subset of GCA patients without ocular involvement, and in a control group composed of healthy controls. We performed an observational study on the eyes of GCA patients affected by arteritic AION both in acute and chronic phases, unaffected eyes of AION, eyes of GCA patients without ocular involvement, and in a control group of healthy eyes of healthy individuals. All patients underwent a complete ophthalmic examination and an OCT and OCTA of the macula and the disk. The study evaluated 10 eyes of GCA patients with AION (AION group), 8 unaffected eyes of GCA patients with AION in another eye (unaffected eyes of AION group), 16 eyes of GCA patients without ocular involvement (non-ocular group), and 22 eyes of healthy patients (healthy group). The ganglion cell complex (GCC) superior and inferior thicknesses were significantly lower in the AION group compared to the unaffected eyes of the AION group (p = 0.045 and p = 0.034, respectively). All OCTA vascular density parameters of the optic disk analyzed in this study (optic nerve head (ONH) whole, superior, inferior, radial peripapillary capillary plexus (RPCP) whole, superior, inferior, lamina cribrosa (LC) whole, superior, inferior) resulted significantly lower in the AION group compared to the unaffected eyes group (p < 0.05 for all the comparisons). The ONH whole and inferior were statistically higher in the healthy group in comparison to the group of GCA patients without ocular involvement (p = 0.008 and p = 0.006, respectively). The ONH inferior was also statistically higher in the unaffected eyes of the AION group in comparison to the non-ocular group (p = 0.045). Regarding the OCTA macular vessel density parameters, the superficial capillary plexus (SCP), whole and inner, were statistically lower in the AION group compared with the unaffected eyes of the AION group. We found a profound vascular impairment in eyes affected by AION and areas of hypoperfusion in the eyes of patients with GCA without ocular involvement, good BCVA, and no clinically significant features. We hypothesized that these areas of lower vessel density might represent areas of subclinical hypoperfusion that cannot be detected ophthalmoscopically.

Self-limited giant cell arteritis: The dilemma associated with its diagnosis and treatment.

Giant cell arteritis (GCA) can result in visual loss and other sequelae. An 81-year-old man presented with a one-week history of fever. He had bilateral temporal headache, jaw claudication, tenderness of the temporal arteries and a recent skin rash. A temporal artery biopsy showed typical GCA, but the symptoms were self-limiting. We continued close observation, without administering prednisolone treatment. Five months later, the symptoms did not recur, and prednisolone again was not administered. Our patient presented with an atypical course of GCA that created a clinical dilemma. The final diagnosis was self-limiting GCA.

Impact of Exposure to Environmental Particulate Matter on the Onset of Giant Cell Arteritis.

The aim of this study was to investigate the association between exposure to particulate matter with an aerodynamic diameter ≤10 μm (PM10) and the development of giant cell arteritis (GCA) and its ischemic complications. This was case-crossover study on consecutive patients who received a diagnosis of GCA in three hospitals in northern Italy between 2013 and 2021. The PM10 hourly and daily average concentrations, collected in the Italian monitoring network and archived by Istituto Superiore per la Protezione e la Ricerca Ambientale, were determined using European reference. We used a Bayesian hierarchical model to determine patients' daily exposures to them. We employed conditional logistic regression to estimate the effect of exposure on GCA symptoms onset or ischemic complications. We included 232 patients. A positive association was observed between exposure to PM10 and GCA risk, with an incremental odd of 27.1% (95% confidence interval 5.8-52.6) for every 10-μg/m3 increase in PM10 concentration within a 60-day period. We did not find any significant association for shorter periods or with ischemic complications. Subgroup analysis found a significantly higher incremental risk at a 60-day lag for patients ≥70 years old. Comparing patients who were chronically exposed to high PM10 levels (26.9 ± 13.8 μg/m3) to those who were not (11.9 ± 7.9 μg/m3) revealed that only in the former group was there an association between GCA onset and increased PM10 levels in the preceding 60 days. Exposure to environmental PM10 in the preceding 60 days seems to be associated with an increased risk of developing GCA, especially in older individuals with prolonged exposure to high levels of air pollution.

