[18F]FDG-PET of giant-cell aortitis

Current Controversies in Large-Vessel Inflammatory Vasculitis and Thoracic Aortic Aneurysm Disease

Large-vessel vasculitis encompasses the spectrum of vasculitides, which pathologically cause chronic granulomatous inflammatory changes, primarily in the aorta and its major branches. These patients are at risk of developing life-threatening aortic lesions that, without recognition and prompt treatment, can cause detrimental effects. Many provocative issues surrounding large-vessel vasculitis and its surgical treatment still remain, spanning from recognition to management. In this review, we discuss the main large-vessel vasculitides, Takayasu's arteritis and giant cell arteritis. We include the key points and current controversies surrounding diagnostic imaging, timing of interventions, and patient outcomes.

Spectrum of Aortic Disease in the Giant Cell Arteritis Population

We report the spectrum of aortic involvement in patients with giant cell arteritis (GCA) following review of medical records of 4,006 patients including those with imaging studies. A total of 1,450 patients (36%) had a confirmed diagnosis of GCA. Of these, 974 had aortic imaging. Of the 974 patients with imaging, 435 (45%) had an identified aortopathy. The most common aortopathy was aneurysm/dilation (69%). Overall, an annual aneurysmal growth rate of 1.5 mm/y was calculated. In patients with aneurysm/dilation, aortic dissection occurred in 18 patients (6%), and these patients had a significantly higher aneurysmal growth rate compared with those without dissection (4.5 vs 1.4 mm/y, p = 0.005). The median size of the aorta at the time of dissection was 51 mm, with 7 (39%) occurring with a maximal aortic aneurysm/dilation <50 mm. In conclusion, our findings indicate higher aneurysmal growth rate in GCA compared with that reported for degenerative aortic disease. Moreover, patients who develop dissection had a significantly higher growth rate than those without dissection with over a third of these patients suffering dissection at a caliber <50 mm.

Magnetic resonance imaging in the diagnosis and follow-up of giant cell arteritis: case report and review of literature

A female patient with giant cell vasculitis of the abdominal aorta and its branches and strongly suspected of having extrapulmonary tuberculosis is presented. The diagnoses were based on the clinical picture, laboratory findings, and magnetic resonance imaging (MRI) findings. MRI is highly useful in cases where echosonography and/or vascular biopsy for histopathological analyses are not possible. A combination of giant cell vasculitis and extrapulmonary tuberculosis is extremely rare, and therefore, choosing the right treatment presents a considerable challenge. MRI performed after 6-month antituberculous therapy and 1-year glucocorticoid plus methotrexate therapy showed normal wall of the aorta and its branches, which was consistent with clinical and laboratory remission. Patients with large vessel vasculitis require regular follow-up by MRI.

Usefulness of 18F-fluorodeoxyglucose positron emission tomography for diagnosis of asymptomatic giant cell arteritis in a patient with Alzheimer's disease

It is often difficult to diagnose disease in elderly patients, in particular those with dementia, who do not present with typical symptoms. This report describes our experience of an elderly patient (an 83-year-old woman) who presented with a chief complaint of memory loss, showed a marked inflammatory response, and was diagnosed with large-vessel giant cell arteritis (GCA) on the basis of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) findings. She had no symptoms typical of GCA including jaw claudication, visual field defect and heavy headed feeling. Corticosteroid therapy resulted in a trend toward improvement in the inflammatory response and then she first recognized that she might have experienced slight dull headache before treatment of GCA. This was probably because this patient had large-vessel GCA, which produces a few symptoms in the head and neck, and because she had Alzheimer's disease and could not accurately describe her symptoms. Our experience suggests the usefulness of FDG-PET for the diagnosis of GCA, particularly in elderly patients without typical symptoms.

[Vasculitis assessment with [18F]FDG positron emission tomography]

[18F]fluorodeoxyglucose positron emission tomography (PET) is a noninvasive metabolic imaging modality that is well-suited to the assessment of activity and extent of large vessel vasculitis. PET imaging has demonstrated its usefulness in diagnosing giant cell arteritis (notably in its silent form), Takayasu's arteritis, and unclassified aortitis. PET imaging could be more effective than magnetic resonance imaging in detecting the earliest stages of vascular wall inflammation. The visual grading of vascular [18F]FDG uptake makes it possible to discriminate arteritis from active atherosclerosis, providing therefore high specificity. High sensitivity can also be achieved provided scanning is performed during active inflammatory phase, preferably before starting corticosteroid treatment. Prospective studies are needed to determine the exact value of PET imaging in assessing other vasculitis subsets, infectious aortitis, and large vessel vasculitis outcome and response to immunosuppressive treatment.