Diagnostic accuracy of serum biomarkers to identify giant cell arteritis in patients with polymyalgia rheumatica

IntroductionPolymyalgia rheumatica (PMR) and giant cell arteritis (GCA) are frequently overlapping conditions. Unlike in GCA, vascular inflammation is absent in PMR. Therefore, serum biomarkers reflecting vascular remodelling could be used...

Optic nerve sheath measurement to monitor disease activity in giant cell arteritis: a pilot study

Introduction/ObjectivesOptic nerve sheath (ONS) enhancement using magnetic resonance imaging of the orbits was observed in patients with giant cell arteritis (GCA). We previously showed that ONS diameter (ONSD) by bedside ultrasound is increased in patient with active GCA. This study aims to assess whether ONSD decreases with clinical remission in patients with GCA.MethodsA prospective cohort study was conducted from June 2022 to January 2023. Patients who had an optic nerve ultrasound at GCA diagnosis as part of a previous crosssectional study were eligible. Optic nerve ultrasound was performed by the same investigator at diagnosis and month 3. ONSD (includes the optic nerve and its sheath) and optic nerve diameter (OND) were measured. Descriptive statistics for baseline characteristics and paired sample t-test were performed to assess the mean difference in OND and ONSD between diagnosis and month 3.ResultsNine patients with GCA were included. The median age at disease onset was 79 years (interquartile range (IQR) of 79–82 years), and 7 patients were males. All patients were in clinical remission at month 3 on prednisone (median dose of 15 mg/day, IQR of 10–25 mg). The mean ONSD was lower at month 3 (3.76 mm) compared to baseline (5.98 mm), with a paired mean difference of 2.22 mm (95% CI 1.41–3.03 mm, p < 0.001). As anticipated, OND measurements did not vary between diagnosis and month 3.ConclusionONSD on ultrasound improves after 3 months of therapy in patients with GCA. A longer prospective study is required to determine if ONSD is useful to assess disease activity in GCA.Key Points• ONS ultrasound can identify patients with active GCA.• The ONSD on ultrasound is dynamic and improved after 3 months of GCA therapy.• ONS ultrasound may be useful to monitor disease activity in GCA.

Association between diabetes mellitus and giant cell arteritis: a bidirectional 2-sample mendelian randomization study

ObjectiveRecent studies have indicated a potential association between giant cell arteritis (GCA) and diabetes mellitus, encompassing both type 1 diabetes (T1D) and type 2 diabetes (T2D). However, the exact nature of this relationship requires further investigation to be fully elucidated.MethodsGenetic links between T1D/T2D and GCA were explored using data from genome-wide association studies available to the public, focusing on populations of European ancestry. We applied a bidirectional mendelian randomization (MR) approach to assess the potential association between these diseases. Confirmatory analyses, including additional datasets and a comprehensive meta-analysis, were utilized. The inverse-variance-weighted (IVW) method was applied to pinpoint heterogeneity and pleiotropy, while subsequent sensitivity analyses aimed to trace the origins of any heterogeneity.ResultsInitial analysis demonstrated a correlation between T1D and an elevated likelihood of developing GCA (IVW odds ratio = 1.33, with a 95% confidence interval of 1.22–1.46, and a P-value of 9.42E−10). The causal association was verified through four validation datasets and meta-analysis (all P-value < 0.001). However, the reverse MR analysis was unable to detect any genetic basis for the increased risk of T1D due to GCA. Furthermore, we could not establish any causal links between T2D and GCA.ConclusionT1D patients may have a higher risk of developing GCA, whereas an inverse causal relationship was not evident. Furthermore, no causal relationship was detected between T2D and GCA. These insights shed light on the possible pathological mechanisms underlying GCA and may influence the future clinical handling of both T1D and GCA.

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.

New-onset of giant cell arteritis with ischemic optic neuropathy following the seventh-dose of COVID-19 mRNA vaccination: A case report and literature review.

Coronavirus disease (COVID-19) vaccines have demonstrated excellent efficacy in reducing the morbidity and severity of the disease. However, some patients have been reported to develop systemic rheumatic diseases, such as rheumatoid arthritis, myocarditis, Guillain-Barre syndrome, and giant cell arteritis (GCA) following COVID-19 vaccination. We present a case of GCA with ischemic optic neuropathy following COVID-19 mRNA vaccination. A 73-year-old woman developed headache, myalgia, scalp tenderness, and jaw claudication 4 days after her seventh dose of the vaccination; she also developed severe visual disturbances 1 month after the vaccination. The blood examination tests showed an increased serum C-reactive protein level and erythrocyte sedimentation rate. The echogram for the temporal artery showed a halo sign. Ophthalmic examination revealed ischemic optic neuropathy in both eyes. The patient was treated with a high-dose glucocorticoid and tocilizumab under the diagnosis of GCA with ischemic optic neuropathy, obtaining mild improvement of the symptoms. This report underscores the need for clinical vigilance and further data collection regarding GCA cases after COVID-19 vaccination.

Faster steroid-free remission with tocilizumab compared to methotrexate in giant cell arteritis: a real-life experience in two reference centres.

Glucocorticoids (GCs) are still the mainstay of treatment of giant cell arteritis (GCA). Although GCs are highly effective in GCA, the high burden of toxicity of GCs as well as the disease relapse during GC tapering is well documented. To compare the efficacy and rapidity of TCZ and MTX as steroid-sparing agents in a real-life cohort of GCA patients. A retrospective analysis was conducted including patients with newly diagnosed GCA from the Rheumatology Units of Udine and Rome. The inclusion criterion was the treatment with TCZ or MTX as first steroid-sparing drug. 112 GCA patients (81 females) with a median age of 70 (IQ 65-75) years were collected. Thirty-one out of 112 (27.7%) patients were treated with TCZ (162mg/week), while 81/112 (72.3%) patients received MTX (up to 20mg/week) as a GC-sparing agent. At month 6 after GCA onset, 5/31 (16.1%) patients in TCZ group and none in MTX group were in GC-free sustained remission (p value = 0.001). Similarly, at month 12, 64.5% (20/31) and 11.1% (9/81) of patients were in sustained GC-free remission in TCZ and MTX group, respectively (p value <0.001). At month 24 of follow-up, at least one relapse of the disease occurred in 7/31 (22.6%) in TCZ-treated and 28/81 (34.6%) in MTX-treated patients, respectively (p value = 0.22). TCZ allowed a faster discontinuation of steroid therapy than MTX in GCA patients, without increasing the risk of relapse.

Increased interest with the introduction of fast-track diagnostic pathway is associated with the regionally increased frequency of giant cell arteritis in Poland: a study based on POLVAS registry data.

Slavic populations, such as those in Poland, are considered to have a low prevalence of giant cell arteritis (GCA), although epidemiological data are sparse. The study aimed to compare the reported frequency of GCA in various regions of Poland and analyze the differences between them. We conducted a multicenter, retrospective study of all GCA patients included in the POLVAS registry-the first large multicenter database of patients with vasculitis in Poland. The data from the POLVAS registry were compared with the reported prevalence provided by national insurers from the corresponding regions. A 10-fold increase in the diagnostic rates of GCA was observed in Poland between 2008 and 2019, reaching 8.38 per 100,000 population > 50 years old. It may be attributed to increased interest accompanied by improved diagnostic modalities with the introduction of ultrasound-based, fast-track diagnostic pathways in some centers. However, regional inequities are present, resulting in 10-fold differences (from 2.57 to 24.92) in reported prevalence between different regions. Corticosteroid (CS) monotherapy was the main stem of treatment. Further cooperation and education are needed to minimize regional inequities. This observational study suggests some potential for further increase of the recognizability of GCA and wider use of other than CS monotherapy treatment regimens. We hope that the Polish experience might be interesting and serve as some guidance for the populations where GCA is underdiagnosed.