Long-term follow-up of aortic involvement in giant cell arteritis: a series of 48 patients

To date, only a few series have analyzed the long-term outcome of giant cell arteritis (GCA) patients with aortic involvement, which prompted us to conduct the current retrospective study. Our aims were to 1) determine the prevalence of GCA in patients exhibiting nonatherosclerotic aortic involvement (that is, aortitis, aortic ectasia, and/or aneurysm); and 2) evaluate clinical features and long-term outcome of GCA patients exhibiting aortitis, aortic ectasia, and/or aortic aneurysm.From January 1997 to March 2008, 66 consecutive patients in the Department of Internal Medicine at the University of Rouen medical center received a diagnosis of nonatheromatous aortic complications (aortitis, aortic ectasia, and/or aneurysm). In these 66 patients, aortic involvement was related to GCA (n = 48), Takayasu arteritis (n = 6), relapsing polychondritis (n = 1), and infection (n = 11).Of the 48 patients with GCA, aortic involvement preceded the initial GCA diagnosis in 1 patient. Aortic involvement was identified in association with GCA in 40 patients (83.3%), and developed after the onset of GCA in the 7 remaining patients (14.6%). Aortic involvement was more often asymptomatic (77.1%). The aortic helical computed tomography (CT)-scan procedure principally showed isolated aortitis (circumferential thickening of the aortic wall >3 mm) in 41 patients (85.4%). In the remaining 7 patients with GCA (14.6%), aortic helical CT scan demonstrated aortic thoracic ectasia and aortitis (n = 3), aortic thoracic aneurysm and both thoracic and abdominal aortitis (n = 3), and both aortic abdominal aneurysm and aortitis (n = 1). All patients were given steroid therapy at a median daily dose of 1 mg/kg initially.At 6-month follow-up, 34 of 48 patients systematically underwent both thoracic and abdominal CT scan. Aortic helical CT scan demonstrated complete disappearance of aortitis in 8.8% of patients, improvement of aortitis in 47.1%, unchanged pattern of aortitis and/or aortic thoracic ectasia/aneurysm in 41.2%, and deterioration of aortic thoracic aneurysm in 1 patient (2.9%). At 18-month follow-up, 11 patients systematically underwent both thoracic and abdominal CT scan. Aortic helical CT scan showed complete disappearance of aortitis (n = 1), improvement of aortitis (n = 1), unchanged pattern of aortic thoracic ectasia/aneurysm (n = 2), and deterioration of aortic thoracic aneurysm (n = 1). At patients' last follow-up, the median daily dose of prednisone was 7 mg. Steroid therapy could be discontinued in 17 patients (35.4%).The current retrospective study suggests that aortic impairment may be more prevalent than previously reported. Our findings suggest that specific inflammatory thickening of the aortic wall is common at the time of GCA diagnosis, and that aortitis may be the first manifestation of GCA-associated aortic complications. Whether isolated aortitis leads to vascular wall injury responsible for late-onset aneurysmal disease remains to be determined. At this time, we recommend long-term monitoring for aortic aneurysms, especially in high-risk subjects, although the optimal frequency and imaging modality have not yet been determined. A yearly screening strategy for thoracic/abdominal aortic aneurysms has been proposed for patients with GCA, including physical examination, 2-view chest radiograph, and abdominal ultrasound.

[18F]Fluorodeoxyglucose PET in Large Vessel Vasculitis

[(18)F]fluorodeoxyglucose (FDG) PET is a noninvasive metabolic imaging modality based on the regional distribution of [18F]FDG that is highly effective in assessing the activity and extent of giant cell arteritis and Takayasu's arteritis, respectively. Metabolic imaging using [18F]FDG-PET has been shown to identify more affected vascular regions than morphologic imaging with MRI in both diseases. The visual grading of vascular [18F]FDG uptake helps to discriminate arteritis from atherosclerosis and therefore provides high specificity. High sensitivity is attained by scanning during the active inflammatory phase. Thus, [18F]FDG-PET has the potential to develop into a valuable tool in the diagnostic workup of giant cell arteritis and Takayasu's arteritis.

Aortite inflammatoire et maladie de Horton. À propos du suivi évolutif scanographique prospectif d'une série de 11 patients

PURPOSE

To determine clinical and radiological features, using computed tomography (CT-scan) in patients with aortic involvement related to giant cell arteritis (GCA), and to assess both clinical and CT-scan outcome after therapy institution.

METHODS

Aortic involvement due to GCA was investigated in all patients, using CT-scan at diagnosis, and at 3, 6 and 12 months follow-up after therapy institution.

RESULTS

The 11 consecutive patients consisted of 4 men and 7 women with mean age of 64.5 years. Patients exhibited: constitutional symptoms (N=9; 82%), dorsalgia (N=3; 27%), clinical signs of GCA (N=3; 27%) and of upper limb large vessel impairment (N=6; 55%). CT-scan showed aortitis involving both thoracic and abdominal aorta (N=6; 55%), abdominal (N=2; 18%) or thoracic aorta (N=2; 18%) and thoracic aortic aneurysm (N=1; 9%). At one-year follow-up, CT-scan revealed: complete resolution (N=7; 64%) and improvement (N=3; 27%) of aortic damage; the patient, who had thoracic aortic aneurysm, underwent surgical treatment, as aortic lesion remained unchanged on CT-scan.

CONCLUSION

Our study underlines that CT-scan is a helpful test in diagnosis and follow-up of aortic involvement in patients with GCA.