Polymyalgia rheumatica: What's new?

Currently, only 25% of all polymyalgia rheumatica (PMR) patients are referred to specialists. An expert committee has recently recommended confirmation of diagnosis by specialist care. This can help to avoid misdiagnoses and hospital stays and can result in lower glucocorticoid doses.Using ultrasound, magnetic resonance imagining (MRI), or positron emission tomography-computed tomography (PET-CT), typical periarticular inflammatory changes are observed, especially in the shoulder and pelvic girdle area. However, for clinical use, ultrasound is usually sufficient.In 20-25% of newly diagnosed PMR patients without symptoms of giant cell arteritis (GCA), GCA can be detected through vascular ultrasound. These patients require higher glucocorticoid doses in analogy to GCA therapy. There is growing awareness of a joint GCA-PMR spectrum disease.Glucocorticoids remain the primary treatment. The interleukin-6 inhibitor Sarilumab has recently been approved in the USA for patients with recurrent PMR. Studies have also demonstrated the effectiveness of Tocilizumab in PMR.

Risk factors and treatment window in arteritic anterior ischaemic optic neuropathy: a case study

A 76-year-old NZ European man presented with sudden onset visual loss in his left eye after experiencing intermittent temporal aches and blurry vision for over a month. He had a history of stroke and hyper- tension but no past ophthalmological history. A pale optic disc, raised inflammatory markers, and temporal artery biopsy confirmed a diag- nosis of acute arteritic anterior ischaemic optic neuropathy secondary to giant cell arteritis. High-dose intravenous methylprednisolone was administered within 24 hours of presentation, but the likelihood of vision loss reversal was unlikely.

Integrating point-of-care ultrasound into rheumatology practice.

A scenario‑based probability approach integrating point‑of‑care rheumatology ultrasound (POCRUS) into rheumatology practice has recently been proposed as a teaching methodology to encourage greater awareness of US among practicing clinicians, especially with respect to the management of overlapping clinical conditions. This article reviews the rheumatological areas where application of POCRUS substantially enhances clinical reasoning to confirm or exclude target conditions. It highlights the definitions of US‑detected pathologies in rheumatoid arthritis, spondylarthritis, gout and crystal arthritis, osteoarthritis, and polymyalgia rheumatica, and discusses the added value of POCRUS in diagnosing these conditions. Additionally, it summarizes advances in predicting giant cell arteritis with sequential application of a probability score and US, and discusses the potential role of salivary gland US in the diagnostic workup of suspected Sjögren syndrome. Other areas for POCRUS application, such as in suspected nerve entrapment, are also reviewed.

Optic Nerve Sheath Measurement on Ultrasound: A Novel Diagnostic Test for Giant Cell Arteritis.

Optic nerve sheath enhancement on magnetic resonance imaging has been reported in patients with giant cell arteritis (GCA), with or without visual manifestations. Whether similar findings can be documented on ultrasound is unknown. Optic nerve ultrasound is a point-of-care, easy to learn, rapid, and noninvasive technique. This study aims to investigate whether optic nerve sheath diameter (ONSD) measured on ultrasound is useful in the diagnosis of active, new-onset GCA. A single-center, diagnostic accuracy study was performed from June to November 2022 on consecutive eligible patients referred for suspected GCA. Optic nerve ultrasound was performed on both eyes. The ONSD (includes the optic nerve and its sheath) and optic nerve diameter (OND) were measured 3 mm behind the ocular globe. The presence or absence of GCA was confirmed clinically 6 months later. Multivariable linear regression, adjusting for age and sex, was used to determine the association between optic nerve ultrasound measures and final GCA diagnosis. Thirty participants were enrolled, including nine participants with a final diagnosis of GCA. Mean ± SD ONSD was 5.98 ± 1.17 mm in patients with GCA and 4.02 ± 0.99 mm in patients without GCA. Mean ONSD was greater by 1.26 mm in patients with GCA (95% confidence interval 0.30-2.21 mm, P = 0.01) compared with those without GCA, adjusting for age and sex. Mean ± SD OND was 2.97 ± 0.46 mm in patients with GCA and 2.47 ± 0.58 mm in patients without GCA. There was no evidence of an association between GCA diagnosis and OND. Patients with GCA had a significantly greater ONSD on ultrasound than patients without GCA. Optic nerve ultrasound may represent a novel, rapid, bedside diagnostic test for GCA. A large prospective study is required to confirm these findings and evaluate whether ONSD can be used as a disease activity biomarker in GCA.

Magnetic resonance imaging to monitor disease activity in giant cell arteritis treated with ultra-short glucocorticoids and tocilizumab.

MRI is well established for diagnosing GCA. Its role in monitoring disease activity has yet to be determined. We investigated vascular and musculoskeletal inflammation using MRI in the patients of the GUSTO trial to assess the utility of MRI in monitoring disease activity. Eighteen patients with newly diagnosed GCA received 500 mg methylprednisolone intravenously for 3 consecutive days followed by tocilizumab monotherapy from day 3 until week 52. Cranial, thoracic and abdominal MRI exams were performed at baseline (active, new-onset disease), and at weeks 24, 52 (remission on-treatment), and 104 (remission off-treatment). MRI findings typical for PMR as well as extent and severity of vasculitic disease were rated. In total, 673 vascular segments and 943 musculoskeletal regions in 55 thoracic/abdominal MRI and 490 vascular segments in 49 cranial MRI scans of 18 patients were analysed. Vasculitic vessels were still detectable in one in four cranial segments at week 24. At weeks 52 and 104, no cranial vascular segment showed a vasculitic manifestation. Large vessels, except for the ascending aorta, and PMR displayed little or no decrease in inflammatory findings over time. Vasculitic manifestations in the cranial vessels normalised after 52 weeks of treatment, whereas large vessel and PMR findings persisted despite lasting full remission. The dynamics of cranial vessel signals suggest that MRI of these arteries might qualify as a potential diagnostic tool for monitoring disease activity and for detecting relapse after 52 weeks of treatment.

Novel and characteristic radiological features of neurosyphilis: a case series

BackgroundTreponema pallidum can invade the central nervous system (CNS) early in its infection, causing neurosyphilis. Neurosyphilis typically presents with meningovasculitis in the acute or subacute phase, while tabes dorsalis and dementia paralytica are classical conditions in the later stages. However, syphilis is often misdiagnosed as other conditions such as tumors or autoimmune diseases including vasculitis and encephalitis, which is why the condition is known as “The Great Mimicker.” The increasing incidence of syphilis in recent years emphasizes the importance of early diagnosis and treatment; however, its multiple clinical manifestations impose diagnostic challenges for clinicians because it resembles other diseases. In this case series, we present the impressive manifestations of neurosyphilis through three unique radiological presentations.Case presentationCase 1 details optic nerve involvement in an HIV-positive male, where MRI and fundoscopic findings confirmed syphilitic optic neuritis. Case 2 describes a patient in her pregnancy initially suspected of acoustic neuroma on MRI, later diagnosed with syphilitic gumma affecting the inner ear canal. Case 3 is a young male with clinical features mimicking temporal arteritis, ultimately identified as skull osteomyelitis secondarily causing inflammation of the musculus temporalis and meningitis.ConclusionsThese cases underscore the necessity of considering syphilis in differential diagnoses, given the diversity of its clinical presentations. Radiology plays an important role in avoiding unnecessary interventions. The increasing prevalence of recurrent syphilis imposes diagnostic challenges, emphasizing the importance of the early diagnosis and treatment of neurosyphilis by clinicians.

Subclinical Aortic Inflammation in Patients with Polymyalgia Rheumatica.

To examine the clinicopathologic features of patients with polymyalgia rheumatica (PMR) who had thoracic aorta repair surgery. Findings were compared with those of a cohort of patients with giant cell arteritis (GCA) requiring thoracic aorta repair. All patients evaluated at Mayo Clinic in Rochester, MN, with Current Procedural Terminology (CPT) codes for thoracic aorta repair surgery between 2000- 2021 were identified. All patients were screened for prior PMR diagnosis. Patients with PMR and no signs of GCA were categorized as clinically isolated PMR. The medical records of all patients were manually reviewed, and pathologists re-examined all the aortic tissues. Of the 4621 patients with at least one CPT code for thoracic aorta repair surgery, 43 patients were diagnosed with clinically isolated PMR before the surgery. Detailed histopathological examination of the aortic tissues revealed active inflammation in 30/43 (70%) patients after a median (IQR) of 10.0 (4.7- 13.3) years from the PMR diagnosis. When compared with aortic tissue from patients with a prior diagnosis of GCA, the aorta of patients with PMR had more severe inflammation (Grade 3: 15/30 [50%] vs 5/34 [15%], p= 0.002). Patients with PMR and thoracic aorta repair may experience a 40% increased risk of mortality compared with the general population, but this did not reach statistical significance (standardized mortality ratio: 1.40; 95% CI: 0.91- 2.07). Some patients with PMR have subclinical aortic inflammation that is detectable many years after initial diagnosis and may contribute to the development of aortic aneurysm.

Subclinical Giant Cell Arteritis in Polymyalgia Rheumatica: Is Vascular Imaging Really Ready to Determine Steroid Dosing?

Subclinical Giant Cell Arteritis in Polymyalgia Rheumatica: Is Vascular Imaging Really Ready to Determine Steroid Dosing?

Positron Emission Tomography/Computed Tomography in Polymyalgia Rheumatica: When and for What-A Critical Review.

Polymyalgia rheumatica (PMR) is an inflammatory disease common in people aged 50 years and older. This condition is characterized by the presence of pain and stiffness involving mainly the shoulder and pelvic girdle. Besides the frequent association with giant cell arteritis (GCA), several conditions may mimic PMR or present with PMR features. Since the diagnosis is basically clinical, an adequate diagnosis of this condition is usually required. Positron emission tomography/computed tomography (PET-CT) has proved to be a useful tool for the diagnosis of PMR. The use of 18F-FDG-PET imaging appears promising as it provides detailed information on inflammatory activity that may not be evident with traditional methods. However, since PET-CT is not strictly necessary for the diagnosis of PMR, clinicians should consider several situations in which this imaging technique can be used in patients with suspected PMR.

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

Background/ObjectivesGiant cell arteritis (GCA) is an inflammatory vascular disease in which prompt and accurate diagnosis is critical. The efficacy of temporal artery biopsy (TAB) is limited by ‘skip’ lesions and a delay in histological analysis. This first-in-man ex-vivo study aims to assess the accuracy of optical frequency domain imaging (OFDI) in diagnosing GCA.Subjects/Methods29 TAB samples of patients with suspected GCA were submerged in 0.9% sodium chloride and an OFDI catheter was passed through the lumen to create cross-sectional images prior to histological analysis. The specimens were then preserved in formalin for histological examination. Mean intimal thickness (MIT) on OFDI was measured, and the presence of both multinucleate giant cells (MNGCs) and fragmentation of the internal elastic lamina (FIEL) was assessed and compared with histology, used as the diagnostic gold standard.ResultsMIT in patients with/without histological evidence of GCA was 0.425 mm (±0.43) and 0.13 mm (±0.06) respectively compared with 0.215 mm (±0.09) and 0.135 mm (±0.07) on OFDI. MIT measured by OFDI was significantly higher in patients with histologically diagnosed arteritis compared to those without (p = 0.0195). For detecting FIEL and MNGCs, OFDI had a sensitivity of 75% and 28.6% and a specificity of 100% and 77.3% respectively. Applying diagnostic criteria of MIT > 0.20 mm, or the presence of MNGCs or FIEL, the sensitivity of detecting histological arteritis using OFDI was 91.4% and the specificity 94.1%.ConclusionsOFDI provided rapid imaging of TAB specimens achieving a diagnostic accuracy comparable to histological examination. In-vivo imaging may allow imaging of a longer arterial section.